Long-term Impact of Bariatric Surgery on Major Adverse Cardiovascular Events in Patients with Obesity, Diabetes and Hypertension: a Population-level Study.

Background: The literature on long-term impact of bariatric/metabolic surgery on incidence of major adverse cardiovascular events (MACE) in patients with obesity and metabolic syndrome is still lacking. We aimed to evaluate the long-term relationship between metabolic surgery and MACE in such patients.

Methods: In a population-based cohort study, we compared all patients with obesity, diabetes mellitus (DM) and/or hypertension (HTN), who underwent bariatric surgery in Quebec, Canada during 2007-2012, with matched controls with obesity. The incidence of a composite MACE outcome (coronary artery events, heart failure, cerebrovascular events, and all-cause mortality) after bariatric surgery was compared between both groups. Cox regression was used to evaluate the long-term impact of surgery on MACE outcomes.

Results: The study cohort included 3627 surgical patients, who were matched to 5420 controls with obesity. Baseline demographics were comparable between groups, but DM was more prevalent among the surgical group. Median follow-up time was 7.05 years for the study cohort (range: 5-11 years). There was a significant long-term difference in the incidence of MACE between the surgical group and controls (19.6% vs. 24.8%, respectively; p < 0.01). After accounting for confounders, bariatric surgery remained an independent protective predictor of long-term MACE (hazard ratio [HR], 0.83 [95%CI, 0.78-0.89]). The 10-year absolute risk reduction (ARR) for the surgical group was 5.14% (95%CI, 3.41-6.87).

Conclusions: Among patients with obesity, DM and HTN, bariatric/metabolic surgery is associated with a sustained (≥ 10 years) decrease in the incidence of MACE. The results from this population-level observational study should be validated in randomized controlled trials.