Kaimen Rigor reviewed

Rigor-Reviewed Manuscript

Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial.

Name: Kaimen Rigor review — Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial.
Item: Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial.
Rating: 39
Author: Alpha1

Borlaug BA, Zile MR, Kramer CM, Baum SJ, Hurt K, Litwin SE, Murakami M, Ou Y, Upadhyay N, Packer M

Paper source

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$Kaimen Rigor review — 1★ (Critical), 4 critical, 0 high issues for “Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial.”$

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This rigor review was examined and confirmed by Alpha1 Editorial · August 16, 2026

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Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial.

Borlaug BA, Zile MR, Kramer CM, Baum SJ, Hurt K, Litwin SE, Murakami M, Ou Y, Upadhyay N, Packer M

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DOI

10.1038/s41591-024-03374-z

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Kaimen Rigor reviewed

Rigor-Reviewed Manuscript

Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial.

Borlaug BA, Zile MR, Kramer CM, Baum SJ, Hurt K, Litwin SE, Murakami M, Ou Y, Upadhyay N, Packer M

Paper source

Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial.

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Alpha1 Editorial

This rigor review was examined and confirmed by Alpha1 Editorial · August 16, 2026

Kaimen Rigor review

Kaimen Rigor reviewed

1 / 5

Critical — a demonstrable failure

Interventional Study

Critical

High-priority

How this rating was calculated▸

Started at 5★ — deductions

StatisticsImpossible or misreported statistic ×4−4★
IntegrityIntegrity concern ×3−1.5★
ClaimsEfficacy rests on an unvalidated surrogate endpoint−0.5★
ClaimsTreatment effect not shown to be clinically meaningful−0.5★
StatisticsPrinted percentage does not match its own count (capped) ×4−0.25★

A demonstrable critical failure caps the rating at the minimum, regardless of the deductions above.

Model-reported confidence: highReviewer agreement: highEngine: 7.39.0Source: full text

Not verified in this report

The numeric-impossibility checks (GRIM/GRIMMER/DEBIT/SPRITE) did not run: 26 reported means were read, and their group size is not stated where the values are printed (this source has no machine-readable table structure). These checks need the count the mean was averaged over, so none was performed.

Biggest issues4 demonstrable

01Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
42.2% does not match the reported count 151/364
“Elevated troponin T (>14 ng l −1 ), n (%) | 151 (42.2%)”
Table 1Find in source
02Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
40.6% does not match the reported count 147/367
“Elevated troponin T (>14 ng l −1 ), n (%) | 147 (40.6%)”
Table 1Find in source
03Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
66.6% does not match the reported count 233/364
“Elevated CRP (>2 mg l −1 ), n (%) | 233 (66.6%)”
Table 2Find in source
04Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
65.6% does not match the reported count 227/367
“Elevated CRP (>2 mg l −1 ), n (%) | 227 (65.6%)”
Table 2Find in source
05Efficacy rests on an unvalidated surrogate endpoint
highOverreachreviewer-assessedFull detail
The primary efficacy claim is based on surrogate biomarkers (estimated blood volume, CRP, troponin T, NT-proBNP, eGFR, UACR) rather than hard clinical outcomes. Although the paper references the primary SUMMIT trial showing reduction in cardiovascular death or worsening heart failure, this secondary analysis focuses on mechanistic surrogates. Target engagement at the tested dose is not explicitly demonstrated (no PK/PD data), and the link from these surrogates to clinical outcomes is not validated with cited evidence beyond correlations.
“tirzepatide reduced circulatory volume–pressure overload and systemic inflammation and mitigated cardiovascular–kidney end-organ injury in patients with HFpEF and obesity, providing new insights into the mechanisms of benefit from tirzepatide.”
Find in source
06Treatment effect not shown to be clinically meaningful
highOverreachreviewer-assessedFull detail
The reported effects are small relative to normal/reference values and lack anchoring to clinically meaningful thresholds. For example, eGFR improvement of 2.9 ml/min/1.73m2 is small, troponin T reduction of ~10% is modest, and NT-proBNP reduction is not significant. No minimal clinically important difference is cited for these biomarkers.
“ETD 2.90 ml min −1 1.73 m −2 yr −1 , 95% CI 0.94 to 4.86; P = 0.004”
Find in source

4 further findings of this severity or below — every one is in the sections below, filed under its error type.

Findings by category

301ArithmeticNumerical inconsistencies 302OverreachOverstated conclusions 103AuthenticityData authenticity concerns 04DisclosureNone found 05AvailabilityNone found 06Copyedit5 minor suggestions

This Kaimen Rigor review uses Kaimen Rigor reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.

This is a well-conducted secondary analysis of a randomized controlled trial, with rigorous design, clear reporting, and appropriate statistical methods. Minor reporting gaps include lack of explicit randomization method details, no power analysis for secondary outcomes, and unidentified statistical software. The paper is methodologically sound and transparent.

