Myocardial early systolic lengthening predicts mid-term outcomes in patients with hypertrophic cardiomyopathy.

In this study, we investigated whether early systolic lengthening (ESL) which reflects subclinical ischemia and other echocardiographic and clinic parameters predict primary outcome [appropriate ICD shock, cardiovascular mortality and ventricular tachycardia (VT) or fibrillation] in patients with hypertrophic cardiomyopathy (HCM). 202 Patients with HCM (68% male, mean age 48 ± 13.9 years) were included in the study. Patients' clinical, electrocardiographic, 2D classic and speckle tracking echocardiography (STE) data were collected. ESL was defined as time from onset of the Q wave on ECG (onset of the R wave if the Q wave was absent) to maximum myocardial systolic lengthening. Patients were divided into two groups as occurrence or absence of primary outcome during 5 years follow up. During the follow-up period of 5 years (mean follow-up duration, 45.9 ± 10.8 months), 31 patients (15%) developed primary outcome [appropriate ICD shock 22 (11%), cardiovascular death 6 (3%), VT/VF 3(1.5%)]. Higher HCM Risk SCD score, longer ESL, and decreased global longitudinal peak strain (GLPS) were observed in patients with primary outcome. A Cox regression analysis, ESL, GLPS and HCM Risk SCD score were found to be independent predictors of occurrence of primary outcome. In ROC curve analysis, ESL > 53.5 msn could discriminate between groups with and without a primary outcome (AUC 0.768, 80% sensitivity and 60% specificity, CI 95% 0.666-0.871). ESL were found to be predictive for primary outcome in patients with HCM. Readily measurable ESL could be helpful to distinguish patients at high risk who could optimally benefit from ICD therapy.