A retrospective cohort study used pooled TriNetX electronic health records to compare 424,269 patients with obesity initiating tirzepatide with an equal number initiating semaglutide between June 2021 and August 2026. One-year incidence of new-onset heart failure was 1.0% with tirzepatide against 1.3% with semaglutide, an absolute difference of 0.3 percentage points (HR 0.9, 95% CI 0.86-0.93), with lower all-cause mortality and lower new-onset systolic heart failure in the tirzepatide group and no difference in atrial fibrillation or flutter.
Why it is interesting: A head-to-head comparison of the two leading incretin drugs on a hard cardiovascular endpoint, though observational and with modest absolute differences.