The FDA has approved a new indication for Mounjaro (tirzepatide): lowering the risk of major adverse cardiovascular events — cardiovascular death, non-fatal heart attack, or non-fatal stroke — in adults with type 2 diabetes who are at high risk for them. Eli Lilly announced the approval on 28 August 2026. It is the first cardiovascular indication granted to a dual GIP and GLP-1 receptor agonist. What the approval does not establish is that tirzepatide beats the GLP-1 drug it was tested against. The trial behind it was built to show non-inferiority, and non-inferiority is what it showed.
What SURPASS-CVOT actually tested
SURPASS-CVOT (NCT04255433) randomised 13,299 adults with type 2 diabetes and established atherosclerotic cardiovascular disease 1:1 across 640 sites in 30 countries. One arm received tirzepatide at 15 mg or the highest dose the participant tolerated; the other received dulaglutide (Trulicity) at 1.5 mg, both once weekly — the doses written into the registered trial protocol. Median follow-up was 210.1 weeks, a little over four years. The primary endpoint was time to a first MACE-3 event.
Lilly reports a hazard ratio of 0.92 for tirzepatide versus dulaglutide, with a 95.3% confidence interval of 0.83 to 1.01. Read that plainly: the single best estimate is an 8% lower event rate on tirzepatide, but the range of results compatible with the data runs from a 17% reduction to a 1% increase. Because that range includes 1.00 — no difference at all — the pre-specified non-inferiority test passed and superiority was not established. The ClinicalTrials.gov record lists the trial as completed on 12 June 2025, with summary results posted on 8 July 2026, and confirms the enrolment figure and the randomised, double-blind, parallel-group design.
Why the comparator changes how you read it
Nearly every cardiovascular outcomes trial in this drug class has been run against placebo. This one was run against dulaglutide, which already carries its own indication for reducing major cardiovascular events. That makes the bar higher and the result more useful: the claim the label now supports is “at least as good as a drug already proven to lower these events,” which is a genuinely different statement from “better than nothing.” It is not a claim of superiority, and any marketing that implies tirzepatide outperforms dulaglutide on cardiovascular events is running ahead of the evidence.
Two boundaries are worth holding onto. First, this indication sits on the Mounjaro label, which is a type 2 diabetes label. Zepbound is the same molecule sold for weight management under a separate approval, and this decision does not extend a cardiovascular claim to people taking tirzepatide for obesity without diabetes — a distinction we keep drawing in our GLP-1 research hub because the two products are routinely discussed as though they were interchangeable. Second, everyone enrolled already had established atherosclerotic disease, so this is evidence about secondary prevention in a high-risk group, not about the general population. For anyone weighing which of these drugs to ask a prescriber about, the practical question is usually still what it will cost, which we cover in our guide to GLP-1 pricing without insurance.
What is not yet known
The confidence interval crosses 1.00, so this trial cannot tell you whether tirzepatide is genuinely better, equal, or marginally worse than dulaglutide for preventing these events. It also cannot tell you anything about cardiovascular risk in people without type 2 diabetes. Lilly states that full results were published in the New England Journal of Medicine; we have not accessed that paper, and the figures above come from the company’s own release and the ClinicalTrials.gov record, so the peer-reviewed safety tables and subgroup analyses remain unread here. The release describes adverse events as mostly gastrointestinal and concentrated during dose escalation but gives no rates. Mounjaro’s boxed warning for thyroid C-cell tumours is unchanged.
Sources: Eli Lilly and Company, “FDA approves Lilly’s Mounjaro (tirzepatide) to reduce cardiovascular risk in adults with type 2 diabetes,” company news release, 28 August 2026; ClinicalTrials.gov, “The Effect of Tirzepatide Versus Dulaglutide on Major Adverse Cardiovascular Events in Patients With Type 2 Diabetes (SURPASS-CVOT),” NCT04255433, results posted 8 July 2026.
