This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Comparison of StentOptimizer With IntraVenous Ultrasound and 2D Quantitative Coronary Angiography (NCT00973921), a registered phase not stated study. The primary outcome is The Accuracy (Percent of Correct Decisions) of Post-dilatation Decisions Based on the Stent Optimizer (SO) Software, With IVUS as Gold Standard..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00973921 |
| Phase | Phase not stated |
| Condition | Coronary Artery Disease |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 40 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Paieon Inc. |
| Results posted | Yes |
2. Clinical Question
Population
Patients with coronary artery disease who underwent PCI with stent implantation. The record describes 40 consecutive patients enrolled; only 31 had analyzable IVUS results.
Intervention
Post-deployment evaluation using StentOptimizer, an angiography-based software application. The software was used independently and blindly to assess whether post-dilatation was indicated.
Comparator
IVUS served as the gold standard for post-dilatation decisions. IVUS and 2D QCA were also used for diameter measurements, with diameter correlations specified as secondary outcomes.
Primary question
What percentage of post-dilatation decisions made using StentOptimizer agreed with the decisions based on IVUS on the procedure day?
The central statistical question is one of diagnostic agreement: how often did the software classify a stent in the same way as the IVUS-based reference decision? This is not a comparison of outcomes between randomized treatment groups. The registry describes patients who underwent IVUS-guided stent implantation and whose procedures were evaluated with StentOptimizer, IVUS, and QCA.
That distinction matters. Agreement with a reference method addresses whether two assessment approaches produce matching decisions in the evaluated procedures. It does not by itself establish that either decision improves patient outcomes, nor does it establish what would happen if clinicians used one method rather than another to guide care. The record also describes an assessment of whether StentOptimizer could influence post-deployment treatment strategy, but it does not report a result for that question.
The registry lists the study as observational because the software, IVUS, and QCA were part of the clinical procedure outside the study, while analyses of decisions and measurements were retrospective. The treatment allocation is not stated, and the record does not describe a randomized comparison. The primary clinical question is therefore limited to the accuracy of the software’s decisions against the IVUS reference, rather than a causal comparison of treatments.
3. Trial Design
The registry describes a completed observational study of post-deployment stent assessment. Its enrollment was 40, and the study group consisted of patients who underwent IVUS-guided stent implantation. Stent deployment evaluation used StentOptimizer as well as IVUS and QCA. The record gives a start date of 2009-09 and a primary completion date of 2010-03.
The study’s primary objective was to assess the diagnostic efficiency and accuracy of StentOptimizer. The primary outcome focused on post-dilatation decisions: IVUS was used as the gold standard to decide whether a stent required post-dilatation, and StentOptimizer was used independently and blindly to make the same decision. The registry describes the outcome as the percentage of correct decisions by the software compared with the IVUS reference, measured on the procedure day.
The registry also identifies secondary outcomes concerning correlations of stent diameter measurements between StentOptimizer and IVUS, and between QCA and IVUS. It does not report the numerical results for these outcomes. The software, IVUS, and QCA were all part of the clinical procedure outside the study; the retrospective analysis of treatment decisions and diameter measurements is the basis for the registry’s observational classification.
This design does not assign participants to competing diagnostic strategies as a randomized trial would. The record does not state an allocation procedure, and it explicitly does not describe a randomized comparison. The planning illustration’s equal-allocation assumption between two arms should not be read as evidence that this study had two randomized arms. The registry describes one study group and does not provide a like-for-like control comparison.
Of the 40 enrolled patients, 31 had analyzable IVUS results. The registry does not explain why IVUS results were not analyzable for the remaining enrolled patients, nor does it state the precise analysis denominator used for the primary outcome. These omissions limit interpretation of the study’s analysis population and the completeness of its reference-standard assessments.
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
| Stage | Coronary Stenting Evaluation With IVUS |
|---|---|
| STARTED | 40 |
| COMPLETED | 31 |
| NOT COMPLETED | 9 |
Reasons for not completing this period:
| Reason | Coronary Stenting Evaluation With IVUS |
|---|---|
| IVUS results were not available | 9 |
Analysis population for the primary outcome, as defined in the registry: Total of 40 consecutive patients who underwent PCI with stent implantation were enrolled. Only 31 of them had analyzable IVUS results.
