# Do GLP-1 Drugs Prevent Heart Attacks and Strokes? One, Not Both | This GLP In 52,971 adults, MACE occurred in 2.9% on tirzepatide against 4.4% on sitagliptin at one year (HR 0.68, NNT 70), with stroke unchanged at HR 0.91. Publisher: This GLP Editorial Team Canonical: https://thisglp.com/research/do-glp1-drugs-prevent-heart-attacks-and-strokes Updated: 2026-09-17 Published: 2026-09-17 [← Research](https://thisglp.com/research) Evidence # Do GLP-1 Drugs Prevent Heart Attacks and Strokes? One, Not Both A 52,971-person cohort with a neutral active comparator and two negative control outcomes. Heart attacks fell; strokes did not. [This GLP Editorial Team](https://thisglp.com/about)September 20266 min read Tirzepatide vs sitagliptin, hazard ratios at one year · 1.0 · MACE composite · heart attack · ischemic stroke · Stroke crosses 1.0. Two negative controls showed nothing. **Research, not medical advice.** This GLP is independent and educational. Nothing here is a substitute for individualized care from a licensed clinician, and reading it creates no doctor–patient relationship. Talk to your own provider before starting, stopping, or changing any medication, peptide, or therapy. See our [methodology](https://thisglp.com/methodology) and [terms](https://thisglp.com/terms). ## Key takeaways - A population-based cohort of 52,971 adults with type 2 diabetes and established cardiovascular disease compared tirzepatide initiators against sitagliptin, a cardiovascular-neutral comparator. - At one year, major adverse cardiovascular events occurred in 2.9% against 4.4% — a risk difference of -1.4% (95% CI -2.1 to -0.7), number needed to treat 70, hazard ratio 0.68 (95% CI 0.58 to 0.80). - Heart attack fell (HR 0.67, 95% CI 0.52 to 0.87) while ischemic stroke did not (HR 0.91, 95% CI 0.64 to 1.28, NNT 2500). - Two negative control outcomes showed no association, a check on residual confounding that most observational studies skip. Heart attacks, yes. Strokes, not in this cohort. Among 52,971 adults with type 2 diabetes and established cardiovascular disease, tirzepatide initiators had major adverse cardiovascular events in 2.9% against 4.4% on a cardiovascular-neutral comparator. That is a hazard ratio of 0.68 and a number needed to treat of 70. Split the composite and the two halves part company. Heart attack fell, at a hazard ratio of 0.67 (95% CI 0.52 to 0.87). Ischemic stroke did not, at 0.91 (95% CI 0.64 to 1.28), where the number needed to treat works out at 2,500. A composite that moves is not every component moving, and this one names which. A randomized trial reached a similar place from the other direction. Tirzepatide against dulaglutide in 13,299 people met noninferiority and missed superiority, at P=0.09 [\[2\]](https://thisglp.com/research/do-glp1-drugs-prevent-heart-attacks-and-strokes#ref-2). Matching an older drug is not beating it. The study here also did something most observational work skips: it ran two negative control outcomes, and neither showed an association. That is a check on residual confounding rather than an assumption that none exists. Most observational drug comparisons on this site fail on the same problem: people who get the newer drug differ from people who do not, in ways no adjustment fully captures. This one built three defenses against that, and it is worth reading for the method as much as the result [\[1\]](https://thisglp.com/research/do-glp1-drugs-prevent-heart-attacks-and-strokes#ref-1). It is the standard this site applied in [the study that checked its own work](https://thisglp.com/research/do-glp1-drugs-cause-blood-clots). First, the comparator. Tirzepatide initiators, 35,353 of them, were not compared against untreated people. The comparator was sitagliptin initiators (17,618) — a drug chosen because its cardiovascular effect is neutral, making it a proxy for placebo among people who are being actively treated. Second, propensity score overlap weighting balanced baseline characteristics. Third, the authors tested two negative control outcomes, lumbar radiculopathy and abdominal hernia, which no drug in this class should affect. Neither showed an association. On the result, major adverse cardiovascular events occurred in 2.9% of the tirzepatide group and 4.4% of the sitagliptin group at one year. That is a risk difference of 1.4 percentage points, a number needed to treat of 70, and a hazard ratio of 0.68. Heart attack drove it, at a hazard ratio of 0.67 and an NNT of 130. That is an absolute gain of the kind this site keeps separating from relative ones in [sixteen percent lower, six hundredths of a point](https://thisglp.com/research/can-you-take-a-glp1-with-epilepsy). Stroke did not move, and the composite contains death Ischemic stroke came in at a hazard ratio of 0.91 with an interval from 0.64 to 1.28 and a number needed to treat of 2,500 — which is the paper’s way of saying no meaningful difference. And the MACE composite here is heart attack, stroke and all-cause mortality together. A composite carrying deaths from any cause is a different thing from a composite of cardiovascular events, and this site keeps that distinction in [the mortality number that could not be right](https://thisglp.com/research/do-glp1-drugs-help-intracranial-hypertension). Two findings sit outside the cardiovascular story and deserve reporting without explanation. Infections requiring hospital admission were lower on tirzepatide (HR 0.64, 95% CI 0.55 to 0.75, NNT 48), as was infection-related mortality (HR 0.40, 95% CI 0.26 to 0.61). All-cause mortality came in at 0.55 (95% CI 0.42 to 0.72). Those are large and this site will not speculate about why they appear. The limits are ordinary and real. Follow-up ran one year and was censored at discontinuation or switching, so this measures the first year of continuous use rather than a durable effect. And claims data records prescriptions and diagnoses, not people. What makes the study unusual is what its authors did next. They asked their own data to prove it was not lying — the practice this site wants more of, and rarely gets, as in [the result extrapolated to everyone](https://thisglp.com/research/how-many-heart-attacks-could-semaglutide-prevent). ## Frequently asked How much did tirzepatide reduce cardiovascular events? Major adverse cardiovascular events occurred in 2.9% against 4.4% at one year, a hazard ratio of 0.68 with a number needed to treat of 70. Did it prevent strokes? Not measurably. Ischemic stroke came in at a hazard ratio of 0.91 with a confidence interval from 0.64 to 1.28 and a number needed to treat of 2,500. Why compare against sitagliptin rather than no drug? Because sitagliptin is cardiovascular-neutral, so it acts as a placebo proxy among people who are being actively treated, removing much of the difference between treated and untreated populations. ## Sources 1. \[1\] Krüger N, Schneeweiss S, Wang SV (2026). Tirzepatide and the risk of atherosclerotic cardiovascular events: population based cohort study The BMJ. [PMID 42556854](https://pubmed.ncbi.nlm.nih.gov/42556854/) 2. \[2\] Nicholls SJ, et al. (2025). Cardiovascular Outcomes with Tirzepatide versus Dulaglutide in Type 2 Diabetes The New England Journal of Medicine. [PMID 41406444](https://pubmed.ncbi.nlm.nih.gov/41406444/) ## Where to get it ### Best GLP-1 injections Every injectable seller we can verify, with the price each one publishes and an honest read of what the trials measured. 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