Obesity as a risk factor for sustained ventricular tachyarrhythmias in MADIT II patients.
BACKGROUND
Obesity, as defined by body mass index > or =30 kg/m(2), has been shown to be a risk factor for cardiovascular disease. However, data on the relationship between body mass index (BMI) and the risk of ventricular arrhythmias and sudden cardiac death are limited. The aim of this study was to evaluate the risk of ventricular tachyarrhythmias and sudden death by BMI in patients after myocardial infarction with severe left ventricular dysfunction.


METHODS
The risk of appropriate defibrillator therapy for ventricular tachycardia or ventricular fibrillation (VT/VF) by BMI status was analyzed in 476 nondiabetic patients with left ventricular dysfunction who received an implantable cardioverter defibrillator (ICD) in the Multicenter Automatic Defibrillator Implantation Trial-II (MADIT II).


RESULTS
Mean BMI was 27 +/- 5 kg/m(2). Obese patients comprised 25% of the study population. After 2 years of follow-up, the cumulative rates of appropriate ICD therapy for VT/VF were 39% in obese and 24% in nonobese patients, respectively (P = 0.014). In multivariate analysis, there was a significant 64% increase in the risk for appropriate ICD therapy among obese patients as compared with nonobese patients, which was attributed mainly to an 86% increase in the risk of appropriate ICD shocks (P = 0.006). Consistent with these results, the risk of the combined endpoint of appropriate VT/VF therapy or sudden cardiac death (SCD) was also significantly increased among obese patients (Hazard Ratio 1.59; P = 0.01).


CONCLUSIONS
Our findings suggest that in nondiabetic patients with ischemic left ventricular dysfunction, a BMI > or =30 kg/m(2) is an independent risk factor for ventricular tachyarrhythmias.
Pietrasik
Grzegorz
G
Heart Research Follow-up Program, Cardiology Division, University of Rochester Medical Center, Rochester, New York, USA.
Goldenberg
Ilan
I
McNitt
Scott
S
Moss
Arthur J
AJ
Zareba
Wojciech
W
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000517:prevention & control; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000628:therapy; D009765:Obesity / Q000401:mortality*; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000401:mortality* / Q000517:prevention & control*; D018487:Ventricular Dysfunction, Left / Q000401:mortality* / Q000517:prevention & control*