SELECT Trial: Semaglutide Protects Heart Independent

Semaglutide - best known as the active ingredient in Wegovy/Ozempic - may do more than shrink waistlines. New analyses from a major trial suggest it protects the heart even when people barely lose weight. The SELECT trial has been a landmark in cardiology since 2023, showing that semaglutide (Wegovy) reduces major adverse cardiovascular events (MACE, e.g. heart attack, stroke, or cardiovascular death) by 20% in people with overweight or obesity and established cardiovascular disease - but without diabetes. Now, two new analyses provide groundbreaking details on how this protection works.

Why does semaglutide protect the heart even without major weight loss?

A pre-planned secondary analysis published in The Lancet in October 2025 (known as a prespecified analysis, where researchers defined this exact question before looking at the data) examined exactly this question. The result: The heart-protective effect of semaglutide was independent of baseline body weight, waist circumference, and the amount of weight lost. Even participants with minimal weight reduction experienced significant benefits. The authors, led by Prof. John Deanfield, conclude that semaglutide and other GLP-1 receptor agonists - the drug class that includes semaglutide, originally developed for diabetes and now best known as the active ingredient in Wegovy/Ozempic - should be re-evaluated as treatments that actively change the course of the disease itself (so-called disease-modifying treatments) - meaning they treat the root cause, not just the symptom of weight gain - not solely as weight-loss or glycemic-control medications. This has direct implications for prescribing policies: BMI thresholds or weight-loss targets may inappropriately restrict access for patients who would still benefit.

What about kidney outcomes in SELECT?

A parallel analysis published in Nature Medicine 2024 examined kidney endpoints in the SELECT trial. The hard composite kidney endpoint - death from kidney disease, renal replacement therapy (dialysis), reaching an eGFR ≤15 ml/min/1.73 m² (kidney failure), or persistent ≥50% eGFR decline (eGFR = a blood value showing how well the kidneys filter waste) - occurred in 1.8% vs. 2.2%. This translates into a 22% risk reduction. The result was statistically significant: the hazard ratio - simply put, a value that compares risk between two groups (below 1.0 means fewer events in the semaglutide group) - was 0.78, expressing that same ~22% risk reduction. The chance that this difference occurred by random chance was only 2 percent (p = 0.02). The benefit was most pronounced in patients with pre-existing kidney impairment (eGFR below 60 ml/min). This suggests a genuine kidney-protective effect (nephroprotective) beyond weight loss.

What do these findings mean in practice?

The SELECT secondary analyses suggest that semaglutide acts directly on the vascular wall and on inflammatory pathways - independently of its primary metabolic effects (like lowering blood sugar or reducing weight). For patients with cardiovascular disease and overweight, this means a treatment attempt may be worthwhile even if substantial weight loss is not expected. For more details on mechanisms and evidence, see the semaglutide evidence profile and the tirzepatide comparison.

Medical disclaimer: This article is for informational and educational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any therapy with semaglutide or other GLP-1 medications.