Association of left atrial strain with long-term cardiovascular mortality in hypertrophic cardiomyopathy

Abstract

Abstract Background Hypertrophic cardiomyopathy (HCM) is a relatively common genetic cardiac disease affecting 1 in 200 people. Although sudden cardiac death (SCD) is considered the most devastating event in patients with HCM, cardiovascular death (CVD) is the leading cause of death in this population. Little is known about the predictors of cardiovascular mortality. Purpose The aim of this study was to investigate prognostic implication of left atrial (LA) strain on long-term cardiovascular mortality in patients with HCM. Methods Peak longitudinal LA strain was measured on echocardiography at initial evaluation using vendor-independent speckle-tracking software. Among a prospective cohort of 865 HCM patients collected at two large tertiary centers, 697 with adequate echocardiographic images to measure biplane LA strain were included in the analysis. The primary endpoint was CVD during 10 years after initial evaluation. Results The median age was 56.0 years and 74.6% were male. Among the 697 patients, 25 died due to cardiovascular cause for 10 years. Among clinical and echocardiographic variables, older age, female sex, previous myocardial infarction, previous stroke, higher SCD risk score by European Society of Cariology, presence of SCD risk factors by American College of Cardiology, obstructive HCM, larger LA diameter, and lower LA strain were associated with CVD. LA strain had the highest predictive power for CVD occurrence, with a c-statistic of 0.79 (Figure 1). In multivariable Cox analysis, LA strain remains an independent predictor of CVD (hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.82–0.94). Patients with LA strain <19.4% (the lowest quartile), compared with those with LAS ≥19.4%, had a significantly higher risk of CVD (19.5% vs. 2.1%, HR 7.31, 95% CI 3.15–16.95), as well as death by any cause, SCD, and a composite of CVD, heart failure admission, and stroke (Figure 2). Conclusions In patients with HCM, LA strain is an independent predictor of long-term CVD.