Medically Reviewed
This article has been reviewed by Dr. Ajit Jha, MBBS, MD Medicine, IMA Lifetime Member. Content is for informational purposes only and does not constitute medical advice. Always consult your doctor before making health decisions.
In August 2023, the New England Journal of Medicine published results that changed cardiovascular medicine. The SELECT trial — the largest randomised trial of a GLP-1 drug in cardiovascular patients — showed that semaglutide reduced the risk of heart attacks, strokes, and cardiovascular death by 20%. The finding went beyond weight loss. It changed how cardiologists think about this class of drugs.
📋 Key Takeaways
- The SELECT trial showed semaglutide reduced major cardiovascular events by 20% over 3+ years
- The trial enrolled people with heart disease and obesity — without diabetes — a first for this drug class
- The cardiovascular benefit appeared to go beyond what weight loss alone explains
- Semaglutide also reduced C-reactive protein (inflammation) by 40% — a key cardiac risk marker
- The FDA approved semaglutide specifically for cardiovascular risk reduction in 2024
What Was the SELECT Trial?
The SELECT trial (Semaglutide Effects on Cardiovascular Outcomes in People with Overweight or Obesity) was a phase 3 randomised controlled trial conducted across 41 countries and 804 sites. It enrolled 17,604 participants — one of the largest cardiovascular outcome trials ever conducted.
Who Was Enrolled
This is what made SELECT unique and important:
- Adults aged 45 or older with a BMI of 27 or above
- Established cardiovascular disease (prior heart attack, stroke, or peripheral artery disease)
- No type 2 diabetes — this was specifically a non-diabetic population
Previous GLP-1 cardiovascular trials (LEADER, SUSTAIN-6, PIONEER-6) had enrolled diabetic patients. SELECT was the first to test whether GLP-1 drugs protect hearts in people who just have obesity and heart disease — without diabetes. The answer was a resounding yes.
Trial Design
Participants were randomised to weekly semaglutide 2.4mg (Wegovy dose) or placebo. Both groups continued standard medical care for their cardiovascular conditions. The trial ran for a median of 3.2 years, with some participants followed for over 5 years.
The Results: What SELECT Actually Showed
| Outcome | Semaglutide | Placebo | Risk Reduction |
|---|---|---|---|
| MACE (heart attack + stroke + CV death) | 6.5% | 8.0% | 20% |
| Non-fatal heart attack | 2.9% | 3.7% | 22% |
| Non-fatal stroke | 1.4% | 1.7% | 18% |
| Cardiovascular death | 2.5% | 3.1% | 15% |
| All-cause mortality | 3.2% | 4.2% | 19% |
In absolute numbers: for every 1,000 patients treated with semaglutide for 3 years, approximately 15 major cardiovascular events were prevented. This is a large absolute benefit for a cardiovascular drug — comparable to statins and superior to many established treatments.
The Key Question: Is This Just From Weight Loss?
This is the most scientifically important question the SELECT trial raised — and the answer has major implications.
Average weight loss in the SELECT trial was 9.4% in the semaglutide group vs 0.9% in placebo. Statistical analyses by the trial investigators found that weight loss explained only a portion of the cardiovascular benefit. Even after adjusting for weight reduction, a significant protective effect remained.
The mechanisms that appear to work independently of weight loss:
- Anti-inflammatory effects — C-reactive protein (CRP), a key cardiac inflammatory marker, fell by 40% in the semaglutide group vs 9% in placebo. This inflammation reduction occurred early — before significant weight loss — suggesting a direct drug effect
- Blood pressure reduction — Systolic blood pressure fell by an average of 3.8mmHg more in the semaglutide group. Part is from weight loss; part appears direct
- Direct cardiac GLP-1 effects — GLP-1 receptors are expressed on cardiac muscle cells. GLP-1 receptor activation has been shown to reduce ischaemia-reperfusion injury (damage when blood flow is restored after a blockage) in animal models
- Endothelial function — Semaglutide appears to improve the function of the cells lining blood vessels, reducing plaque vulnerability
What This Means for Indian Heart Patients
India has one of the highest burdens of premature cardiovascular disease globally. Indians develop heart disease on average a decade earlier than Western populations — often at ages 40–55 — and obesity is an increasingly significant contributing factor. The SELECT trial data is directly applicable to this population.
