Medical AISELECT: semaglutide and cardiovascular outcomes without diabetes.
SELECT was a secondary-prevention cardiovascular outcomes trial of semaglutide 2.4 mg in adults with established cardiovascular disease and overweight or obesity, but no diabetes. The primary composite of cardiovascular death, nonfatal MI, and nonfatal stroke fell by about 20%.
SELECT (Semaglutide Effects on Cardiovascular Outcomes in People With Overweight or Obesity) tested whether once-weekly subcutaneous semaglutide 2.4 mg, added to standard care, reduces major adverse cardiovascular events in adults who have established cardiovascular disease and overweight or obesity but who do not have diabetes.[1,2] It is a cardiovascular outcomes trial, not a weight-loss study, and that distinction matters for how the result should be read.
The population was specific: adults aged 45 or older, BMI of 27 or higher, with established cardiovascular disease (prior myocardial infarction, prior stroke, or symptomatic peripheral arterial disease), and without diabetes. About 17,604 patients were randomized to semaglutide 2.4 mg or placebo and followed for a mean of roughly 40 months.[1,2]
The primary composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke occurred in 6.5% of the semaglutide group versus 8.0% of the placebo group, a hazard ratio of 0.80 (95% CI 0.72 to 0.90; P<0.001): about a 20% relative risk reduction.[1] This was a non-diabetic, secondary-prevention population.
What was tested
Both arms received guideline-directed standard care for cardiovascular risk factors; semaglutide or placebo was added on top. The intervention was titrated up to the 2.4 mg maintenance dose used in obesity, not the lower glucose-lowering doses.[1,2] Because everyone already had cardiovascular disease, the trial answers a secondary-prevention question, not a primary-prevention one.
What the trial showed
Over a mean follow-up of about 40 months, the primary three-point MACE composite fell by roughly 20% with semaglutide (HR 0.80; 95% CI 0.72 to 0.90; P<0.001).[1] Mean body weight fell by about 9.4% with semaglutide. The cardiovascular benefit is generally discussed as more than a pure consequence of weight loss, though the trial was not designed to fully separate the mechanisms.
The SELECT primary result at a glance. Read the full paper for secondary endpoints, subgroups, and safety.
| Element | SELECT | Note |
|---|---|---|
| Population | Established CVD, BMI ≥ 27, no diabetes | Secondary prevention [1,2] |
| Intervention | Semaglutide 2.4 mg weekly vs placebo | Added to standard care [1] |
| Size and follow-up | ~17,604 randomized; mean ~40 months | Event-driven outcomes trial [1] |
| Primary MACE | HR 0.80 (95% CI 0.72-0.90); P<0.001 | 6.5% vs 8.0%; ~20% relative reduction [1] |
| Regulatory result | Wegovy CV label expansion | FDA, March 8, 2024 [3] |
What it changed
On March 8, 2024, the FDA expanded the Wegovy (semaglutide 2.4 mg) label to include reducing the risk of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke in adults with established cardiovascular disease and either obesity or overweight, based on SELECT.[3] That made it the first anti-obesity medication carrying a cardiovascular risk-reduction indication.
How to read it carefully
The result applies to the population studied: established cardiovascular disease, overweight or obesity, no diabetes. It does not by itself establish a primary-prevention benefit, and it does not speak to people without cardiovascular disease.[1] As with any chronic incretin therapy, the durability question matters: the benefit is tied to ongoing treatment, and gastrointestinal tolerability and adherence shape who actually reaches and stays on the maintenance dose.
A 20% relative reduction is large for a secondary-prevention population, but it is a secondary-prevention population. Match the trial to the patient.- Section synthesis
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The useful question with an outcomes trial is who it actually applies to and what the effect size really was. Ask, and read the trial against your patient.
This explainer is verified against the cited primary sources. Confirm the SELECT primary result, population, and the current Wegovy label against the cited sources before clinical application.
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