Cardiac Resynchronization Therapy and Hypertrophic Cardiomyopathy: A Comprehensive Review

Abstract

Hypertrophic cardiomyopathy (HCM) is an inherited primary myocardial disease characterized by asymmetrical/symmetrical left ventricle (LV) hypertrophy, with or without LV outflow tract (LVOT) dynamic obstruction, and poor prognosis. Cardiac resynchronization therapy (CRT) has emerged as a minimally invasive tool for patients with heart failure (HF) with decreased LV ejection fraction (LVEF) and prolonged QRS duration of over 120 ms with or without left bundle branch block (LBBB). Several HCM patients are at risk of developing LBBB because of disease progression or secondary to septal myomectomy, while others might develop HF with decreased LVEF, alleged end-stage/dilated HCM, especially those with thin myofilament mutations. Several studies have shown that patients with myectomy-induced LBBB might benefit from left bundle branch pacing or CRT to relieve symptoms, improve exercise capacity, and increase LVEF. Otherwise, patients with end-stage/dilated HCM and prolonged QRS interval could gain from CRT in terms of NYHA class improvement, LV systolic performance increase and, to some degree, LV reverse remodeling. Moreover, several electrical and imaging parameters might aid proper selection and stratification of HCM patients to benefit from CRT. Nonetheless, current available data are scarce and further studies are still required to accurately clarify the view. This review reassesses the importance of CRT in patients with HCM based on current research by contrasting and contextualizing data from various published studies.

The Role of Sacubitril/Valsartan and Gliflozins in Heart Failure with Reduced Ejection Fraction after Cardiac Resynchronization Therapy

“…In order to avoid possible confounding factors and make our population homogeneous, we included only ischemic (ICM) and non-ischemic (NICM) patients excluding other reversible causes of HF (such as acute viral myocarditis, alcohol-induced heart disease and tachycardiarelated cardiomyopathy), valvular diseases 11 , chemotherapy-induced cardiomyopathy 12 and dilated-phase hypertrophic cardiomyopathy 13 . Other exclusion criteria were age below 18, lack of complete echocardiography or medical therapy data at 12-months follow-up and patients in ARNi or SGLT2i treatment > 3 months before CRTD implant.…”