Semaglutide and Tirzepatide Cut Heart Failure Hospitalizations by Over 40%
A large real-world study finds GLP-1 drugs semaglutide and tirzepatide dramatically reduce heart failure hospitalization and death in HFpEF patients.
Summary
A national US claims-data study of over 58,000 patients with cardiometabolic heart failure with preserved ejection fraction (HFpEF) found that both semaglutide and tirzepatide reduced the composite risk of heart failure hospitalization or all-cause mortality by more than 40% compared with sitagliptin, a glucose-lowering drug with no known heart failure benefit. The study emulated two prior clinical trials to validate its methods, then expanded eligibility criteria to reflect real-world clinical practice. Head-to-head comparison showed tirzepatide offered no meaningful additional benefit over semaglutide. Safety profiles were broadly acceptable. These findings extend early small trial results and support GLP-1 receptor agonist use in this high-risk population.
Detailed Summary
Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure in the US and disproportionately affects people with obesity and type 2 diabetes — a phenotype increasingly termed 'cardiometabolic HFpEF.' Despite its prevalence and morbidity, effective treatment options have historically been limited. Early randomized trials of semaglutide (STEP-HFpEF DM) and tirzepatide (SUMMIT) showed symptom improvements, but were underpowered for clinical events like hospitalizations and mortality, leaving treatment guidance uncertain.
This study used US national health care claims data from 2018 to 2024 to conduct five preregistered cohort studies. Researchers first emulated the STEP-HFpEF DM and SUMMIT trials as benchmarks to validate their observational methods, achieving high agreement with trial results across prespecified metrics. They then expanded eligibility criteria to reflect patients seen in routine clinical practice — capturing a broader, more generalizable population with cardiometabolic HFpEF and type 2 diabetes.
The primary endpoint was a composite of hospitalization for heart failure or all-cause mortality over up to 52 weeks of follow-up. Sitagliptin, a dipeptidyl peptidase-4 inhibitor with established glucose-lowering effects but no impact on heart failure outcomes, served as an active placebo comparator. Propensity score weighting was applied to balance a comprehensive set of pretreatment patient characteristics across groups.
Among 58,333 patients in the semaglutide vs. sitagliptin cohort, semaglutide initiators had a 42% lower risk of the primary endpoint (HR 0.58; 95% CI, 0.51–0.65). Among 11,257 patients in the tirzepatide vs. sitagliptin cohort, tirzepatide initiators had a 58% lower risk (HR 0.42; 95% CI, 0.31–0.57). In the head-to-head comparison of 28,100 patients, tirzepatide showed no statistically meaningful benefit over semaglutide (HR 0.86; 95% CI, 0.70–1.06). Negative control outcomes, secondary endpoints, subgroup analyses, and sensitivity analyses all yielded consistent results. No substantially increased risk was observed for prespecified safety endpoints.
These findings are clinically significant because they translate early trial signals into large-scale real-world evidence, supporting the use of both drugs in cardiometabolic HFpEF beyond the narrow trial populations. While tirzepatide's dual GIP/GLP-1 mechanism produces greater weight loss, this did not translate into superior cardiovascular event reduction over the study period. Physicians can likely use either agent with confidence in this setting, guided by tolerability, patient preference, and cost.
Key Findings
- Semaglutide reduced heart failure hospitalization or all-cause mortality by 42% vs. sitagliptin (HR 0.58).
- Tirzepatide reduced the same composite endpoint by 58% vs. sitagliptin (HR 0.42).
- Head-to-head, tirzepatide showed no meaningful advantage over semaglutide (HR 0.86; CI crosses 1.0).
- Trial emulation benchmarking validated observational methods before expanding to broader populations.
- No substantially increased safety risks were identified for either GLP-1 drug in this population.
Methodology
Five preregistered cohort studies used US national health care claims data (2018–2024) with active comparator new-user designs. Trial emulation benchmarking was performed prior to expanded-eligibility analyses. Propensity score weighting adjusted for comprehensive pretreatment covariates; follow-up was up to 52 weeks.
Study Limitations
As an observational study, residual confounding cannot be fully excluded despite propensity score adjustment. The comparator sitagliptin is not a true placebo, and unmeasured differences in disease severity or prescribing patterns may influence results. The 52-week follow-up may be insufficient to detect longer-term divergences between tirzepatide and semaglutide.
Enjoyed this summary?
Get the latest longevity research delivered to your inbox every week.