Bariatric surgery may improve cardiac outcomes in obese patients

Obese individuals have higher rates of coronary artery disease (CAD) and coronary-related mortality. Now, according to a new study, bariatric surgery may improve cardiac outcomes in such individuals. The study presented at the Society of American Gastrointestinal and Endoscopic Surgeons meeting found that obese patients who underwent bariatric surgery had lower rates of percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) and myocardial infarction compared to those who did not have bariatric surgery.

Bariatric surgery has been shown to lead to durable weight loss and improvements in obesity-related cardiac risk factors, including hypertension, hyperlipidemia, and diabetes. However, there is very little data on the impact of bariatric surgery on long-term macrovascular outcomes.

A few recent studies "showed substantial reductions in the long-term risk of myocardial infarction and stroke for obese patients with diabetes. In contrast, a recent study that included both patients with diabetes, and patients without diabetes, demonstrated a reduction in cardiac risk factors following gastric bypass, but no reduction in the rate of myocardial infarction," he continued.

In this propensity-matched score analysis, bariatric surgery was tied to significantly lower rates of coronary revascularization and the incidence of coronary events.

Nonsurgical patients and bariatric surgery patients were matched 1:1 on the propensity score, which led to 3,242 participant-pairs. There were no differences in baseline risk factors such as age, sex, primary payer status, prior coronary interventions, and obesity-related comorbidities between the two groups. The surgery group had a higher BMI than the non-surgery group (48.0 vs 47.7).

Patients (mean age about 43; 88% white) were assessed over a median follow-up of 7.2 years. They were all at a single institution, and underwent bariatric surgery over about a 20-year period. Using institutional clinical data repository, the researchers identified a control group of morbidly obese patients over the same time frame who did not have bariatric surgery to propensity match 1:1 on patient comorbidities and demographics. Univariate analyses were done to compare outcomes between the two groups.

Patients who underwent bariatric surgery had significantly lower rates of coronary artery bypass grafting (CABG) at 0.6% vs. 2.3%, percutaneous coronary intervention (PCI) at 0.4% vs 7.8%), coronary catheterization (1.9% vs 8.8%), and MI (1.8% vs 10.0%) versus those who did not have bariatric surgery, reported Alex Michaels, MD, of the University of Virginia (UVA) in Charlottesville, and colleagues.

• CABG: 1.5% surgery vs 0.4% non-surgery, relative risk 0.29 (P=0.0002)


• PCI 5.2% vs 0.3%, RR 0.05 (P<0.0001)


• Coronary catheterization: 6.8% vs 1.5%, RR 0.22 P<0.0001)


• MI: 7.6% vs 1.7%, RR 0.22 (P<0.0001)

For patients with diabetes, the researchers also found the following outcomes between the two groups:

• CABG: 4.6% surgery vs 0.9% non-surgery, RR 0.20 (P<0.0001)


• PCI: 14.6% vs 0.8%, RR 0.05 (P<0.0001)


• Coronary catheterization: 14.4% vs 2.8%, RR 0.20 (P<0.0001)


• MI: 16.3% vs 2.0%, RR 0.12 (P<0.001)