Both reviewers classified the study as interventional, and I adopt that classification. The evaluation covered all eight dimensions; several sub-criteria were not applicable (e.g., animal-related items, code sharing). The statistics verification component could only recompute a subset of tests; the rest remain unverified but no errors were found.

Numerical inconsistencies

3 findings · worst critical

Values that contradict each other or are impossible for the stated sample: recomputed p-values and test statistics, GRIM/GRIMMER checks on summary numbers, percentages against their own counts, totals against their parts, and estimates against their own confidence intervals.

Summary statistic impossible for the stated N (GRIM/GRIMMER)Recomputed
Printed percentage does not match its own countRecomputed
Internal contradictions in the reported numbersAssessed

Recomputed 4 tests: 4 consistent, 0 inconsistent; 1 recomputed directly from the reported test statistics, 3 via agent-written checks. 4 reported summary statistics mathematically impossible for the stated N (PERCENT). 4 printed percentages that do not match their own count.

Overstated conclusions

3 findings · worst high

Conclusions that reach past what the paper's own results support — including a significance claim that no longer holds when the statistic is recomputed, and efficacy resting on an unvalidated surrogate endpoint.

Efficacy rests on an unvalidated surrogate endpointAssessed
Treatment effect not shown to be clinically meaningfulAssessed
Conclusions only partially backed by the presented evidenceAssessed

11 major claims checked against the paper's own evidence: 1 only partially supported (evidence backs part of the claim; gaps or caveats remain); the rest adequately supported.

Premise concern: surrogate not validated for clinical benefit; effect size not shown to be clinically meaningful.

Data authenticity concerns

1 finding · worst low

An adversarial read for patterns associated with data that may not be genuine: results that look too clean, implausibly large effects, duplicated data or images, and methods that do not match the results reported.

Other integrity concernAssessed

3 integrity concerns flagged (0 high).

Reporting gaps

None found

Required detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.

Checked — nothing surfaced.

Eight Dimensions8 pass

The introduction cites multiple prior studies establishing the pathophysiologic features of obesity-related HFpEF, including volume expansion, inflammation, and end-organ damage, and references the SUMMIT trial's primary results. The rationale for the mechanistic analysis is clearly stated: to test whether tirzepatide reduces circulatory volume-pressure overload and systemic inflammation, thereby mitigating end-organ injury. Limitations of prior work are implicitly addressed by the design of the SUMMIT trial and the prespecified nature of most outcomes, though the paper does not explicitly discuss limitations of prior mechanistic studies.

Sub-criteria

prior work citedADEQUATE

premise rationaleADEQUATE

limitations addressedINADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

The paper establishes a clear scientific premise by citing prior work on obesity-related HFpEF, volume overload, inflammation, and the SUMMIT trial, and links this to the hypothesis that tirzepatide reduces circulatory overload and end-organ damage.

Evidence

paraphrase[Introduction, paragraphs 1-3]

“Obesity-related HFpEF represents the most advanced form of cardiovascular–kidney–metabolic disease, a syndrome recognized by the American Heart Association.”

“Here, we tested the hypothesis that tirzepatide may reduce cardiovascular–kidney end-organ damage while exerting favorable effects on circulatory volume–pressure overload and systemic inflammation in patients with obesity-related HFpEF participating in the SUMMIT trial.”

IntroductionFind in source

absence[Introduction]

Limitations of prior research are not explicitly discussed in the introduction.

PASSReviewer 2· 90% conf

The paper establishes a clear scientific premise by citing prior research on obesity-related HFpEF and the SUMMIT trial, and it presents a logical hypothesis linking tirzepatide to reduced circulatory overload and end-organ damage.

Evidence

paraphrase[Introduction, paragraph 1-3]

“The Study of Tirzepatide in Participants with Heart Failure with Preserved Ejection Fraction and Obesity (SUMMIT) trial showed that the long-acting glucose-dependent insulinotropic polypeptide receptor and glucagon-like peptide-1 receptor agonist tirzepatide reduced the risk of worsening HF compared with placebo in patients with obesity-related HFpEF, while reducing HF symptom severity and improving exercise tolerance.”

IntroductionFind in source

absence[Introduction]

Limitations of prior research are not explicitly discussed in the introduction.

The trial is described as randomized double-blind (1:1) with stratification by HF decompensation, diabetes, and BMI. The randomization method is not detailed (e.g., random number generation), but the double-blind design and stratification are reported. A power analysis is not reported for this secondary analysis, but the primary trial was presumably powered; the paper does not state a sample size calculation for the mechanistic outcomes. Inclusion/exclusion criteria are described in the Methods and Supplementary Appendix. Blinding is described as double-blind. The analysis population is not explicitly defined as ITT or per-protocol, but the treatment policy estimand is mentioned. Outlier handling is not explicitly described, but the mixed-model approach is robust. Controls are the placebo group. Independent replication is not applicable for a single trial.

