Ruwald, Anne-Christine2; Pietrasik, Grzegorz3; Goldenberg, Ilan4; Kutyifa, Valentina5; Daubert, James P6; Ruwald, Martin H2; Jons, Christian2; McNitt, Scott7; Wang, Paul8; Zareba, Wojciech7; Moss, Arthur J7
1 Medicinsk Afdeling GLO, Amager and Hvidovre Hospital, The Capital Region of Denmark2 Cardiology, Herlev and Gentofte Hospital, The Capital Region of Denmark3 University of Buffalo4 University of Rochester Medical Center, Heart Research Follow-Up Program, Rochester, New York; Heart Institute, Sheba Medical Center, Tel Hashomer, Israel.5 University of Rochester Medical Center, Heart Research Follow-Up Program, Rochester, New York; Semmelweis University Heart Center, Budapest, Hungary.6 Duke University Medical Center, Durham, North Carolina.7 University of Rochester8 Stanford University
a MADIT-CRT substudy (Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy)
OBJECTIVES: This study aimed to investigate the effect of both history of intermittent atrial tachyarrhythmias (IAT) and in-trial IAT on the risk of heart failure (HF) or death comparing cardiac resynchronization therapy with defibrillator (CRT-D) to implantable cardioverter-defibrillator (ICD) treatment in mildly symptomatic HF patients with left bundle branch block (LBBB). BACKGROUND: Limited data exist regarding the benefit of CRT-D in patients with IAT. METHODS: The benefit of CRT-D in reducing the risk of HF/death was evaluated using multivariate Cox models incorporating the presence of, respectively, a history of IAT at baseline and time-dependent development of in-trial IAT during follow-up in 1,264 patients with LBBB enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy) study. RESULTS: The overall beneficial effect of CRT-D versus ICD on the risk of HF/death was not significantly different between LBBB patients with or without history of IAT (HR: 0.50, p = 0.028, and HR: 0.46, p < 0.001, respectively; p for interaction = 0.79). Among patients who had in-trial IAT, CRT-D was associated with a significant 57% reduction in the risk of HF/death compared with ICD-only therapy (HR: 0.43, p = 0.047), similar to the effect of the device among patients who did not have IAT (HR: 0.47, p < 0.001; p for interaction = 0.85). The percentage of patients with biventricular pacing ≥92% was similar in both groups (p = 0.43). Consistent results were shown for the benefit of CRT-D among patients who had in-trial atrial fibrillation/flutter (HR: 0.30, p = 0.027; p for interaction = 0.41). CONCLUSIONS: In the MADIT-CRT study, the clinical benefit of CRT-D in LBBB patients was not attenuated by prior history of IAT or by the development of in-trial atrial tachyarrhythmias. (MADIT-CRT: Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy; NCT00180271).
Journal of the American College of Cardiology, 2014, Vol 63, Issue 12, p. 1190-7