Using national claims data to emulate a head-to-head trial, investigators compared new users of semaglutide and tirzepatide among adults with overweight or obesity and established atherosclerotic cardiovascular disease, excluding those with diabetes. The primary outcome was revised 5-point MACE: myocardial infarction, stroke, hospitalization for heart failure or unstable angina, coronary revascularization, and death. Semaglutide showed a hazard ratio of 1.21 (95% CI 0.99-1.51) versus tirzepatide, statistically non-significant, and secondary endpoints agreed. Sensitivity analyses moved with early-event handling, off-label use, and outcome definitions.
The point estimate leans toward tirzepatide, but the confidence interval crosses 1.0 and no one should read it as a verdict. Semaglutide has dedicated outcome-trial evidence for this population (SELECT showed roughly a 20% MACE reduction versus placebo), while tirzepatide's cardiovascular data in non-diabetic obesity are still maturing; SURMOUNT-MMO is the trial that will answer this properly. Target trial emulation improves on naive observational comparison, but claims data carry real weaknesses: residual confounding by prescriber choice, insurance coverage and drug access, no direct measure of weight loss achieved, and short follow-up for a newer drug. The authors' own sensitivity analyses show how fragile the estimate is. Editorially, this is confirmatory and hypothesis-generating rather than practice-changing. For patients with obesity and prior heart attack or stroke, the actionable point is that both agents appear reasonable, and the choice should rest on tolerability, access, and the weight-loss goals discussed with a clinician.