Contrast Volume Reduction During PCI With the Use of a New Assisting Software Package: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Contrast Volume Reduction During PCI With the Use of a New Assisting Software Package (NCT02927990), a registered phase not stated study. The primary outcome is Amount [mL] of Contrast Used for Completion of the Coronary Intervention.

2. Clinical Question

The study focuses on contrast use during percutaneous coronary intervention, rather than on a patient follow-up outcome. Its stated objective is to investigate the amount of contrast used with the software and compare it with control-group data to define a possible reduction. That objective describes the intended comparison, not a demonstrated result.

The registry identifies the study as terminated and says only Phase 1 data were collected; Phase 2 was not initiated. It also states that no data were gathered for the primary outcome. Consequently, the central clinical question cannot be answered from the posted primary endpoint results. The record does not report a contrast-use estimate for either group or a comparison between them.

Allocation is not stated, and the record identifies the study as not randomized. The control procedures described in the summary may come from a period before installation or after removal of the software. Without a reported analysis establishing how the groups were formed and compared, the intended contrast is a question the study set out to examine, not a like-for-like causal estimate.

3. Trial Design

The registry describes a study of percutaneous coronary interventions with and without additional imaging from a new software package. The study group is defined as procedures using the package, while the control group is defined as procedures without it. The brief summary says control-group data would be drawn from before the package was installed or after it was removed. The record does not state how procedures were allocated to these groups, and it identifies the comparison as nonrandomized.

The registry lists enrollment of 80. That figure does not establish how many participants contributed data to any particular outcome. In particular, the registry states that no data were gathered for the primary outcome. It says only Phase 1 data were collected and that Phase 2 was not initiated. The study status is terminated. The start date is 2017-12-15, and the primary completion date is 2019-06-30.

The primary outcome was intended to measure the amount of contrast used to complete the coronary intervention. The registry describes a single assessment at the end of the procedure and says there was no patient follow-up. Secondary outcomes named in the record concern cumulative dose area product, cumulative air-kerma, total fluoroscopy time, and procedure efficiency. The record lists 7 outcome measures overall, but it does not report analyses for them.

There are no analyses listed in the registry record. The statistical plan, including the intended method for comparing groups, is not reported in the registry record. Details about participant eligibility, the timing and conduct of group assignment, and the handling of departures from the intended intervention are also not reported in the registry record. These omissions limit what can be inferred about the design beyond its stated intervention, comparator, and endpoint.

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: No data gathered for the primary outcome. Phase 2 not initiated Only phase 1 data was collected

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 Amount [mL] of Contrast Used for Completion of the Coronary Intervention, measured over Amount of contrast [mL] will be determined once, at the end of the Percutaneous Coronary Intervention. There is no patient follow-up..

The primary endpoint is the amount of contrast used to complete a coronary intervention, measured in mL. The registry describes the intended assessment as occurring once, at the end of the procedure, with no patient follow-up. This is a procedure-level measure: it is intended to quantify use during the intervention rather than a later clinical outcome.

Contrast volume is used in this study because the stated objective is to investigate whether the imaging software is associated with a different amount of contrast being used during percutaneous coronary intervention. The endpoint directly reflects that objective. It does not, by itself, describe whether an intervention was successful, whether a patient experienced a complication, or whether there was a lasting effect. Those would be separate questions requiring their own outcomes and analyses.

The registry lists the primary measure as a median with standard deviation as its dispersion measure. In general, a median describes the middle of an ordered distribution, while a standard deviation describes spread around a mean; they represent different summaries and should be interpreted according to the analysis actually conducted. The record does not report the endpoint data, the group summaries, or an analysis explaining the choice or use of these summaries. It explicitly states that no data were gathered for the primary outcome because Phase 2 was not initiated. Therefore, there is no posted primary endpoint estimate to interpret.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical methods that were actually used for the primary endpoint cannot be reconstructed from the registry. The record states that no primary outcome data were gathered and lists no analyses. The planned endpoint is described as a median with standard deviation, but the record does not report a group comparison method, an estimate, a confidence interval, or a significance test. The intended statistical plan is not reported in the registry record.

What can a median and standard deviation tell readers?

In general, a median identifies the central position when observed values are ordered. It can be useful when a distribution is asymmetric or includes unusually large values, because extreme observations have less influence on the median than on the mean. A standard deviation is a measure of spread based on deviations from the mean. It is most naturally interpreted alongside a mean, so a median paired with a standard deviation may not fully describe the distribution. A fuller account could include distributional information or a spread measure aligned with the median, but the registry does not report any observed summaries or explain its descriptive choices.

Those are general statistical considerations, not a description of an analysis conducted in this study. Without group data, it is not possible to check distribution shape, outliers, or whether the reported summary measures would be suitable. No recalculated estimate can be made from the registry record.

