Different response criteria to cardiac resynchronization therapy in patients with congestive heart failure

Aim. To investigate the agreement among different response criteria to cardiac resynchronization therapy (CRT) and long-term mortality in patients with congestive heart failure (CHF).Methods. The study enrolled 141 patients (men 77.3%; women 22.7%) with CHF (65.2% ischemic and 34.8% non-ischemic etiology). Mean age was 58.6 [53.0;66.0] years. All patients had NYHA II-IV, left ventricular ejection fraction (LVEF) ≤35%; QRS ≥130 мs and/or left bundle branch block. Mean follow-up period was 45.0±34.2 months. Response to CRT was defined according to dynamics of NYHA functional class, LVEF, and left-ventricular end-systolic volume (LVESV).Results. Moderate agreement was found among LVEF and LVESV (Cohen’s k coefficient 0.591±0.068) while we did not find the agreement among echocardiographic criteria and NYHA. Long-term mortality had moderate negative correlation with LVESV (r=-0.486; pConclusion. Agreement between different criteria to define response to CRT is poor. The strongest correlation with long-term mortality was found for LVESV. This inconsistency among different response criteria severely limits the ability to generalize results over multiple CRT studies.