SURPASS-CVOT: Tirzepatide vs Dulaglutide Heart Outcomes

What SURPASS-CVOT Measured

A cardiovascular outcomes trial (CVOT) is designed to answer a specific safety-and-benefit question: when people take this medication over time, what happens to hard cardiovascular events. The standard yardstick is three-point MACE, short for major adverse cardiovascular events, which combines cardiovascular death, non-fatal heart attack, and non-fatal stroke into one composite endpoint.

SURPASS-CVOT enrolled roughly 13,000 adults who had both type 2 diabetes and established atherosclerotic cardiovascular disease, meaning they already had documented arterial disease and were therefore at elevated risk. That high-risk population is deliberate: it lets a trial accumulate enough events to draw statistical conclusions in a reasonable timeframe.

The defining feature was the comparator. Participants received either tirzepatide, a dual GIP and GLP-1 receptor agonist, or dulaglutide, a single-target GLP-1 receptor agonist with its own prior cardiovascular evidence base. Comparing two active drugs head-to-head is far less common than comparing one drug to placebo, which is precisely why this trial drew attention.

Non-Inferiority: What HR 0.92 Actually Means

The headline result is that tirzepatide was non-inferior to dulaglutide on three-point MACE, with a hazard ratio of 0.92. This number is easy to misread, so it is worth slowing down.

A hazard ratio compares the rate of events between two groups. A value of 1.0 means the two groups had the same event rate. A value below 1.0, like 0.92, points numerically in the direction of fewer events in the tirzepatide group. But the trial's primary question was non-inferiority, not superiority. Non-inferiority asks whether the newer drug is "not meaningfully worse" than the comparator within a pre-specified margin. The answer here was yes: tirzepatide met that bar.

What HR 0.92 does not establish is that tirzepatide is proven superior to dulaglutide for preventing heart attacks or strokes. A point estimate that leans favorable is encouraging, but unless a trial is formally powered and pre-specified to test superiority, and unless that test clears statistical significance, the honest interpretation is non-inferiority. Treating "0.92" as proof of superiority is exactly the overreach that careful readers and regulators push back on.

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The Secondary Findings, and Why the Asterisk Matters

Beyond the primary endpoint, SURPASS-CVOT reported a set of secondary results that favored tirzepatide. These included approximately 16 percent lower all-cause mortality and greater improvements in A1C, weight, lipids, and renal measures.

On the surface, that reads as a strong story. But there is an important methodological caveat that determines how much weight any reader should give those numbers. The secondary endpoints were not controlled for type-1 error, meaning there was no multiplicity adjustment. When a trial tests many endpoints without statistically correcting for all those comparisons, some apparently positive results can arise by chance. That is why the convention is to label such findings supportive or exploratory rather than confirmatory.

In plain terms: the secondary findings are consistent with a favorable picture, and they are worth noting, but they are not the same caliber of evidence as a pre-specified, multiplicity-protected primary endpoint. A roughly 16 percent lower all-cause mortality signal is the kind of result that generates further study, not the kind that, on its own, proves a mortality benefit. Holding that distinction is what separates an accurate read of the trial from a hyped one.

How This Differs From a Placebo Trial

It is worth dwelling on why an active-comparator design changes interpretation. In a placebo-controlled CVOT, a positive result tells you the drug beats no treatment. That is useful, but it does not tell you how the drug stacks up against other agents a clinician might already reach for.

SURPASS-CVOT, by setting tirzepatide against dulaglutide, asks the more clinically practical question of relative performance between two real options. The non-inferiority result means tirzepatide cleared the bar of holding its own against an established GLP-1 with its own cardiovascular pedigree. For anyone weighing the evidence behind these medications, that is a meaningfully different and arguably more demanding test than beating placebo. It also raises the standard for how future trials in this class may be designed. None of this changes the core compliance point: what any individual should do is a clinician-directed decision, and this article is reporting evidence, not prescribing a course.

What to Track: Biomarkers Worth Monitoring

The value of SURPASS-CVOT for an individual who tracks their own health is that it points to a concrete set of biomarkers that moved in the trial. These map directly to common, trackable lab tests. People using GLP-1 medications, working alongside their providers, frequently keep an eye on metabolic, lipid, and renal markers over time. None of the following is a recommendation to test or treat. It is a list of what is commonly tracked so you can organize your own data and discuss it with your provider.