Why does the comparison design matter?

In general, random allocation helps make comparison groups similar in expectation with respect to factors that might affect an outcome. This record identifies the study as nonrandomized and does not state how allocation occurred. Its summary says control data would come from before software installation or after removal. If groups differ in timing, care practices or participant characteristics could also differ. An observed contrast, if one were reported, would need to be interpreted in light of these design features and any methods used to address them. The registry does not report such methods.

Group comparisons can be presented as an absolute difference in outcome summaries, with a confidence interval to show the range of values compatible with the data and analysis assumptions. In general, a confidence interval communicates uncertainty; it does not make a biased comparison unbiased, and it is not a guarantee that the true value lies within its limits. No contrast estimate or interval is reported for the primary endpoint in this record.

What do the planning illustrations represent?

The record describes sample-size illustrations based on an observed effect and states that they are not the trial's own design. Their assumptions are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the target effect defined as a stated fraction of the observed effect. The record's instructions distinguish participants per arm for non-time-to-event outcomes from total events for time-to-event outcomes. These are planning assumptions, not evidence that the study was designed or conducted that way.

In general, such illustrations ask how much information a hypothetical future study might need under specified assumptions. They are not observed power, and they do not show that the present study had a particular probability of detecting an effect. Because the registry reports no primary outcome data, the posted record does not establish an observed primary effect on which to base an interpretation. Any sample-size illustration should therefore not be mistaken for a trial result or a justification recorded for the trial's enrollment.

Why does over-dispersion matter in general?

For outcomes whose variability is greater than a model assumes, standard errors can be too small and intervals can be too narrow if that extra variation is ignored. Methods that account for over-dispersion can better reflect uncertainty in appropriate settings. This is a general statistical point; the registry does not report that over-dispersion was assessed or that a model requiring such an adjustment was used. The primary outcome is not reported in a form that permits checking its distribution or variability.

Overall, the record supports an explanation of the intended endpoint and the limitations of the design description, but not a reconstruction of the primary analysis. The method, assumptions, covariate handling, and uncertainty calculation are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 7 outcome measures and names secondary outcomes concerning cumulative dose area product, cumulative air-kerma, total fluoroscopy time, and procedure efficiency. It lists no analyses. The record does not say which outcomes were measured, which comparisons were intended, or whether any outcome was designated for a formal statistical test beyond the named primary endpoint.

When a study tests several outcomes or makes several comparisons, the chance of a misleading positive result can increase if the analyses are treated as independent opportunities for success. In general, a statistical analysis plan can specify a hierarchy, adjustment procedure, or other approach to multiplicity. The registry does not report a multiplicity strategy, so it is not possible to determine how any potential multiple testing was handled. This is especially consequential when no results or analyses are posted: there are no test results to interpret, adjusted or otherwise.

Missingness also cannot be characterized from the primary endpoint record. The registry states that no data were gathered for that outcome because Phase 2 was not initiated. That is not the same as reporting that outcome measurements were collected and then missing for some participants. The record does not provide participant-level flow, reasons for nonparticipation, or a missing-data method. It is therefore not possible to assess whether missingness within an analyzed population could have affected an estimate.

The record lists enrollment of 80, but does not report the analysis population or the number contributing to any endpoint. It does not describe an intention-to-treat, per-protocol, or other analysis population. These terms refer generally to ways of defining which participants contribute to an analysis; none should be attributed to this study without a registry statement. The absence of primary data and analysis details prevents evaluation of exclusions, protocol deviations, or sensitivity analyses.

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.

For the registry entry titled PCI Phase 1, the record lists 24 participants at risk for serious adverse events and 0 affected. It also lists 24 at risk for other adverse events and 0 affected, and reports 0 deaths. No serious adverse-event terms are listed.

These figures describe the Phase 1 safety entry only. They do not provide a comparison of safety between the software and control groups, because the entry does not report separate group results. Nor do the figures provide detail about event definitions, monitoring procedures, or the duration of safety observation. Such information is not reported in the registry record.

In general, a zero count in a registry entry means that no events were recorded in the stated entry; it does not prove that an event is impossible or that a procedure is free from risk. The registry also says there was no patient follow-up for the primary endpoint, but it does not specify the safety-observation window in this entry. The listed zero counts should therefore be read narrowly, without extending them beyond the recorded Phase 1 safety figures or treating them as evidence about unreported groups, outcomes, or observation periods.

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

The record documents a study intended to compare contrast use during percutaneous coronary intervention performed with and without additional imaging from a software package. It identifies contrast volume at the end of the intervention as the primary endpoint and describes control data from before installation or after removal of the software. It also records that the study was terminated, that only Phase 1 data were collected, and that Phase 2 was not initiated.

