Does Having Diabetes Affect How Well Tirzepatide Works for Heart Failure?
Tirzepatide reduced heart failure events equally in patients with and without type 2 diabetes, despite less weight loss in diabetic patients.
Quick Facts
What This Study Found
Tirzepatide benefits for heart failure were consistent regardless of diabetes status: HR 0.64 with diabetes vs. 0.61 without diabetes.
Key Numbers
- 731 patients randomized; median follow-up 104 weeks
- Overall composite endpoint HR: 0.62 (95% CI 0.41-0.95, p=0.026)
- With diabetes HR: 0.64 (95% CI 0.35-1.15)
- Without diabetes HR: 0.61 (95% CI 0.33-1.10); interaction p=0.95
- Weight loss: 10.4% (diabetes) vs 12.9% (no diabetes); interaction p=0.04
- Similar reductions in left ventricular mass and paracardiac fat in both groups
How They Did This
Pre-specified stratification analysis of the SUMMIT double-blind RCT with 731 patients, median 104-week follow-up.
Why This Research Matters
Since many HFpEF patients have diabetes and diabetes often attenuates weight-loss drug effects, confirming that tirzepatide works equally in both groups is clinically important.
The Bigger Picture
Tirzepatide's heart failure benefits appear to be partly independent of the magnitude of weight loss, suggesting additional cardioprotective mechanisms.
What This Study Doesn't Tell Us
Sub-analysis of a larger trial; not powered for subgroup comparisons. Relatively modest sample size for subgroup analyses.
Questions This Raises
- ?What mechanisms beyond weight loss explain tirzepatide's heart failure benefits?
- ?Should tirzepatide be used for heart failure even without significant obesity?
Trust & Context
- Key Stat:
- 38% Overall reduction in cardiovascular death or worsening heart failure with tirzepatide vs. placebo
- Evidence Grade:
- Pre-specified subgroup analysis of a well-designed RCT. Moderate-to-high evidence quality.
- Study Age:
- Published in 2025 from the SUMMIT trial.
- Original Title:
- Influence of Type 2 Diabetes on the Effects of Tirzepatide in Patients With Heart Failure and a Preserved Ejection Fraction With Obesity: A Prespecified Stratification-Based Analysis.
- Published In:
- Journal of the American College of Cardiology, 86(10), 696-707 (2025)
- Authors:
- Packer, Milton(6), Zile, Michael R(6), Kramer, Christopher M(5), DiMaria, Joseph M, Baum, Seth J, Litwin, Sheldon E, Murakami, Masahiro, Zhou, Chunmei, Ou, Yang, Koeneman, Lisette, Borlaug, Barry A
- Database ID:
- RPEP-12910
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
Does diabetes reduce tirzepatide's heart failure benefits?
No. Despite diabetic patients losing less weight, the reduction in heart failure events was nearly identical to non-diabetic patients.
How long was the study?
Patients were followed for a median of 104 weeks (about 2 years), making it one of the longer heart failure trials with tirzepatide.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-12910APA
Packer, Milton; Zile, Michael R; Kramer, Christopher M; DiMaria, Joseph M; Baum, Seth J; Litwin, Sheldon E; Murakami, Masahiro; Zhou, Chunmei; Ou, Yang; Koeneman, Lisette; Borlaug, Barry A. (2025). Influence of Type 2 Diabetes on the Effects of Tirzepatide in Patients With Heart Failure and a Preserved Ejection Fraction With Obesity: A Prespecified Stratification-Based Analysis.. Journal of the American College of Cardiology, 86(10), 696-707. https://doi.org/10.1016/j.jacc.2025.06.058
MLA
Packer, Milton, et al. "Influence of Type 2 Diabetes on the Effects of Tirzepatide in Patients With Heart Failure and a Preserved Ejection Fraction With Obesity: A Prespecified Stratification-Based Analysis.." Journal of the American College of Cardiology, 2025. https://doi.org/10.1016/j.jacc.2025.06.058
RethinkPeptides
RethinkPeptides Research Database. "Influence of Type 2 Diabetes on the Effects of Tirzepatide i..." RPEP-12910. Retrieved from https://rethinkpeptides.com/research/packer-2025-influence-of-type-2
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.