The effect of the cardiac myosin activator, omecamtiv mecarbil, on right ventricular structure and function in chronic systolic heart failure (COSMIC‐HF)

Right ventricular (RV) dysfunction due to post-capillary pulmonary hypertension is a common sequela of elevated left ventricular (LV) filling pressures in patients with heart failure (HF) which has been demonstrated to be associated with poor clinical outcomes.1–3 Measures of RV–pulmonary artery (RV-PA) coupling that evaluate indices of RV function and pulmonary hypertension severity have been shown to be associated with clinical outcomes.4,5 A phase 2 trial, COSMIC-HF (Chronic Oral Study of Myosin Activation to Increase Contractility in Heart Failure, NCT01786512) demonstrated that treatment with omecamtiv mecarbil (OM), a selective cardiac myosin activator, known as a myotrope, was related to an improved LV systolic function, beneficial reverse remodelling, sympathetic withdrawal and a reduction in N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in patients with HF with reduced ejection fraction (HFrEF).6 In this research letter, we report the treatment effect of OM on RV structure and function together with RV-PA coupling in patients with HFrEF.