Weight loss and heart drug shows significant benefit in high-risk people living with obesity
A new analysis from the landmark SUMMIT trial has revealed that tirzepatide, a drug already approved for weight loss and type 2 diabetes, offers significant benefits for people living with obesity, chronic kidney disease (CKD), and heart failure with preserved ejection fraction (HFpEF).
Presented at the American College of Cardiology’s Annual Scientific Session (ACC.25) and published in the Journal of the American College of Cardiology, the study showed that tirzepatide reduced the risk of cardiovascular death or worsening heart failure by 38 per cent after one year, compared with placebo. These benefits were consistent across people both with and without CKD, highlighting the drug’s potential for a particularly high-risk group with a substantial unmet clinical need.
The trial included 731 adults with HFpEF and a body mass index (BMI) of 30 kg/m² or greater. Of these, around 60 per cent were also living with CKD. Participants were randomly assigned to receive either tirzepatide or a placebo, with neither individuals nor clinicians aware of which treatment was being administered.
Alongside the cardiovascular improvements, tirzepatide significantly improved kidney function, as measured by both creatinine and cystatin C levels. These markers were assessed at 12, 24, and 52 weeks, with patients receiving tirzepatide consistently outperforming those on placebo.
Dr Milton Packer, first author of the study and Distinguished Scholar in Cardiovascular Science at Baylor University Medical Center, said: “The interplay of obesity, HFpEF, and CKD defines a population at exceptional risk. Tirzepatide improved outcomes across all three conditions, offering a new therapeutic approach for patients who currently lack effective treatment.”
HFpEF occurs when the heart muscle is unable to expand properly, leading to elevated pressure and impaired cardiac function. CKD, meanwhile, results from the kidneys’ reduced ability to filter waste, contributing to the build-up of toxins. Both conditions frequently overlap with obesity and are known to worsen each other over time.
People taking tirzepatide also reported better quality of life, as measured by the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS), the study’s second primary endpoint. While those with CKD generally experienced more severe symptoms and worse outcomes, they still saw improvements comparable to patients without CKD.
Tirzepatide works by targeting two hormone receptors to reduce body fat and improve metabolic health, easing the strain on both the heart and kidneys. While previous drugs in the same class have shown some kidney benefit, this is the first major trial to evaluate tirzepatide in patients with this combination of serious chronic conditions.
The researchers now plan further analysis to better understand the molecular mechanisms behind these benefits and explore how tirzepatide may reshape future treatment strategies.
The SUMMIT trial was funded by Eli Lilly and Company.