No-touch versus conventional vein in coronary artery bypass grafting: three year follow-up of multicentre randomised PATENCY trial.
Tian M, Wang X, Feng W, Wang H, Liu S, Liu Z, Chen Y, Miao Q, Su P, Li X, Wang Y, Lu B, Chen K, Zhang C, Hu S
- DOI
- 10.1136/bmj-2024-082883
- Record issued
- 2026-08-15
- Engine
- 7.39.0
- Exported
- 2026-09-22
Prepared by Alpha1. This document is confidential: it is intended for the recipient it was shared with and must not be redistributed. The live record at alpha1science.com/verify/3571ac30-bd38-4fc2-88a3-a046c68d5e82 is authoritative.
How this rating was calculated
- StatisticsStatistic did not reproduce ×2−1★
- IntegrityIntegrity concern−0.5★
- ClaimsEfficacy rests on an unvalidated surrogate endpoint−0.5★
- ReportingData & code availability partially met−0.25★
- The numeric-impossibility checks (GRIM/GRIMMER/DEBIT/SPRITE) did not run: 9 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.
- No data or code availability links were detected to verify.
- 01Printed percentage does not match its own count
99.4% does not match the reported count 2621/2655
“99.4% (2621) attended the three year follow-up visit”
Results ¶1Find in source - 02Printed percentage does not match its own count
86.5% does not match the reported count 2281/2655
“86.5% (2281) received computed tomography angiography”
Results ¶1Find in source - 03Efficacy rests on an unvalidated surrogate endpoint
The primary efficacy claim is based on vein graft occlusion detected by CT angiography, which is a surrogate marker for clinical outcomes. Although the trial also reports reductions in clinical events (myocardial infarction, repeat revascularization), the primary endpoint is graft occlusion. The paper does not provide evidence of target engagement at the tested dose (e.g., PK/PD) nor does it cite validated evidence linking graft occlusion to clinical outcomes, though it mentions that vein graft failure is associated with adverse outcomes. However, the link is not formally validated in the paper.
“The primary outcome for the initial trial was three month vein graft occlusion, as diagnosed by computed tomography (CT) angiography or earlier clinically driven coronary angiography.”
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, well-reported multicentre RCT with rigorous design, clear ethical approvals, and transparent reporting. The main weakness is the vague data availability statement, and there are minor copyediting issues including an internal inconsistency in the reported angina recurrence rate.
Both reviewers agreed on all dimensions and study type (interventional). The statistics verification component recomputed only a subset of tests (6 tests, 4 consistent, 2 inconsistent) and cannot verify all reported statistics; the inconsistency was not specified, so it does not change the pass status but warrants caution. The copyedit pass flagged minor issues, including a potential internal contradiction in the angina recurrence rate.
Numerical inconsistencies
2 findings · worst highValues 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
- 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. 2 reported summary statistics mathematically impossible for the stated N (PERCENT).
- PERCENT99.4% does not match the reported count 2621/2655
“99.4% (2621) attended the three year follow-up visit”
Results ¶1Find in source - PERCENT86.5% does not match the reported count 2281/2655
“86.5% (2281) received computed tomography angiography”
Results ¶1Find in source
- CONSISTENTreported p = .010 · recomputed p = .008Recomputed hazard ratio 0.45 (95% CI 0.25–0.81), reported p=0.01
“hazard ratio 0.45, 95% confidence interval 0.25 to 0.81; P=0.01”
Taken as given: 0.25–0.81 is a two-sided 95% confidence interval for the hazard ratio of 0.45, not a range, an IQR, or a different interval level; the hazard ratio is a RATIO measure, so the interval is symmetric on the log scale; p=0.01 is the p for THIS estimate, not for another comparison in the same sentenceMethod: back the two-tailed p out of the log-scale CI width and compare it against the printed pHow we recomputed it: pCI(0.45, 0.25, 0.81, 1) - CONSISTENTreported p < .001 · recomputed p = <.001Reviewers 1, 2Primary outcome: three-year vein graft occlusion per graft, no-touch vs conventional.
“At the graft level, the occlusion rate of vein graft was 5.7% (114/1988) in the no-touch group and 9.0% (175/1953) in the conventional group.”
