Temporal Influence of Heart Failure Hospitalizations Prior to Implantable Cardioverter Defibrillator or Cardiac Resynchronization Therapy With Defibrillator on Subsequent Outcome in Mild Heart Failure Patients (from MADIT-CRT)

The temporal effect of heart failure (HF) hospitalization occurring at different time periods before implantation has not yet been studied in detail. The aim of the present study was to investigate the potential association between time from last HF hospitalization to device implantation and effects on subsequent outcomes and benefit from cardiac resynchronization therapy with a defibrillator (CRT-D). Multivariate Cox models were used to determine the temporal influence of previous HF hospitalization on the end point of HF or death within all left bundle branch block implantable cardioverter-defibrillator (ICD) and CRT-D patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT) trial (n = 1,250) and to evaluate the clinical benefit of CRT-D implantation, comparing CRT-D patients with ICD patients within each previous HF hospitalization group. The patients with previous HF hospitalization ≤12 months before device implantation had the greatest incidence of HF or death during 4-year follow-up (31%), while those with previous HF hospitalization >12 months and those with no previous HF hospitalization had similar lower rates of HF or death (22% and 24%, respectively). All patients treated with CRT-D derived significant clinical benefit compared with their ICD counterparts, regardless of time of previous hospitalization (hazard ratios 0.38 [no previous hospitalization], 0.49 (≤12 months), and 0.45 (>12 months); p for interaction = 0.67). In conclusion, in the present study of patients with mild HF with prolonged QRS intervals and LBBB, a previous HF hospitalization ≤12 months was associated with increased risk for HF or death compared with >12 months and no previous HF hospitalizations. The clinical benefit of CRT-D was evident in all patients regardless of time from last HF hospitalization to implantation compared with ICD only.