Relation of Body Mass Index to Long-Term Survival After Cardiac Resynchronization Therapy.

Obesity confers a paradoxical survival benefit in patients with heart failure, but this obesity paradox has not been well established in those who have undergone cardiac resynchronization therapy with a defibrillator (CRT-D). We sought to determine the impact of body mass index (BMI) on long-term survival in patients with heart failure after CRT-D. We identified 113 patients implanted with CRT-D at our institution from May 2002 to November 2003. Patients were divided into 3 categories by pre-implant BMI (kg/m(2)): normal weight (BMI <25), overweight (BMI 25-29), and obese (BMI ≥30). Ten-year survival free from orthotopic heart transplant or ventricular assist device implantation was analyzed with Kaplan-Meier plots, the log-rank test, and Cox proportional hazards modeling. Thirty-three patients (29%) were normal weight, 47 (42%) were overweight, and 33 were obese (29%). Median follow-up time was 4.5 years (interquartile range 1.9 to 8.7 years). Obese patients were younger and had a higher proportion of women (both p <0.05). Ten-year survival free of orthotopic heart transplant or ventricular assist device was highest in obese patients (36.3%) followed by overweight (19.2%) and then normal-weight patients (12.1%), log-rank p trend = 0.004. After adjustment for clinical risk factors, every 1 kg/m(2) increase in BMI was associated with a 8% reduction in the risk of the primary end point (adjusted hazard ratio 0.92, 95% confidence interval 0.88 to 0.97, p = 0.002). In conclusion, higher BMI is associated with improved long-term survival after CRT-D.