Direct study · 2025

SUMMIT

Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity.

Packer M, Zile MR, Kramer CM, Baum SJ, Litwin SE, Menon V, Ge J, Weerakkody GJ, Ou Y, Bunck MC, Hurt KC, Murakami M, Borlaug BA, SUMMIT Trial Study Group. · The New England journal of medicine

Study record

Population: 731 patients with obesity and heart failure with ejection fraction at least 50%.
Read source · Abstract-level extractionPrimary abstract — Methods and Results
Formulation: Sponsor-supplied tirzepatide or placebo in single-dose autoinjector pens; listed tirzepatide strengths span 2.5–15 mg. This is the registered study preparation, not proof of equivalence to research products or verification of every administered batch.
Read source · Study protocolProtocol I8F-MC-GPID(c), Section 6.1, printed page 57
Route: Subcutaneous injection.
Read source · Abstract-level extractionPrimary abstract — Methods and Results
Dose & frequency: Up to 15 mg once weekly.
Read source · Abstract-level extractionPrimary abstract — Methods and Results
Study design: Double-blind, randomized 1:1 against placebo.
Read source · Abstract-level extractionPrimary abstract — Methods and Results
Duration: At least 52 weeks; median follow-up 104 weeks.
Read source · Abstract-level extractionPrimary abstract — Methods and Results
Reported findings: Cardiovascular death or worsening heart failure: 9.9% versus 15.3%; HR 0.62 (95% CI 0.41–0.95).
Read source · Abstract-level extractionPrimary abstract — Methods and Results
Adverse events: Participants with serious adverse events — Tirzepatide - MTD: 96/364; Placebo: 94/367. Events are not necessarily treatment-caused.
Read source · Registry resultsResults — Adverse Events, Serious Adverse Events summary; Baseline Up To 162 Weeks
Monitoring: Protocol-planned monitoring: Physical and symptom-directed examinations with attention to heart-failure signs; apical heart rate, single 12-lead ECG and laboratory review. Clinically significant abnormalities repeated; investigator assesses management and reports qualifying changes. These planned assessments are not a personal monitoring schedule or proof every assessment occurred. Registry safety reporting and its observation window are cited separately under adverse events.
Read source · Study protocolSection 8.2, printed pages 73–74

What it supports

Addresses SUMMIT outcomes in its specified population and comparison.

What it does not establish

Composite benefit is not proven mortality benefit: cardiovascular deaths were 8 versus 5 (HR 1.58; 95% CI 0.52–4.83). Abstract/registry extraction; unverified full-text details remain flagged.

Funding

Eli Lilly funded the study (primary abstract).

Publication and registry context

The registry agrees on 36/364 versus 56/367 participants with cardiovascular death or worsening heart failure (hazard ratio 0.62), with outcomes assessed up to week 160. Its other primary endpoint, KCCQ clinical summary score at week 52, improved by 19.51 versus 12.68 points in 301 and 313 evaluable participants. A separately reported Hodges–Lehmann median difference of 6.9 points is not the same statistic as the difference between those model-based means. Serious events were 96/364 versus 94/367 through week 162.

Inspect NCT04847557 results

Literature search cutoff: 2026-09-08 · Not independently clinically reviewed

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