Predictors and Prognosis of End-Stage Hypertrophic Cardiomyopathy

Background: Burned-out hypertrophic cardiomyopathy (BO-HCM) is complicated by substantial adverse events. However, few studies have focused on clinical or echocardiographic features and their prognostic values among patients with BO-HCM.

Objective: This study evaluated the clinical manifestations and prognostic value of echocardiography in patients with BO-HCM.

Methods: The present retrospective study evaluated 401 consecutive patients referred to the echocardiography ward of Rajaie Cardiovascular Center for evaluation of HCM during the period from January 2010 to February 2018. Three hundred six patients who completed the follow-up were included: 78 (25.4%) had BO-HCM and an EF of < 50% (group 1), and 228 (74.5%) had a normal EF in their baseline TTE (group 2). Among the group 2 population, 183 patients had a preserved EF of > 50% (group 2B), and 45 became BO-HCM at the end of their follow-up (group 2A). Clinical data were analyzed, including medical history, electrocardiography, and echocardiography. Generalized estimating equation (GEE) regression was performed to assess the association between patient characteristics and burned-out HCM.

Results: An atrial fibrillation (AF) rhythm was more common in the groups with BO-HCM (groups 1 and 2A) (32.8 vs. 14%; P = 0.002), as were Frequent premature ventricular contractions (PVCs) (13.98 vs. 5%; P = 0.040). Moderate or severe systolic anterior motion (SAM) was significantly more common in group 2B (LVEF > 50%) compared with group 1 and 2A, who had an EF of ≤ 50% (32.3% vs. 7.6%; P = 0.006). The S-wave of the right ventricle was significantly lower in groups 1 and 2A (9.73 vs. 11.8 cm/s; P < 0.001). Systolic pulmonary artery pressure (SPAP) was significantly higher in groups 1 and 2A (38.28 vs. 29.74 mmHg, P < 0.001). The differences in the prevalence of asymmetrical septal hypertrophy (ASH), left ventricular outlet (LVOT) obstruction, pericardial effusion (PE), diastolic dysfunction, and mitral regurgitation (MR) were insignificant between all groups.

 Conclusions: Among the patients suffering from HCM, the presence of AF rhythm, frequent PVCs, significant RV dysfunction, and absence of systolic anterior motion (SAM) of mitral valve leaflets have prognostic value and might be considered predictors for progression to BO-HCM.