POLish Bifurcation Optimal Treatment Strategy Study for Left Main Bifurcation Percutaneous Coronary Intervention (PCI): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for POLish Bifurcation Optimal Treatment Strategy Study for Left Main Bifurcation Percutaneous Coronary Intervention (PCI) (NCT03508219), a na na study. The primary outcome is Non-inferiority Comparison of Patient-oriented Composite Endpoint (PoCE) of BiOSS LIM C to a Pre-specified Objective Performance Goal (OPC)..

2. Clinical Question

3. Trial Design

The POLish Bifurcation Optimal Treatment Strategy Study evaluated a treatment strategy for left-main bifurcation PCI using the BiOSS LIM C device. The registry lists the study as single-group, with one intervention and an enrollment of 130. Allocation is recorded as NA and masking as none. The phase is also listed as NA.

The intervention description places treatment after diagnostic angiography demonstrating significant distal unprotected left-main disease. A local Heart Team discussion applied the anatomic SYNTAX Score before the PCI strategy. The primary population is described as intention-to-treat. The registry record does not report how many participants were included in the primary analysis or whether every enrolled participant completed follow-up.

The primary endpoint timeframe was 12 months. The listed start date is 2018-08-10 and the primary completion date is 2021-04-15. The study status is terminated. The reason for termination is not reported in the registry record.

The intended comparison was against a prespecified objective performance goal (OPC), not a randomized concurrent control group. The OPC is described as based on data collected in the Excel study. Because there is no like-for-like control arm in this single-group design, the comparison depends on the chosen external benchmark and its relevance to the enrolled population. Details of the benchmark value and its uncertainty are not reported in the registry record.

The record names secondary outcomes including PoCE, target vessel failure, target lesion failure, mortality, stroke, myocardial infarction, revascularization, and stent thrombosis. It lists 9 outcome measures but no analyses. Numerical results for those outcomes 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.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intention-to-treat population

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.

Population: The intended sample size was 260, but the study was terminated prematurely and only 130 participants were enrolled.

6. Primary Endpoint

The registry lists the primary outcome as Non-inferiority Comparison of Patient-oriented Composite Endpoint (PoCE) of BiOSS LIM C to a Pre-specified Objective Performance Goal (OPC)., measured over 12 months.

The primary endpoint was Patient-oriented Composite Endpoint (PoCE) at 12 months. It combines events considered relevant to patients: all-cause mortality; stroke, defined as a Modified Ranking Scale score of at least 1; any myocardial infarction, including one in a non-target vessel territory; and any unplanned revascularization for ischemia, including procedures involving target and non-target vessels.

A composite endpoint can capture several kinds of clinically important events in one measure. This may make a single summary outcome more informative than focusing on only one event type, particularly when the individual components differ in frequency or seriousness. The trade-off is that a composite result does not by itself show which component contributed most. Component-specific results and their definitions are therefore useful for interpretation, but numerical component results are not reported in the registry record.

The stated objective was to compare the 12-month PoCE with a prespecified objective performance goal in a real-world left-main bifurcation population. The record says the safety and efficacy objective with respect to PoCE was not confirmed. It does not report the observed PoCE percentage, the benchmark value, a confidence interval, or a test statistic. The direction and precision of the observed difference therefore cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation starts with the design. This is recorded as a single-group study with no masking and allocation listed as NA. Its primary comparison is against an objective performance goal rather than a concurrent randomized control group. A performance-goal design asks whether an observed outcome is compatible with a prespecified benchmark under a defined analysis plan. The benchmark’s value, uncertainty, and detailed comparison procedure are not reported in the registry record.

What does a non-inferiority comparison assess?

In general, a non-inferiority analysis asks whether the outcome with an intervention is not unacceptably worse than a comparator by a prespecified amount. The acceptable margin or criterion must be set in advance and interpreted in the context of the outcome and comparator. A confidence interval is useful because it describes a range of values compatible with the data under the analysis assumptions. For a non-inferiority conclusion, the interval’s relationship to the margin matters, not just whether a conventional significance test is statistically significant. The registry record does not report the OPC value, non-inferiority margin, confidence interval, or test details, so the criterion cannot be independently examined.

Why does the single-group design matter?

Without a concurrent control group, the estimate for BiOSS LIM C is judged against an external benchmark. Such interpretation depends on whether the benchmark population, endpoint definition, follow-up, and methods are sufficiently comparable to the study population and conduct. The record identifies the Excel study as the basis for the OPC, but does not report details that would allow those features to be compared. This design does not support the same direct, randomized between-group interpretation as a trial with a concurrent control arm. The record itself cautions that this is not a like-for-like control comparison.

