MPO-ANCA–Positive Eosinophilic Granulomatosis with Polyangiitis Presenting as Acute Reversible Cardiomyopathy: A Case Report.

MPO-ANCA–Positive Eosinophilic Granulomatosis with Polyangiitis Presenting as Acute Reversible Cardiomyopathy: A Case Report. | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report MPO-ANCA–Positive Eosinophilic Granulomatosis with Polyangiitis Presenting as Acute Reversible Cardiomyopathy: A Case Report. Stephanie Ammari, Nawras Ibrahim, Bahaeddin Shabaneh This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8607437/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Eosinophilic granulomatosis with polyangiitis (EGPA) isa rare autoimmune vasculitis characterized by asthma, blood and tissue eosinophilia, and small-vessel vasculitis. It is among the rarest of ANCA-associated vasculitides, and ANCA is present in only 30–40% of patients. ANCA-positive patients have more vasculitic complications, such as mononeuritis multiplex and glomerulonephritis, whereas ANCA-negative patients are more likely to have cardiomyopathy. Case: A 65yearold man with adult-onset asthma presented with acute dyspnea, bronchodilator-resistant wheeze, markedly elevated high-sensitivity troponin (peak 1980 ng/L), peripheral eosinophilia (peak 1550/mm³), and new left ventricular systolic dysfunction (LVEF 30–34%) with normal coronary angiography. He improved rapidly after intravenous corticosteroids; LVEF normalized to 55–60% within six weeks. MPO-ANCA was positive (6.0 U; normal < 0.9). Cardiac MRI and endomyocardial biopsy were not performed because they were unavailable, and the patient had rapid clinical recovery; we document serial labs, imaging, and the diagnostic application of the LATEEAST score to support a presumptive diagnosis of EGPA-related eosinophilic myocarditis. Conclusion The case indicates that MPO-ANCA–positive EGPA can manifest as acute reversible cardiomyopathy without apparent vasculitic manifestations, presumably secondary to eosinophilic myocarditis. When cardiac MRI or biopsy are unavailable, careful integration of clinical features, serial biomarkers, echocardiography, ANCA testing, validated clinical scores, and response to therapy can support a working diagnosis of EGPA-related eosinophilic myocarditis. Early corticosteroid therapy may reverse cardiac dysfunction. Eosinophilic Granulomatosis with Polyangiitis MPO-ANCA Eosinophilic Myocarditis LATEEAST score Reversible Cardiomyopathy Case Report Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Eosinophilic granulomatosis with polyangiitis (EGPA) is an ANCA associated small vessel vasculitis characterized by adult-onset asthma, eosinophilia, and variable organ involvement. EGPA typically develops in three clinical phases, beginning with asthma, followed by tissue eosinophilia and finally systemic vasculitis. Cardiac involvement occurs in about 62%, but symptomatic presentation is observed only in 26%. ( 1 ) MPO-ANCA positivity occurs in 30–40% of the cases, usually with vasculitic complications like neuropathy or renal disease, whereas ANCA-negative patients are more likely to have cardiomyopathy. ( 2 , 3 ) Reversible post-myocarditis cardiomyopathy has been reported but remains underemphasized in MPO-ANCA–positive EGPA, highlighting the importance of early recognition and early initiation of corticosteroid therapy. ( 2 , 4 ) We report a rare case of MPO-ANCA–positive EGPA-related eosinophilic myocarditis (EGPA-EM) with acute, reversible cardiomyopathy in the setting of no overt vasculitic disease manifestations. Case Presentation A 65-year-old male non-smoker with adult-onset asthma (4 years), allergic rhinitis, hydrocephalus with ventriculoperitoneal shunt, presented with acute dyspnea and bronchodilator-resistant wheezing. On examination, he was tachypneic with fine wheezes and bilateral crackles, and saturation on ambient air was 98%. Labs showed elevated high-sensitivity troponin (peak 1980 ng/L; normal < 14), eosinophilia (1310/mm³, 13.5%), elevated D-dimer (5664 ng/mL) and normal BNP. The chest X-ray and ECG were unremarkable. CT angiogram excluded pulmonary embolism but showed only a calcified granuloma in the left lower lobe. Transthoracic echocardiogram showed left ventricular systolic dysfunction (LVEF 30–34%) with global hypokinesis. The coronary angiogram was normal, showing patent coronary arteries. Viral serologies, blood cultures, and toxicology screens were negative. The patient was started on Methyl-prednisone 40 mg twice a day for five days and bronchodilators, which resulted in remarkable improvement in clinical status. Subsequently, he was discharged on prednisone taper and guideline-directed medical therapy for heart failure. Six weeks after discharge, he returned with progressive dyspnea and, status asthmaticus requiring intubation. Labs were significant for eosinophilia (1300–1550/mm³, 15–18%), elevated ESR 34 mm/hr, and elevated CRP 18 mg/dL. BNP and troponin levels were normal. Repeated echocardiography revealed normalization of LVEF (55–60%) with no regional wall motion abnormalities. The combination of cardiomyopathy and history of eosinophilic asthma prompted autoimmune screen which revealed positive MPO-ANCA (6.0 U; normal < 0.9) and negative PR3-ANCA, fulfilling the 2022 ACR/EULAR classification criteria for EGPA with a score ≥ 6 (eosinophilia + 5, asthma + 3). ( 3 ) Endomyocardial biopsy and Cardiac MRI were deferred due to clinical improvement and unavailability as well. He was treated for asthma exacerbation and discharged on inhaled triple therapy and prednisone taper; outpatient follow-up arranged to consider adjunctive therapy. Table 1 Objective data (serial values) Parameter First admission Week 6 (readmission) Notes High-sensitivity troponin I 1980 ng/L (peak) Normalized to reference range Marked elevation at presentation with subsequent normalization. Eosinophil count 1310 /mm³; 13.5% 1550 /mm³; 15–18% Persistent peripheral eosinophilia. BNP Within normal limits Within normal limits No biochemical heart-failure signal despite LV dysfunction. ECG Normal sinus rhythm; nonspecific ST changes No persistent ischemic pattern reported No ischemic ECG evolution. Coronary angiography Normal coronary arteries Not repeated Ischemic etiology excluded on index angiography. Echocardiography (LVEF) 30–34% (global hypokinesis) 55–60% (normalized) Rapid recovery of systolic function after steroids. Autoimmune testing Not tested MPO-ANCA 6.0 U (normal < 0.9); PR3-ANCA