Long-Term Echocardiographic Outcome in Super-Responders to Cardiac Resynchronization Therapy and the Association With Mortality and Defibrillator Therapy

Super-response to cardiac resynchronization therapy (CRT) is associated with significant left ventricular (LV) reverse remodeling and improved clinical outcome. The study aimed to: (1) evaluate whether LV reverse remodeling remains sustained during long-term follow-up in super-responders and (2) analyze the association between the course of LV reverse remodeling and ventricular arrhythmias. Of all, primary prevention super-responders to CRT were selected. Super-response was defined as LV end-systolic volume reduction of ≥30% 6 months after device implantation. Cox regression analysis was performed to investigate the association of LV ejection fraction (LVEF) as time-dependent variable with implantable-cardioverter defibrillator (ICD) therapy and mortality. A total of 171 super-responders to CRT-defibrillator were included (mean age 67 ± 9 years; 66% men; 37% ischemic heart disease). Here of 129 patients received at least 1 echocardiographic evaluation after a median follow-up of 62 months (25th to 75th percentile, 38 to 87). LV end-diastolic volume, LV end-systolic volume, and LVEF after 6-month follow-up were comparable with those after 62-month follow-up (p = 0.90, p = 0.37, and p = 0.55, respectively). Changes in LVEF during follow-up in super-responders were independently associated with appropriate ICD therapy (hazard ratio 0.94, 95% CI 0.90 to 0.98; p = 0.005) and all-cause mortality (hazard ratio 0.95, 95% CI 0.91 to 1.00; p = 0.04). A 5% increase in LVEF was associated with a 1.37 times lower risk of appropriate ICD therapy and a 1.30 times lower risk of mortality. In conclusion, LV reverse remodeling in super-responders to CRT remains sustained during long-term follow-up. Changes in LVEF during follow-up were associated with mortality and ICD therapy.