Semaglutide Is the Only Obesity Drug Proven to Reduce Heart Attack, Stroke, and Death — Here Is the Evidence

Semaglutide, the GLP-1 receptor agonist sold under the brand name Wegovy (and Ozempic for type 2 diabetes), is the only obesity pharmacotherapy with completed cardiovascular outcomes trial data showing it reduces the risk of death, heart attack, stroke, and heart failure. This distinction is backed by the landmark SELECT trial, FDA approval for cardiovascular risk reduction, and a growing body of meta-analyses that set it apart from competitors like tirzepatide.

What the SELECT Trial Found

The Semaglutide Effects on Heart Disease and Stroke in Patients with Overweight or Obesity (SELECT) trial was a multicenter, randomized, double-blind, placebo-controlled study of 17,604 patients aged 45 years or older with overweight or obesity and established cardiovascular disease, but without diabetes . Patients received once-weekly subcutaneous semaglutide 2.4 mg or placebo over a mean of approximately 40 months.

The primary results were unambiguous. Semaglutide reduced the risk of the primary composite MACE endpoint — cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke — by 20% (hazard ratio 0.80; 95% CI 0.72–0.90; p < 0.001) . In absolute terms, 6.5% of patients in the semaglutide group experienced a primary endpoint event versus 8.0% in the placebo group .

Specific Risk Reductions for Heart Attack, Heart Failure, and Death

Beyond the primary composite endpoint, semaglutide showed benefits across several individual outcomes:

• All-cause mortality: Reduced by 15% . A separate meta-analysis found semaglutide significantly reduced all-cause death compared with placebo (OR 0.84; 95% CI 0.77–0.92; p < 0.001) .
• Heart failure hospitalizations: Reduced by 18% in SELECT . A meta-analysis reported a 24% relative risk reduction for hospitalization due to heart failure (RR 0.24; 95% CI 0.12–0.57) .
• Combined CV death or worsening heart failure: A pooled analysis of the STEP-HFpEF trials found a 31% reduced risk (HR 0.69; 95% CI 0.53–0.89; p = 0.0045) .
• Cardiovascular death in patients with heart failure at baseline: A 17% reduction (HR 0.76; 95% CI 0.59–0.97) .
• MACE in patients with prior coronary artery bypass graft (CABG): A 28% reduction (HR 0.72; 95% CI 0.54–0.95) .

Importantly, cardiovascular benefits emerged within the first three months of treatment, before clinically meaningful weight loss occurred, suggesting weight-independent mechanisms .

Regulatory Milestones: FDA Approval and Medicare Coverage

In March 2024, the U.S. Food and Drug Administration approved Wegovy to reduce the risk of cardiovascular death, heart attack, and stroke in adults with cardiovascular disease and either obesity or overweight — the first obesity drug to receive a cardiovascular risk-reduction indication . In December 2024, the FDA expanded approval for secondary prevention of cardiovascular events in people with a BMI of 27 kg/m² or higher without diabetes .

This FDA decision opened the door for Medicare coverage. The U.S. Centers for Medicare and Medicaid Services (CMS) announced it would allow Part D plans to cover Wegovy for patients with elevated BMI and established cardiovascular disease, regardless of diabetes status . One analysis estimated that covering semaglutide for all newly eligible cardiovascular disease patients could cost Medicare Part D between $34 billion and $145 billion annually, raising significant budget-impact questions .

In parallel, in April 2026, the National Institute for Health and Care Excellence (NICE) recommended Wegovy for routine use within NHS cardiovascular care pathways in England, with an estimated 1.2 million people becoming eligible .

How Semaglutide Compares to Tirzepatide

The competitive landscape between semaglutide and tirzepatide (Mounjaro/Zepbound) is defined by a clear trade-off. Head-to-head trials consistently show tirzepatide achieves superior weight loss — 4.61% greater percentage body weight reduction in a meta-analysis — but as of mid-2026, tirzepatide has no completed cardiovascular outcomes trial specific to obesity.

A recent real-world study comparing semaglutide and tirzepatide in patients with obesity and heart failure with preserved ejection fraction found no statistically significant difference in clinical outcomes over a median follow-up of 24 weeks (HR 1.14; 95% CI 0.89–1.46; p = 0.286) . However, the SELECT trial provides decades-worth of long-term data for semaglutide that tirzepatide cannot yet match.

An Institute for Clinical and Economic Review (ICER) comparative effectiveness assessment noted that tirzepatide showed an 8% reduction in MACE risk and a 16% reduction in all-cause mortality when compared indirectly against dulaglutide, but this falls short of the SELECT-level evidence . The SELECT study remains the first — and to date, the only — cardiovascular outcome trial conducted specifically in the context of pharmacological treatment for obesity .

Why This Matters for Patients and the Market

Semaglutide's cardiovascular data creates what analysts call a unique regulatory and commercial moat. The drug addresses the leading cause of death in people with obesity — cardiovascular disease — with trial-proven results. This distinction drives Medicare coverage decisions, NICE recommendations, and physician prescribing patterns.

For patients, the clinical implications are clear. Semaglutide is the only obesity medication with proven, trial-supported reductions in cardiovascular death, heart attack, stroke, and heart failure. For the estimated 3.6 million Medicare beneficiaries newly eligible for coverage, the drug represents a major advance in cardiovascular risk prevention .