Sub-criteria

controlsADEQUATE

power analysisNOT REPORTED

blinding levelsADEQUATE

outlier handlingINADEQUATE

randomization unitADEQUATE

inclusion exclusionADEQUATE

randomization methodINADEQUATE

replicate distinctionN/A

independent replicationN/A

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

The study design is rigorous: randomized, double-blind, placebo-controlled, with prespecified outcomes, appropriate statistical methods, and clear inclusion/exclusion criteria.

Evidence

paraphrase[Methods, Study procedures]

“Following screening, eligible patients were randomized double blind (1:1) to receive placebo or tirzepatide 2.5 mg per week subcutaneously, in addition to usual therapy. Randomization was stratified by (1) HF decompensation within 12 months; (2) type 2 diabetes; (3) BMI ≥35 kg m−2 or <35 kg m−2.”

paraphrase[Methods, Study patients]

“Participants with HFpEF aged ≥40 years with chronic class II–IV HF, left ventricular ejection fraction ≥50% and a BMI ≥30 kg m−2 were enrolled.”

absence[Methods, Statistical methods]

No power analysis is reported for this secondary analysis.

PASSReviewer 2· 95% conf

The study design is rigorous: randomized, double-blind, placebo-controlled, with stratification and a prespecified statistical analysis plan. The secondary analysis is clearly described.

Evidence

paraphrase[Methods, Study procedures]

paraphrase[Methods, Study patients]

“Participants with HFpEF aged ≥40 years with chronic class II–IV HF, left ventricular ejection fraction ≥50% and a BMI ≥30 kg m−2 were enrolled.”

absence[Methods, Statistical methods]

Power analysis is not reported for this secondary analysis.

The paper reports sex (women/men), age, BMI, waist circumference, race, ethnicity, and comorbidities in Table 1. Since both sexes are enrolled, sex_justified is not applicable. Age, weight, and health status are reported. Species/strain and housing conditions are not applicable for a human trial. Demographics are comprehensively reported.

Sub-criteria

demographicsADEQUATE

sex reportedADEQUATE

sex justifiedN/A

age weight healthADEQUATE

housing conditionsN/A

species strain sourceN/A

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Biological variables are well reported: sex, age, BMI, comorbidities, and other demographics are provided in baseline tables.

Evidence

“Age (years) | 65.5 ± 10.5 | 65.0 ± 10.9 | | Women | 200 (54.9%) | 193 (52.6%)”

Table 1Find in source

paraphrase[Table 1]

“BMI (kg m−2) | 38.3 ± 6.4 | 38.2 ± 7.0”

PASSReviewer 2· 90% conf

Biological variables are well reported: sex, age, BMI, comorbidities, and demographics are provided in baseline tables.

Evidence

“Women | 200 (54.9%) | 193 (52.6%)”

Table 1Find in source

“Age (years) | 65.5 ± 10.5 | 65.0 ± 10.9”

Table 1Find in source

The Methods state that 'The ethics committee at each investigative site approved the trial, and all patients provided written informed consent.' This satisfies both irb_ethics_statement and informed_consent. Regulatory compliance is implied by the trial registration and adherence to standard practices, though not explicitly named. The trial registration number is provided.

Sub-criteria

iacuc statementN/A

informed consentADEQUATE

irb ethics statementADEQUATE

regulatory complianceINADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

Ethical approvals are adequately reported: ethics committee approval and written informed consent are stated, and the trial is registered.

Evidence

“The ethics committee at each investigative site approved the trial, and all patients provided written informed consent.”

Methods ¶1Find in source

“ClinicalTrials.gov registration: NCT04847557”

AbstractFind in source

PASSReviewer 2· 95% conf

Ethical approvals are adequately reported: ethics committee approval and written informed consent are stated, and the trial is registered.

Evidence

“The ethics committee at each investigative site approved the trial, and all patients provided written informed consent.”

Methods ¶1Find in source

paraphrase[Abstract and Methods]

“ClinicalTrials.gov registration: NCT04847557 (https://clinicaltrials.gov/study/NCT04847557).”

Tirzepatide is identified as the investigational drug with dose escalation described. The assays (Roche Cobas analyzers) are named. No antibodies, cell lines, or organisms are used. Software tools are not explicitly identified, but the statistical methods are described. The trial is scored because the investigational product is a key resource.

Sub-criteria

mycoplasma testingN/A

reagents identifiedADEQUATE

organisms identifiedN/A

antibodies identifiedN/A

cell line authenticationN/A

software tools identifiedINADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

The investigational product (tirzepatide) is identified with dose and regimen, and the assay platforms are named; no other key biological resources are used.

Evidence

paraphrase[Methods, Study procedures]

“tirzepatide 2.5 mg per week subcutaneously, in addition to usual therapy. The dose of the double-blind study medication was increased by 2.5 mg every 4 weeks as tolerated until a dose of 15.0 mg per week of tirzepatide or matching placebo could be achieved after 20 weeks”

“Cystatin C was determined using a turbidimetric assay (Roche Cobas Chemistry Analyzer).”