negative MPO-ANCA positivity documented during workup. Diagnostic procedures not performed and rationale Cardiac MRI : unavailable at the treating facility during the acute presentation; patient improved rapidly and transfer for MRI was deferred to avoid delay in therapy. Endomyocardial biopsy : not performed because ( 1 ) invasive procedure risk in a clinically improving patient, ( 2 ) limited local availability, and ( 3 ) the pretest probability of eosinophilic myocarditis was high given the constellation of asthma, eosinophilia, elevated troponin, non-ischemic LV dysfunction, MPO-ANCA positivity, and rapid steroid response. These reasons are explicitly documented in the chart and discussed with the patient and family. Table 2 Timeline of Clinical Events and Treatment Response Time Point Clinical Status & Findings Intervention / Diagnostic Score Day 1: Admission Acute dyspnea, wheezing, global hypokinesis (LVEF 30–34%). Trop-I peak: 1,980 ng/L; Eosinophils: 1,310/mm³. LATEEAST Score: 4.5 (High probability of EGPA myocarditis) Day 2: Treatment Rapid clinical stabilization following coronary angiography (normal coronaries). Initiation of IV Methylprednisolone (40 mg BID) Day 7: Discharge Normalization of peripheral eosinophilia and troponin levels. Improvement in respiratory status. Transition to oral Prednisone taper and GDMT for heart failure. Week 6: Follow-up Status asthmaticus (required intubation); however, cardiac function showed normalization of LVEF (55–60%) . Positive MPO-ANCA (6.0 U) confirmed EGPA diagnosis (ACR/EULAR score: 8). Discussion This case demonstrates an atypical form of MPO-ANCA–positive EGPA presenting as reversible cardiomyopathy without systemic features of vasculitis. Cardiac involvement occurs in up to 60% of EGPA cases and remains a leading cause of disease-related mortality. However, it is more commonly associated with ANCA-negative disease and higher eosinophil counts. (2,4) MPO-ANCA positivity typically correlates with systemic vasculitic manifestations such as neuropathy and glomerulonephritis (GN). (1,3) While vasculitic features (like purpura or GN) are more common in MPO-positive cases, this case proves that eosinophilic-driven tissue infiltration (myocarditis) can still dominate the clinical picture. The presence of isolated, severe, and reversible post-myocarditis cardiomyopathy in an MPO-ANCA–positive patient represents an unusual and diagnostically challenging phenotype. In this case, the diagnosis of EGPA-EM was based upon fulfilling the 2022 ACR/EULAR classification criteria for EGPA (3) due to the presence of adult-onset asthma and severe eosinophilia. Going further, the diagnosis of eosinophilic myocarditis is presumptive, based on reversible LV dysfunction, elevated troponin, normal coronary arteries, and rapid corticosteroid response in the context of EGPA. The recently proposed LATE-EAST score, developed by Liu et al. (2025) from a cohort of 193 EGPA patients (118 with cardiac involvement), is a 7-item tool designed to differentiate EGPA-related eosinophilic myocarditis (EGPA-EM) from chronic inflammatory cardiomyopathy (EGPA-ICM). The score ranges from 0 to 9 points, with a cutoff ≥4 points yielding good diagnostic performance (AUC 0.85, sensitivity 78%, specificity 86). (4) When applied to our case, the patient scored 4.5 points (no pulmonary infiltrates, 0.5; troponin I >1.9 ng/mL, 2; LVEF <40%, 2), which exceeds the diagnostic threshold and is consistent with EGPA-EM rather than alternative etiologies. Although cardiac MRI and endomyocardial biopsy were not performed, the LATE-EAST score; combined with the patient’s clinical presentation and rapid response to corticosteroids, provides strong supportive evidence for eosinophilic myocarditis. (4) Although an endomyocardial biopsy was not performed, the rapid recovery of the LVEF from 30% to 60% following corticosteroid therapy provides strong ex-juvantibus evidence for the diagnosis of eosinophilic myocarditis. Table3: Table: Application of the LATE-EAST Score to the Current Case Item Patient Value Criteria Met Points L VEF, % 30–34% 1.90 ng/ml 2.0 E osinophil Count 1.55 × 10⁹/L < 6.38 × 10⁹/L 0 A bsence of Lung Infiltrates CT: Normal (no infiltrates) Yes 0.5 S T-T Abnormalities Unremarkable No 0 T issue (Edema on CMR) Not performed N/A 0 Total Score 4.5 Although endomyocardial biopsy is the gold standard and cardiac MRI is increasingly used for noninvasive confirmation of myocarditis, (5,6,7), their absence in this case underscores the importance of integrating clinical, laboratory, and echocardiographic findings. The exclusion of viral, ischemic, and toxic etiologies, combined with the patient’s eosinophilia, MPO-ANCA positivity, and rapid steroid response, supports the presumptive diagnosis. Furthermore, application of the recently validated LATE-EAST score provides objective reinforcement of EGPA-related eosinophilic myocarditis, situating this case within evolving diagnostic frameworks. While endomyocardial biopsy remains the gold standard, our case highlights the utility of clinical scoring systems like the LATE-EAST score in guiding management when invasive procedures are deferred due to rapid clinical stabilization. Early corticosteroid treatment in our patient was pivotal in reversing the left ventricular dysfunction, indicating the importance of early diagnosis and therapy (2,4,7). Long-term management may include adjunctive immunosuppressive or anti–IL-5 therapies to reduce corticosteroid toxicity and maintain remission. (4,7) Key Learning Points Adult‑onset asthma with persistent eosinophilia should prompt consideration of EGPA. Acute non‑ischemic LV dysfunction with elevated troponin and eosinophilia can represent eosinophilic myocarditis even in MPO‑ANCA–positive patients. When cardiac MRI or biopsy are unavailable, a transparent, reproducible diagnostic pathway (exclusion of alternatives, serial objective data, validated clinical scores, and documented therapeutic response) strengthens the case for EGPA‑related myocarditis. Early corticosteroid therapy may reverse cardiac dysfunction; plan for long‑term follow‑up and steroid‑sparing strategies. Table 4. Comparative Table of Reported EGPA‑Related Myocarditis Cases (Focused on MPO‑ANCA and Diagnostic Certainty) Study / Year ANCA Status Cardiac Phenotype Diagnostics Used Treatment Outcome / Key Insight Condurache et al., 2022 (7). p‑ANCA / MPO‑ANCA positive Acute eosinophilic myocarditis with chest pain, troponin