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.
| Characteristic | Unit | Coronary Stenting Evaluation With IVUS |
|---|---|---|
| Participants analysed | 40 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 12 |
| Age, Categorical: >=65 years | Participants | 28 |
| Age, Continuous | years | 62.2 (SD 9.2) |
| Sex: Female, Male: Female | Participants | 10 |
| Sex: Female, Male: Male | Participants | 30 |
| Region of Enrollment: United States | participants | 40 |
6. Primary Endpoint
The registry lists the primary outcome as The Accuracy (Percent of Correct Decisions) of Post-dilatation Decisions Based on the Stent Optimizer (SO) Software, With IVUS as Gold Standard., measured over On the procedure day.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percentage of correct decisions by SO |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint measures the percentage of post-dilatation decisions made using StentOptimizer that were correct when judged against IVUS. In the registry description, IVUS is the gold standard for deciding whether a stent required post-dilatation. StentOptimizer was used independently and blindly to make the corresponding decision, and accuracy was defined as the percentage of decisions matching the IVUS-based reference.
This endpoint is used to assess diagnostic agreement for a specific procedural decision. A percentage of correct classifications can communicate how often the software matched the reference in the analyzed cases. Its interpretation depends on knowing the number of evaluable decisions, the number classified correctly, and how uncertain the estimate is. The registry record does not report those result details, a confidence interval, or the primary accuracy percentage.
Agreement with IVUS is not the same as evidence that using StentOptimizer changes clinical decisions or improves patient outcomes. It also does not establish that IVUS is error-free; the registry designates it as the reference standard for this analysis. The outcome is limited to post-dilatation decisions on the procedure day and does not, by itself, measure longer-term clinical outcomes.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a clinically focused diagnostic question: whether StentOptimizer’s post-dilatation decisions agreed with IVUS-based decisions. However, the primary accuracy value is not reported in the registry record. Without the number of correct decisions and the corresponding denominator, the degree of agreement cannot be quantified from the record. There is also no reported confidence interval or other measure of uncertainty for this endpoint.
The enrollment information gives important context for interpreting any potential estimate. The registry reports 40 consecutive patients who underwent PCI with stent implantation, but only 31 had analyzable IVUS results. Since IVUS was the reference standard for the primary decision, the number of cases with usable reference assessments is relevant to what can be learned. The record does not state the primary analysis denominator or explain why some IVUS results were not analyzable. Consequently, the completeness and selection of cases contributing to the accuracy assessment cannot be evaluated.
The design supports an assessment of agreement, not a causal claim that one diagnostic strategy is better than another. The record describes the study as observational because all three modalities were part of the clinical procedure outside the study and the analyses were retrospective. Allocation is not stated, and the registry does not describe a randomized comparison. A percentage of correct decisions, even if available, would describe performance relative to the designated IVUS reference in the analyzed cases; it would not by itself show that use of the software changes management or improves health outcomes.
Secondary outcomes concern correlations in stent diameter measurements involving StentOptimizer, QCA, and IVUS. Their numerical results are not reported in the registry record. Correlation and agreement also answer different questions: correlation describes how measurements vary together, while agreement concerns how close paired measurements are. A strong relationship between measurements would not alone demonstrate that they are interchangeable for a particular decision.
The adverse-event listing reports zero serious and zero other adverse events for the study group, with 40 at risk in each category. The record does not provide a duration of safety follow-up or further detail about ascertainment. Those counts should therefore be read as registry-reported events for this group, not as proof that the procedures or assessment methods carry no risk.
Overall, the record establishes the intended comparison and some features of the study population and design, but it does not provide the efficacy-style numerical findings needed to judge diagnostic performance. Conclusions about accuracy, precision, diameter-measurement relationships, or influence on treatment strategy cannot be drawn from the information reported.
9. Statistical Methods Explained
Diagnostic accuracy evaluates how an index method classifies cases relative to a reference standard. In this study, StentOptimizer is the index method and IVUS is the designated reference for deciding whether post-dilatation was required. The registry’s primary outcome is the percentage of software decisions that were correct against that reference. This definition focuses on matching decisions, rather than on a comparison of clinical outcomes.
For an accuracy percentage to be interpretable, its numerator and denominator need to be clear. The numerator would represent decisions matching the reference, and the denominator would represent the decisions included in that calculation. The registry describes 40 enrolled patients and says 31 had analyzable IVUS results, but it does not report the primary accuracy result or the exact denominator used. It also does not report how the cases without analyzable IVUS were handled in the primary analysis. The percentage therefore cannot be independently interpreted or checked using the registry record.