Taken as given: The numbers 114 and 175 are the event counts in each group.; The denominators 1988 and 1953 are the total grafts in each group.; The test used is Pearson's chi-square test for 2x2 table.Method: Pearson's chi-square test on the 2x2 table of graft occlusion counts.How we recomputed it: pChi2x2(114, 1988-114, 175, 1953-175) - CONSISTENTreported p = .010 · recomputed p = .007Reviewers 1, 2Secondary outcome: non-fatal myocardial infarction at three years.
“At three years, the incidence of non-fatal myocardial infarction was significantly lower in the no-touch group than the conventional group (1.2% v 2.7%; hazard ratio 0.45, 95% confidence interval 0.25 to 0.81; ARD −1.5%, 95% confidence interval −2.6% to −0.4%; P=0.01).”
Taken as given: The numbers 16 and 35 are the event counts in each group.; The denominators 1325 and 1313 are the total patients in each group.; The test used is Pearson's chi-square test for 2x2 table.Method: Pearson's chi-square test on the 2x2 table of MI counts.How we recomputed it: pChi2x2(16, 1325-16, 35, 1313-35) - CONSISTENTreported p = .030 · recomputed p = .031Reviewer 1Secondary outcome: repeat revascularisation at three years.
“Similarly, the need for repeat revascularisation was lower in the no-touch group than the conventional group (1.1% v 2.2%; 0.51, 0.27 to 0.95; −1.1%, −2.1% to −0.1%; P=0.03).”
Taken as given: The numbers 15 and 29 are the event counts in each group.; The denominators 1325 and 1313 are the total patients in each group.; The test used is Pearson's chi-square test for 2x2 table.Method: Pearson's chi-square test on the 2x2 table of revascularisation counts.How we recomputed it: pChi2x2(15, 1325-15, 29, 1313-29)
- lowinternal contradictionThe recurrence of angina at three years is reported as 8.2% in the Discussion but 8.4% in Table 3 and the Results section.
“The recurrence of angina was also less common in the no-touch group at three years (6.2% v 8.2%)”
DiscussionFind in source
Overstated conclusions
2 findings · worst highConclusions 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
- Conclusions only partially backed by the presented evidenceAssessed
4 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.
- partialReviewers 1, 2The no-touch technique reduces several cardiac events by one third to one half within three years.Non-fatal MI and repeat revascularisation are reduced, but all-cause death and MACCE are not significantly different.Evidence: Non-fatal MI: HR 0.45 (0.25-0.81); repeat revascularisation: HR 0.51 (0.27-0.95); all-cause death: HR 1.15 (0.77-1.74); MACCE: HR 0.89 (0.67-1.19).
“The no-touch technique consistently and robustly reduced the risk of vein graft occlusion and several cardiac events by one third to one half within three years after coronary artery bypass grafting surgery.”
ConclusionFind in source - supportedReviewers 1, 2The no-touch technique reduces vein graft occlusion at three years compared with conventional harvesting.The primary outcome analysis shows a statistically significant reduction with OR 0.62 and CI excluding 1.Evidence: Primary outcome: 5.7% vs 9.0%, OR 0.62 (0.48-0.80), P<0.001.
“At three years, the no-touch group showed a significantly lower vein graft occlusion rate (5.7% v 9.0%, P<0.001) than the conventional group (odds ratio 0.62, 95% confidence interval 0.48 to 0.80)”
AbstractFind in source - supportedReviewer 1The no-touch technique reduces the risk of non-fatal myocardial infarction and repeat revascularisation.Both secondary outcomes show statistically significant reductions with hazard ratios and CIs excluding 1.Evidence: Non-fatal MI: HR 0.45 (0.25-0.81), P=0.01; Repeat revascularisation: HR 0.51 (0.27-0.95), P=0.03.
“At three years, the incidence of non-fatal myocardial infarction was significantly lower in the no-touch group than the conventional group (1.2% v 2.7%; hazard ratio 0.45, 95% confidence interval 0.25 to 0.81; ARD −1.5%, 95% confidence interval −2.6% to −0.4%; P=0.01).”
ResultsFind in source - supportedReviewers 1, 2The no-touch technique ensures sustained graft patency over an extended period.The three-year follow-up shows persistent benefit, supporting sustained patency.Evidence: Occlusion rates at 3 months, 12 months, and 3 years all significantly lower in no-touch group.
“The findings from this extended follow-up study of the PATENCY trial underscore the substantial influence of the no-touch vein harvesting technique on sustained graft patency and clinical outcomes in the medium to long term after CABG surgery.”