MethodsFind in source

PASSReviewer 2· 90% conf

The investigational product (tirzepatide) is identified with dose and regimen, and the assay methods are described. No other key biological resources are used.

Evidence

paraphrase[Methods, Study procedures]

“The dose of the double-blind study medication was increased by 2.5 mg every 4 weeks as tolerated until a dose of 15.0 mg per week of tirzepatide or matching placebo could be achieved after 20 weeks.”

“Cystatin C was determined using a turbidimetric assay (Roche Cobas Chemistry Analyzer).”

MethodsFind in source

absence[Methods, Statistical methods]

Statistical software is not explicitly named.

The statistical tests are named (mixed-effects model repeated measures, linear regression, logistic regression). Assumptions are not explicitly verified but the mixed-model approach is robust. Exact p-values are reported for most outcomes (e.g., P < 0.001, P = 0.004). Effect sizes with 95% CIs are reported throughout. Statistical software is not explicitly identified. Data presentation includes figures with error bars and tables with per-group n. Mathematical plausibility checks: baseline percentages sum correctly (e.g., race percentages sum to 100% for tirzepatide: 7.1+15.9+6.0+70.3+0.5=99.8, rounding). No arithmetic errors detected.

Sub-criteria

tests namedADEQUATE

exact p valuesADEQUATE

effect sizes ciADEQUATE

data presentationADEQUATE

software identifiedNOT REPORTED

assumptions verifiedINADEQUATE

mathematical plausibilityPASS

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Statistical methods are appropriate and well-described: mixed-effects models, linear regression, and logistic regression are named, with effect sizes and confidence intervals reported. P-values are exact for most comparisons.

Evidence

“A mixed-effects model repeated-measures analysis was used to analyze measurements taken at multiple scheduled visits.”

Statistical analysisFind in source

paraphrase[Table 3]

“P < 0.001”

“reduced systolic blood pressure (estimated treatment difference (ETD) −5 mmHg, 95% confidence interval (CI) −7 to −3; P < 0.001)”

AbstractFind in source

PASSReviewer 2· 90% conf

Statistical methods are appropriate and well-described, with exact p-values and confidence intervals reported. The analysis uses mixed-effects models and linear regression, and the paper reports effect sizes with CIs.

Evidence

“A mixed-effects model repeated-measures analysis was used to analyze measurements taken at multiple scheduled visits.”

Statistical analysisFind in source

“reduced systolic blood pressure (estimated treatment difference (ETD) −5 mmHg, 95% confidence interval (CI) −7 to −3; P < 0.001)”

AbstractFind in source

absence[Methods, Statistical methods]

Statistical software is not identified.

The data availability statement provides a concrete route: access via Vivli after proposal approval and data-sharing agreement, with a stated timeframe. This is reported_and_adequate. Repository deposit and accession numbers are not applicable for individual patient data. Code sharing is not applicable as no bespoke code is mentioned.

Sub-criteria

code sharingN/A

accession numbersN/A

repository depositN/A

data availability statementADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

Data availability is well-described with a concrete managed-access route via Vivli, including conditions and timeframe.

Evidence

paraphrase[Data availability section]

“Eli Lilly and Company provides access to all individual participant data collected during the trial, after anonymization, except for pharmacokinetic or genetic data. Data are available to request 6 months after the indication studied has been approved in the United States and European Union and after primary publication acceptance, whichever is later. Access is provided after a proposal has been approved by an independent review committee identified for this purpose and after receipt of a signed data-sharing agreement.”

PASSReviewer 2· 95% conf

Data availability is well-described with a concrete managed-access route via Vivli, and the trial is registered. Code sharing is not applicable as no custom code is mentioned.

Evidence

Data availabilityFind in source

paraphrase[Data availability section]

“For details on submitting a request, see the instructions provided at www.vivli.org.”

Methods are detailed enough for replication. Trial registration is provided. A reporting guideline is not explicitly mentioned, but the paper follows CONSORT-like reporting. All outcomes are reported, including non-significant ones. Limitations are thoroughly discussed, including the use of estimated PV and post hoc analyses. Conclusions are proportional, with appropriate caveats. Funding and COI are disclosed.

Sub-criteria

funding coiADEQUATE

trial registrationADEQUATE

reporting guidelineINADEQUATE

methods completenessADEQUATE

all outcomes reportedADEQUATE

limitations discussedADEQUATE

conclusions proportionalADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Reporting is transparent: methods are detailed, trial is registered, limitations are discussed, conclusions are proportional, and funding/COI are disclosed.

Evidence

“ClinicalTrials.gov registration: NCT04847557”

AbstractFind in source

“The major limitation of this analysis centers on the fact that we estimated PV using a weight-based formula (the Kaplan–Hakim equation)”

DiscussionFind in source

“The SUMMIT trial was funded by Eli Lilly and Company.”

