Outcomes of cardiac resynchronization therapy in patients with intermittent atrial fibrillation or atrial flutter in the COMPANION trial.
Controlled clinical trial data are lacking for cardiac resynchronization therapy (CRT) outcomes in patients with advanced heart failure (HF) from reduced left ventricular ejection fraction (HFrEF) and intermittent atrial fibrillation or flutter (IAF/AFL).



The purpose of this study was to describe CRT outcomes in patients with IAF/AFL and advanced HF.



HF outcomes in patients in the COMPANION (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure) trial with New York Heart Association class III or IV HFrEF, left ventricular ejection fraction ≤0.35, sinus rhythm at randomization, and no history of baseline arrhythmia were compared with those with a history of IAF/AFL.



In those with no history of baseline arrhythmia (n = 887), compared with optimal pharmacological therapy (OPT) with no CRT, the CRT + OPT arms exhibited a significant reduction in the end points of death or any hospitalization (hazard ratio [HR] 0.73 [95% Confidence Interval (CI): 0.60 to 0.89]; P = .002) and death or HF hospitalization (HR 0.53 [95% CI: 0.41 to 0.68]; P < .001). In contrast, in the IAF/AFL subgroup (n = 293), CRT did not result in improved outcomes compared with OPT (death or any hospitalization: HR 1.16 [95% CI: 0.83 to 1.63]; P = .38; death or HF hospitalization: HR 0.97 [95% CI: 0.64 to 1.46]; P = .88). The interaction between history of AF/AFL and CRT was statistically significant for both outcomes (P < .05).



In the COMPANION trial, patients with moderate to severe HFrEF and a history of IAF/AFL had no benefit from CRT.
University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
Matthew M
MM
Kalscheur
Keck School of Medicine, University of Southern California, Los Angeles, California.
Leslie A
LA
Saxon
University of California San Francisco, San Francisco, California.
Byron K
BK
Lee
Columbia University College of Physicians and Surgeons, New York, New York.
Jonathan S
JS
Steinberg
University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
Chaoqun
C
Mei
University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
Kevin A
KA
Buhr
University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
David L
DL
DeMets
University of Colorado Anschutz Medical Campus, Denver, Colorado.
Michael R
MR
Bristow
Veterans Affairs Hospital, Washington, District of Columbia. Electronic address: Nankumar.singh@va.gov.
Steven N
SN
Singh
D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D001282:Atrial Flutter / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D013318:Stroke Volume / Q000502:physiology*; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*
Atrial fibrillation; Biventricular pacing; Cardiac resynchronization therapy; Heart failure; Intermittent atrial fibrillation or flutter