rise, non‑ischemic LV dysfunction CMR showing myocardial edema + LGE, echo, biomarkers, normal coronaries High‑dose corticosteroids CMR‑confirmed eosinophilic myocarditis in an ANCA‑positive patient; rapid recovery with steroids. Nakayama et al., 2018 (6). ANCA not emphasized Dilated cardiomyopathy with active eosinophilic myocarditis Endomyocardial biopsy positive, CMR nondiagnostic Steroids ± immunosuppression EMB detected active myocarditis when imaging was inconclusive. Sartorelli et al., 2022 (Series) (4). Mixed (MPO+, MPO–, PR3–) Acute EM, chronic inflammatory cardiomyopathy, HF, arrhythmias CMR widely used, EMB in selected cases Steroids; cyclophosphamide or other agents for severe disease CMR improved detection; fibrosis predicted poorer prognosis. Liu et al., 2025 (LATE‑EAST cohort) (2). Mixed; MPO‑ANCA associated with vasculitic phenotype Acute EM vs chronic ICM Clinical data, biomarkers, echo; CMR/EMB variably used; LATE‑EAST score validated Steroids ± immunosuppression Score ≥4 predicted acute EM; useful when MRI/EMB unavailable. Current Case (2025) p‑ANCA negative/ MPO‑ANCA positive (6.0 U) Acute reversible cardiomyopathy consistent with eosinophilic myocarditis Echo (LVEF 30–34% → 55–60%), marked troponin, normal coronaries; CMR/EMB unavailable; LATE‑EAST score = 4.5 IV steroids → rapid recovery Rare MPO‑ANCA EM phenotype; diagnosis supported by structured reasoning + scoring system. CMR and EMB increase diagnostic certainty; when unavailable, apply structured scores and document exclusion of alternatives. Conclusion MPO-ANCA–positive EGPA presenting as isolated reversible cardiomyopathy is rare. EGPA-EM should be considered in adults with asthma, eosinophilia, and non-ischemic cardiomyopathy. The recognition of this presentation allows timely corticosteroid therapy, which can prevent irreversible cardiac injury. Abbreviations ACR/EULAR American College of Rheumatology/European Alliance of Associations for Rheumatology ANCA Anti-Neutrophil Cytoplasmic Antibody AUC Area Under the Curve BNP Brain Natriuretic Peptide CMR Cardiac Magnetic Resonance CRP C-Reactive Protein CT Computed Tomography ECG Electrocardiogram EGPA Eosinophilic Granulomatosis with Polyangiitis EGPA-EM Eosinophilic Granulomatosis with Polyangiitis-related Eosinophilic Myocarditis EGPA-ICM Eosinophilic Granulomatosis with Polyangiitis-related Chronic Inflammatory Cardiomyopathy EMB Endomyocardial Biopsy ESR Erythrocyte Sedimentation Rate GN Glomerulonephritis IL-5 Interleukin-5 LATE-EAST LATE-EAST score LVEF Left Ventricular Ejection Fraction MPO-ANCA Myeloperoxidase Anti-Neutrophil Cytoplasmic Antibody MRI Magnetic Resonance Imaging PR3-ANCA Proteinase 3 Anti-Neutrophil Cytoplasmic Antibody Declarations Informed consent The patient provided written informed consent for publication of this case and associated images. Funding No funding was received for this study. Author Contribution SA and NI contributed to the clinical care of the patient and drafted the initial manuscript. BS provided cardiology expertise, reviewed the imaging, and critically revised the manuscript for important intellectual content. NI acted as the corresponding author and oversaw the project. All authors read and approved the final manuscript. References Rout P, Maher L Eosinophilic Granulomatosis With Polyangiitis (Churg-Strauss Syndrome) [Updated 2025 Dec 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537099/ Sartorelli S, Chassagnon G, Cohen P et al (2022) Revisiting characteristics, treatment and outcome of cardiomyopathy in eosinophilic granulomatosis with polyangiitis. Rheumatology 61(3):1175–1184. 10.1093/rheumatology/keab514 Grayson PC, Ponte C, Suppiah RDCVAS, Study Group et al (2022) American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for Eosinophilic Granulomatosis with Polyangiitis. Annals of the Rheumatic Diseases 2022;81:309–314 Liu X, Zhou Y, Li J et al (2025) Cardiac involvement in eosinophilic granulomatosis with polyangiitis: acute eosinophilic myocarditis and chronic inflammatory cardiomyopathy. Rheumatology 64(2):722–731. 10.1093/rheumatology/keae085 Basso C, Myocarditis (2022) N Engl J Med 387(16):1488–1500. 10.1056/NEJMra2114478 Nakayama T, Murai S, Ohte N (2018) Dilated cardiomyopathy with eosinophilic granulomatosis with polyangiitis in which active myocardial inflammation was only detected by endomyocardial biopsy. Intern Med 57(18):2675–2679. 10.2169/internalmedicine.0330-17 Condurache D-G, Raisi-Estabragh Z, Baslas R, Hamdulay S (August 2022) A case report of myocarditis secondary to eosinophilic granulomatosis with polyangiitis. Eur Heart J - Case Rep 6:ytac307. https://doi.org/10.1093/ehjcr/ytac307 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8607437","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":580787686,"identity":"106a9ef1-fe33-4736-bec3-7b28dccadf48","order_by":0,"name":"Stephanie Ammari","email":"","orcid":"","institution":"HCA Houston Healthcare Clear Lake","correspondingAuthor":false,"prefix":"","firstName":"Stephanie","middleName":"","lastName":"Ammari","suffix":""},{"id":580787687,"identity":"445cdcb7-1329-4526-a43e-e3b3c95379bd","order_by":1,"name":"Nawras Ibrahim","email":"data:image/png;base64,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","orcid":"","institution":"HCA Healthcare (United States)","correspondingAuthor":true,"prefix":"","firstName":"Nawras","middleName":"","lastName":"Ibrahim","suffix":""},{"id":580787689,"identity":"53d33368-99ba-4aa9-ae27-590d3ecf9154","order_by":2,"name":"Bahaeddin Shabaneh","email":"","orcid":"","institution":"University of Houston - Clear Lake","correspondingAuthor":false,"prefix":"","firstName":"Bahaeddin","middleName":"","lastName":"Shabaneh","suffix":""}],"badges":[],"createdAt":"2026-01-15 06:23:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8607437/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8607437/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101753592,"identity":"95c6fda4-2246-4105-ba7f-910591a9ab28","added_by":"auto","created_at":"2026-02-03 10:40:18","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":424964,"visible":true,"origin":"","legend":"\u003cp\u003eChest radiograph demonstrating cardiomegaly with pulmonary vascular congestion\u003c/p\u003e","description":"","filename":"Screenshot20250825012714.png","url":"https://assets-eu.researchsquare.com/files/rs-8607437/v1/0c056a9cc1ca442257115584.png"},{"id":101752973,"identity":"617a3040-a6df-44ed-a47c-41a026762665","added_by":"auto","created_at":"2026-02-03 10:38:35","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":475659,"visible":true,"origin":"","legend":"\u003cp\u003eCT angiogram shows a calcified granuloma in the left lower lobe.