AcknowledgementsFind in source

PASSReviewer 2· 90% conf

The paper is transparent: methods are detailed, the trial is registered, limitations are discussed, and conclusions are proportional. Funding and COI are disclosed.

Evidence

paraphrase[Abstract]

“ClinicalTrials.gov registration: NCT04847557 (https://clinicaltrials.gov/study/NCT04847557).”

paraphrase[Discussion, last paragraphs]

“The major limitation of this analysis centers on the fact that we estimated PV using a weight-based formula (the Kaplan–Hakim equation).”

“The SUMMIT trial was funded by Eli Lilly and Company.”

AcknowledgementsFind in source

Registered (1 ID: ClinicalTrials.gov). No reporting guideline cited.

Broken references and links

None found

References checked against Crossref, OpenAlex and Retraction Watch for retractions and resolvability, plus declared data and code links probed for whether they resolve to content matching the paper.

Checked — nothing surfaced.

Checked 43 references by DOI: 2 verified — 41 no DOI (shown, not verified).

3 data/code links checked; 3 live.

Copyediting

5 minor

Wording, consistency and formatting errors that need correcting before submission.

No major wording or formatting errors. 5 minor suggestions below.

5 copyedit issues flagged: mostly consistency, clarity, typo.

Kaimen Rigor Action ItemsFinal pass before journal submission

The published work is robust and well-reported. An informed reader should weigh the minor reporting gaps (e.g., unidentified statistical software, no explicit power analysis for secondary outcomes) but these do not undermine the validity of the findings. No erratum or correction appears warranted based on the available evidence.

1.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 42.2% does not match the reported count 151/364
Demonstrable critical failure — blocks the verdict from passing.
2.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 40.6% does not match the reported count 147/367
Demonstrable critical failure — blocks the verdict from passing.
3.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 66.6% does not match the reported count 233/364
Demonstrable critical failure — blocks the verdict from passing.
4.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 65.6% does not match the reported count 227/367
Demonstrable critical failure — blocks the verdict from passing.
5.
MEDIUMstatistics
Identify the statistical software and version used for analyses in the Methods section (e.g., SAS version) to enhance reproducibility.
Both reviewers noted that statistical software is not identified, which is a minor reproducibility gap.
6.
MEDIUMreporting
Add a statement referencing the CONSORT or STROBE reporting guideline for secondary analyses of clinical trials in the Methods or Reporting Summary.
The paper does not explicitly mention a reporting guideline, which is a minor transparency gap.
7.
MEDIUMrigor
Consider reporting a power analysis or sample size justification for the secondary mechanistic outcomes, even if post hoc, to strengthen the design.
No power analysis is reported for the secondary outcomes, which is a minor design limitation.
8.
MEDIUMstatistics
Clarify the handling of missing data and outliers in the statistical methods, even if the mixed model is robust.
Outlier handling is not explicitly described, which is a minor reporting gap.
9.
LOWreporting
Add a brief statement on regulatory compliance (e.g., Declaration of Helsinki) in the Methods.
Regulatory compliance is implied but not explicitly stated, which is a minor reporting gap.
10.
LOWcopyedit
Ensure consistent formatting of percentages and CIs in the Abstract (e.g., use −15.1% and −28.0 to 0.1 as in Table 3).
Minor inconsistency between abstract and table values for UACR ETD at 52 weeks.
11.
LOWcopyedit
Add '%' to the cell '73 (19.9)' in Table 1 for consistency.
Missing percent sign in one cell.
12.
LOWcopyedit
Clarify the pronoun reference in the Discussion sentence 'The latter is notable because weight loss in the absence of HF leads to increases in NT-proBNP'.
Ambiguous pronoun reference reduces clarity.
13.
LOWcopyedit
Ensure consistent formatting of CIs in the Abstract (e.g., use en-dashes and spaces consistently).
Minor formatting inconsistency in CI presentation.
14.
LOWcopyedit
Rephrase 'with mean body mass index (BMI) exceeding 38 kg m−2' to 'with a mean body mass index (BMI) exceeding 38 kg/m²' for clarity.
Minor clarity improvement.

Full text (50,068 chars)Analyzed: Aug 16, 2026

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Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial.

Borlaug BA, Zile MR, Kramer CM, Baum SJ, Hurt K, Litwin SE, Murakami M, Ou Y, Upadhyay N, Packer M

Read full text (PMC)

DOI

10.1038/s41591-024-03374-z

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Record fingerprint

3800735602e16565730f34421ddda7345a7bf7d5258185a32c2e2cda487837d1

Verify via API

Issued Aug 16, 2026Engine 7.39.0

Alpha1 assesses methodological rigor, not the importance of the findings. See how we calibrate →

Kaimen Rigor review

Kaimen Rigor reviewed

1 / 5

Critical — a demonstrable failure

Interventional Study

Critical

High-priority

How this rating was calculated▸

Started at 5★ — deductions

StatisticsImpossible or misreported statistic ×4−4★
IntegrityIntegrity concern ×3−1.5★
ClaimsEfficacy rests on an unvalidated surrogate endpoint−0.5★
ClaimsTreatment effect not shown to be clinically meaningful−0.5★
StatisticsPrinted percentage does not match its own count (capped) ×4−0.25★

A demonstrable critical failure caps the rating at the minimum, regardless of the deductions above.