For an Indian with:
- Prior heart attack or angioplasty
- Established coronary artery disease on medication
- Prior stroke or TIA
- Peripheral artery disease
- And a BMI above 27 (overweight by Indian standards)
…semaglutide now has a class I or class II indication depending on which cardiology guideline you follow. The European Society of Cardiology 2024 guidelines explicitly recommend GLP-1 receptor agonists for cardiovascular risk reduction in people with obesity and established CVD.
The FDA's Response: A New Indication
Based on the SELECT trial, the FDA in March 2024 approved semaglutide 2.4mg (Wegovy) for a new indication: reduction of cardiovascular mortality, non-fatal heart attack, and non-fatal stroke in adults with established cardiovascular disease and either obesity or overweight. This made semaglutide the first weight-management drug in history to receive FDA approval for a cardiovascular outcome indication.
This regulatory milestone changes how insurers, health systems, and individual prescribers view these drugs — from 'lifestyle medications' to legitimate cardiovascular medicines.
Beyond the Heart: SELECT's Secondary Findings
The SELECT trial also reported several pre-specified secondary outcomes:
- Heart failure hospitalisation — Significantly reduced with semaglutide
- New onset diabetes — 73% reduction in the semaglutide group (remarkable, given the non-diabetic population)
- Kidney outcomes — Consistent with FLOW trial findings; semaglutide preserved kidney function
- Mental health — No increase in anxiety, depression, or suicidal ideation — contrary to earlier theoretical concerns
- Migraines — A sub-analysis found significant migraine reduction, consistent with emerging research on Ozempic's effects beyond weight loss covered in our earlier article on Ozempic's surprising benefits
Dr. Ajit Jha's Clinical Perspective
“The SELECT trial data genuinely shifted how I counsel post-MI patients with obesity. Previously, the conversation was: lose weight for your heart. Now I can say: this drug will directly reduce your cardiovascular risk, and the weight loss is a bonus. The 20% MACE reduction is a number that compares favourably to adding a statin or a beta-blocker. For patients who can access and afford it, semaglutide has become part of the post-MI pharmacological toolkit in my practice. The limitation, as always in India, is cost — ₹10,000 per month is simply not accessible for most patients who need it most.”
— Dr. Ajit Jha, MBBS, MD Medicine, IMA Lifetime Member
Frequently Asked Questions
Does Ozempic protect the heart in people without diabetes?
Yes — this is precisely what the SELECT trial demonstrated. The 17,604 participants had established cardiovascular disease and obesity, but no diabetes. Semaglutide reduced MACE by 20% in this non-diabetic population, proving the cardiovascular benefit is independent of blood sugar effects.
How long does it take for Ozempic to show cardiovascular benefit?
SELECT showed separation in cardiovascular event curves beginning around 3–6 months after starting treatment. The early inflammation reduction (CRP dropping by 40% in the first months) suggests some cardiovascular benefits begin even before significant weight loss occurs.
Should all heart patients take Ozempic?
Not necessarily. The indication applies to people with established cardiovascular disease (prior MI, stroke, or peripheral artery disease) and overweight or obesity. People with heart disease but normal weight are not part of the SELECT population and are not routinely recommended semaglutide. Discuss with your cardiologist.
Is Ozempic safe after a heart attack?
Yes — the SELECT trial specifically enrolled people with prior heart attacks and showed both safety and significant cardiovascular benefit. Semaglutide is compatible with standard post-MI medications including statins, ACE inhibitors, beta-blockers, and antiplatelets.
What is the difference between Ozempic and Wegovy for the heart?
Both are semaglutide — the same molecule. Ozempic (0.5–2mg/week) is approved for type 2 diabetes. Wegovy (2.4mg/week) is approved for obesity and cardiovascular risk reduction. The SELECT trial used the 2.4mg Wegovy dose. For purely cardiovascular indication in someone without diabetes, Wegovy is the appropriate formulation.
📖 Related Articles