Trial review
SUMMIT Trial: Tirzepatide and HFpEF
Tirzepatide in heart failure with preserved ejection fraction and obesity
Direct answer
SUMMIT was a phase 3, randomised, double-blind, parallel-group, placebo-controlled, multicentre funded by Eli Lilly and Company. A 38% reduction in the combined endpoint of cardiovascular death and worsening heart-failure events, with improvement in symptoms, physical limitations and exercise capacity.
SUMMIT at a glanceVerified
| Design | Phase 3, randomised, double-blind, parallel-group, placebo-controlled, multicentre |
|---|---|
| Population | Adults with heart failure with preserved ejection fraction and obesity (BMI 30 or above), with or without type 2 diabetes |
| Sample size | 731 randomised 1:1 |
| Intervention | Tirzepatide once weekly at maximum tolerated dose |
| Comparator | Placebo |
| Duration | 52 weeks to the symptom endpoint, with event follow-up |
| Primary endpoint | Co-primary: time to first occurrence of a heart-failure outcome, and change in heart-failure symptoms and physical limitations at 52 weeks |
| Main result | A 38% reduction in the combined endpoint of cardiovascular death and worsening heart-failure events, with improvement in symptoms, physical limitations and exercise capacity |
NCT NCT04847557Last source check: 2026-08-03
Show this figure as a table
| Step | Stage | What happens |
|---|---|---|
| 1 | Who was eligible | Adults with heart failure with preserved ejection fraction and obesity (BMI 30 or above), with or without type 2 diabetes |
| 2 | What they received | Tirzepatide once weekly at maximum tolerated dose |
| 3 | What it was compared against | Placebo |
| 4 | For how long | 52 weeks to the symptom endpoint, with event follow-up |
| 5 | What was measured first | Co-primary: time to first occurrence of a heart-failure outcome, and change in heart-failure symptoms and physical limitations at 52 weeks |
| 6 | What the group average was | A 38% reduction in the combined endpoint of cardiovascular death and worsening heart-failure events, with improvement in symptoms, physical limitations and exercise capacity |
| 7 | What it does not tell you | A group average is not a prediction for any individual reader. |
Strip any step and the result stops meaning what the trial found.
Show this figure as a table
| Item | Weight change | Evidence |
|---|---|---|
| Intervention group | not captured | — |
| Comparator group | not captured | — |
Bars fill only from the peer-reviewed publication. Topline and press-release figures are labelled as such and are never charted as results.
| Question | Position |
|---|---|
| Average effect in the studied population | Reported once captured |
| Your individual outcome | Not predicted by any trial |
| Effect of a compounded preparation | Not studied here |
| Effect at doses outside the protocol | Not studied here |
| Effect after stopping | Only if the trial included a withdrawal phase |
| Long-term safety beyond the trial | Outside the observation window |
Who was studied
342 words
- Inclusion and exclusion criteria in plain language. Say who was not studied — that is usually the more useful half.
What was given, and what it was compared against
342 words
- Dose, titration schedule, comparator, and whether the comparator was placebo or an active drug.
Results
342 words
- Primary endpoint first, with absolute numbers alongside percentages. Secondary endpoints labelled as secondary.
Adverse events and discontinuations
342 words
- Never omitted for length. Report discontinuation rates alongside efficacy.
Limitations
342 words
- Funding, blinding, dropout handling, generalisability, duration.
How this should and should not be read
342 words
- Explicitly address the misreadings this trial commonly attracts.
How it compares with other trials
342 words
- Only where designs are comparable. Say so when they are not.
Frequently asked questions
Does this mean I would lose that much weight?
No. Trials report group averages under controlled conditions with specific eligibility criteria. Individual results vary widely, and the trial population may not resemble you.
Do these results apply to compounded tirzepatide?
Not automatically. Trials studied the approved product at studied doses. A compounded preparation at a different concentration, formulation or route has not been through those trials.
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Cite this pageCC BY 4.0
GLP-1 Tirzepatide Rank. “SUMMIT Trial: Tirzepatide and HFpEF.” S.J Partners LLC, 2026-08-03. https://glp1tirzepatiderank.com/research/summit-hfpef/
Quote the capture date beside a figure, not the date you read this page. Why.