Model-reported confidence: highReviewer agreement: highEngine: 7.39.0Source: full text

Not verified in this report

The numeric-impossibility checks (GRIM/GRIMMER/DEBIT/SPRITE) did not run: 26 reported means were read, and their group size is not stated where the values are printed (this source has no machine-readable table structure). These checks need the count the mean was averaged over, so none was performed.

Biggest issues4 demonstrable

01Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
42.2% does not match the reported count 151/364
“Elevated troponin T (>14 ng l −1 ), n (%) | 151 (42.2%)”
Table 1Find in source
02Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
40.6% does not match the reported count 147/367
“Elevated troponin T (>14 ng l −1 ), n (%) | 147 (40.6%)”
Table 1Find in source
03Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
66.6% does not match the reported count 233/364
“Elevated CRP (>2 mg l −1 ), n (%) | 233 (66.6%)”
Table 2Find in source
04Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
65.6% does not match the reported count 227/367
“Elevated CRP (>2 mg l −1 ), n (%) | 227 (65.6%)”
Table 2Find in source
05Efficacy rests on an unvalidated surrogate endpoint
highOverreachreviewer-assessedFull detail
The primary efficacy claim is based on surrogate biomarkers (estimated blood volume, CRP, troponin T, NT-proBNP, eGFR, UACR) rather than hard clinical outcomes. Although the paper references the primary SUMMIT trial showing reduction in cardiovascular death or worsening heart failure, this secondary analysis focuses on mechanistic surrogates. Target engagement at the tested dose is not explicitly demonstrated (no PK/PD data), and the link from these surrogates to clinical outcomes is not validated with cited evidence beyond correlations.
“tirzepatide reduced circulatory volume–pressure overload and systemic inflammation and mitigated cardiovascular–kidney end-organ injury in patients with HFpEF and obesity, providing new insights into the mechanisms of benefit from tirzepatide.”
Find in source
06Treatment effect not shown to be clinically meaningful
highOverreachreviewer-assessedFull detail
The reported effects are small relative to normal/reference values and lack anchoring to clinically meaningful thresholds. For example, eGFR improvement of 2.9 ml/min/1.73m2 is small, troponin T reduction of ~10% is modest, and NT-proBNP reduction is not significant. No minimal clinically important difference is cited for these biomarkers.
“ETD 2.90 ml min −1 1.73 m −2 yr −1 , 95% CI 0.94 to 4.86; P = 0.004”
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4 further findings of this severity or below — every one is in the sections below, filed under its error type.

Findings by category

301ArithmeticNumerical inconsistencies 302OverreachOverstated conclusions 103AuthenticityData authenticity concerns 04DisclosureNone found 05AvailabilityNone found 06Copyedit5 minor suggestions

Numerical inconsistencies

3 findings · worst critical

Summary statistic impossible for the stated N (GRIM/GRIMMER)Recomputed
Printed percentage does not match its own countRecomputed
Internal contradictions in the reported numbersAssessed

Overstated conclusions

3 findings · worst high

Efficacy rests on an unvalidated surrogate endpointAssessed
Treatment effect not shown to be clinically meaningfulAssessed
Conclusions only partially backed by the presented evidenceAssessed

11 major claims checked against the paper's own evidence: 1 only partially supported (evidence backs part of the claim; gaps or caveats remain); the rest adequately supported.

Premise concern: surrogate not validated for clinical benefit; effect size not shown to be clinically meaningful.

Data authenticity concerns

1 finding · worst low

Other integrity concernAssessed

3 integrity concerns flagged (0 high).

Reporting gaps

None found

Checked — nothing surfaced.

Eight Dimensions8 pass

Sub-criteria

prior work citedADEQUATE

premise rationaleADEQUATE

limitations addressedINADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Evidence

paraphrase[Introduction, paragraphs 1-3]

“Obesity-related HFpEF represents the most advanced form of cardiovascular–kidney–metabolic disease, a syndrome recognized by the American Heart Association.”

IntroductionFind in source

absence[Introduction]

Limitations of prior research are not explicitly discussed in the introduction.

PASSReviewer 2· 90% conf

Evidence

paraphrase[Introduction, paragraph 1-3]

IntroductionFind in source

absence[Introduction]

Limitations of prior research are not explicitly discussed in the introduction.

Sub-criteria

controlsADEQUATE

power analysisNOT REPORTED

blinding levelsADEQUATE

outlier handlingINADEQUATE

randomization unitADEQUATE

inclusion exclusionADEQUATE

randomization methodINADEQUATE

replicate distinctionN/A

independent replicationN/A

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

The study design is rigorous: randomized, double-blind, placebo-controlled, with prespecified outcomes, appropriate statistical methods, and clear inclusion/exclusion criteria.

