Staging of Fabry cardiomyopathy in clinical practice: an algorithm proposal

Area of Science:

• Cardiology
• Genetics
• Medical Imaging

Background:

• Fabry disease (FD) is a genetic disorder characterized by hypertrophic cardiomyopathy.
• Early diagnosis and staging are crucial for managing FD, guiding treatment with enzyme replacement or chaperone therapies.
• A recent clinical staging proposal for Fabry cardiomyopathy categorizes patients into five stages (0A, 0B, IA, IB, II, III) based on cardiac imaging findings like hypertrophy and fibrosis.

Purpose of the Study:

• To evaluate the applicability of the Meucci et al. 2024 clinical staging proposal for Fabry cardiomyopathy in a cohort of FD patients.
• To assess the utility of cardiac imaging evaluations, including hypertrophy and fibrosis characterization, within the proposed staging framework.

Main Methods:

• A retrospective observational study involving patients diagnosed with Fabry disease.
• Application of a hierarchical flowchart staging system based on left ventricular ejection fraction (LVEF), late gadolinium enhancement (LGE), left ventricular (LV) wall thickness, and other cardiac findings.
• Full algorithm application to 44 out of 53 FD patients due to the necessity of cardiac magnetic resonance and echocardiogram parameters.

Main Results:

• The staging system successfully classified different stages of Fabry disease cardiomyopathy.
• The majority of patients (29.5%) were classified in the non-hypertrophic stage 0.
• Stage I (hypertrophic) included 27.2% of patients, stage II (hypertrophic fibrotic) included 29.5%, and stage III (advanced fibrosis/impaired function) included 13.6%.

Conclusions:

• The proposed staging scheme effectively classifies Fabry disease cardiomyopathy.
• Most patients were identified in early disease stages, potentially due to familial screening protocols.
• The stepwise algorithm facilitates clinical application but requires validation in larger, prospective studies.