Combined global longitudinal strain and intraventricular mechanical dyssynchrony predicts long-term outcome in patients with systolic heart failure

Abstract

Background: Left ventricular (LV) ejection fraction (EF) and QRS duration enable prediction of outcome in patients with systolic heart failure (SHF). We assessed the predictive value of global longitudinal strain (GLS) and mechanical dyssynchrony for prognosis in SHF patients. Methods and Results: Two-hundred and forty SHF patients with LVEF ≤40% were studied. Global LV function and intraventricular mechanical dyssynchrony were calculated as GLS and SD of the time to peak longitudinal strain (SDε) over 18 LV segments. The added value of GLS and SDε for outcome prediction was assessed using nested Cox models. Sixty-six patients (28%) reached the study endpoint of all-cause mortality/heart transplantation over a median follow-up period of 45 months. Baseline variables associated with adverse outcome were age, glomerular filtration rate, pulmonary artery systolic pressure, diabetes and LV end-systolic volume (model χ2=69.8). The predictive power of the clinical variables was greater with addition of GLS (χ2=81.1) or SDε (χ2=102.3) than with LVEF (χ2=73.9) or QRS duration (χ2=75.5; both P<0.005). GLS (HR, 1.88; P=0.03) and SDε (HR, 1.48; P=0.04) were independent predictors after adjustment for the baseline variables. Patients with impaired GLS (≥–7.8%) and mechanical dyssynchrony (SDε ≥72 ms) had poor outcome. Conclusions: Combined assessment of global LV function and mechanical dyssynchrony using speckle-tracking strain enabled the prediction of long-term outcome in SHF patients.