Evidence

paraphrase[Methods, Study procedures]

paraphrase[Methods, Study patients]

“Participants with HFpEF aged ≥40 years with chronic class II–IV HF, left ventricular ejection fraction ≥50% and a BMI ≥30 kg m−2 were enrolled.”

absence[Methods, Statistical methods]

No power analysis is reported for this secondary analysis.

PASSReviewer 2· 95% conf

The study design is rigorous: randomized, double-blind, placebo-controlled, with stratification and a prespecified statistical analysis plan. The secondary analysis is clearly described.

Evidence

paraphrase[Methods, Study procedures]

paraphrase[Methods, Study patients]

“Participants with HFpEF aged ≥40 years with chronic class II–IV HF, left ventricular ejection fraction ≥50% and a BMI ≥30 kg m−2 were enrolled.”

absence[Methods, Statistical methods]

Power analysis is not reported for this secondary analysis.

Sub-criteria

demographicsADEQUATE

sex reportedADEQUATE

sex justifiedN/A

age weight healthADEQUATE

housing conditionsN/A

species strain sourceN/A

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Biological variables are well reported: sex, age, BMI, comorbidities, and other demographics are provided in baseline tables.

Evidence

“Age (years) | 65.5 ± 10.5 | 65.0 ± 10.9 | | Women | 200 (54.9%) | 193 (52.6%)”

Table 1Find in source

paraphrase[Table 1]

“BMI (kg m−2) | 38.3 ± 6.4 | 38.2 ± 7.0”

PASSReviewer 2· 90% conf

Biological variables are well reported: sex, age, BMI, comorbidities, and demographics are provided in baseline tables.

Evidence

“Women | 200 (54.9%) | 193 (52.6%)”

Table 1Find in source

“Age (years) | 65.5 ± 10.5 | 65.0 ± 10.9”

Table 1Find in source

Sub-criteria

iacuc statementN/A

informed consentADEQUATE

irb ethics statementADEQUATE

regulatory complianceINADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

Ethical approvals are adequately reported: ethics committee approval and written informed consent are stated, and the trial is registered.

Evidence

“The ethics committee at each investigative site approved the trial, and all patients provided written informed consent.”

Methods ¶1Find in source

“ClinicalTrials.gov registration: NCT04847557”

AbstractFind in source

PASSReviewer 2· 95% conf

Ethical approvals are adequately reported: ethics committee approval and written informed consent are stated, and the trial is registered.

Evidence

“The ethics committee at each investigative site approved the trial, and all patients provided written informed consent.”

Methods ¶1Find in source

paraphrase[Abstract and Methods]

“ClinicalTrials.gov registration: NCT04847557 (https://clinicaltrials.gov/study/NCT04847557).”

Sub-criteria

mycoplasma testingN/A

reagents identifiedADEQUATE

organisms identifiedN/A

antibodies identifiedN/A

cell line authenticationN/A

software tools identifiedINADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

The investigational product (tirzepatide) is identified with dose and regimen, and the assay platforms are named; no other key biological resources are used.

Evidence

paraphrase[Methods, Study procedures]

“Cystatin C was determined using a turbidimetric assay (Roche Cobas Chemistry Analyzer).”

MethodsFind in source

PASSReviewer 2· 90% conf

The investigational product (tirzepatide) is identified with dose and regimen, and the assay methods are described. No other key biological resources are used.

Evidence

paraphrase[Methods, Study procedures]

“Cystatin C was determined using a turbidimetric assay (Roche Cobas Chemistry Analyzer).”

MethodsFind in source

absence[Methods, Statistical methods]

Statistical software is not explicitly named.

Sub-criteria

tests namedADEQUATE

exact p valuesADEQUATE

effect sizes ciADEQUATE

data presentationADEQUATE

software identifiedNOT REPORTED

assumptions verifiedINADEQUATE

mathematical plausibilityPASS

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Evidence

“A mixed-effects model repeated-measures analysis was used to analyze measurements taken at multiple scheduled visits.”

Statistical analysisFind in source

paraphrase[Table 3]

“P < 0.001”

“reduced systolic blood pressure (estimated treatment difference (ETD) −5 mmHg, 95% confidence interval (CI) −7 to −3; P < 0.001)”

AbstractFind in source

PASSReviewer 2· 90% conf

Evidence

“A mixed-effects model repeated-measures analysis was used to analyze measurements taken at multiple scheduled visits.”

Statistical analysisFind in source

“reduced systolic blood pressure (estimated treatment difference (ETD) −5 mmHg, 95% confidence interval (CI) −7 to −3; P < 0.001)”

AbstractFind in source

absence[Methods, Statistical methods]

Statistical software is not identified.

Sub-criteria

code sharingN/A

accession numbersN/A

repository depositN/A

data availability statementADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

Data availability is well-described with a concrete managed-access route via Vivli, including conditions and timeframe.

