NEW ORLEANS — The substantial weight loss often seen with bariatric surgery is associated with a significant reduction in risk of heart failure among obese patients, according to data presented at the 2016 American Heart Association Scientific Sessions.
Although evidence has suggested a link between obesity and incidence of heart failure, the nature of the relationship remains uncertain, Johan Sundstrom, MD, PhD, senior author of the study and professor of epidemiology at Uppsala University in Sweden, and colleagues noted in their abstract.
To learn more, the researchers compared 25,804 bariatric surgery patients from the Scandinavian Obesity Surgery Registry with 13,701 obese Swedish nationwide registry patients treated with a structured intensive lifestyle program. This program included a diet of 500 calories per day for 3 to 10 weeks followed by 2 to 8 weeks of gradual incorporation of food and 9 months of a weight maintenance regimen that involved regular exercise, dietary advice, and behavioral therapy. Approximately 20% dropped out by the first year.
At baseline, neither group had a history of heart failure before starting treatment, and patients had an average BMI greater than 30 kg/m2 and an average weight of 119 kg. Cox regression analyses were used to evaluate associations of treatment with incidence of heart failure.
Patients who underwent bariatric surgery lost an average of 18.8 kg more weight after 1 year and an average of 22.6 kg more weight after 2 years than those who underwent lifestyle modification. The rate of death and myocardial infarction was similar between groups, but those who underwent bariatric surgery had fewer incidences of atrial fibrillation.
After a median of 4.1 years, heart failure risk was 46% lower in the bariatric surgery group compared with the lifestyle modification group (hazard ratio: 0.54; 95% confidence interval [CI], 0.36-0.82). Associations were not mediated by the effects of weight loss on myocardial infarction but partly by interim atrial fibrillation, diabetes, and hypertension.
“Our study shows an association between obesity and heart failure and offers support for efforts to prevent and treat obesity aggressively, including the use of bariatric surgery,” Dr Sundstrom said in a press release. “Bariatric surgery might affect the incidence of atrial fibrillation, diabetes and hypertension—known risk factors of heart failure—explaining the lower risk of heart failure we observed.”
Although the study supports the hypothesis that obesity causes heart failure, it does not demonstrate causality, noted Dr Sundstrom. Further, the findings may not be generalizable due to the fact that the study population was comprised of a most likely white Scandinavian population. He also added that because none of the patients had heart failure prior to losing weight, “the study does not provide any advice on how to treat cardiovascular disease in obese patients.”
Disclosures: One or more of the researchers disclosed a relationship with Itrim. Dr Ottosson is director of the SOReg (Scandinavian Obesity Surgery Registry.
- Sundstrom J, Bruze G, Ottosson J, Marcus C, Näslund I, Neovius M. Poster M2019. Weight loss and heart failure. Presented at: the 2016 American Heart Association Scientific Sessions; November 12-16, 2016; New Orleans, LA.
- Bariatric surgery may reduce heart failure risk [press release]. Dallas, TX: American Heart Association/American Stroke Association Newsroom; November 14, 2016.