\u003c/p\u003e","description":"","filename":"Screenshot20250825013158.png","url":"https://assets-eu.researchsquare.com/files/rs-8607437/v1/7c1ac129d52a631651d4fb05.png"},{"id":101752810,"identity":"7ed5e480-23a1-4a73-9cc9-378197fdb007","added_by":"auto","created_at":"2026-02-03 10:32:46","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":165314,"visible":true,"origin":"","legend":"\u003cp\u003eInitial ECG; normal sinus rhythm, with the presence of anterior Q waves and nonspecific ST abnormalities\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-8607437/v1/32958a0a57d3d538dd07b589.png"},{"id":101753188,"identity":"e9f632eb-8d43-45bd-8492-b17763799ae2","added_by":"auto","created_at":"2026-02-03 10:39:19","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":550017,"visible":true,"origin":"","legend":"\u003cp\u003eCoronary angiography revealed no evidence of obstructive coronary artery disease.\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-8607437/v1/1ba68811c63ecf528c38094b.png"},{"id":101752946,"identity":"440ebc6a-fb9c-420e-a3f8-84c905e712e9","added_by":"auto","created_at":"2026-02-03 10:38:18","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":280651,"visible":true,"origin":"","legend":"\u003cp\u003eTransthoracic echocardiogram demonstrating left ventricular systolic dysfunction during the first admission (Left), with normalization of systolic function noted during the second admission (Right).\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8607437/v1/ef12be2f144f33c65fea6a76.png"},{"id":101755768,"identity":"93144fb5-6318-4f5c-96ca-a2a5a8edab87","added_by":"auto","created_at":"2026-02-03 10:54:38","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2768551,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8607437/v1/2af2c933-e3fb-43f4-95a0-707e2b6c3d79.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":" MPO-ANCA–Positive Eosinophilic Granulomatosis with Polyangiitis Presenting as Acute Reversible Cardiomyopathy: A Case Report.","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEosinophilic granulomatosis with polyangiitis (EGPA) is an ANCA associated small vessel vasculitis characterized by adult-onset asthma, eosinophilia, and variable organ involvement. EGPA typically develops in three clinical phases, beginning with asthma, followed by tissue eosinophilia and finally systemic vasculitis. Cardiac involvement occurs in about 62%, but symptomatic presentation is observed only in 26%. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eMPO-ANCA positivity occurs in 30\u0026ndash;40% of the cases, usually with vasculitic complications like neuropathy or renal disease, whereas ANCA-negative patients are more likely to have cardiomyopathy. (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eReversible post-myocarditis cardiomyopathy has been reported but remains underemphasized in MPO-ANCA\u0026ndash;positive EGPA, highlighting the importance of early recognition and early initiation of corticosteroid therapy. (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eWe report a rare case of MPO-ANCA\u0026ndash;positive EGPA-related eosinophilic myocarditis (EGPA-EM) with acute, reversible cardiomyopathy in the setting of no overt vasculitic disease manifestations.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eA 65-year-old male non-smoker with adult-onset asthma (4 years), allergic rhinitis, hydrocephalus with ventriculoperitoneal shunt, presented with acute dyspnea and bronchodilator-resistant wheezing.\u003c/p\u003e \u003cp\u003eOn examination, he was tachypneic with fine wheezes and bilateral crackles, and saturation on ambient air was 98%. Labs showed elevated high-sensitivity troponin (peak 1980 ng/L; normal\u0026thinsp;\u0026lt;\u0026thinsp;14), eosinophilia (1310/mm\u0026sup3;, 13.5%), elevated D-dimer (5664 ng/mL) and normal BNP. The chest X-ray and ECG were unremarkable. CT angiogram excluded pulmonary embolism but showed only a calcified granuloma in the left lower lobe.\u003c/p\u003e \u003cp\u003eTransthoracic echocardiogram showed left ventricular systolic dysfunction (LVEF 30\u0026ndash;34%) with global hypokinesis. The coronary angiogram was normal, showing patent coronary arteries. Viral serologies, blood cultures, and toxicology screens were negative.\u003c/p\u003e \u003cp\u003eThe patient was started on Methyl-prednisone 40 mg twice a day for five days and bronchodilators, which resulted in remarkable improvement in clinical status. Subsequently, he was discharged on prednisone taper and guideline-directed medical therapy for heart failure.\u003c/p\u003e \u003cp\u003eSix weeks after discharge, he returned with progressive dyspnea and, status asthmaticus requiring intubation. Labs were significant for eosinophilia (1300\u0026ndash;1550/mm\u0026sup3;, 15\u0026ndash;18%), elevated ESR 34 mm/hr, and elevated CRP 18 mg/dL. BNP and troponin levels were normal. Repeated echocardiography revealed normalization of LVEF (55\u0026ndash;60%) with no regional wall motion abnormalities.\u003c/p\u003e \u003cp\u003eThe combination of cardiomyopathy and history of eosinophilic asthma prompted autoimmune screen which revealed positive MPO-ANCA (6.0 U; normal\u0026thinsp;\u0026lt;\u0026thinsp;0.9) and negative PR3-ANCA, fulfilling the 2022 ACR/EULAR classification criteria for EGPA with a score\u0026thinsp;\u0026ge;\u0026thinsp;6 (eosinophilia\u0026thinsp;+\u0026thinsp;5, asthma\u0026thinsp;+\u0026thinsp;3). (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) Endomyocardial biopsy and Cardiac MRI were deferred due to clinical improvement and unavailability as well.\u003c/p\u003e \u003cp\u003eHe was treated for asthma exacerbation and discharged on inhaled triple therapy and prednisone taper; outpatient follow-up arranged to consider adjunctive therapy.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eObjective data (serial values)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFirst admission\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWeek 6 (readmission)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNotes\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHigh-sensitivity troponin I\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1980 ng/L (peak)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNormalized to reference range\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMarked elevation at presentation with subsequent normalization.