DiscussionFind in source
Premise concern: surrogate not validated for clinical benefit.
- INADEQUATESurrogate endpointThe primary efficacy claim is based on vein graft occlusion detected by CT angiography, which is a surrogate marker for clinical outcomes. Although the trial also reports reductions in clinical events (myocardial infarction, repeat revascularization), the primary endpoint is graft occlusion. The paper does not provide evidence of target engagement at the tested dose (e.g., PK/PD) nor does it cite validated evidence linking graft occlusion to clinical outcomes, though it mentions that vein graft failure is associated with adverse outcomes. However, the link is not formally validated in the paper.
“The primary outcome for the initial trial was three month vein graft occlusion, as diagnosed by computed tomography (CT) angiography or earlier clinically driven coronary angiography.”
- ADEQUATEEffect sizeThe effect size is reported as an absolute risk difference of -3.2% (95% CI -5.0% to -1.4%) for vein graft occlusion at three years, with a relative reduction of about 38% (odds ratio 0.62). The paper also reports reductions in clinical events such as myocardial infarction (ARD -1.5%) and repeat revascularization (ARD -1.1%). These effects are statistically significant and are presented as clinically meaningful, with the authors stating that the reductions translate into meaningful clinical benefits.
“The no-touch technique consistently and robustly reduced the risk of vein graft occlusion and several cardiac events by one third to one half within three years after coronary artery bypass grafting surgery.”
Data authenticity concerns
None foundAn 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.
Checked — nothing surfaced.
Reporting gaps
1 finding · worst mediumRequired detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.
- Data/code availability incompleteAssessed
The introduction cites prior small trials and guidelines, explains the biological rationale for the no-touch technique, and identifies gaps in evidence (e.g., extended efficacy and clinical benefit). The limitations of prior studies (small sample sizes, low angiographic follow-up) are explicitly mentioned, and the study aims to address these gaps.
“Previous small trials, mostly with sample sizes less than 300 patients and angiographic follow-up rates lower than 80%, have implied reduced occlusion of saphenous vein grafts harvested using the no-touch approach.”
“This study aims to address the critical gap in evidence regarding the extended efficacy of the no-touch vein harvesting technique in CABG surgery.”
“Previous research on vein graft failure has primarily relied on older observational data, which are prone to confounders and biases.”
“Previous small trials, mostly with sample sizes less than 300 patients and angiographic follow-up rates lower than 80%, have implied reduced occlusion of saphenous vein grafts harvested using the no-touch approach.”
“This study aims to address the critical gap in evidence regarding the extended efficacy of the no-touch vein harvesting technique in CABG surgery.”
Randomization method is described (web-based central system, fixed block size, stratified by centre). Blinding is described for outcome adjudication (central Core Laboratory, unaware of treatment assignments). Power analysis is reported with sample size recalculation. Inclusion/exclusion criteria are pre-specified. Outlier handling is addressed via ITT and mITT analyses with multiple imputation. Controls are inherent in the randomized comparison. Independent replication is not applicable for a single pivotal trial.
“A web based central randomisation system incorporated in the registration system was used for allocation ( https://ccsr.cvs-china.com/ ). The randomisation code with fixed block size was generated by SAS.”
“CT angiography results and clinical outcomes were centrally adjudicated by research personnel who were unaware of the treatment assignments.”
“Using a two sided significance level of 0.05 and aiming for 90% power, the initial calculation indicated that 2000 patients would be required to achieve sufficient statistical power.”
“CT angiography results and clinical outcomes were centrally adjudicated by research personnel who were unaware of the treatment assignments.”
Sex is reported (22% female). Age and health status are reported (mean age 61±8 years, comorbidities). Demographics are reported in Table 1. Species/strain and housing conditions are not applicable for a human trial.
“22% were women.”
“Mean age of participants was 61 years (standard deviation ±8 years)”
“Data are numbers (%) unless stated otherwise. Baseline characteristics are presented for all randomised patients (n=2655).”
“Mean age of participants was 61 years (standard deviation ±8 years) and 22% were women.”
“Table 1 Baseline characteristics of participants”
The protocol was approved by the institutional review board of Fuwai Hospital (2016-827). Written informed consent was obtained from all participants. Compliance with the Declaration of Helsinki and Good Clinical Practice is stated.
“The protocol for PATENCY was reviewed and approved by the independent institutional review board of Fuwai Hospital, Chinese Academy of Medical Science (2016-827).”
“All participants provided written informed consent to participate in the trial.”
“This study was conducted in accordance with the Declaration of Helsinki and Guidelines for Good Clinical Practice.”
“The protocol for PATENCY was reviewed and approved by the independent institutional review board of Fuwai Hospital, Chinese Academy of Medical Science (2016-827).”
“All participants provided written informed consent to participate in the trial.”
“This study was conducted in accordance with the Declaration of Helsinki and Guidelines for Good Clinical Practice.”
The no-touch and conventional techniques are described in detail. Statistical software (SAS 9.4, R 4.0.1) is identified. No antibodies, cell lines, or mycoplasma testing are applicable. The surgical technique is the intervention, not a reagent, but it is adequately described.
“All analyses were performed using SAS 9.4 (SAS Institute, Cary, North Carolina, USA) and R (version 4.0.1, R Foundation for Statistical Computing, Vienna, Austria).”
“In the no-touch technical group, venous adventitia and perivascular tissue were meticulously preserved, and manual distension of the veins was strictly avoided.”
“All analyses were performed using SAS 9.4 (SAS Institute, Cary, North Carolina, USA) and R (version 4.0.1, R Foundation for Statistical Computing, Vienna, Austria).”
Tests are named (t-test, Mann-Whitney, chi-square, GEE, Cox). Assumptions are handled by design (GEE for clustering). Exact p-values are reported. Effect sizes with CIs are reported throughout. Software is identified. Data presentation includes per-group n and CIs. Mathematical plausibility checks were not performed due to large N and continuous outcomes.
“Comparisons across the groups were performed using a two tailed unpaired t test for normally distributed continuous variables and Mann-Whitney for non-normally distributed variables.”
“odds ratio 0.62, 95% confidence interval 0.48 to 0.80”
“Comparisons across the groups were performed using a two tailed unpaired t test for normally distributed continuous variables and Mann-Whitney for non-normally distributed variables. Pearson’s χ 2 test was performed for categorical variables.”
“The no-touch group showed a significantly lower vein graft occlusion rate (5.7% v 9.0%, P<0.001) than the conventional group (odds ratio 0.62, 95% confidence interval 0.48 to 0.80)”
The data availability statement says de-identified data are available from the corresponding author on reasonable request, but does not specify a platform, conditions, or timeframe. This is reported_but_inadequate. No repository deposit or accession numbers are provided. Code sharing is not applicable.
“De-identified participant level and graft level data underlying the results reported in this article, together with the README/”
“De-identified participant level and graft level data underlying the results reported in this article, together with the README/”
Trial registration is provided (NCT03126409). Methods are detailed. Limitations are discussed. Conclusions are proportional. Funding and COI are stated. Reporting guideline (CONSORT) is not explicitly mentioned, but the paper follows it.
“ClinicalTrials.gov NCT03126409”
“Despite the strengths of this study, several limitations should be acknowledged.”
“This study was supported by National High Level Hospital Clinical Research Funding (grant No 2023-GSP-RC-07)”
“Trial registration ClinicalTrials.gov NCT03126409 .”
“Despite the strengths of this study, several limitations should be acknowledged.”
Registered (1 ID: ClinicalTrials.gov). No reporting guideline cited.
Broken references and links
None found · partly checkedReferences 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.
Nothing surfaced — but not everything feeding this category ran (missing: data/code link verification), so read this as a partial clean bill.
Checked 50 references by DOI: 50 verified.
Every extracted reference resolved against Crossref/OpenAlex with no retraction flags.
Copyediting
6 minorWording, consistency and formatting errors that need correcting before submission.
No major wording or formatting errors. 6 minor suggestions below.
6 copyedit issues flagged: mostly typo, consistency, clarity.
- MINORtypoAbstract, Results“absolute risk difference−3.2%”→ Add space: 'absolute risk difference −3.2%'Missing space before minus sign.
- MINORconsistencyDiscussion, Policy implications“6.2% v 8.2%”→ Check if this should be 8.4% to match Table 3.Recurrent angina rate in conventional group is 8.4% in Table 3, but 8.2% here.
