Effect of weight loss on predicted cardiovascular risk: change in cardiac risk after bariatric surgery

Objective: Our goal was to assess the effect of bariatric surgery on cardiovascular risk estimations of preventable, long‐term adverse outcomes. Research Methods and Procedures: We performed a population‐based, historical cohort study between 1990 and 2003 of 197 consecutive patients from Olmsted County, MN, with Class II to III obesity (defined as BMI ≥35 kg/m²) treated with Roux‐en‐Y gastric bypass and 163 non‐operative patients assessed in a weight‐reduction program. We used the observed change in cardiovascular risk factors and risk models derived from data from the National Health and Nutrition Examination Survey (NHANES) I and the NHANES I Epidemiological Follow‐up Study (NHEFS) to calculate the predicted impact on cardiovascular events and mortality for the operative and non‐operative groups. Results: Mean follow‐up was 3.3 years. Hypertension, diabetes, and dyslipidemia all improved after bariatric surgery. The estimated 10‐year risk for cardiovascular events for the operative group decreased from 37% at baseline to 18% at follow‐up, while the estimated risk for the non‐operative group did not change from 30% at baseline to 30% at follow‐up. Risk modeling to predict 10‐year outcomes estimated 4 overall deaths and 16 cardiovascular events prevented by bariatric surgery per 100 patients compared with the non‐operative group. Conclusions: Bariatric surgery induces an improvement in cardiovascular risk factors in patients with Class II to III obesity. Weight loss predicts a major, 10‐year reduction in cardiovascular events and deaths. Bariatric surgery should be considered as an alternative approach to reduce cardiovascular risk in patients with Class II to III obesity.