Implantable cardioverter-defibrillator programming after first occurrence of ventricular tachycardia in the Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy (MADIT-RIT).

Abstract

BackgroundImplantable cardioverter-defibrillator (ICD) programming to novel settings can reduce the risk of inappropriate therapies.ObjectiveThe purpose of this study was to evaluate the impact of novel ICD programming after the first occurrence of ventricular tachycardia (VT).MethodsIn MADIT-RIT (Multicenter Automatic Defibrillator Implantation Trial–Reduce Inappropriate Therapy) patients who experienced a first occurrence of VT, the risk of subsequent inappropriate and appropriate ICD therapies and adverse cardiovascular events by ICD programming to Arm A (conventional: VT ≥170 bpm), Arm B (high rate: VT ≥200 bpm), or Arm C (duration delay: ≥60-second delay before therapy ≥170 bpm) was determined.ResultsAmong 205 patients, ICD programming changes were made in 30 patients (15%) after they experienced a VT episode; 117 patients (57%) were programmed to Arm A settings and 88 patients (43%) to Arm B/C settings. At 15-month follow-up, the cumulative probability of inappropriate ICD therapy was significantly lower in Arm B/C compared to Arm A (9% vs 20%; log-rank P = .029 for overall difference). The rate of appropriate ICD therapy also was significantly lower in Arm B/C compared to Arm A (32% vs 64%; log-rank P = .001 for overall difference). Multivariate analysis showed that patients programmed to Arm B/C after the occurrence of VT had a 71% reduction (P = .02) in the risk of inappropriate ICD therapies and a 43% reduction (P = .02) in the risk of appropriate ICD therapies compared to Arm A.ConclusionThe benefit of high-rate cutoff or duration delay settings in patients with an ICD is maintained after the first occurrence of VT.