Weight Loss Surgery Helps Prevent Secondary Cardiovascular Events for Severely Obese

Erik Naslund, MD, PhD

This article was originally published on Endocrinology Network's sister site, PracticalCardiology.Com.

A new study analyzing data from a pair of European registries is offering clinicians an overview of the various health benefits associated with metabolic surgery in severely obese patients with a history of myocardial infarction (MI).

The study’s results indicate undergoing Roux-en-Y gastric bypass and sleeve gastrectomy procedures was associated a lower risk of mortality, new MI, and other major adverse cardiovascular events (MACE) in severely obese patients with a history of MI.

"We found that individuals operated on for their obesity were at a much lower risk of suffering another myocardial infarction, of death and of developing heart failure," said lead investigator Erik Näslund, MD, PhD, professor at the Department of Clinical Sciences at Danderyd Hospital of the Karolinska Institute, in a statement. "These data suggest that severely obese people who suffer a myocardial infarction should be offered metabolic surgery for their obesity as a secondary prevention."

With the prevalence of obesity increasing throughout the world, determining the most effective course of treatment for obese patients is paramount. In an effort to evaluate whether metabolic surgery was an effective strategy for secondary prevention among obese patients, Naslund and colleagues designed the current study as an analysis of data from the SWEDEHEART and SOReg registries.

By combining data from the registries, investigators identified 509 patients with a BMI greater than 35 for inclusion in their analysis. These patients were then matched in a 1:1 ratio to controls with a history of MI but not undergoing metabolic surgery based on the sex, age, year of MI, and BMI of each patient. Investigators noted both groups were well-matched but pointed out patients in the surgery group had a lower proportion of reduced ejection fraction after MI (7% vs 12%), previous heart failure (10% vs 19%), atrial fibrillation (6% vs 10%), and chronic obstructive pulmonary disease (4% vs 7%).

The primary outcome of interest was MACE, which was defined as first occurrence of death or readmission with MI or stroke. Investigators chose individual components of the primary outcome, admission with not previously known atrial fibrillation, and admission because of previously unknown heart failure as secondary outcomes of the study.

During an 8-year follow-up period, which lasted a median of 4.6 (2.7–7.1) years, investigators found the probably of MACE was lower among patients who underwent metabolic surgery (18.7%; 95% CI, 15.9-21.5% vs 36.2%; 33.2-39.3% [aHR, 0.44; 95% CI, 0.32-0.61]).Patients undergoing surgery also had a lower risk of death (aHR, 0.45; 95% CI, 0.29-0.70), MI (aHR, 0.24; 95% CI, 0.14-0.41), and new onset heart failure. However, investigators pointed out there were no significant differences regarding stroke (aHR, 0.91; 95% CI, 0.38-2.20) and new onset atrial fibrillation (aHR, 0.56; 95% CI, 0.31-1.01).

Investigators also noted additional health changes at 2 years after metabolic surgery which could have contributed to reductions in primary and secondary outcome measures. Among these were a 67% remission in sleep apnea, 22% remission in hypertension, and a 29% remission in cholesterol and triglyceride levels in the surgery group. Additionally, results suggested more than half of the patients with type 2 diabetes experienced clinical remission after surgery.

This study, “Association of Metabolic Surgery With Major Adverse Cardiovascular Outcomes in Patients With Previous Myocardial Infarction and Severe Obesity,” was published in Circulation.