Cardiac resynchronization therapy in patients with permanent atrial fibrillation: results from the Resynchronization for Ambulatory Heart Failure Trial (RAFT)

Cardiac resynchronization (CRT) prolongs survival in patients with systolic heart failure and QRS prolongation. However, most trials excluded patients with permanent atrial fibrillation. The Resynchronization for Ambulatory Heart Failure Trial (RAFT) randomized patients to an implantable cardioverter defibrillator (ICD) or ICD+CRT, stratified by the presence of permanent atrial fibrillation. Patients with permanent atrial fibrillation were randomized to CRT-ICD (n=114) or ICD (n=115). Patients receiving a CRT-ICD were similar to those receiving an ICD: age (71.6±7.3 versus 70.4±7.7 years), left ventricular ejection fraction (22.9±5.3% versus 22.3±5.1%), and QRS duration (151.0±23.6 versus 153.4±24.7 ms). There was no difference in the primary outcome of death or heart failure hospitalization between those assigned to CRT-ICD versus ICD (hazard ratio, 0.96; 95% CI, 0.65-1.41; P=0.82). Cardiovascular death was similar between treatment arms (hazard ratio, 0.97; 95% CI, 0.55-1.71; P=0.91); however, there was a trend for fewer heart failure hospitalizations with CRT-ICD (hazard ratio, 0.58; 95% CI, 0.38-1.01; P=0.052). The change in 6-minute hall walk duration between baseline and 12 months was not different between treatment arms (CRT-ICD: 19±84 m versus ICD: 16±76 m; P=0.88). Patients treated with CRT-ICD showed a trend for a greater improvement in Minnesota Living with Heart Failure score between baseline and 6 months (CRT-ICD: 41±21 to 31±21; ICD: 33±20 to 28±20; P=0.057). Patients with permanent atrial fibrillation who are otherwise CRT candidates appear to gain minimal benefit from CRT-ICD compared with a standard ICD.