GLP-1 drugs prove they protect the heart

Overview

Updated Aug 29

The FDA approved tirzepatide (Mounjaro) on August 28 to lower the risk of heart attack, stroke, and cardiovascular death in adults with type 2 diabetes at high risk. The decision rests on SURPASS-CVOT, a 13,000-patient trial that found tirzepatide matched an older GLP-1 medicine, dulaglutide (Trulicity), on major heart events, with an estimated 8% lower rate.

Real-world data back it up. A Harvard analysis of 53,000 U.S. patients, published in The BMJ this month, found a 2.9% one-year heart-event risk on tirzepatide versus 4.4% on sitagliptin, which has no known heart effect. Tirzepatide is sold as Mounjaro for diabetes and Zepbound for weight loss.

Why it matters

Heart disease is the top killer of people with type 2 diabetes, and a drug millions already take now cuts that risk.

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Key Indicators

52,971

Adults in the real-world study

U.S. patients with type 2 diabetes, obesity or overweight, and established heart disease.

2.9%

1-year heart-event risk on tirzepatide

Compared with 4.4% for sitagliptin, a drug with no known heart effect.

13,299

Patients randomized in SURPASS-CVOT

The randomized trial across 30 countries that led to the FDA approval.

Estimated lower heart-event rate vs dulaglutide

SURPASS-CVOT result (hazard ratio 0.92); the trial met non-inferiority, not superiority.

16%

Lower all-cause mortality vs dulaglutide

SURPASS-CVOT result for tirzepatide against an older GLP-1 drug.

20%

Heart-event drop with semaglutide

The 2023 SELECT trial that extended the evidence to patients without diabetes.

Voices

Curated perspectives — historical figures and your fellow readers.

Ever wondered what historical figures would say about today's headlines?

People Involved

Nils Krüger

Lead author, real-world tirzepatide study

Published findings in The BMJ, August 2026

Stephen Nicholls

Lead investigator, SURPASS-CVOT trial

SURPASS-CVOT led to the FDA's August 2026 approval of Mounjaro for cardiovascular risk reduction

Organizations Involved

Eli Lilly and Company

Pharmaceutical company

Maker of tirzepatide (Mounjaro, Zepbound); FDA approved Mounjaro for cardiovascular risk reduction in August 2026

The Indianapolis drugmaker that developed tirzepatide, a dual GIP and GLP-1 receptor agonist.

Novo Nordisk

Pharmaceutical company

Maker of semaglutide (Ozempic, Wegovy)

The Danish drugmaker whose semaglutide first won an FDA heart-protection label among these drugs.

U.S. Food and Drug Administration

Federal regulatory agency

Sets drug labels and approves new uses

The federal agency that decides which health claims a drug's label can carry.

Timeline

June 2016 August 2026

6 events Latest: August 18th, 2026 · 4 weeks ago

Tap a bar to jump to that date

August 2026
Tirzepatide cuts stroke risk in heart-rhythm patients
Latest Study

A review of records from about 28,000 patients with atrial fibrillation and type 2 diabetes found lower stroke and death risk on tirzepatide than on other GLP-1 drugs. The observational study was published in Nature Communications.
August 18th, 2026
Real-world data confirm the benefit
Study

A Harvard analysis in The BMJ finds tirzepatide users had a 2.9% one-year heart-event risk versus 4.4% on sitagliptin.
August 7th, 2026
December 2025
SURPASS-CVOT published
Clinical Trial

Tirzepatide matches dulaglutide on heart events and lowers all-cause deaths by 16% across 13,165 patients in 30 countries.
December 17th, 2025
March 2024
FDA approves a heart claim
Regulatory

The FDA clears semaglutide (Wegovy) to reduce cardiovascular risk, the first of these drugs to earn the label.
March 8th, 2024
November 2023
SELECT trial changes the picture
Clinical Trial

Semaglutide cuts major heart events by 20% in overweight or obese patients with heart disease and no diabetes.
November 11th, 2023
June 2016
First GLP-1 heart benefit
Clinical Trial

