Surgical obesity treatment and the risk of heart failure.

Abstract

Obesity is associated with increased risk for heart failure. We analysed data from the Swedish Obese Subjects (SOS) study, a prospective matched cohort study, to investigate whether bariatric surgery reduces this risk. From the total SOS population (n = 4047), we identified 4033 obese individuals with no history of heart failure at baseline, of whom 2003 underwent bariatric surgery (surgery group) and 2030 received usual care (control group). First-time principal diagnoses of heart failure were identified by crosschecking the SOS database with the Swedish National Patient Register and the Swedish Cause of Death Register using diagnosis codes. During a median follow-up of 22 years, first-time heart failure occurred in 188 of the participants treated with surgery and in 266 of those receiving usual care. The risk of developing heart failure was lower in the surgery group than in the control group [sub-hazard ratio 0.65, 95% confidence interval (CI) 0.54-0.79; P < 0.001]. After pooling data from the two study groups, the quartile of subjects with the largest weight loss after 1 year (mean -41 kg) displayed the greatest risk reduction (sub-hazard ratio 0.51, 95% CI 0.30-0.70; P < 0.001). This association remained statistically significant after adjustment for surgical intervention and potential baseline confounders (sub-hazard ratio 0.60, 95% CI 0.36-0.97; P = 0.038). Compared with usual care, bariatric surgery was associated with reduced risk of heart failure among persons being treated for obesity. The risk of heart failure appeared to decline in parallel with a greater degree of weight loss. NCT01479452.