Effect of bariatric surgery on long-term cardiovascular outcomes: a systematic review and meta-analysis of population-based cohort studies

This meta-analysis aimed to compare the effects of bariatric surgery and nonsurgery on cardiovascular outcomes in patients with obesity. A systematic literature search of the Medline (via PubMed), Embase, and Cochrane Central Register of Controlled Trials databases was performed until August 18th, 2021. Population-based cohort studies comparing long-term cardiovascular outcomes for patients with obesity undergoing bariatric surgery or not were included. A meta-analysis of relative risks (RRs) was performed for all outcomes. We conducted subgroup analyses and meta-regression to explore sources of heterogeneity and the stability of the results. Twenty-one population-based cohort studies involving 2,857,016 participants were identified. The major adverse cardiovascular event (MACE) RR in the bariatric surgery group was .53 (95% confidence interval [CI] = .45-.62, P < .001) relative to the nonsurgical group. Relative to the nonsurgical group, the risk of myocardial infarction (MI) (RR = .40, 95% CI = .30-.52, P < .001), stroke (RR = .60, 95% CI = .46-.79, P < .001), cardiovascular death (RR = .43, 95% CI = .35-.54, P < .001), and all-cause death (RR = .44, 95% CI = .32-.59, P < .001) was significantly reduced for patients who underwent bariatric surgery. In subgroup analyses, as the proportion of patients with diabetes mellitus increased, lower RRs for MACE, MI, and stroke were observed in the surgery group relative to the nonsurgical group. The decreased risk of MACE was also observed in the subgroup with median follow-up duration ≥5 years.Bariatric surgery improves cardiovascular outcomes in patients with obesity, especially providing long-term benefits, and this effect is more pronounced in patients with comorbid diabetes.