Trial for A Novel Facilitated Antegrade Steering Technique in Revascularization of Coronary Chronic Total Occlusions: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Trial for A Novel Facilitated Antegrade Steering Technique in Revascularization of Coronary Chronic Total Occlusions (NCT03901079), a registered phase not stated study. The primary outcome is Technical Success: Successfully Facilitate Placement of a Guidewire Beyond a CTO Lesion in the True Vessel Lumen/Within the Collaterals.

2. Clinical Question

The registry frames the study as an assessment of safety and efficacy in a multicenter study in the Chinese population. Its primary endpoint is a procedural measure: whether guidewire placement beyond the lesion was successfully facilitated in the specified location. This question concerns technical success, rather than a comparison of clinical outcomes between randomized groups.

The registry lists a total enrollment of 20, while the outcome description states that only 6 subjects have results for technical success or failure. It reports success for 5 of those 6 and failure for one. The outcome data therefore describe a subset of the enrolled participants, and the registry record does not explain why results are available for only that subset. The record also does not report a comparator or a treatment-effect estimate against another strategy.

3. Trial Design

The study is described as prospective, multicenter, non-randomized, and conducted in the Chinese population. Its registered intervention is a single-arm study of the CTO BridgePoint system. The system is described as including the CrossBoss Catheter, Stingray LP Catheter, Stingray Guidewire, and Extension Wire. The registry does not describe a control arm, and allocation is not stated; the study should therefore not be read as a randomized comparison.

The registry lists enrollment of 20. The primary outcome is technical success, defined as successfully facilitating placement of a guidewire beyond a CTO lesion in the true vessel lumen or within the collaterals. The outcome description says that results are available for only 6 subjects: 5 had technical success and one failed. It does not clarify why these results are available for only part of the enrolled group, or how the reported subset relates to the full enrolled population.

The study started on 2018-10-08, and primary completion is listed as 2020-01-10. The status is TERMINATED. These registry entries describe the recorded study timeline and status; they do not explain why the study was terminated or whether termination affected the collection or reporting of outcomes.

For follow-up, the registry states that contact would occur by telephone or clinic visit at 30 days,6 and 12 months after the index procedure. The record does not clarify whether the primary technical-success outcome was assessed at a particular one of these follow-up contacts, or how follow-up was completed for participants without reported primary outcome data. The study's sample-size justification, detailed protocol, and statistical analysis plan 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: Only 6 subjects have the results of technical success or not.

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: Subject demographics, Physical assessment, Medical history, Angina assessment, LVEF, Cardiac medication, risk factors, and pre-procedure lesion characteristics will be summarized using descriptive statistics for continuous variables and frequency tables for discrete variables. No formal statistical testing will be done since this is a single-arm trial.

6. Primary Endpoint

The registry lists the primary outcome as Technical Success: Successfully Facilitate Placement of a Guidewire Beyond a CTO Lesion in the True Vessel Lumen/Within the Collaterals, measured over Subject follow up will occur via telephone contact or clinic visit at 30 days,6 and 12 months post index procedure..

The primary endpoint is technical success, counted as participants for whom placement of a guidewire beyond a CTO lesion was successfully facilitated in the true vessel lumen or within the collaterals. The endpoint is reported as a count of participants, with success and failure categories. It represents whether the intended procedural crossing step was achieved according to the stated definition.

Technical success is used as a direct measure of whether the studied system can facilitate guidewire passage beyond a lesion in the specified location. In general, a procedural endpoint can describe an immediate technical result without, by itself, establishing longer-term clinical benefit or comparing one strategy with another. Such broader conclusions require suitable outcome data and a design that supports the relevant comparison.

The registry reports technical success for 5 of the 6 subjects with results, or 83.3%; one subject, or 16.7%, failed. The registry states that only 6 subjects have results for this outcome, despite listing enrollment of 20. It does not explain the relationship between the outcome data and the overall enrolled group. The follow-up description gives contact at 30 days,6 and 12 months after the index procedure, but the timing of primary endpoint ascertainment is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count mean?

The primary endpoint is recorded as a count of participants, divided into technical success and failure. A count makes the number of observed outcomes explicit. A proportion places that count in relation to the participants with reported outcome data. Here, the registry reports 5 successes among 6 subjects with results, alongside the stated percentage of 83.3%. It also reports one failure and the stated percentage of 16.7%.

These percentages describe the outcome-data subset. The registry's enrollment figure is 20, but it explicitly says only 6 subjects have the results for technical success or failure. The denominator for the reported outcome is therefore not interchangeable with total enrollment. The registry record does not explain the absence of primary outcome results for the other enrolled participants, so it is not possible to determine whether the observed subset differs systematically from the full enrolled group.

What can a confidence interval add?

In general, a confidence interval conveys statistical uncertainty around an estimate. It describes a range of values that are reasonably compatible with the observed data under the assumptions of the chosen method. A narrow interval indicates greater precision, while a wide interval indicates more uncertainty. For a binary outcome, interval methods account for the fact that the result is a proportion based on counts rather than a continuous measurement.

