Tirzepatide shows broader heart and kidney benefit than dulaglutide in post hoc SURPASS-CVOT analysis

A post hoc analysis of the SURPASS-CVOT trial reports that tirzepatide (sold as Mounjaro and Zepbound) was associated with fewer combined heart and kidney events than dulaglutide in people with diabetes and cardiovascular disease ^[1].

When researchers widened the outcome to a six-part composite — death from any cause, heart attack, stroke, coronary revascularization, hospitalization for heart failure and a composite of adverse kidney events — those events occurred in 23.7 percent of participants taking tirzepatide compared with 27.4 percent of those taking dulaglutide ^[1]. That works out to a number needed to treat of 27, meaning 27 people would need to be treated with tirzepatide instead of dulaglutide to prevent one additional event of this type ^[1].

The analysis reported that each of the six components contributed to the overall difference, and that the kidney composite on its own had a hazard ratio of 0.79 ^[1]. A hazard ratio below 1.0 indicates a lower rate of that event in the tirzepatide group. The findings appear in JAMA Cardiology as a post hoc analysis of a randomized clinical trial; the analysis used a Cox proportional hazards model stratified by whether patients were taking an SGLT-2 inhibitor, and the median follow-up was 4.0 years ^[1].

Two details shape how these numbers should be read. The comparison was against dulaglutide, an existing GLP-1 medicine, rather than a placebo, so the analysis speaks to how two treatments compare with each other rather than to how either compares with no treatment ^[1]. And the six-part endpoint was analyzed after the trial was designed and run, which is what “post hoc” means; that kind of result is not the same as a pre-specified comparison ^[1].

JAMA Cardiology also published an editor's note on the paper, titled “Exploring Additional Cardiorenal Outcomes” ^[1].

Why it matters for patients

For adults with type 2 diabetes and existing cardiovascular disease, the choice among GLP-1 medicines often comes down to factors beyond blood sugar and weight. This analysis suggests the differences between tirzepatide and dulaglutide may extend to a broader set of heart and kidney outcomes over roughly four years of follow-up ^[1]. Kidney outcomes in particular showed a lower rate with tirzepatide in this analysis, with a hazard ratio of 0.79 for the kidney composite ^[1].

The analysis does not report how each individual component performed on its own in statistical terms, so it is not known from this paper which specific outcomes drove the overall result or whether each one was separately significant. Whether the findings apply to people who take these medicines for weight loss without diabetes or established heart disease has not been reported; the trial enrolled people with diabetes and cardiovascular disease ^[1].

Because the wider endpoint was tested after the fact, the results carry less weight than a pre-specified trial result ^[1]. Nothing in this analysis changes what the Food and Drug Administration has approved these medicines for, and no guidance for individual treatment decisions has been issued based on it.

What happens next

The paper is published in JAMA Cardiology alongside an accompanying editor's note ^[1]. No dates have been announced for regulatory review, label changes or guideline updates tied to this analysis, and none has been reported.