How should the composite endpoint be read?

PoCE combines all-cause mortality, stroke, any myocardial infarction, and any unplanned revascularization for ischemia. In general, a composite endpoint summarizes whether one or more specified events occurred. It can represent a broader outcome, but the combined result can be influenced by components that occur at different rates or have different clinical implications. Component-level results can help explain the overall composite. Here, the registry record defines the components but does not give numerical primary or component results. No component contribution can therefore be inferred.

What can be learned from the recorded analysis information?

The primary population is labeled intention-to-treat, a general analysis principle that retains participants in the group to which they were assigned or treated as specified by the trial plan. In a single-group study, the registry’s label alone does not reveal how missing endpoint data, protocol deviations, or eligibility issues were handled. The number analyzed and the missing-data approach are not reported in the registry record. The record lists 0 analyses, so it does not offer an analysis output from which to inspect the method or result.

General statistical interpretation also distinguishes an estimate from its precision. The estimate describes the observed outcome; a confidence interval indicates uncertainty around it. A p-value, where reported, addresses compatibility with a specified statistical model or null hypothesis and does not describe effect size or clinical importance on its own. None of these primary numerical results is reported in the registry record.

Any sample-size planning illustrations associated with the reported statistics should be read as hypothetical planning exercises, not as observed power or as the study’s actual design justification. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. The actual study is listed as single-group, and its design assumptions or sample-size justification are not reported in the registry record. Planning illustrations cannot fill in the absent primary result or establish the study’s achieved precision.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("BiOSS LIM C Arm")
n      <- c(130)
events <- c(49)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  BiOSS LIM C Arm  130  49  37.7  29.3  46.6  29.8  46.3  29.8  46.3

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary endpoint and several secondary outcomes, including PoCE, target vessel failure, target lesion failure, mortality, stroke, myocardial infarction, revascularization, and stent thrombosis. It does not describe a multiplicity strategy, such as an ordering of hypotheses or an adjustment for testing multiple outcomes. The number of outcome measures is listed as 9, while the number of analyses is listed as 0. Any control of false-positive findings across outcome tests is therefore not reported in the registry record.

The primary population is identified as intention-to-treat, but the record does not report the number of participants included in the primary analysis, the number with available 12-month outcome data, or how missing outcomes were treated. It also does not report whether additional populations were analyzed. These omissions matter because missing outcome data can affect both the estimated event frequency and the precision of a comparison with an external performance goal.

Details such as censoring rules, handling of participants lost to follow-up, imputation, sensitivity analyses, and protocol deviations are not reported in the registry record. Their absence from the record does not establish that no such methods were used; it means the registry does not document them. With no numerical primary result or analysis output, it is not possible to assess the impact of missing data or multiplicity on the stated conclusion.

12. 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 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: in-stent restenosis (20.0%), myocardial infarction (6.9%), bleeding (3.8%), anemia (3.1%), chest pain (2.3%).

The adverse-event entry lists 130 participants at risk for serious adverse events and 43 participants affected. It also lists 130 at risk and 0 affected for the other adverse-event category, and records 2 deaths. These counts describe the registry’s adverse-event reporting; they are not the primary PoCE result. The record does not clarify in this entry whether participants could contribute more than one event, or provide the timing and circumstances of each event.

The registry lists the leading serious adverse event terms with percentages: in-stent restenosis, 20.0%; myocardial infarction, 6.9%; bleeding, 3.8%; anemia, 3.1%; chest pain, 2.3%; and coronary stenosis, 2.3%. These percentages should be read as the reported figures for those event terms, not as a complete description of all safety outcomes. The denominator and any rules for grouping or coding events are not reported in the registry record.

Serious adverse events and the PoCE are distinct measures, even though some event types may overlap conceptually. The registry’s adverse-event counts cannot be used to reconstruct the primary endpoint, which has its own definition and timeframe. No causal relationship between the device and any reported event is established by these figures alone.

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

The record establishes that the study evaluated BiOSS LIM C for left-main bifurcation PCI in a single-group design, with a 12-month PoCE comparison against an external performance goal. It also records a narrative conclusion that the safety and efficacy objective with respect to PoCE was not confirmed. That is the extent of the primary result available in the registry record.

