A new study is adding to the growing body of evidence suggesting that tirzepatide, a medication used to treat type 2 diabetes, may do more than improve blood sugar levels and promote weight loss. 

Researchers found that when tirzepatide was added to standard care for people with type 2 diabetes and established heart disease, patients experienced a significantly lower risk of major cardiovascular events—including heart attack and stroke—compared with those taking another diabetes medication, sitagliptin.

Sold under the brand names Mounjaro and Zepbound, tirzepatide is an injectable prescription medication that acts as a dual GIP and GLP-1 receptor agonist, which means it copies two natural gut hormones to manage blood sugar and reduce appetite. 

While experts caution that more research is needed before drawing definitive conclusions, the findings offer hope for millions of people living with both type 2 diabetes and cardiovascular disease, two conditions that frequently occur together and substantially increase the risk of serious health complications.

Sanjeev Kumar Gulati, M.D., executive deputy director of Baptist Health Heart & Vascular Care and the system chief of cardiovascular medicine, says the study reinforces what clinicians have increasingly been seeing with this newer class of medications.

"These findings are encouraging and consistent with the growing amount of evidence suggesting that tirzepatide provides benefits beyond just blood sugar (glucose) control and weight loss," Dr. Gulati says. "What is particularly noteworthy is the observed reduction in major cardiovascular events among patients with type 2 diabetes and established atherosclerotic cardiovascular disease, a population at especially high risk for heart attacks and other adverse outcomes."

Understanding the Study

Researchers analyzed real-world clinical data from two large U.S. health insurance claims databases collected between May 2022 and May 2025. The study included nearly 53,000 adults with type 2 diabetes, a body mass index (BMI) of at least 25, and established cardiovascular disease.

Participants who began treatment with tirzepatide were compared with patients who started sitagliptin, a diabetes medication that has not been shown to affect cardiovascular outcomes. Researchers adjusted for numerous factors, including age, sex, body mass index, existing medical conditions, previous heart problems, and medication use to help make the comparison as balanced as possible.

After one year of follow-up, patients taking tirzepatide experienced a 32 percent relative reduction in major adverse cardiovascular events (MACE)—a combined measure of heart attack, stroke, and death from any cause—compared with those taking sitagliptin.

The study also found:

• A 33 percent lower risk of heart attack among patients taking tirzepatide.
• Lower rates of infections requiring hospitalization.
• Fewer deaths related to infection.
• Lower overall mortality during the study period.

Researchers estimated that for every 70 patients treated with tirzepatide instead of sitagliptin, one major cardiovascular event could potentially be prevented over one year.

Why Heart Health Matters in Diabetes

Heart disease remains the leading cause of illness and death among people with type 2 diabetes. Elevated blood sugar can damage blood vessels over time, while obesity, high blood pressure, abnormal cholesterol levels, and chronic inflammation often occur alongside diabetes, creating a combination of risk factors that significantly increases the likelihood of heart attack and stroke.

For years, diabetes treatment focused primarily on lowering blood glucose. More recently, researchers have recognized that some medications may also improve cardiovascular outcomes—a shift that is changing how physicians approach diabetes care.

The latest findings suggest tirzepatide could become an increasingly important option for patients who have both diabetes and cardiovascular disease.

Why Might Tirzepatide Protect the Heart?

Scientists are still working to understand exactly why tirzepatide appears to reduce cardiovascular risk.

Unlike older diabetes medications that primarily target blood sugar, tirzepatide activates two hormone receptors involved in regulating blood glucose, appetite, and metabolism. The medication often leads to substantial weight loss while also improving several metabolic risk factors associated with heart disease.

Dr. Gulati says the cardiovascular benefits are likely the result of multiple effects working together.

"We are still learning about all of the mechanisms involved; tirzepatide appears to do more than lower blood sugar," he explains. "Its effects on weight reduction, insulin resistance, blood pressure, inflammation, and overall cardiometabolic health likely work together to reduce cardiovascular risk."

He adds that the study raises additional questions about how the medication may work inside blood vessels themselves.

"With relatively short follow-up and early positive benefits, it makes me wonder if the medication has a direct effect on reducing inflammation as well as having direct positive effects on vascular biology," Dr. Gulati explains.

Those possibilities remain under investigation, but researchers believe reducing inflammation may play an important role in preventing plaque buildup and improving blood vessel function.

A Growing Role for GLP-1 Medications

Tirzepatide belongs to a newer generation of medications that has transformed the treatment of type 2 diabetes. In addition to lowering blood sugar, these therapies have demonstrated meaningful benefits for weight management, and researchers continue to explore their impact on multiple organ systems.

As evidence accumulates, physicians are increasingly interested in understanding which patients stand to benefit most from these medications beyond diabetes management alone.

Dr. Gulati says continued research is essential because cardiovascular health represents just one piece of a much larger picture.

"The most important question is how they affect overall health and long-term outcomes," he says. "As evidence continues to emerge regarding heart health, kidney protection, weight management, and other potential benefits, ongoing research will help us optimize care and ensure that the right patients receive the greatest benefit from these therapies."

Future studies may also help determine whether these medications can prevent cardiovascular disease before it develops or whether their greatest benefit remains among people who already have established heart disease.

Important Limitations

Although the findings are encouraging, researchers emphasize that this was an observational study rather than a randomized clinical trial, which remains the gold standard for determining cause and effect.

The study followed patients for only one year, making it difficult to know whether the cardiovascular benefits continue over longer periods. In addition, because the research relied on insurance claims data, some information about medication use and health outcomes may have been incomplete or inaccurately recorded.

The results also may not apply to patients who do not already have established cardiovascular disease or to populations outside the U.S. healthcare system.

An accompanying editorial noted that while the study provides compelling real-world evidence supporting tirzepatide's cardiovascular benefits, it does not answer important questions about long-term mortality, how the medication should be sequenced with other therapies, or which patients are most likely to benefit. Cost, insurance authorization requirements, medication availability, and long-term adherence also remain significant barriers for many patients.

What Comes Next?

For Dr. Gulati, the next phase of research is clear.

"I would like to see longer-term studies that help determine whether the cardiovascular benefits observed with tirzepatide are sustained over many years and whether they extend to broader patient populations, including those without established cardiovascular disease," he says. "Randomized studies will be important for us to have a better understanding of the potential benefits of tirzepatide."

Those studies could help answer whether the medication should become a standard part of cardiovascular risk reduction strategies for certain patients with diabetes.

What Patients Should Know

For people living with type 2 diabetes and heart disease, the new research offers another encouraging sign that treatment options continue to improve. However, experts stress that no single medication replaces a comprehensive approach to cardiovascular health.

Managing blood pressure and cholesterol, maintaining a healthy diet, staying physically active, avoiding tobacco, and taking prescribed medications all remain essential components of reducing cardiovascular risk.

Patients interested in tirzepatide should speak with their healthcare provider to determine whether it is appropriate for their individual medical history, overall health, and treatment goals.