A reference standard is a method treated as the basis for classifying a condition or decision for an evaluation. Calling IVUS the gold standard in this registry means that its decision is the benchmark used to assess StentOptimizer. It does not establish that IVUS is infallible. If the reference classification has error, agreement with it can differ from agreement with the underlying truth. This is a general limitation of diagnostic-accuracy studies, and the registry does not report a separate procedure for resolving uncertain or discordant IVUS decisions.
Blinding and independent assessment are relevant because knowledge of one method’s result can influence interpretation of another method. The registry states that StentOptimizer decisions were made independently and blindly relative to the IVUS-based decisions. That description helps clarify the intended assessment process. Further procedural details, including how assessments were organized and whether blinding was maintained in every case, are not reported in the registry record.
Accuracy percentages are also affected by the mix of cases and decisions in the population being assessed. For example, an overall percentage can conceal different performance across decision categories. General diagnostic evaluation may therefore consider measures such as sensitivity and specificity, which separately describe classification of reference-positive and reference-negative cases. The registry does not report those measures, the underlying classification counts, or a breakdown by decision category. They cannot be reconstructed from the reported information.
A confidence interval expresses uncertainty around an estimate, reflecting that an observed result in a study sample may not exactly represent performance in a broader population. A narrower interval generally indicates greater precision, while a wider interval indicates more uncertainty. The registry record does not report a confidence interval for the primary outcome. Without an estimate and its uncertainty, it is not possible to judge how precisely the study measured decision accuracy.
The secondary diameter outcomes are described as correlations between measurements from StentOptimizer and IVUS, and between QCA and IVUS. Correlation is a measure of the strength and direction of association between paired measurements. In general, correlation can be high even when two methods differ systematically in their measurement values. Assessment of interchangeability would require information about the differences between paired measurements and an appropriate agreement analysis. Those numerical findings and methods are not reported in the registry record, so the listed correlation questions cannot be evaluated.
Multiplicity arises when multiple outcomes or analyses are examined. In general, conducting several statistical tests can increase the chance of finding at least one apparently noteworthy result by chance, particularly when all are treated as confirmatory. The registry lists four outcome measures and three analyses, but it does not report a multiplicity strategy, a hierarchy among outcomes, or which analyses were intended to be confirmatory. The reported counts alone do not establish which comparisons were performed or how their interpretation was adjusted.
The study’s observational and retrospective character also shapes interpretation. In general, randomized allocation can help balance participant characteristics across comparison groups, whereas observational analyses may be affected by selection and other sources of bias. This study is not described as a randomized comparison and has no stated allocation process. Its central use of paired diagnostic assessments is different from an intervention comparison, but the absent allocation details and retrospective analysis still limit claims about how using one method would affect clinical decisions.
The sample-size planning material is described as an illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Such planning calculations are not observed power and are not evidence that a study was designed with those assumptions. The registry does not report its own sample-size justification. Moreover, the equal-allocation assumption does not correspond to the registry’s description of an observational study group and should not be treated as a description of actual allocation.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists four outcome measures and three analyses. It identifies the primary accuracy outcome and names secondary diameter-correlation outcomes, but the registry record does not report a formal multiplicity plan, an outcome hierarchy beyond those labels, or a statistical analysis plan. It is therefore unclear whether any adjustment for multiple analyses was intended or how results were to be distinguished as confirmatory or exploratory. The outcome and analysis counts do not establish which specific tests were conducted.
Missingness is relevant to the primary endpoint because the registry reports 40 enrolled patients but says only 31 had analyzable IVUS results. It does not report why some IVUS results were not analyzable, whether the issue arose before or after StentOptimizer assessment, or how cases without usable IVUS were handled. The exact primary analysis denominator is not reported in the registry record. The number enrolled should not automatically be taken as the number contributing to the accuracy calculation.
The registry does not report an analysis population definition, such as which participants were included for each outcome, or how incomplete diameter measurements were handled. It also does not state whether missingness was assessed for patterns or whether any sensitivity analysis was used. These details matter because an analysis limited to cases with complete assessments may not represent all enrolled patients if availability of usable measurements is related to participant or procedure characteristics.
These are reporting gaps, not evidence that a particular method was or was not used. The registry record does not provide enough information to assess how missing data or multiplicity may have affected the reported analyses.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Coronary Stenting Evaluation With IVUS | 0 | 40 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Coronary Stenting Evaluation With IVUS | 0 of 40 |
The adverse-event listing identifies the group as “Coronary Stenting Evaluation With IVUS” and reports zero serious adverse events and zero other adverse events, with 40 at risk in each category. These are the registry’s recorded counts for the listed group. The death field is not reported in the registry record.