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEosinophil count\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1310 /mm\u0026sup3;; 13.5%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1550 /mm\u0026sup3;; 15\u0026ndash;18%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePersistent peripheral eosinophilia.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBNP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWithin normal limits\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWithin normal limits\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNo biochemical heart-failure signal despite LV dysfunction.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eECG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNormal sinus rhythm; nonspecific ST changes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNo persistent ischemic pattern reported\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNo ischemic ECG evolution.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCoronary angiography\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNormal coronary arteries\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNot repeated\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eIschemic etiology excluded on index angiography.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEchocardiography (LVEF)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30\u0026ndash;34% (global hypokinesis)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e55\u0026ndash;60% (normalized)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eRapid recovery of systolic function after steroids.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAutoimmune testing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNot tested\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMPO-ANCA 6.0 U (normal\u0026thinsp;\u0026lt;\u0026thinsp;0.9); PR3-ANCA negative\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMPO-ANCA positivity documented during workup.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eDiagnostic procedures not performed and rationale\u003c/h2\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eCardiac MRI\u003c/b\u003e: unavailable at the treating facility during the acute presentation; patient improved rapidly and transfer for MRI was deferred to avoid delay in therapy.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eEndomyocardial biopsy\u003c/b\u003e: not performed because (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) invasive procedure risk in a clinically improving patient, (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) limited local availability, and (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) the pretest probability of eosinophilic myocarditis was high given the constellation of asthma, eosinophilia, elevated troponin, non-ischemic LV dysfunction, MPO-ANCA positivity, and rapid steroid response. These reasons are explicitly documented in the chart and discussed with the patient and family.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTimeline of Clinical Events and Treatment Response\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime Point\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eClinical Status \u0026amp; Findings\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eIntervention / Diagnostic Score\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDay 1: Admission\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAcute dyspnea, wheezing, global hypokinesis (LVEF 30\u0026ndash;34%). Trop-I peak: 1,980 ng/L; Eosinophils: 1,310/mm\u0026sup3;.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eLATEEAST Score: 4.5\u003c/b\u003e (High probability of EGPA myocarditis)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDay 2: Treatment\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRapid clinical stabilization following coronary angiography (normal coronaries).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eInitiation of IV Methylprednisolone\u003c/b\u003e (40 mg BID)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDay 7: Discharge\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNormalization of peripheral eosinophilia and troponin levels. Improvement in respiratory status.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTransition to oral Prednisone taper and GDMT for heart failure.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWeek 6: Follow-up\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eStatus asthmaticus (required intubation); however, cardiac function showed \u003cb\u003enormalization of LVEF (55\u0026ndash;60%)\u003c/b\u003e.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePositive MPO-ANCA (6.0 U) confirmed EGPA diagnosis (ACR/EULAR score: 8).\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis case demonstrates an atypical form of MPO-ANCA\u0026ndash;positive EGPA presenting as reversible cardiomyopathy without systemic features of vasculitis. Cardiac involvement occurs in up to 60% of EGPA cases and remains a leading cause of disease-related mortality. However, it is more commonly associated with ANCA-negative disease and higher eosinophil counts. (2,4) MPO-ANCA positivity typically correlates with systemic vasculitic manifestations such as neuropathy and glomerulonephritis (GN). (1,3) While vasculitic features (like purpura or GN) are more common in MPO-positive cases, this case proves that eosinophilic-driven tissue infiltration (myocarditis) can still dominate the clinical picture. The presence of isolated, severe, and reversible post-myocarditis cardiomyopathy in an MPO-ANCA\u0026ndash;positive patient represents an unusual and diagnostically challenging phenotype.