The LEADER trial shows liraglutide (Victoza) cuts heart events in diabetes patients, the first GLP-1 drug to do so.
June 13th, 2016

Scenarios

FDA adds a heart-protection claim to tirzepatide's label

Likely Resolves by End of 2027

Discussed by: Eli Lilly investor communications; TCTMD cardiology coverage

Lilly now has both a randomized trial and real-world data behind tirzepatide's heart effects. The company is expected to seek an FDA cardiovascular risk-reduction indication, as Novo Nordisk did for semaglutide in 2024. Approval would let Lilly market the drug for heart protection and could widen insurance coverage.

Diabetes guidelines name tirzepatide a preferred choice for patients with heart disease

Possible Resolves by Feb 28, 2027

Discussed by: American Diabetes Association Standards of Care; American College of Cardiology

Each January the American Diabetes Association updates its Standards of Care. After SURPASS-CVOT and the new real-world data, the guidelines could list tirzepatide among preferred drugs for type 2 diabetes patients with established heart disease, alongside semaglutide and SGLT2 inhibitors.

Tirzepatide overtakes semaglutide in new U.S. diabetes prescriptions

Possible Resolves by Q2 2027

Discussed by: IQVIA prescription tracking; Reuters and Bloomberg pharma coverage

Tirzepatide has been gaining share against Novo Nordisk's semaglutide, and fresh heart data could speed the shift. If reported prescription data show tirzepatide products passing semaglutide products in new U.S. type 2 diabetes starts, Lilly's lead in the category would be clear.

Head-to-head evidence keeps semaglutide ahead on heart protection

Uncertain Resolves by End of 2027

Discussed by: NeurologyLive; peer-reviewed real-world comparison studies

Some real-world analyses suggest semaglutide may cut heart attacks and strokes more than tirzepatide, even though tirzepatide wins on weight and blood sugar. A direct comparison or pooled analysis could confirm semaglutide's heart edge, complicating the case that tirzepatide leads on heart protection.

European regulators approve tirzepatide for cardiovascular risk reduction

Likely Resolves by Q2 2027

Discussed by: Lilly regulatory filings; European Medicines Agency

Lilly says regulatory submissions based on SURPASS-CVOT are under review in additional markets. The EU already lists the trial data in Mounjaro's product information, so a formal heart-protection claim there could follow the U.S. approval.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

November 1994

Scandinavian Simvastatin Survival Study (1994)

The 4S trial followed 4,444 heart patients and found simvastatin cut deaths by 30%, proving cholesterol drugs prevent heart attacks.

Then

Statins became standard care for people with heart disease.

Now

It made long-term preventive medication routine for hundreds of millions of people.

Why this matters now

GLP-1 drugs may trace the statin arc: a drug class that starts targeted and ends up widely prescribed to prevent heart events.

May 2007

Rosiglitazone safety scare (2007)

Cardiologist Steven Nissen published a meta-analysis linking the diabetes pill rosiglitazone (Avandia) to a 43% higher risk of heart attack. Prescriptions and sales fell sharply.

Then

The FDA added strong warnings and heavily restricted the drug's use.

Now

In 2008 the FDA began requiring new diabetes drugs to prove they do not raise heart risk, making the cardiovascular outcome trial a standard hurdle.

Why this matters now

That mandate is why tirzepatide was tested against the heart at all. A rule meant to catch harm now surfaces benefit.

September 2015

EMPA-REG OUTCOME trial (2015)

A trial of the diabetes drug empagliflozin in 7,020 patients found it cut death from cardiovascular causes by 38%, a result few expected from a blood-sugar drug.

Then

Guidelines moved SGLT2 inhibitors toward the front line for diabetes patients with heart disease.

Now

It reset expectations, showing a diabetes drug could actively protect the heart rather than merely avoid harm.

Why this matters now

Tirzepatide follows the same path from metabolic drug to heart drug, changing how doctors pick diabetes treatments.