Overview
- A BMJ analysis of 52,971 US insured patients who started tirzepatide or sitagliptin between May 2022 and May 2025 found one-year major adverse cardiovascular event rates of 2.9% with tirzepatide versus 4.4% with sitagliptin, an estimated 32–33% relative reduction in MACE and heart attacks.
- The researchers used sitagliptin as a neutral comparator and applied propensity score overlap weighting to balance the groups, and they estimate one MACE prevented per 70 patients treated with tirzepatide at one year.
- Authors and a linked editorial stress key limits: the study is observational, follow-up was short so effects or harms over time may be missed, outcome or treatment misclassification is possible, and results may not generalize beyond the insured US population studied.
- The analysis also reported fewer infection‑related hospital admissions and lower all‑cause mortality with tirzepatide, but those secondary signals need confirmation in randomized or longer pragmatic studies.
- Use and spending for tirzepatide have surged this year, raising questions about affordability, access and how health systems should weigh these promising but non‑causal findings against emerging safety reports such as hair‑loss complaints to regulators.