Remission of left ventricular systolic dysfunction and of heart failure symptoms after cardiac resynchronization therapy: Temporal pattern and clinical predictors

Background: The aim of the study was to determine whether cardiac resynchronization therapy (CRT) may induce a heart failure (HF) remission phase (recovery to New York Heart Association functional class I-II and regression of left ventricular [LV] dysfunction: LV ejection fraction [EF] ≥50%) and to define the incidence and predictors of such a process. Methods: Cardiac resynchronization therapy devices were successfully implanted in 520 consecutive HF patients from 1999 to 2006 (mean age 66 years, 82% male sex, New York Heart Association class ≥II, LVEF 28%, QRS 164 milliseconds, 6-minute hall walk distance 302 m) at our institution. Follow-up data were prospectively collected every 3 to 6 months. Continuous variables were stratified in tertiles. Results: Over a median follow-up of 28 months, 26% of patients achieved LV remission (rate: 16 per 100 person-years). At univariate analysis, female sex (P = .032), non-coronary artery disease (CAD) etiology (P <.001), mitral regurgitation