Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes

The SELECT trial was a randomized, double-blind, placebo-controlled, event-driven study that evaluated whether semaglutide could reduce cardiovascular events in patients with obesity and established cardiovascular disease, but without diabetes. The study included 17,604 adults with BMI >=27 and atherosclerotic cardiovascular disease, randomized to semaglutide 2.4 mg or placebo weekly, with a mean follow-up of 39.8 months (more than 3 years).

The primary composite endpoint (MACE) included cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke. The results were statistically significant and clinically relevant:

• 20% reduction in MACE with semaglutide (HR 0.80; 95% CI 0.72-0.90; P<0.001)
• Separation of event curves began early and increased progressively
• Consistent benefit across all pre-specified subgroups

Additional analyses demonstrated:

• 18% reduction in cardiovascular death (HR 0.82)
• Mean weight loss of 9.4% vs. 0.88% with placebo
• Significant improvements in inflammatory markers (C-reactive protein) and metabolic parameters
• Event reduction occurred independently of weight loss, suggesting direct anti-atherosclerotic mechanisms

SELECT was transformative for the field because, for the first time, it demonstrated that treating obesity with a drug can reduce major cardiovascular events — previously, only weight loss through bariatric surgery had demonstrated this benefit. These results expand the indication for semaglutide beyond weight management, positioning it as a cardioprotective therapy in obese patients with cardiovascular disease.