Cardiovascular Outcomes with Tirzepatide versus Dulaglutide in Type 2 Diabetes

The SURPASS-CVOT trial was a phase 3, randomized, double-blind, active-comparator study designed to evaluate the cardiovascular safety and efficacy of tirzepatide compared to dulaglutide (a GLP-1 agonist with established CV benefit) in patients with type 2 diabetes and atherosclerotic cardiovascular disease. 13,299 participants were randomized to weekly tirzepatide (up to 15 mg) or dulaglutide 1.5 mg, with a median follow-up of 4 years.

The primary endpoint was MACE-3 (cardiovascular death, non-fatal MI, or non-fatal stroke):

• 12.2% with tirzepatide vs. 13.1% with dulaglutide (HR 0.92; 95% CI 0.83-1.01)
• Non-inferiority achieved (P=0.003), but superiority not established (P=0.09)
• Expanded MACE (including coronary revascularization): significant reduction with tirzepatide (HR 0.88)
• All-cause mortality: reduction with tirzepatide (16% relative), apparently driven by lower non-cardiovascular mortality

Metabolic benefits were robustly superior with tirzepatide: HbA1c reduction of 1.66% (to 6.7%) vs. 0.88% with dulaglutide, with significant differences in blood pressure, lipids, and weight loss. Gastrointestinal events were more frequent with tirzepatide, but the overall safety profile was consistent between groups.

SURPASS-CVOT is the first CVOT (Cardiovascular Outcomes Trial) of a dual GIP/GLP-1 agonist with an active comparator. The data confirm tirzepatide's cardiovascular safety, satisfying the regulatory requirement, and suggest that GIP/GLP-1 agonism offers superior metabolic benefits that translate into broader event reduction and mortality benefit — even compared to another already-proven GLP-1 agonist.