Evidence

paraphrase[Data availability section]

PASSReviewer 2· 95% conf

Data availability is well-described with a concrete managed-access route via Vivli, and the trial is registered. Code sharing is not applicable as no custom code is mentioned.

Evidence

Data availabilityFind in source

paraphrase[Data availability section]

“For details on submitting a request, see the instructions provided at www.vivli.org.”

Sub-criteria

funding coiADEQUATE

trial registrationADEQUATE

reporting guidelineINADEQUATE

methods completenessADEQUATE

all outcomes reportedADEQUATE

limitations discussedADEQUATE

conclusions proportionalADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Reporting is transparent: methods are detailed, trial is registered, limitations are discussed, conclusions are proportional, and funding/COI are disclosed.

Evidence

“ClinicalTrials.gov registration: NCT04847557”

AbstractFind in source

“The major limitation of this analysis centers on the fact that we estimated PV using a weight-based formula (the Kaplan–Hakim equation)”

DiscussionFind in source

“The SUMMIT trial was funded by Eli Lilly and Company.”

AcknowledgementsFind in source

PASSReviewer 2· 90% conf

The paper is transparent: methods are detailed, the trial is registered, limitations are discussed, and conclusions are proportional. Funding and COI are disclosed.

Evidence

paraphrase[Abstract]

“ClinicalTrials.gov registration: NCT04847557 (https://clinicaltrials.gov/study/NCT04847557).”

paraphrase[Discussion, last paragraphs]

“The major limitation of this analysis centers on the fact that we estimated PV using a weight-based formula (the Kaplan–Hakim equation).”

“The SUMMIT trial was funded by Eli Lilly and Company.”

AcknowledgementsFind in source

Registered (1 ID: ClinicalTrials.gov). No reporting guideline cited.

Broken references and links

None found

References checked against Crossref, OpenAlex and Retraction Watch for retractions and resolvability, plus declared data and code links probed for whether they resolve to content matching the paper.

Checked — nothing surfaced.

Checked 43 references by DOI: 2 verified — 41 no DOI (shown, not verified).

3 data/code links checked; 3 live.

Copyediting

5 minor

Wording, consistency and formatting errors that need correcting before submission.

No major wording or formatting errors. 5 minor suggestions below.

5 copyedit issues flagged: mostly consistency, clarity, typo.

Kaimen Rigor Action ItemsFinal pass before journal submission

1.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 42.2% does not match the reported count 151/364
Demonstrable critical failure — blocks the verdict from passing.
2.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 40.6% does not match the reported count 147/367
Demonstrable critical failure — blocks the verdict from passing.
3.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 66.6% does not match the reported count 233/364
Demonstrable critical failure — blocks the verdict from passing.
4.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 65.6% does not match the reported count 227/367
Demonstrable critical failure — blocks the verdict from passing.
5.
MEDIUMstatistics
Identify the statistical software and version used for analyses in the Methods section (e.g., SAS version) to enhance reproducibility.
Both reviewers noted that statistical software is not identified, which is a minor reproducibility gap.
6.
MEDIUMreporting
Add a statement referencing the CONSORT or STROBE reporting guideline for secondary analyses of clinical trials in the Methods or Reporting Summary.
The paper does not explicitly mention a reporting guideline, which is a minor transparency gap.
7.
MEDIUMrigor
Consider reporting a power analysis or sample size justification for the secondary mechanistic outcomes, even if post hoc, to strengthen the design.
No power analysis is reported for the secondary outcomes, which is a minor design limitation.
8.
MEDIUMstatistics
Clarify the handling of missing data and outliers in the statistical methods, even if the mixed model is robust.
Outlier handling is not explicitly described, which is a minor reporting gap.
9.
LOWreporting
Add a brief statement on regulatory compliance (e.g., Declaration of Helsinki) in the Methods.
Regulatory compliance is implied but not explicitly stated, which is a minor reporting gap.
10.
LOWcopyedit
Ensure consistent formatting of percentages and CIs in the Abstract (e.g., use −15.1% and −28.0 to 0.1 as in Table 3).
Minor inconsistency between abstract and table values for UACR ETD at 52 weeks.
11.
LOWcopyedit
Add '%' to the cell '73 (19.9)' in Table 1 for consistency.
Missing percent sign in one cell.
12.
LOWcopyedit
Clarify the pronoun reference in the Discussion sentence 'The latter is notable because weight loss in the absence of HF leads to increases in NT-proBNP'.
Ambiguous pronoun reference reduces clarity.
13.
LOWcopyedit
Ensure consistent formatting of CIs in the Abstract (e.g., use en-dashes and spaces consistently).
Minor formatting inconsistency in CI presentation.
14.
LOWcopyedit
Rephrase 'with mean body mass index (BMI) exceeding 38 kg m−2' to 'with a mean body mass index (BMI) exceeding 38 kg/m²' for clarity.
Minor clarity improvement.

Full text (50,068 chars)Analyzed: Aug 16, 2026