\u003c/p\u003e\n\u003cp\u003eIn this case, the diagnosis of EGPA-EM was based upon fulfilling the 2022 ACR/EULAR classification criteria for EGPA (3) due to the presence of adult-onset asthma and severe eosinophilia. Going further, the diagnosis of eosinophilic myocarditis is presumptive, based on reversible LV dysfunction, elevated troponin, normal coronary arteries, and rapid corticosteroid response in the context of EGPA. The recently proposed LATE-EAST score, developed by Liu et al. (2025) from a cohort of 193 EGPA patients (118 with cardiac involvement), is a 7-item tool designed to differentiate EGPA-related eosinophilic myocarditis (EGPA-EM) from chronic inflammatory cardiomyopathy (EGPA-ICM). The score ranges from 0 to 9 points, with a cutoff \u0026ge;4 points yielding good diagnostic performance (AUC 0.85, sensitivity 78%, specificity 86). (4)\u003c/p\u003e\n\u003cp\u003eWhen applied to our case, the patient scored 4.5 points (no pulmonary infiltrates, 0.5; troponin I \u0026gt;1.9 ng/mL, 2; LVEF \u0026lt;40%, 2), which exceeds the diagnostic threshold and is consistent with EGPA-EM rather than alternative etiologies. Although cardiac MRI and endomyocardial biopsy were not performed, the LATE-EAST score; combined with the patient\u0026rsquo;s clinical presentation and rapid response to corticosteroids, provides strong supportive evidence for eosinophilic myocarditis. (4) Although an endomyocardial biopsy was not performed, the rapid recovery of the LVEF from 30% to 60% following corticosteroid therapy provides strong ex-juvantibus evidence for the diagnosis of eosinophilic myocarditis.\u003c/p\u003e\n\u003cp\u003eTable3: Table: Application of the LATE-EAST Score to the Current Case\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"3\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eItem\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePatient Value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCriteria Met\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePoints\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eL\u003c/strong\u003eVEF, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e30\u0026ndash;34%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt; 40.00%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e2.0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eA\u003c/strong\u003eNCA Status\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eMPO-ANCA Positive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eANCA Positive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eT\u003c/strong\u003eroponin I (cTnI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.98 ng/ml (1980 ng/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026gt; 1.90 ng/ml\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e2.0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eE\u003c/strong\u003eosinophil Count\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.55 \u0026times; 10⁹/L\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt; 6.38 \u0026times; 10⁹/L\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eA\u003c/strong\u003ebsence of Lung Infiltrates\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCT: Normal (no infiltrates)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0.5\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eS\u003c/strong\u003eT-T Abnormalities\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eUnremarkable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eT\u003c/strong\u003eissue (Edema on CMR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNot performed\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eTotal Score\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e4.5\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAlthough endomyocardial biopsy is the gold standard and cardiac MRI is increasingly used for noninvasive confirmation of myocarditis, (5,6,7), their absence in this case underscores the importance of integrating clinical, laboratory, and echocardiographic findings. The exclusion of viral, ischemic, and toxic etiologies, combined with the patient\u0026rsquo;s eosinophilia, MPO-ANCA positivity, and rapid steroid response, supports the presumptive diagnosis. Furthermore, application of the recently validated LATE-EAST score provides objective reinforcement of EGPA-related eosinophilic myocarditis, situating this case within evolving diagnostic frameworks. While endomyocardial biopsy remains the gold standard, our case highlights the utility of clinical scoring systems like the LATE-EAST score in guiding management when invasive procedures are deferred due to rapid clinical stabilization. Early corticosteroid treatment in our patient was pivotal in reversing the left ventricular dysfunction, indicating the importance of early diagnosis and therapy (2,4,7). Long-term management may include adjunctive immunosuppressive or anti\u0026ndash;IL-5 therapies to reduce corticosteroid toxicity and maintain remission. (4,7)\u003c/p\u003e\n\u003cp\u003eKey Learning Points\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eAdult‑onset asthma with persistent eosinophilia should prompt consideration of EGPA.\u003c/li\u003e\n \u003cli\u003eAcute non‑ischemic LV dysfunction with elevated troponin and eosinophilia can represent eosinophilic myocarditis even in MPO‑ANCA\u0026ndash;positive patients.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eWhen cardiac MRI or biopsy are unavailable, a transparent, reproducible diagnostic pathway (exclusion of alternatives, serial objective data, validated clinical scores, and documented therapeutic response) strengthens the case for EGPA‑related myocarditis.\u003c/li\u003e\n \u003cli\u003eEarly corticosteroid therapy may reverse cardiac dysfunction; plan for long‑term follow‑up and steroid‑sparing strategies.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4.\u0026nbsp;\u003c/strong\u003eComparative Table of Reported EGPA‑Related Myocarditis Cases (Focused on MPO‑ANCA and Diagnostic Certainty)\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"3\" cellpadding=\"0\" width=\"762\" class=\"fr-table-selection-hover\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 100px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eStudy / Year\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eANCA Status\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCardiac Phenotype\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDiagnostics Used\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTreatment\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 183px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOutcome / Key Insight\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 100px;\"\u003e\n \u003cp\u003eCondurache et al., 2022 (7).