Molecular imaging of fibroblast activation in multiple non-ischemic cardiomyopathies

Abstract Purpose This pilot study aimed to evaluate the in vivo fibroblast activation in non-ischemic cardiomyopathies by 68Ga-FAPI-04 PET/CT. Methods 29 consecutive patients with symptomatic non-ischemic cardiomyopathies who underwent 68Ga-FAPI-04 PET/CT was prospectively recruited. Clinical characteristics and echocardiographic parameters were recorded. Cardiac uptake was quantified by standardized uptake values (SUVmax, SUVmean, SUVR) and left ventricular metabolism volume (LVMV). The relationship between 68Ga-FAPI-04 uptake with clinical and echocardiography parameters was investigated. Results Heterogenous 68Ga-FAPI-04 uptake was observed in different subtypes of non-ischemic cardiomyopathies. 22 (75.9%) patients showed elevated 68Ga-FAPI-04 uptake in the left ventricle and 10 (34.5%) patients also showed slightly diffuse elevated uptake in the right ventricle. Cardiac uptake values were significantly correlated with enlarged ventricular volume evaluated by echocardiography. Conclusion FAPI PET/CT presents a potential value for in vivo visualization and quantification of fibroblast activation on the molecular level. Further study is warranted for investigating the theranostic and prognostic value of elevated FAP signal.