Prognostic Implications of Left Ventricular Hypertrophy and Mechanical Function in Fabry Disease: A Longitudinal Cohort Study

Abstract

The prognostic value of different grades of left ventricular hypertrophy (LVH) and left ventricular (LV) mechanical function in Fabry disease is unclear. We aimed to evaluate the association between the severity of LVH, LV mechanical function, and clinical outcomes in Fabry disease. We conducted a retrospective cohort study from a single-center registry of adult patients with Fabry disease. Left ventricular mass index (LVMI) was measured by echocardiography. The severity of LVH was categorized by LVMI using the sex-specific cutoff values. Left ventricular mechanical function was measured as LV global longitudinal strain (GLS) by speckle-tracking analysis. The primary outcome was a composite of major adverse cardiovascular events (MACE) at 5years, including heart failure hospitalization, sustained ventricular tachycardia, acute ischemic stroke, and all-cause mortality. The study included 268 patients (age 50.4±15.4years, men 46.6%) with Fabry disease (83.2% IVS4+919G>A mutation), and 106 patients (39.6%) had LVH. Patients with mild, moderate, or severe LVH had 5-year MACE rates of 7.4%, 10%, and 30.5%, respectively (P<.001). Moreover, patients with impaired LV GLS (<14.1%) had a higher 5-year MACE rate than those with preserved LV GLS (32.1% vs 2.4%, P<.001). Severe LVH was an independent predictor of MACE compared with absence of LVH (adjusted hazard ratio, 12.73; 95% CI, 1.3-124.71; P=.03), after adjusting for age, sex, hypertension, hyperlipidemia, atrial fibrillation, renal function, average E/e', enzyme replacement therapy, and LV GLS. Patients with severe LVH and impaired LV GLS had the highest incidence for MACE (log-rank P<.05), irrespective of sex, genotypes, and whether receiving enzyme replacement therapy or not. Sex-specific grading of LVH by LVMI is practical for risk stratification in patients with Fabry disease, and impaired LV GLS further refines the prognostication.