Left ventricular remodelling and change in left ventricular global longitudinal strain after cardiac resynchronization therapy: prognostic implications.

Abstract

Cardiac resynchronization therapy (CRT) can reduce left ventricular end-systolic volume (LVESV), and a decrease of ≥15% is defined as a response. CRT can also improve LV global longitudinal strain (GLS). Changes in LVESV and LV GLS are individually associated with outcome post-CRT. We investigated LVESV and LV GLS changes and prognostic implications of improvement in LVESV and/or LV GLS, compared with no improvement in either parameter. Baseline and 6-month echocardiograms were analysed from CRT recipients with heart failure. LV reverse remodelling was defined as a ≥15% reduction in LVESV at 6 months post-CRT. A ≥5% absolute improvement in LV GLS was defined as a change in LV GLS. A total of 1185 patients were included (mean age 65 ± 10 years, 73% male), and those with an improvement in LVESV and LV GLS (n = 131, 11.1%) had significantly lower mortality compared with other groups. On multivariable analysis, an improvement in both LVESV and LV GLS [hazard ratio (HR): 0.47; 95% confidence interval (CI): 0.31-0.71; P < 0.001] or an improvement in either LVESV or LV GLS (HR: 0.57; 95% CI: 0.47-0.71; P < 0.001) were independently associated with better prognosis, compared with no improvement in either parameter. Either a reduction in LVESV and/or an improvement in LV GLS at 6 months post-CRT are independently associated with improved long-term prognosis, compared with no change in both LVESV and LV GLS. This supports the use of LV GLS as a meaningful parameter in defining CRT response.