Sex-specific prognostic thresholds of left ventricular hypertrophy in Fabry disease

Aims: Left ventricular hypertrophy (LVH) is one of the main prognostic factors in Fabry disease (FD). Despite the known impact of sex on the phenotypic expression of the disease, a "fixed" threshold of left ventricular maximal wall thickness (LVMWT)>12 mm is conventionally used for defining overt cardiac involvement. We aimed to investigate sex-differences in the association between LVH degree and cardiovascular outcomes in FD. Methods and results: In this multicenter retrospective study, 347 patients with FD (57% women) were enrolled and echocardiographic data collected. The study endpoint was defined as the composite of mortality, hospitalization for heart failure, atrial fibrillation, major brady- or tachy-arrhythmias and ischemic stroke.Women had lower LV wall thickness and LV mass than men and these differences were confirmed also indexing for body surface area (BSA) (all p<0.001). After a median follow-up of 53 (IQR: 26-90) months, 64 patients (18%) met the study endpoint. The composite-event rate at 8 years was significantly higher in men versus women (33% versus 11%; p=0.015). Values of LVMWT>10 mm (or indexed LVMWT>6.1 mm/m2) were associated with an increased risk of the composite endpoint in women, while a LVMWT prognostic threshold of 13 mm (or 6.9 mm/m2) was identified in men (both p<0.001). These cut-off values were independently associated with outcomes, after adjustment for age, exposure to specific therapy and renal function. Conclusions: In FD patients, sex-specific prognostic thresholds of LVH were identified, with women experiencing cardiovascular events at significantly lower values of LVMWT than men, even after accounting for BSA.