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Bariatric Tx Linked With Better Cardiac Outcomes

— Obese patients who underwent surgery had lower rates of MI, PCI, and more

Last Updated April 8, 2019
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BALTIMORE -- Bariatric surgery was tied to significantly lower rates of coronary revascularization and incidence of coronary events, according to a propensity matched analysis.

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.

Obese individuals have higher rates of coronary artery disease (CAD) and coronary-related mortality than the general U.S. population, noted Michaels at the Society of American Gastrointestinal and Endoscopic Surgeons meeting.

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

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.

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.

In a subgroup analysis, the investigators reported the following long-term cardiac outcomes for patients with diabetes

  • 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)

Study limitations included its retrospective nature, it's conduct at a single institution, and it's reliance on a clinical data repository that captures operations and diagnoses that are reported by the patients or happen at UVA.

Disclosures

Michaels disclosed no relevant relationships with industry.

Primary Source

Society of American Gastrointestinal and Endoscopic Surgeons

Michaels AD, et al "Bariatric surgery reduces long-term rates of coronary events: a propensity-matched analysis" SAGES 2019.