Risk Stratification in Coronary Artery Disease using NH3-PET Myocardial Flow Reserve and CAD-RADS on Coronary CT Angiography

Abstract PurposeMyocardial flow reserve (MFR) derived from 13N-ammonia positron emission tomography (NH3-PET) can predict the prognosis of patients with various heart diseases. Coronary computed tomography angiography (CCTA) is a non-invasive investigation for ischemic heart disease. The coronary artery disease reporting and data system (CAD-RADS) was established to standardize and facilitate the reporting of CCTA data regarding CAD. This study aimed to investigate the prognostic value of CAD-RADS and MFR.MethodsA total of 133 patients who underwent NH3-PET and CCTA within 3 months were enrolled. Patients were divided into groups with CAD-RADS 0-2 and ≥3 and into groups with MFR ≥2.0 and <2.0. The endpoint was major adverse cardiac events (MACE) comprising all-cause death, acute coronary syndrome, hospitalization due to heart failure, and cerebrovascular disease. The ability of CAD-RADS and MFR to predict MACE was analyzed using Kaplan-Meier analysis.ResultsThere was no significant difference in MFR between patients with CAD-RADS 0-2 and ≥3 (2.3±0.9 vs. 2.2±0.7, p=0.50). The MACE rate for patients with CAD-RADS 0-2 and ≥3 was equivalent (log-rank test, p=0.64). Patients with MFR <2.0 had a significantly higher MACE rate than those with MFR ≥2.0 (p=0.017). In patients with CAD-RADS ≥3, patients with MFR <2.0 had a significantly higher MACE rate than those with MFR ≥2.0 (p=0.034).ConclusionCAD-RADS did not contribute to MACE prediction. Conversely, MFR was useful in predicting MACE, allowing for further risk stratification in addition to CAD-RADS.