Surgical obesity treatment and the risk of heart failure

Abstract

Aims: 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.

Methods and results: 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).

Conclusion: 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.

Clinicaltrials.gov identifier: NCT01479452.

Keywords: Bariatric surgery; Heart failure; Obesity; Weight loss.

Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.

Figures

Figure 1

Change in body mass index in patients without baseline heart failure during 20 years of follow-up. Bariatric surgery lowered the mean BMI of 42.4 kg/m2 by 25% at year 1, by 18% at year 6, by 16% at year 15, and by 16% at year 20 whereas the mean BMI of 40.1 in the control group remained largely unchanged during follow-up.

Figure 2

The use of conventional heart failure medication including beta-blockers, renin–angiotensin system inhibitors, and loop-diuretics were lower in the surgery group as compared with control subjects, whereas the usage of mineralocorticoid receptor antagonists did not differ between groups.

Figure 3

Forest plot of hazard ratios and 95% confidence intervals for the risk of heart failure by 1-year weight change quartiles. The study groups were pooled in these analyses. The risk of heart failure declined across quartiles with a greater degree of weight loss. This association remained statistically significant after adjustment for surgical intervention (Model 2) and, in addition, potential baseline confounders (Model 3).

Figure 4

Hazard ratios for the risk of heart failure in subgroups. There were no significant interactions between treatment and subgroups.

Take home figure

Surgical obesity treatment and the risk of heart failure during long-term follow-up.