Abstract 12708: Similar Risk of Heart Failure Hospitalization in MADIT-RIT Programming Arms

Abstract

Background: In MADIT-RIT (Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy), we reported a significant reduction in inappropriate ICD therapy and mortality with novel ICD programming, either a high-rate cut-off (VT zone ≥ 200 bpm, Arm B) or 60-sec delayed therapy in the VT zone 170-199 bpm (Arm C), as compared to conventional programming (VT zone>170 bpm, Arm A). However, the effect of novel ICD programming on heart failure (HF) events has not been investigated. Methods: In MADIT-RIT patients (n=1500), we assessed risk of hospitalization with heart failure (HF) in the three programming arms. Brief summaries of each hospitalization were independently reviewed by three experienced cardiologists and HF events identified according to pre-specified criteria. Discrepancies were resolved by a fourth cardiologist. Kaplan-Meier cumulative probabilities and multivariable Cox hazards regression analyses were performed. Results: There was a similar probability of HF hospitalization (p=0.341) and HF hospitalization or death (p=0.207) in all three programming arms in MADIT-RIT (Figure). There were no differences in HF hospitalization in Arm B vs. A (HR=0.91, 95%CI: 0.63-1.33, p=0.629) or Arm C vs. A (HR=1.20, 95%CI: 0.84-1.72, p=0.310) after multivariable adjustments for age, NYHA class, diabetes, ICD vs. CRT-D, ejection fraction, and ischemic vs. non-ischemic cardiomyopathy. Similarly, there were no differences in HF or death in Arm B vs. A (HR=0.78, 95%CI: 0.56-1.10, p=0.154), or in Arm C vs. A (HR=1.06, 95%CI: 0.77-1.45, p=0.723) after multivariable adjustments. Risk of multiple hospitalizations was also the similar in the three programming arms. Conclusions: In MADIT-RIT, the mortality benefit seen with novel ICD programming was not accompanied by reduction in heart failure events. Conversely, greater mortality risk with conventional ICD programming was not associated with increased risk of heart failure hospitalization.