Key Facts
- Drug: Tirzepatide; dual GIP/GLP-1 agonist
- Indication: Type 2 diabetes with high CV risk
- Trial: SURPASS-CVOT, phase 3
- Enrollment: 13,299 adults
- Primary result: HR, 0.92 vs dulaglutide
- Conclusion: Noninferior; not superior
- Safety: Mainly gastrointestinal events
- Status: FDA-approved in the United States
Participants were randomly assigned 1:1 to receive once-weekly subcutaneous tirzepatide, titrated to 15 mg or the maximum tolerated dose, or dulaglutide 1.5 mg. The primary end point was time to first 3-point major adverse cardiovascular event, defined as cardiovascular death, myocardial infarction, or stroke.
During a median follow-up of 210.1 weeks, tirzepatide met the prespecified criterion for noninferiority to dulaglutide. The hazard ratio for the primary end point was 0.92 (95.3% CI, 0.83-1.01), corresponding to an 8% lower relative event rate with tirzepatide.¹ Superiority over dulaglutide was not established.
That distinction is clinically important. Data from the SURPASS-CVOT trial showed that cardiovascular outcomes with tirzepatide were no worse than those with an active comparator already known to reduce cardiovascular risk; it did not demonstrate that tirzepatide was superior.
Cardiovascular risk remains central to type 2 diabetes management. An analysis of US adults found a substantial burden of subclinical cardiovascular disease among people with diabetes, including disease not previously recognized clinically.³ Dulaglutide and other agents with cardiovascular outcome data already form part of the treatment landscape, making the active-comparator design relevant to therapeutic decision-making.
Tirzepatide is a once-weekly peptide that activates glucose-dependent insulinotropic polypeptide and GLP-1 receptors. Its metabolic effects include glucose-dependent insulin secretion, reduced glucagon concentrations, delayed gastric emptying, and reduced food intake.⁴ The cardiovascular indication adds an outcomes-based use to its established glycemic indication.
Safety findings in SURPASS-CVOT were consistent with tirzepatide’s known profile. Gastrointestinal events were most common, were generally mild to moderate, and occurred primarily during dose escalation. The prescribing information also warns about pancreatitis, hypoglycemia when used with insulin or sulfonylureas, acute kidney injury associated with dehydration, severe gastrointestinal reactions, gallbladder disease, hypersensitivity, and aspiration risk during anesthesia or deep sedation. Tirzepatide is contraindicated in patients with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2.⁴
Remaining questions include absolute cardiovascular benefit, comparative effects across patient subgroups, treatment discontinuation, and applicability to patients without established atherosclerotic cardiovascular disease. Although the FDA indication covers adults considered at high cardiovascular risk, the pivotal trial specifically enrolled patients with established disease.
References
- Eli Lilly and Company. FDA approves Lilly’s Mounjaro (tirzepatide) to reduce cardiovascular risk in adults with type 2 diabetes. News release. Published August 28, 2026. Accessed August 28, 2026. https://investor.lilly.com/news-releases/news-release-details/fda-approves-lillys-mounjaro-tirzepatide-reduce-cardiovascular
- ClinicalTrials.gov. A study of tirzepatide versus dulaglutide on major cardiovascular events in participants with type 2 diabetes (SURPASS-CVOT). NCT04255433.
- Fang M, Wang D, Tang O, et al. Subclinical cardiovascular disease in US adults with and without diabetes. J Am Heart Assoc. 2023;12(11):e029083. doi:10.1161/JAHA.122.029083
- Mounjaro (tirzepatide) prescribing information. Eli Lilly and Company; revised August 2026.