\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003ep‑ANCA / MPO‑ANCA positive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003eAcute eosinophilic myocarditis with chest pain, troponin rise, non‑ischemic LV dysfunction\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003eCMR showing myocardial edema + LGE, echo, biomarkers, normal coronaries\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106px;\"\u003e\n \u003cp\u003eHigh‑dose corticosteroids\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 183px;\"\u003e\n \u003cp\u003eCMR‑confirmed eosinophilic myocarditis in an ANCA‑positive patient; rapid recovery with steroids.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 100px;\"\u003e\n \u003cp\u003eNakayama et al., 2018\u003c/p\u003e\n \u003cp\u003e(6).\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003eANCA not emphasized\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003eDilated cardiomyopathy with active eosinophilic myocarditis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003eEndomyocardial biopsy positive, CMR nondiagnostic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106px;\"\u003e\n \u003cp\u003eSteroids \u0026plusmn; immunosuppression\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 183px;\"\u003e\n \u003cp\u003eEMB detected active myocarditis when imaging was inconclusive.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 100px;\"\u003e\n \u003cp\u003eSartorelli et al., 2022 (Series) (4).\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003eMixed (MPO+, MPO\u0026ndash;, PR3\u0026ndash;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003eAcute EM, chronic inflammatory cardiomyopathy, HF, arrhythmias\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003eCMR widely used, EMB in selected cases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106px;\"\u003e\n \u003cp\u003eSteroids; cyclophosphamide or other agents for severe disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 183px;\"\u003e\n \u003cp\u003eCMR improved detection; fibrosis predicted poorer prognosis.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 100px;\"\u003e\n \u003cp\u003eLiu et al., 2025 (LATE‑EAST cohort) (2).\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003eMixed; MPO‑ANCA associated with vasculitic phenotype\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003eAcute EM vs chronic ICM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003eClinical data, biomarkers, echo; CMR/EMB variably used; LATE‑EAST score validated\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106px;\"\u003e\n \u003cp\u003eSteroids \u0026plusmn; immunosuppression\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 183px;\"\u003e\n \u003cp\u003eScore \u0026ge;4 predicted acute EM; useful when MRI/EMB unavailable.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 100px;\"\u003e\n \u003cp\u003eCurrent Case (2025)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 107px;\"\u003e\n \u003cp\u003ep‑ANCA negative/ MPO‑ANCA positive (6.0 U)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003eAcute reversible cardiomyopathy consistent with eosinophilic myocarditis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003eEcho (LVEF 30\u0026ndash;34% \u0026rarr; 55\u0026ndash;60%), marked troponin, normal coronaries; CMR/EMB unavailable; LATE‑EAST score = 4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106px;\"\u003e\n \u003cp\u003eIV steroids \u0026rarr; rapid recovery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 183px;\"\u003e\n \u003cp\u003eRare MPO‑ANCA EM phenotype; diagnosis supported by structured reasoning + scoring system.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eCMR and EMB increase diagnostic certainty; when unavailable, apply structured scores and document exclusion of alternatives.\u003c/strong\u003e\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eMPO-ANCA\u0026ndash;positive EGPA presenting as isolated reversible cardiomyopathy is rare. EGPA-EM should be considered in adults with asthma, eosinophilia, and non-ischemic cardiomyopathy. The recognition of this presentation allows timely corticosteroid therapy, which can prevent irreversible cardiac injury.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eACR/EULAR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAmerican College of Rheumatology/European Alliance of Associations for Rheumatology\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eANCA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAnti-Neutrophil Cytoplasmic Antibody\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAUC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eArea Under the Curve\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eBNP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eBrain Natriuretic Peptide\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCMR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCardiac Magnetic Resonance\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCRP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eC-Reactive Protein\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eComputed Tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eECG\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eElectrocardiogram\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEGPA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEosinophilic Granulomatosis with Polyangiitis\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEGPA-EM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEosinophilic Granulomatosis with Polyangiitis-related Eosinophilic Myocarditis\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEGPA-ICM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEosinophilic Granulomatosis with Polyangiitis-related Chronic Inflammatory Cardiomyopathy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEMB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEndomyocardial Biopsy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eESR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eErythrocyte Sedimentation Rate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGN\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGlomerulonephritis\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIL-5\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInterleukin-5\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLATE-EAST\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLATE-EAST score\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLVEF\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLeft Ventricular Ejection Fraction\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMPO-ANCA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMyeloperoxidase Anti-Neutrophil Cytoplasmic Antibody\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMRI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMagnetic Resonance Imaging\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePR3-ANCA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eProteinase 3 Anti-Neutrophil Cytoplasmic Antibody\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eInformed consent\u003c/h2\u003e \u003cp\u003eThe patient provided written informed consent for publication of this case and associated images.