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

Area of Science:

• Cardiology
• Obesity Research
• Medical Devices

Background:

• The obesity paradox, a survival benefit in obese patients with heart failure, is not well-established after cardiac resynchronization therapy with a defibrillator (CRT-D).
• Understanding the impact of body mass index (BMI) on long-term outcomes in CRT-D recipients is crucial for patient management.

Purpose of the Study:

• To investigate the association between pre-implant body mass index (BMI) and long-term survival in patients with heart failure who received a CRT-D.
• To determine if the obesity paradox extends to patients undergoing CRT-D implantation.

Main Methods:

• A retrospective study of 113 patients implanted with CRT-D between May 2002 and November 2003.
• Patients were categorized by pre-implant BMI: normal weight (<25 kg/m²), overweight (25-29 kg/m²), and obese (≥30 kg/m²).
• Ten-year survival free from orthotopic heart transplant or ventricular assist device implantation was analyzed using Kaplan-Meier plots, log-rank tests, and Cox proportional hazards modeling.

Main Results:

• Obese patients (29%) were younger and had a higher proportion of women compared to normal-weight (29%) and overweight (42%) patients.
• Ten-year survival free from major adverse cardiac events was highest in obese patients (36.3%), followed by overweight (19.2%), and normal-weight patients (12.1%) (log-rank p trend = 0.004).
• Each 1 kg/m² increase in BMI was associated with an 8% reduction in the risk of the primary endpoint (adjusted hazard ratio = 0.92, p = 0.002).

Conclusions:

• Higher body mass index (BMI) is associated with improved long-term survival in patients with heart failure following cardiac resynchronization therapy with a defibrillator (CRT-D).
• The findings support the existence of the obesity paradox in this specific patient population.