Impact of cardiac resynchronization therapy-defibrillator implantation on the association between body mass index and prognosis in patients with heart failure

Purpose: This study aimed to examine the association between body mass index (BMI) and prognosis in heart failure patients after cardiac resynchronization therapy-defibrillator (CRT-D) implantation. Methods: We retrospectively investigated 125 patients (33 overweight [BMI ≥25 kg/m²], 75 normal weight [BMI 18.5–24.9 kg/m²], and 17 underweight patients [BMI <18.5 kg/m²]) who underwent CRT-D implantation. The clinical outcome endpoints were all-cause death and appropriate shock therapy. Results: During the follow-up period (mean 3.1 ± 1.8 years), 23 patients died (1 [3.0 %] overweight, 17 [22.7 %] normal weight, and 5 [29.4 %] underweight patients), and appropriate shock events were observed in 14 patients (2 [6.1 %] overweight, 10 [13.3 %] normal weight, and 2 [11.8 %] underweight patients). All patients survived shock therapy. After adjusting for confounding factors, overweight patients had significantly fewer outcomes relating to all-cause death and appropriate shock events (hazard ratio 0.27, 95 % confidence interval 0.08–0.91, p = 0.034) than normal weight patients. However, the prognostic difference between overweight and normal weight patients could be diminished as a result of the successful shock therapies (p = 0.067). Additionally, prognosis did not differ between overweight and normal weight patients among the responders, but did differ among the non-responders. The underweight patients had a poorer prognosis after CRT-D implantation compared with the other groups. Conclusions: Although high BMI was associated with better outcomes among heart failure patients with CRT-D implantations, the difference in the prognosis between overweight and normal weight patients was reduced because of defibrillator therapy and the improvement in cardiac function provided by CRT-D implantation.