Implantable cardioverter-defibrillator therapy and risk of congestive heart failure or death in MADIT II patients with atrial fibrillation.
BACKGROUND
Atrial fibrillation (AF) contributes to increased risk of morbidity and mortality. Data regarding the effectiveness of implantable cardioverter-defibrillator (ICD) therapy in AF patients are limited.


OBJECTIVE
The purpose of this study was to evaluate the effectiveness of ICD therapy in patients with AF enrolled in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) and to identify their risk for the combined endpoint of hospitalization for congestive heart failure or death.


METHODS
The MADIT II cohort served as the source for data on the clinical course, cardiac events, and effectiveness of ICD therapy in AF patients.


RESULTS
AF was found as baseline rhythm at enrollment in 102 (8%) MADIT II patients. In comparison to 1,007 patients in sinus rhythm, AF patients were older, more frequently were males, had wider QRS complex, and had higher blood urea nitrogen and creatinine levels (P <.05 for all parameters). ICD therapy was effective in reducing 2-year mortality in AF patients from 39% in 41 conventionally treated patients to 22% in 61 ICD-treated patients (hazard ratio = 0.51, P = .079). However, the combined endpoint of hospitalization for heart failure or death at 2 years was 69% and 59%, respectively (NS). AF was predictive for the combined endpoint of heart failure hospitalization or death (hazard ratio = 1.68, P = .040). New-onset AF in patients with baseline sinus rhythm was associated with increased risk of mortality (hazard ratio = 2.70, P <.001).


CONCLUSIONS
MADIT II patients with AF benefit from ICD therapy, which reduces their mortality. MADIT II patients with AF are at high risk for developing heart failure.
Zareba
Wojciech
W
Cardiology Unit, Department of Medicine, University of Rochester Medical Center, New York 14642, USA. wojciech.zareba@heart.rochester.edu
Steinberg
Jonathan S
JS
McNitt
Scott
S
Daubert
James P
JP
Piotrowicz
Katarzyna
K
Moss
Arthur J
AJ
D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000401:mortality / Q000628:therapy*; D002986:Clinical Trials as Topic; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000209:etiology / Q000517:prevention & control*; D006760:Hospitalization; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis