Comparison of Bidirectional Palpation Test and Transit Time Flow Measurement for LIMA-LAD Graft Patency: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparison of Bidirectional Palpation Test and Transit Time Flow Measurement for LIMA-LAD Graft Patency (NCT06934993), a registered phase not stated study. The primary outcome is Reliability of Bidirectional Palpation Test (BPT) in Evaluating LIMA-LAD Graft Patency.

2. Clinical Question

The clinical focus is the LIMA-LAD anastomosis, which the registry description identifies as an important CABG graft because it supplies a large region of the heart and is considered the gold standard for CABG. The study addresses whether an intraoperative palpation finding corresponds to later imaging evidence of patency. This is an assessment question, not a randomized comparison of treatment strategies.

3. Trial Design

The registry describes a completed study of elective coronary artery bypass grafting in patients with LIMA-to-LAD grafts. The cohort description says participants underwent intraoperative assessment with both transit time flow measurement and bidirectional palpation, followed by early postoperative CTA imaging. The primary endpoint timeframe is the postoperative first month. The registry lists a start date of 2023-08-31, a primary completion date of 2024-08-27, and a completed status.

The primary outcome is titled as reliability of BPT in evaluating LIMA-LAD graft patency. According to its description, participants were classified intraoperatively as BPT-positive or BPT-negative. Positive findings were treated as indicating a patent graft, while negative findings were treated as indicating an occluded graft. Early postoperative CCTA was then used to assess patency and compare with the BPT classification.

This is not described as a randomized comparison. The registry record does not state an allocation method, and the cohort description does not identify a separate control group. Rather, BPT and TTFM are intraoperative assessments compared with one another or with the later imaging assessment. The registry does not report whether assessors were blinded, the timing details beyond the stated early postoperative period, or the precise analytic methods used for the comparisons.

The registry lists 116 participants enrolled, but the primary-outcome population description refers to 73 patients. It does not explain the difference, including whether it reflects eligibility, availability of imaging, exclusions, or missing outcome data. The record lists four outcome measures and nine analyses, but the detailed numerical results for the primary and secondary questions are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: Patients were excluded for reasons such as refusing to participate postoperatively, death in the early postoperative period , or conditions like elevated postoperative creatinine that precluded CTCA.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The number of patients with graft occlusion among 73 patients who participated in the study was examined. Then, BPT negativity in patients with graft occlusion and BPT positivity in patients with patent grafts were evaluated.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Reliability of Bidirectional Palpation Test (BPT) in Evaluating LIMA-LAD Graft Patency, measured over Postoperative first month..

The primary endpoint concerns the reliability of the bidirectional palpation test for identifying LIMA-LAD graft patency. Intraoperatively, each participant was categorized as BPT-positive or BPT-negative. The endpoint description treats a positive test as indicating a patent graft and a negative test as indicating an occluded graft. CCTA performed in the early postoperative period was used to assess graft status and compare with those intraoperative classifications.

The primary measure is expressed as a count of participants, and the population description specifies 73 patients. It frames the assessment around graft occlusion and whether BPT findings correspond to graft status on CCTA. The record does not report the count of occlusions, the number of positive or negative BPT results, or the number of CCTA-confirmed patent or occluded grafts. It also does not report a numerical agreement estimate, sensitivity, specificity, predictive values, or confidence intervals.

Comparing an operative assessment with a later imaging assessment is intended to evaluate whether the operative finding tracks the reference assessment of patency. In general, agreement describes how often two classifications match; it does not by itself establish that either assessment causes a clinical outcome. The registry calls CCTA a validated method for assessing graft patency, but detailed information about its interpretation or adjudication is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a binary classification question: BPT findings are positive or negative, and graft status is assessed by early postoperative CCTA. The intended comparison is between the intraoperative classification and imaging assessment. The record does not report the numerical results or identify the statistical procedures used, so the methods below explain how such analyses are generally interpreted rather than asserting which procedures this study used.

What does agreement mean for two classifications?

For two binary assessments, agreement means that the assessments assign the same status to a graft; disagreement means that they assign different statuses. A cross-classification of the BPT and CCTA findings would show the counts in each combination. Those counts are useful because a single overall agreement figure can obscure whether disagreements mostly involve BPT-positive findings with CCTA evidence of occlusion, or BPT-negative findings with CCTA evidence of patency.

Agreement and association are related but not identical concepts. An association measure describes whether results tend to vary together. Agreement asks whether the two assessments give the same classification. Two assessments may be associated while still disagreeing often enough for the distinction to matter. The registry’s primary endpoint uses the word reliability, and its secondary outcome list refers to correlation between TTFM and BPT results. The specific definitions and measures used for reliability or correlation are not reported in the registry record.

How would diagnostic performance be described?

In general, if CCTA is treated as the reference assessment, sensitivity describes how often the test under evaluation is positive among cases classified as having the condition by the reference. Specificity describes how often the test is negative among cases classified as not having the condition. Predictive values instead describe the reference status among positive or negative test results. These measures answer different questions and can be affected by how common the condition is in the assessed population. The registry describes CCTA as a validated method, but it does not report sensitivity, specificity, predictive values, or an explicit statistical definition of BPT reliability.

A measure of agreement may also be reported with a confidence interval. In general, the estimate gives a summary of observed agreement under the selected method, while the interval conveys uncertainty around that estimate. The width of an interval depends on the amount and pattern of available information, as well as the method used. Neither an estimate nor a confidence interval for the primary comparison is reported in the registry record. A p-value alone, if one were available, would not communicate the size or practical importance of agreement and would not replace an interval estimate.

What do TTFM and the risk-score analyses address?

The registry lists a secondary outcome concerning correlation between intraoperative TTFM and BPT results. Correlation can indicate whether two measures tend to change together, but it does not by itself establish that their values are interchangeable or that either one correctly identifies patency. The TTFM variables, correlation measure, handling of any non-binary values, and numerical results are not reported in the registry record.

Another secondary outcome concerns the relationship between SYNTAX 1 and SYNTAX 2 risk scores and LIMA-LAD graft patency. This describes an association question, not a causal effect. The registry does not report the score distributions, analysis model, effect estimates, or uncertainty for these analyses. If several analyses are performed, selective emphasis on the most favorable finding can make results appear more compelling than the full set warrants; whether and how that issue was addressed is not reported in the registry record.

What should be made of planning calculations?

The stated planning illustration uses a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The record explicitly characterizes this as a planning illustration based on the observed effect, not the trial’s own design. Such calculations describe hypothetical participant requirements under chosen assumptions. They are not observed power and do not establish the precision or credibility of the reported study results.

For this study, the listed design is not a randomized two-arm comparison, and no allocation method is stated. Accordingly, an equal-allocation illustration should not be read as a description of how participants were enrolled or analyzed. The number of planning participants for any effect fraction is not reported in the registry record. The statistical analysis plan, any prespecified model, handling of repeated or correlated measurements, and approach to missing observations are also not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures and nine analyses. Those counts indicate that multiple questions or analyses were recorded, but they do not reveal how the analyses were prioritized or whether the statistical plan accounted for multiple testing. The primary question concerns BPT reliability against CCTA; the listed secondary questions include correlation between TTFM and BPT and relationships between SYNTAX scores and graft patency. The registry record does not report a multiplicity adjustment, a hierarchy of hypotheses, or which analyses were prespecified.

When many statistical tests are conducted, the chance of finding at least one apparently notable result by chance can increase. In general, adjustment procedures or a prespecified testing hierarchy can help control that risk, though they may alter interpretation or precision. Whether any such approach was used is not reported in the registry record. Because numerical results and p-values are also not reported, no conclusion about statistical significance across the analyses is possible.

The registry lists enrollment of 116, while the primary-outcome population description refers to 73 patients. The reason for this difference, the availability of BPT, TTFM, and CCTA measurements, and the extent or handling of missing data are not reported in the registry record. The record also does not state whether the analysis included all enrolled participants, only participants with complete measurements, or another analysis population. No imputation method or sensitivity analysis is reported. These omissions limit assessment of selection and missing-data effects.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The adverse-event information lists 0 serious adverse events among 116 participants at risk and 11 other adverse events among 116 participants at risk. It separately lists 3 deaths. These are registry counts and should be kept distinct: the record does not state that deaths are included in either adverse-event category, nor does it give a cause or provide a relationship to the study assessments.

The timeframe for these safety counts, event definitions, severity criteria, and attribution procedures are not reported in the registry record. The record also does not provide event-level descriptions or say whether the listed counts refer to unique participants or event episodes. The counts therefore cannot be used to infer the timing, cause, preventability, or relationship of events to any procedure or assessment.

A count of 0 serious adverse events in the registry entry should be read as the recorded count, not as proof that the underlying risk is absent. More generally, event counts are interpreted in light of their definitions, follow-up period, completeness of reporting, and the population observed. Those details are not available in the registry record, so the safety figures should be treated as descriptive registry entries rather than comparative estimates.

12. What the Result Does, and Does Not, Mean

The study addresses whether a simple, subjective intraoperative palpation assessment corresponds to early postoperative imaging of LIMA-LAD graft patency. It also records the use of TTFM and planned comparisons involving TTFM, BPT, and SYNTAX risk scores. This makes the registry question relevant to the evaluation of operative assessment methods, but the record’s rationale and methods description do not substitute for outcome data.

The registry record does not report the primary outcome counts or any estimate of BPT reliability. It does not provide the number of patent or occluded grafts according to CCTA, the distribution of positive and negative BPT findings, the frequency of disagreement, or a precision estimate. Consequently, the posted information does not establish how closely BPT findings matched CCTA in this cohort. It also does not allow a quantitative comparison of BPT and TTFM.

Even a reported match between two tests would have a specific interpretation: it would describe correspondence in the assessed setting and population. It would not, by itself, prove that either test improves outcomes, that the assessments can be substituted for one another, or that the results apply to other settings. This study is not described as randomized, and it does not assign participants to competing interventions. No causal treatment-effect claim follows from the stated design.

The difference between the enrollment count of 116 and the primary population description of 73 is not explained. Without the relationship between those populations, and without information about missing measurements or exclusions, it is not possible to assess how representative the primary-outcome population is of everyone enrolled. The record also does not report the statistical analysis plan, numerical results, or multiplicity procedures. The appropriate conclusion is therefore limited to the question the study set out to address; its empirical answer is not reported in the registry record.

13. Why This Trial Matters Statistically

This study raises a statistical question about the relationship between an intraoperative assessment and a later imaging assessment of graft patency. Such questions require attention not only to whether results are associated, but also to the structure of agreement and disagreement. The distinction matters because a single summary measure can conceal whether one kind of classification error is more common than another.

The BPT is described as subjective, while CCTA is described as a validated method for assessing patency. Comparing the assessments therefore calls for transparent definitions of the test categories, the reference classification, and the analysis population. The registry supplies a broad description of the comparison but does not report the underlying classification counts, numerical estimates, or uncertainty. Those omissions prevent evaluation of how much information the comparison contributes.

The population descriptions also matter. Enrollment is listed as 116, whereas the primary-outcome population description refers to 73 patients. Understanding how those figures relate would help readers judge the completeness of outcome ascertainment and the potential for selection effects. The registry does not explain that relationship.

Finally, the record lists multiple outcomes and analyses, including TTFM-BPT correlation and relationships between SYNTAX scores and graft patency. A clear analysis plan and transparent reporting of estimates, intervals, and multiplicity handling would help distinguish the principal question from exploratory findings. Those details are not reported in the registry record. The statistical importance of the study lies in the need for a clear, reproducible account of how diagnostic assessments are compared, and of how uncertainty and incomplete information are handled.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The most direct limitation of the registry record is that it does not report numerical results for the primary endpoint. There is no count of graft occlusions, no BPT-by-CCTA classification pattern, and no estimate of agreement or diagnostic performance. Without those details, the primary question cannot be answered from the posted information.

The population description for the primary outcome refers to 73 patients, while the enrollment record lists 116. The reason for the difference is not reported in the registry record. The numbers alone do not indicate whether the difference arose from missing imaging, eligibility decisions, exclusions, or another process. The record does not identify the analysis population or describe missing-data handling.

The registry does not report the method used to quantify reliability or correlation, the statistical model, confidence intervals, p-values, or any adjustment for multiple analyses. It also does not state whether assessments were interpreted independently or whether assessors were blinded. These details would help readers assess measurement and analytic bias but cannot be inferred from the design description.

The safety entries lack reported event definitions and a timeframe, and the relationship between the listed deaths and adverse-event categories is not described. More broadly, the nonrandomized assessment design does not establish a causal effect of using one assessment method rather than another. The stated focus is graft patency assessment, not a randomized comparison of clinical strategies or patient outcomes.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Comparison of Bidirectional Palpation Test and Transit Time Flow Measurement for LIMA-LAD Graft Patency — NCT06934993.
• Registry record last updated 2025-07-08; status last verified 2025-07.
• Results first posted 2025-07-08.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry describes a completed study of elective CABG patients with LIMA-to-LAD grafts. Intraoperative BPT and TTFM assessments were followed by early postoperative CCTA, with the primary question focused on BPT reliability for assessing graft patency. The primary timeframe is the postoperative first month.

Enrollment is listed as 116, while the primary-outcome population description refers to 73 patients; the reason for this difference is not reported in the registry record. The record lists four outcome measures and nine analyses, including secondary questions concerning TTFM-BPT correlation and SYNTAX scores in relation to patency. Numerical outcome estimates, statistical methods, and missing-data procedures are not reported in the registry record.

The adverse-event entry lists 0 serious adverse events, 11 other adverse events, and 3 deaths. Definitions and timeframe are not reported. The registry status is completed, with a start date of 2023-08-31 and primary completion date of 2024-08-27.