Body mass index and outcomes of cardiac resynchronization with implantable cardioverter-defibrillator therapy in older patients with heart failure

Abstract

Aims: To assess the association of body mass index (BMI) with heart failure (HF) outcomes after cardiac resynchronization therapy with defibrillator (CRT-D) implantation. Methods and results: Medicare beneficiaries with HF aged ≥ 65 years (n = 18 922) undergoing first-time CRT-D from the National Cardiovascular Data Registry (NCDR) Implantable Cardioverter-Defibrillator Registry between 2010 and 2013, were followed for 3 years post-implantation. Survival curves and covariate adjusted hazard ratio (aHR) or odds ratio were used to assess the risks for death, readmission, and device-related complications by BMI status. Of 18 922 HF patients receiving CRT-D, 5265 (27.8%) were normal weight, 6896 (37%) were overweight, 6318 (33.4%) were obese, and 353 (1.8%) were underweight. Compared to those of normal weight (BMI 18.5–24.9 kg/m2), underweight patients had a higher 3-year post-device implantation risk of death [aHR: 1.34 (95% confidence interval 1.09–1.65); P < 0.001] and of readmission [sub-aHR: 1.25 (1.09–1.42); P < 0.001]. The corresponding 3-year aHRs for death were 0.83 (0.77–0.89) for overweight, 0.74 (0.67–0.82) for obesity class I (BMI 30–34.9 kg/m2), 0.78 (0.68–0.90) for obesity class II (BMI 35–39.9 kg/m2), and 0.75 (0.60–0.93) for obesity class III (BMI ≥ 40 kg/m2, P for all categories < 0.001). Individuals with class III obesity had a higher risk of readmission [sub-aHR: 1.17 (1.06–1.30)]. There were no differences in rates of device-related complications within 90 days across BMI categories. Conclusion: Most elderly patients with HF receiving CRT-D were overweight or obese. While being underweight was associated with greater risks of death and hospitalization, overweight and obese patients were at lower risk of death after CRT-D.