Management Strategies for Hypertrophic Cardiomyopathy – A Review
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common genetically inherited cardiomyopathy, with a prevalence near 1 in 500. HCM manifests as the presence of left ventricular (LV)hypertrophy that cannot be explained by the hemodynamic conditions. The characteristic histological findings are myocyte disarray and fibrosis. The most common imaging findings are asymmetric hypertrophy of the interventricular septum; this is often associated with a narrowed LV outflow (LVOT) and flow acceleration at that level. Imaging techniques such as echocardiography and cardiac magnetic resonance imaging play a crucial role in the diagnosis and management of patients with HCM. HCM can lead to myocardial ischemia, LVOT obstruction leading to exercise intolerance, heart failure (HF), and increased risk of sudden cardiac death (SCD). Management is focused on reducing the risk of SCD, limiting dynamic LVOT obstruction and progression of symptoms with lifestyle and pharmacologic modulation. HCM represents a challenging condition given the marked genetic and phenotypic heterogeneity in clinical manifestations, disease course, age of onset, pattern and extent of LV hypertrophy, degree of obstruction, and risk for sudden cardiac death. Invasive procedures like septal myectomy and alcohol septal ablation (ASA) are indicated when non-invasive management is unsuccessful. These procedures are associated with improved quality of life and reduction in medication burden. Currently, there are no trials that have compared septal myectomy and ASA, but the European Society of Cardiology and the American College of Cardiology offers conflicting recommendations supporting ASA vs. septal myectomy, respectively. However, both advocate multidisciplinary team discussions with careful consideration of comorbidities, frailty, and patient preferences. This review outlines the pathophysiology and diagnosis of HCM, medical management and then focuses on invasive procedures available, evidence on outcomes, and the guidelines from different bodies governing invasive decision making.