Bariatric surgery has demonstrated improvements in cardiovascular health. The effect on ischemic stroke risk remains unclear. The goal of this study was to compare the risk of stroke among bariatric surgery patients versus controls.
Using Mariner, a national all-payer claims database, we identified patients with BMI > 40, or BMI > 35 with qualifying comorbidities who underwent sleeve gastrectomy or gastric bypass from 2010 to 2019. Similar patients who did not have bariatric surgery were used as controls. Coarsened exact matching in 1:1 fashion was performed, with logistic regression analysis to determine the effect of bariatric surgery on stroke risk at 1, 3, and 5 years.
96094 surgery patients and 1533725 controls were identified. Before matching, the stroke risk for surgery vs control was 0.05% vs 0.26% at 1 year, 0.13% vs 0.43% at 3 years, and 0.21% vs 0.59% at 5 years (p<0.01). After matching, the 1-year stroke risk among 95565 surgery patients and 95565 controls was 0.05% vs 0.15% (OR 0.36, 95% CI 0.26-0.49). The 3-year stroke risk after surgery (n=81050) vs controls (n=81050) was 0.12% vs 0.28% (OR 0.44, 95% CI 0.35-0.55). The 5-year stroke risk of surgery (n=58241) vs controls (n=58241) controls was 0.21% vs 0.41% (OR 0.51, 95% CI 0.41-0.64).
Bariatric surgery is associated with decreased stroke risk at 1,3, and 5 years, with the greatest effect seen in the 1st year. To our knowledge, this is the largest sample size in a study of ischemic cerebrovascular disease in bariatric surgery.