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eNo funding was received for this study.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eSA and NI contributed to the clinical care of the patient and drafted the initial manuscript. BS provided cardiology expertise, reviewed the imaging, and critically revised the manuscript for important intellectual content. NI acted as the corresponding author and oversaw the project. All authors read and approved the final manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eRout P, Maher L Eosinophilic Granulomatosis With Polyangiitis (Churg-Strauss Syndrome) [Updated 2025 Dec 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ncbi.nlm.nih.gov/books/NBK537099/\u003c/span\u003e\u003cspan address=\"https://www.ncbi.nlm.nih.gov/books/NBK537099/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSartorelli S, Chassagnon G, Cohen P et al (2022) Revisiting characteristics, treatment and outcome of cardiomyopathy in eosinophilic granulomatosis with polyangiitis. Rheumatology 61(3):1175\u0026ndash;1184. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/rheumatology/keab514\u003c/span\u003e\u003cspan address=\"10.1093/rheumatology/keab514\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrayson PC, Ponte C, Suppiah RDCVAS, Study Group et al (2022) American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for Eosinophilic Granulomatosis with Polyangiitis. Annals of the Rheumatic Diseases 2022;81:309\u0026ndash;314\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu X, Zhou Y, Li J et al (2025) Cardiac involvement in eosinophilic granulomatosis with polyangiitis: acute eosinophilic myocarditis and chronic inflammatory cardiomyopathy. Rheumatology 64(2):722\u0026ndash;731. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/rheumatology/keae085\u003c/span\u003e\u003cspan address=\"10.1093/rheumatology/keae085\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBasso C, Myocarditis (2022) N Engl J Med 387(16):1488\u0026ndash;1500. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1056/NEJMra2114478\u003c/span\u003e\u003cspan address=\"10.1056/NEJMra2114478\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNakayama T, Murai S, Ohte N (2018) Dilated cardiomyopathy with eosinophilic granulomatosis with polyangiitis in which active myocardial inflammation was only detected by endomyocardial biopsy. Intern Med 57(18):2675\u0026ndash;2679. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2169/internalmedicine.0330-17\u003c/span\u003e\u003cspan address=\"10.2169/internalmedicine.0330-17\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCondurache D-G, Raisi-Estabragh Z, Baslas R, Hamdulay S (August 2022) A case report of myocarditis secondary to eosinophilic granulomatosis with polyangiitis. Eur Heart J - Case Rep 6:ytac307. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/ehjcr/ytac307\u003c/span\u003e\u003cspan address=\"10.1093/ehjcr/ytac307\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Eosinophilic Granulomatosis with Polyangiitis, MPO-ANCA, Eosinophilic Myocarditis, LATEEAST score, Reversible Cardiomyopathy, Case Report","lastPublishedDoi":"10.21203/rs.3.rs-8607437/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8607437/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eEosinophilic granulomatosis with polyangiitis (EGPA) isa rare autoimmune vasculitis characterized by asthma, blood and tissue eosinophilia, and small-vessel vasculitis. It is among the rarest of ANCA-associated vasculitides, and ANCA is present in only 30\u0026ndash;40% of patients. ANCA-positive patients have more vasculitic complications, such as mononeuritis multiplex and glomerulonephritis, whereas ANCA-negative patients are more likely to have cardiomyopathy.\u003c/p\u003e\u003ch2\u003eCase:\u003c/h2\u003e \u003cp\u003eA 65yearold man with adult-onset asthma presented with acute dyspnea, bronchodilator-resistant wheeze, markedly elevated high-sensitivity troponin (peak 1980 ng/L), peripheral eosinophilia (peak 1550/mm\u0026sup3;), and new left ventricular systolic dysfunction (LVEF 30\u0026ndash;34%) with normal coronary angiography. He improved rapidly after intravenous corticosteroids; LVEF normalized to 55\u0026ndash;60% within six weeks. MPO-ANCA was positive (6.0 U; normal\u0026thinsp;\u0026lt;\u0026thinsp;0.9). Cardiac MRI and endomyocardial biopsy were not performed because they were unavailable, and the patient had rapid clinical recovery; we document serial labs, imaging, and the diagnostic application of the LATEEAST score to support a presumptive diagnosis of EGPA-related eosinophilic myocarditis.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThe case indicates that MPO-ANCA\u0026ndash;positive EGPA can manifest as acute reversible cardiomyopathy without apparent vasculitic manifestations, presumably secondary to eosinophilic myocarditis. When cardiac MRI or biopsy are unavailable, careful integration of clinical features, serial biomarkers, echocardiography, ANCA testing, validated clinical scores, and response to therapy can support a working diagnosis of EGPA-related eosinophilic myocarditis. Early corticosteroid therapy may reverse cardiac dysfunction.\u003c/p\u003e","manuscriptTitle":" MPO-ANCA–Positive Eosinophilic Granulomatosis with Polyangiitis Presenting as Acute Reversible Cardiomyopathy: A Case Report.","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-02 05:59:52","doi":"10.21203/rs.3.rs-8607437/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"2f43777f-0663-4676-b3be-2ec106c79693","owner":[],"postedDate":"February 2nd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-02-02T05:59:55+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-02 05:59:52","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8607437","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8607437","identity":"rs-8607437","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}