Tracking these consistently, rather than as scattered one-off results, is what makes the data genuinely useful in a clinical conversation. A single value is a snapshot. A trend line tells a story. If you want a structured starting point, you can browse the full [biomarker library](/biomarkers) for plain-language explanations of each test, and the [tirzepatide profile](/peptides/tirzepatide) for an overview of the compound itself.

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How to Read Trials Like This One

SURPASS-CVOT is a useful template for reading any cardiovascular outcomes trial. A few questions cut through most headlines. First, what was the primary endpoint, and was it a superiority or non-inferiority test? Second, was the comparator placebo or an active drug, since that reframes what a positive result means? Third, which findings were pre-specified and multiplicity-protected, and which were secondary and therefore supportive rather than confirmatory?

Run SURPASS-CVOT through those questions and the honest summary writes itself: a large active-comparator trial in a high-risk population, where the newer dual agonist was non-inferior to an established GLP-1 on hard cardiovascular events, with favorable but not statistically confirmatory secondary signals on mortality, metabolic, lipid, and renal measures. That is a strong and clean result on its own terms, without needing to be inflated into a superiority claim it does not support. For people who track their health seriously, the practical takeaway is to keep clean longitudinal records of the markers these trials care about, so any provider conversation is grounded in your own data over time.

Frequently Asked Questions

What did the SURPASS-CVOT trial find?

SURPASS-CVOT, published in the New England Journal of Medicine on December 17, 2025, compared tirzepatide head-to-head against dulaglutide in roughly 13,000 adults with type 2 diabetes and atherosclerotic cardiovascular disease. On the primary three-point MACE endpoint, tirzepatide was non-inferior to dulaglutide, with a hazard ratio of 0.92. Secondary findings, including approximately 16 percent lower all-cause mortality and greater improvements in A1C, weight, lipids, and renal measures, were supportive but were not controlled for type-1 error, so they are not confirmatory.

Is tirzepatide proven better than dulaglutide for the heart?

No. The primary endpoint was a non-inferiority test, and tirzepatide met that bar, meaning it was not meaningfully worse than dulaglutide on three-point MACE. The hazard ratio of 0.92 leans numerically favorable, but the trial was not designed to prove superiority, and the secondary findings were not multiplicity-protected. So the accurate reading is non-inferiority, not proven superiority for preventing heart attacks or strokes. This is a clinician-directed question, and you should defer to your provider.

Why does it matter that SURPASS-CVOT used an active comparator?

Most prior cardiovascular outcomes trials in the GLP-1 class compared a drug against placebo. SURPASS-CVOT instead compared tirzepatide against dulaglutide, an already-established GLP-1. That makes it the first active-comparator cardiovascular outcomes trial in the class and answers a more clinically practical question: how the newer dual agonist performs against a real, known agent rather than against no treatment at all.

What does "not controlled for type-1 error" mean for the secondary results?

It means the secondary endpoints, like the roughly 16 percent lower all-cause mortality and the metabolic, lipid, and renal improvements, were not adjusted for testing many comparisons at once. Without that multiplicity adjustment, some apparently positive findings can occur by chance. The convention is therefore to treat these results as supportive or exploratory rather than as confirmed, statistically protected conclusions.

Which biomarkers from SURPASS-CVOT can I track over time?

The markers that moved in the trial map to common, trackable lab tests: ApoB, the standard lipid panel including LDL-C and triglycerides, HbA1c, body weight, and eGFR for renal function. MyProtocolStack is an education and tracking tool, not medical advice, so it cannot tell you what to test or take. What you can do is keep an organized, longitudinal record of these markers and discuss the trends with your provider.

Sources

1. HCPLive, "SURPASS-CVOT: Tirzepatide Bests Dulaglutide in Cardiovascular Protection." https://www.hcplive.com/view/surpass-cvot-tirzepatide-bests-dulaglutide-cardiovascular-protection

2. American College of Cardiology, Journal Scan, "SURPASS-CVOT," January 7, 2026. https://www.acc.org/latest-in-cardiology/journal-scans/2026/01/07/14/20/surpass-cvot

3. DocWire News, "Tirzepatide in SURPASS-CVOT: Favorable Cardiovascular Outcomes With Superior Metabolic and Renal Benefits in Type 2 Diabetes." https://www.docwirenews.com/post/tirzepatide-in-surpass%E2%80%91cvot-favorable-cardiovascular-outcomes-with-superior-metabolic-and-renal-benefits-in-type-2-diabetes

*MyProtocolStack is a tracking and education tool, not medical advice, diagnosis, or treatment, and you should always consult a qualified healthcare professional before making any changes to your health protocol.*