- MINORclarityMethods, Statistical analysis“We performed this initial calculation under the assumption of independent samples at the patient and vessel level.”→ Consider rephrasing for clarity: 'We performed this initial calculation assuming independent samples at the patient and vessel level.'Minor grammatical issue.
- MINORtypoAbstract, Results“absolute risk difference−3.2%”→ Add a space: 'absolute risk difference −3.2%'Missing space before the minus sign.
- MINORconsistencyDiscussion, Policy implications“recurrence of angina was also less common in the no-touch group at three years (6.2% v 8.2%)”→ Check the conventional group percentage; elsewhere it is reported as 8.4%.Potential inconsistency with Table 3 which shows 8.4%.
- MINORclarityData availability statement“De-identified participant level and graft level data underlying the results reported in this article, together with the README/”→ Complete the sentence and specify the access mechanism.The statement is truncated and vague.
The published work is robust overall, but an informed reader should weigh the vague data availability statement and the minor internal inconsistency in the reported angina recurrence rate (8.2% vs 8.4%). These are not validity threats but warrant a correction or clarification from the authors.
- 1.HIGHreportingIn the Data availability statement, specify a concrete access mechanism (e.g., a data access committee, a repository like Zenodo, or a managed-access platform) and the conditions/timeframe for requesting data, and complete the truncated sentence.The current statement is vague and truncated, which is a reporting gap that limits reproducibility and transparency.
- 2.HIGHcopyeditIn the Discussion, Policy implications section, correct the recurrent angina rate in the conventional group from 8.2% to 8.4% to match Table 3 and the Results section.The internal inconsistency (8.2% vs 8.4%) is a factual error that could confuse readers and undermine trust in the reported outcomes.
- 3.MEDIUMreportingAdd an explicit statement referencing the CONSORT reporting guideline (e.g., 'This report follows the CONSORT statement') in the Methods or a dedicated section.Explicitly stating adherence to CONSORT improves reporting transparency and is expected for a clinical trial.
- 4.MEDIUMdata codeConsider depositing the statistical analysis code (e.g., SAS and R scripts) in a public repository with a DOI, even if the patient-level data are not publicly available.Sharing analysis code enhances reproducibility and is a low-cost way to strengthen the data/code availability.
- 5.MEDIUMcopyeditIn the Abstract, Results, add a space before the minus sign in 'absolute risk difference−3.2%' to read 'absolute risk difference −3.2%'.The missing space is a minor typographical error that affects readability.
- 6.LOWcopyeditIn the Methods, Statistical analysis, rephrase 'We performed this initial calculation under the assumption of independent samples at the patient and vessel level' to 'We performed this initial calculation assuming independent samples at the patient and vessel level'.The original phrasing is grammatically awkward and can be clarified.
- 7.LOWreportingIn the Discussion, add a brief note on the generalizability of findings to non-Chinese populations, given the single-country setting.This contextualizes the conclusions and addresses a potential limitation for international readers.
The star rating is the report’s one-glance summary. Every paper starts at 5★ and loses stars for the concrete problems the review finds — so a rating is never a vague average, it’s a running total you can read line by line under “How this rating was calculated.”
- Reporting — 8 dimensionseach dimension that fully fails−½★
- each dimension partially met−¼★
- Statistics · Integrity · Claimseach serious problem−1★
- each medium problem−½★
- Citationseach retracted or unverifiable reference−¼★
- Copyeditonly when the manuscript needs a full edit−½★
The rating never drops below 1★, and a demonstrable critical failure (an impossible statistic, a proven ethics violation) caps it at 1★ on its own — so the stars can never look healthy when the verdict is CRITICAL.
The rating draws on a panel of agents. Three independent Kaimen Rigor reviewers grade the eight dimensions below across several independent passes (the shown verdict is their majority vote — steadier than any single run), isolate the paper’s major claims and check its own evidence backs them, and flag integrity concerns. Alongside them, a citation agent resolves every reference against Crossref, OpenAlex, and Retraction Watch; a statistics agent recomputes reported tests; and rule-based checks verify that declared data/code links actually resolve. Full text is required — an abstract-only submission is not analyzed.
Graded against NIH, MDAR, ARRIVE 2.0, CONSORT, EQUATOR, and RRID guidelines. A dimension that doesn’t apply to the study type is skipped, never penalized.
This Kaimen Rigor review is model-assisted and is not a substitute for formal expert review. It complements human evaluation by surfacing potential methodological concerns — verify each finding against the source.