The numerical information needed to judge the result’s magnitude and precision is not reported: the observed PoCE percentage and event count, the OPC value, and a confidence interval or test statistic are absent. Accordingly, the stated conclusion cannot be translated into an estimated difference or a quantified degree of uncertainty. It also cannot show which component of the composite contributed to the result.

The separate statement about POLBOS LM says that BiOSS LIM C was not non-inferior to XIENCE for percutaneous treatment of left-main disease. It should not be read as a randomized comparison from this study. The present record describes a single-group design and an external performance goal, not a concurrent XIENCE arm.

The record lists enrollment of 130 and status as terminated, but does not give a reason for termination or a number analyzed. Those details alone do not explain the outcome or establish the quality of follow-up. Likewise, the adverse-event counts provide safety-reporting information but do not answer the primary endpoint question. The findings should therefore be interpreted within the limits of the available registry information rather than as a complete account of efficacy, comparative performance, or safety.

14. Why This Trial Matters Statistically

This study is statistically notable because it frames a device evaluation as a comparison with an objective performance goal in a single-group setting. Such a design can provide evidence about outcomes relative to a benchmark, but the interpretation relies heavily on the benchmark’s prespecification and relevance. The record identifies the Excel study as the source of the goal, while leaving the benchmark value and key comparison details undocumented.

The distinction between an external goal and a concurrent control is important. A concurrent randomized comparison can balance measured and unmeasured factors through allocation, whereas a historical or external benchmark may differ in population, care, follow-up, or outcome ascertainment. The registry record does not provide enough detail to determine how closely the benchmark corresponds to this study’s real-world left-main bifurcation population.

The case also illustrates why a narrative statement about a conclusion is not a substitute for an estimate and its uncertainty. The record says the performance goal was not confirmed but provides no primary event percentage, interval estimate, or test result. Without those statistics, readers cannot inspect the result’s magnitude, precision, or sensitivity to assumptions. The record’s separate reference to POLBOS LM further underscores the importance of keeping results from distinct studies and designs separate.

Finally, the primary endpoint combines several types of events. A composite may give a broad account of patient-oriented outcomes, but understanding its composition requires component results. Those numerical results are not reported in the registry record. This leaves key questions about the outcome pattern unresolved, despite the listed endpoint definition and follow-up timeframe.

15. 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.

Several trial-specific limitations arise from the information recorded. The study is listed as single-group, with an external performance goal rather than a concurrent control arm. The goal is described as based on the Excel study, but its numerical value and the details needed to assess comparability are not reported in the registry record. This limits independent assessment of the benchmark-based inference.

The primary outcome entry contains a narrative conclusion but no observed PoCE percentage, event count, confidence interval, or p-value. The record also does not give component-specific outcome results. As a result, neither the magnitude and precision of the primary estimate nor the contribution of mortality, stroke, myocardial infarction, and unplanned revascularization can be assessed.

Although the primary population is labeled intention-to-treat and enrollment is listed as 130, the number analyzed and the completeness of 12-month follow-up are not reported in the registry record. The approach to missing outcomes and protocol deviations is also not documented. The registry lists the study as terminated but does not state why.

There is a further interpretive boundary between this study and the separate POLBOS LM statement included in the outcome description. That statement should not be mistaken for a concurrent comparison in this single-group study. Finally, the record lists adverse-event counts and selected terms but does not provide enough detail about event timing, coding, denominators for the term percentages, or attribution to establish a fuller safety interpretation.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: POLish Bifurcation Optimal Treatment Strategy Study for Left Main Bifurcation Percutaneous Coronary Intervention (PCI) — NCT03508219.
• Registry record last updated 2025-09-15; status last verified 2025-08.
• Results first posted 2025-09-15.
• 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.

19. Record Summary

The registry record describes a single-group study of BiOSS LIM C for PCI of left-main bifurcation disease, with enrollment listed as 130 and a primary endpoint of PoCE at 12 months. The intended comparison was with an objective performance goal based on the Excel study. The primary population is labeled intention-to-treat; allocation is NA, masking is none, and phase is NA.

The record lists the study as terminated, with dates of 2018-08-10 and 2021-04-15 for study start and primary completion. It states that the performance goal was not confirmed, but does not report numerical primary results or the reason for termination. It lists 9 outcome measures and 0 analyses. Serious adverse event figures include 43 affected participants among 130 at risk and 2 deaths; additional event terms and percentages are recorded. These safety figures do not supply the missing primary endpoint estimate.