No confidence interval for technical success is reported in the registry record. The posted percentage should therefore be read as a descriptive statistic, not as a result with a documented precision estimate. The small outcome-data subset also means that a single participant's outcome has substantial influence on the observed proportion. This is a general property of proportions based on limited counts, not evidence about why any participant did or did not have a successful procedure.

Why does the study design matter?

A single-arm study describes outcomes among participants receiving the intervention, but it does not directly measure what would have happened under a comparator strategy. Random allocation, when used, supports a fair comparison by reducing systematic differences between groups. This study is described as non-randomized, and the intervention is listed as single-arm. No control arm is described, and allocation is not stated. Thus, the technical-success result is not a comparative treatment effect.

Without a comparator, the result cannot distinguish the contribution of the system from other factors that may affect procedural success. General clinical and procedural context can be relevant, but the registry record does not provide data that quantify such influences. It would be inappropriate to infer comparative efficacy or safety from the single-arm count.

What is a planning illustration?

Sample-size planning asks how many participants might be needed for a future study under specified assumptions about the effect to detect, significance level, allocation, and statistical method. A planning illustration is not an observed trial result and does not establish the study's original design rationale. The record's planning assumptions describe an illustration based on the observed effect, two-sided significance level 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For time-to-event outcomes, the assumption describes total events, while other outcomes use participants per arm.

Those are assumptions for an illustration, not evidence that this study had two arms or used those design choices. The registered study is single-arm, and its own sample-size justification is not reported in the registry record. A planning estimate also should not be called observed power. In general, observed power is not a substitute for reporting the estimate and its uncertainty; a planning calculation instead explores the design implications of chosen assumptions.

How should adverse-event counts be interpreted?

Safety summaries can report serious events, other events, and deaths as distinct categories. These counts depend on the definitions used, the observation period, and how events are attributed and recorded. The registry lists 4 serious adverse events among 20 at risk, 0 other adverse events among 20 at risk, and 0 deaths. These figures should be read as recorded counts, not as evidence that the intervention caused or prevented any event.

The record does not give event-level descriptions beyond the listed serious term, nor does it explain whether one participant could contribute more than one event. A zero count in a category describes what was recorded in this study; in general, it does not prove that the underlying risk is zero. Without a comparator, the counts also cannot establish whether event frequency differs from that under another approach.

What analyses are absent?

The registry lists one outcome measure and no analyses. It does not report a hypothesis test, confidence interval, adjusted estimate, or detailed statistical analysis plan. It also does not report the handling of missing outcome data, a defined analysis population, or interim analyses. These omissions limit statistical interpretation: the posted count can be described, but the methods used to make broader inferences cannot be assessed from the registry record.

10. Multiplicity, Missing Data and Analysis Populations

Multiplicity refers to the risk of false-positive findings when several outcomes, comparisons, or analyses are tested. In general, a prespecified approach can clarify which result is primary and how additional tests are handled. The registry lists one outcome measure and no analyses. A multiplicity adjustment or strategy is not reported in the registry record, so there is no basis to describe how multiple testing was addressed, if it arose in the conduct of the study.

The record identifies the primary endpoint as technical success, but does not report a statistical analysis plan, hypothesis test, or confidence interval. It also does not state whether there were planned secondary analyses, interim analyses, or subgroup analyses. These items are not reported in the registry record; their absence from the posted entry should not be filled in by assumption.

Missing outcome data are particularly relevant because enrollment is listed as 20 while technical-success results are reported for only 6 subjects. The registry says only 6 subjects have results, but does not give reasons for the limited outcome reporting, describe attempts to obtain the other results, or state how unavailable outcomes were treated. It does not report whether the analyzed participants were defined by enrollment, procedure receipt, or another criterion.

The analysis population is therefore unclear beyond the statement that the technical-success result applies to the 6 subjects with outcome data. The record does not say whether these participants represent all eligible or treated participants, or whether any exclusions were applied. Without that information, readers cannot assess the potential effect of missingness or determine whether the reported percentage reflects a prespecified analysis population.

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 serious adverse event terms

Serious events with the highest arm-level rate: coronary artery atherosclerotic heart disease (20.0%).

The registry records 4 serious adverse events among 20 participants at risk in the CTO BridgePoint System group. It records 0 other adverse events among 20 at risk and 0 deaths. These are descriptive safety counts; they do not establish whether an event was caused by the system or whether the observed counts differ from another treatment approach.

The most frequently listed serious term is Coronary artery atherosclerotic heart disease, reported as 20.0%. The registry record does not provide further detail on this term in the posted safety summary. It does not specify the timing, duration, severity criteria, attribution, or participant-level overlap of events. It also does not explain how the listed term relates to the total serious-event count.

In general, an event count depends on the observation period and the definitions used to classify and collect events. The primary outcome's follow-up description refers to telephone contact or clinic visit at 30 days,6 and 12 months after the index procedure, but the record does not establish that these are the safety observation windows. A zero count means no events in that category were recorded in the registry entry; it is not proof that the underlying risk is absent.

