Hypertrophy Regression With N-Acetylcysteine in Hypertrophic Cardiomyopathy (HALT-HCM)

Rationale: Hypertrophic cardiomyopathy (HCM) is a genetic paradigm of cardiac hypertrophy. Cardiac hypertrophy and interstitial fibrosis are important risk factors for sudden death and morbidity in HCM. Oxidative stress is implicated in the pathogenesis of cardiac hypertrophy and fibrosis. Treatment with antioxidant N-acetylcysteine (NAC) reverses cardiac hypertrophy and fibrosis in animal models of HCM. Objective: To determine effect sizes of NAC on indices of cardiac hypertrophy and fibrosis in patients with established HCM. Methods and Results: HALT-HCM (Hypertrophy Regression With N-Acetylcysteine in Hypertrophic Cardiomyopathy) is a double-blind, randomized, sex-matched, placebo-controlled single-center pilot study in patients with HCM. Patients with HCM, who had a left ventricular wall thickness of ≥15 mm, were randomized either to a placebo or to NAC (1:2 ratio, respectively). NAC was titrated ≤2.4 g per day. Clinical evaluation, blood chemistry, and 6-minute walk test were performed every 3 months...