What the result does not provide is a primary outcome estimate. The registry explicitly states that no data were gathered for the primary endpoint. There is no reported contrast volume for either group, no estimated difference, and no uncertainty interval. It is not possible to conclude from the posted primary results that the software reduced contrast use, increased it, or had no effect.

The enrollment listing of 80 does not change that interpretation. Enrollment alone does not reveal how many participants contributed to a particular endpoint, and it cannot be treated as a result. Likewise, the listed Phase 1 adverse-event counts do not answer the contrast-use question or provide a comparative safety analysis.

More generally, even a reported difference in a nonrandomized comparison would require careful interpretation. The registry does not state allocation and describes controls that may come from a different time period. Without information about group comparability and analysis methods, a difference could not automatically be attributed to the software. In this record, the lack of primary endpoint data means that even a descriptive contrast is unavailable.

The appropriate conclusion is about the evidence available in the registry, not about the underlying clinical value of the software: the study's stated primary comparison has no posted outcome result. Any claim about the size, direction, precision, or clinical importance of a contrast-volume effect would go beyond what the record reports.

13. Why This Trial Matters Statistically

This study illustrates an important distinction between a registered objective and an analyzable result. A protocol can specify a clinically relevant measurement and a comparison, but the question can only be answered if outcome data and an analysis are reported. Here, the registry identifies contrast volume as the primary endpoint yet states that no data were gathered for it because Phase 2 was not initiated. That makes the absence of an effect estimate central to interpretation.

The design description also matters. A nonrandomized comparison with controls drawn from before installation or after removal may be susceptible to differences unrelated to the software. In general, statistical adjustment can sometimes address measured differences, but it cannot guarantee control of unmeasured factors. The registry does not report the group-assignment details or an adjusted analysis, so readers cannot assess how a potential comparison would have handled these issues.

The record also helps distinguish procedural outcomes from later patient outcomes. Contrast volume was intended to be measured at the end of the intervention, and no patient follow-up was planned for that endpoint. Secondary outcomes named in the record concern radiation exposure measures and procedure efficiency. Those are distinct questions and require their own reported data and analysis.

Finally, the listed safety counts and the enrollment figure should not be mistaken for evidence addressing the primary endpoint. Understanding what is absent is part of statistical interpretation: without primary outcome observations, there is no estimate to quantify, no precision to assess, and no reported comparison from which to draw a conclusion about contrast use.

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 is that the registry reports no data for the primary endpoint. It states that Phase 2 was not initiated and only Phase 1 data were collected. Because the primary question concerns contrast volume, this prevents estimation of the outcome or a comparison between software-assisted and control procedures.

The record identifies the study as terminated, but does not report the reason for termination. It lists enrollment of 80, but does not state how many participants contributed to each arm or outcome. The primary endpoint description says no data were gathered, so the enrollment listing cannot be used to infer an analyzed sample. Participant flow and the disposition of enrolled participants are not reported in the registry record.

The group comparison is not randomized, and allocation is not stated. The summary describes control data from before the software was installed or after it was removed. The registry does not provide further details about how control procedures were selected, whether groups were comparable, or whether differences in timing or clinical practice were addressed analytically.

The statistical methods are also insufficiently described for evaluation. No analyses are listed, and the statistical plan, treatment of missing data, analysis populations, and multiplicity approach are not reported in the registry record. Although the primary endpoint is described using a median and standard deviation, no observed distribution or group summary is available to assess that choice.

Finally, the Phase 1 safety counts are not separated by study group, and the safety observation period and event definitions are not reported. These limitations leave the safety information descriptive and narrow in scope; they do not compensate for the absent primary endpoint results.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Contrast Volume Reduction During PCI With the Use of a New Assisting Software Package — NCT02927990.
• Registry record last updated 2024-12-06; status last verified 2024-12.
• Results first posted 2024-12-06.
• 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

NCT02927990 is a terminated study titled “Contrast Volume Reduction During PCI With the Use of a New Assisting Software Package.” It concerns percutaneous coronary intervention with additional imaging from the software compared with procedures without it. The registry lists enrollment of 80, a start date of 2017-12-15, and a primary completion date of 2019-06-30.

The primary endpoint was the amount of contrast used to complete the intervention, intended for measurement at the end of the procedure. The registry states that no primary outcome data were gathered: only Phase 1 data were collected, and Phase 2 was not initiated. No analyses are listed, and no primary comparison result is reported.

The record names secondary outcomes related to dose area product, air-kerma, fluoroscopy time, and procedure efficiency. Its Phase 1 safety entry reports 0 serious adverse events, 0 other adverse events, and 0 deaths among the stated at-risk group. These figures do not provide a comparison between study arms.