Staging of Fabry cardiomyopathy in clinical practice: an algorithm proposal

Purpose: Fabry disease (FD) is characterized by hypertrophic cardiomyopathy and early diagnosis is essential, considering the response to enzyme replacement or chaperone therapies. Recently, a new clinical staging for Fabry cardiomyopathy suggested five stages (0A, 0B, IA, IB, II, III), where the imaging characterization of hypertrophy and fibrosis are critical key items. Our study aimed to evaluate the applicability of the recent proposal of Meucci et al. 2024 in patients with FD, considering the last imaging cardiac evaluations. Methods: This retrospective observational study collected clinical data from patients diagnosed with FD. Staging system followed a hierarchical flowchart, staging patients based on LVEF, LGE, LV wall thickness, and other cardiac findings (symptoms, ECG/Echo/CMR abnormalities). Results: We included 53 FD patients. As cardiac magnetic resonance and echocardiogram parameters are essential to complete staging, the algorithm was fully applied to 44 patients. Among these patients, the majority (29,5%) were in the non-hypertrophic stage 0. In hypertrophic stage I, 27,2% of patients were classified according to the maximum wall thickness. The hypertrophic fibrotic stage II included 29,5% of the patients. Patients in stage III (13,6%) presented diffuse myocardial fibrosis ≥ 3 LV segments and/or impaired systolic function (LVEF < 50%). Conclusion: The staging scheme allows us to classify different stages of FD cardiomyopathy. Most patients were in early disease stages, probably related to the diagnosis in the context of familial screening. The stepwise algorithm proposal helped apply the staging in clinical practice; however, it must be validated in more extensive and prospective studies.