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

The posted technical-success result shows that 5 of the 6 subjects with available outcome results were reported as successful, with one reported failure. The registry gives the corresponding percentages as 83.3% and 16.7%. This is a descriptive finding for the reported subset. It should not be generalized automatically to all enrolled participants, since the registry lists enrollment of 20 but says only 6 subjects have technical-success results.

The result does not establish that the system is better or worse than another approach. The study is described as single-arm and non-randomized, with no comparator arm described and allocation not stated. There is no comparative treatment effect in the posted result. Nor does technical success alone describe longer-term clinical outcomes: it records whether guidewire placement beyond a CTO lesion was facilitated in the specified location.

The registry does not report a confidence interval or hypothesis test for the primary outcome. Accordingly, the result has no posted statistical precision estimate. In general, a proportion based on a small set of observed participants is uncertain, and the percentage alone should not be treated as a guarantee of the outcome in other settings or populations.

The safety entries list serious adverse events, other adverse events, and deaths separately, but the record does not provide enough detail to establish event attribution or a comparison with another strategy. The status is TERMINATED, and the registry does not explain the reason for termination or how it affected outcome collection. The sample-size justification, missing-data approach, and analysis population are not reported in the registry record.

In short, the registry supports a limited account of the observed procedural result and safety counts. It does not settle comparative effectiveness, the representativeness of participants with outcome data, or longer-term benefit and risk.

13. Why This Trial Matters Statistically

This trial illustrates why a reported percentage needs its denominator and context. The technical-success percentage is based on 6 subjects with results, while enrollment is listed as 20. Reporting 83.3% without the accompanying count and the outcome-data limitation could make the result appear more representative than the registry supports. The counts and the stated denominator make clear that this is a small subset of the enrolled group.

It also illustrates the distinction between a procedural endpoint and a comparative clinical claim. The endpoint asks whether guidewire placement beyond a CTO lesion was facilitated in the true vessel lumen or within the collaterals. That is a concrete technical outcome. But a single-arm, non-randomized result cannot show what would have happened under another approach, and the registry does not report longer-term clinical results as the primary endpoint.

Statistical interpretation depends not only on the observed percentage, but also on uncertainty, analysis populations, missing outcome data, and study design. No confidence interval or hypothesis test is reported. The reason that outcome data are recorded for only 6 subjects is not reported in the registry record. The design therefore leaves important questions about precision and representativeness unresolved.

The safety counts make a related point: events should be interpreted in light of definitions, follow-up, and comparator information. The record lists 4 serious adverse events, 0 other adverse events, and 0 deaths among 20 at risk, but does not provide enough detail to assess attribution or comparative risk. Transparent reporting of denominators and limitations is essential to prevent descriptive findings from being mistaken for stronger evidence than the design and available data support.

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 main limitation is that technical-success results are reported for only 6 subjects, although enrollment is listed as 20. The registry does not explain why results are available for only this subset, whether outcomes were sought for all enrolled participants, or how participants without reported results were handled. This makes the representativeness of the observed outcome uncertain.

The single-arm, non-randomized design has no described comparator, and allocation is not stated. The observed technical-success count therefore cannot estimate a difference between the system and another strategy. The registry does not report an analysis plan, a confidence interval, a hypothesis test, or a sample-size justification.

The record's follow-up statement describes telephone or clinic contact at 30 days,6 and 12 months after the index procedure. It does not clarify the timing of primary endpoint ascertainment, the completeness of follow-up, or whether the stated contacts were used for safety surveillance. The status is TERMINATED, but the reason for termination and its effect on data collection are not reported in the registry record.

Safety reporting is limited to the posted counts and a listed serious-event term. The registry does not explain event attribution, event-level timing, participant overlap, or the criteria used to classify events. These limitations restrict conclusions about both the frequency and context of safety events. The findings should therefore be treated as descriptive registry results with substantial unresolved questions about outcome completeness, precision, and comparison.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Trial for A Novel Facilitated Antegrade Steering Technique in Revascularization of Coronary Chronic Total Occlusions — NCT03901079.
• Registry record last updated 2023-12-08; status last verified 2023-12.
• Results first posted 2023-12-08.
• 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 prospective, multicenter, non-randomized, single-arm study of the CTO BridgePoint system in the Chinese population. The stated aim was to assess safety and efficacy for recanalization of CTO lesions resistant to a conventional wire approach. The system includes the CrossBoss Catheter, Stingray LP Catheter, Stingray Guidewire, and Extension Wire.

Enrollment is listed as 20; the study started on 2018-10-08, primary completion is listed as 2020-01-10, and status is TERMINATED. The primary endpoint is technical success in facilitating guidewire placement beyond a CTO lesion in the true vessel lumen or within the collaterals. Results are reported for only 6 subjects: 5 successes (83.3%) and one failure (16.7%).

The safety summary lists 4 serious adverse events among 20 at risk, 0 other adverse events among 20 at risk, and 0 deaths. No comparator is described. The registry record does not explain the limited primary outcome reporting, the termination, or the missing statistical details needed for comparative inference.