Zero recorded events should be interpreted as a count in this registry entry, not as proof that no adverse events could occur or that the procedure and assessment methods are risk-free. The record does not provide a safety follow-up duration, detailed definitions of the event categories, or information about how events were collected and adjudicated. It also does not report whether safety data were collected retrospectively or through a separate prospective process.
The safety counts do not establish a comparative safety difference. The study is not described as a randomized comparison and the registry lists one study group rather than a like-for-like control group. These figures therefore describe the recorded events in that group, without supporting a causal comparison between diagnostic approaches.
12. What the Result Does, and Does Not, Mean
The study addresses whether decisions made using StentOptimizer matched decisions based on IVUS for post-dilatation on the procedure day. This is a relevant diagnostic-performance question because it concerns agreement on a specific procedural decision. The registry also sets out secondary questions about the relationship between diameter measurements from the software, QCA, and IVUS.
The record does not report the primary accuracy percentage or the numerical results of the secondary outcomes. It also does not report confidence intervals or the underlying counts needed to assess uncertainty. As a result, the registry entry does not establish how often the methods agreed, how precisely agreement was estimated, or how closely their diameter measurements corresponded.
Even if agreement results were available, their meaning would remain specific to this assessment and its reference method. Agreement with IVUS would indicate concordance with the registry’s designated standard in the analyzed cases. It would not alone show that using StentOptimizer changes clinician behavior, improves the quality of a decision, or leads to better patient outcomes. Those questions require evidence beyond a retrospective comparison of decisions and measurements.
The study’s observational classification is also important. The registry says the modalities were part of the clinical procedure outside the study and the analyses were retrospective. It does not describe random assignment or a like-for-like control comparison. The findings therefore should not be interpreted as a causal comparison of clinical strategies.
Finally, only 31 of the 40 enrolled patients had analyzable IVUS results, and the reason and handling of the unavailable reference assessments are not reported. This limits assessment of the analyzed population. The most supportable conclusion is that the registry records a planned diagnostic-agreement question and describes its general assessment approach, but does not report the outcome values needed to determine the observed performance.
13. Why This Trial Matters Statistically
This study is statistically notable because its principal question is about diagnostic agreement rather than treatment efficacy. A method can be evaluated by comparing its classifications with a reference decision, but the resulting accuracy measure is meaningful only when the reference, denominator, and handling of unavailable assessments are clear. The registry identifies IVUS as the reference and describes independent, blind assessment by StentOptimizer, while leaving the primary result and analysis denominator unreported.
The record also illustrates why correlation and agreement should not be used interchangeably. The secondary questions concern correlations among stent diameter measurements. Correlation can describe whether measurements move together, but it does not by itself show that one measurement method can replace another without consequential differences. Interpreting interchangeability requires attention to measurement differences and their uncertainty, which are not reported.
Another statistical issue is the relationship between the intended study and planning assumptions. The registry describes an observational study with one group and no stated allocation procedure, while its planning illustration uses equal allocation between two arms. Planning assumptions are not a description of the actual design, and a planning calculation based on an observed effect is not observed power. The registry does not report its own sample-size justification.
Finally, the incomplete availability of analyzable IVUS results highlights the importance of defining the analysis population. Diagnostic accuracy depends on evaluable paired assessments, and the record does not say why some reference results were unavailable or how those cases were treated. Together, these features show why registry design descriptions, outcome definitions, and transparent numerical reporting are all needed before a diagnostic-performance result can be interpreted.
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 for interpretation is that the registry record does not report the primary accuracy percentage, the underlying classification counts, or a confidence interval. Without these, the observed agreement and its precision cannot be assessed. The registry also does not report numerical results for its secondary diameter-measurement outcomes.
The analysis population is not fully described. The record reports 40 enrolled patients and 31 with analyzable IVUS results, but does not explain why some results were not analyzable, state the primary outcome denominator, or describe how unavailable assessments were handled. This prevents evaluation of possible selection effects related to missing reference results.
The study is observational and retrospective, with the modalities used as part of the clinical procedure outside the study. Allocation is not stated, and the registry does not describe a randomized comparison. The assessment can address concordance with IVUS, but it does not provide a randomized estimate of the effect of using one strategy rather than another.
Additional statistical details are absent: the registry record does not report a formal analysis plan, multiplicity handling, interval estimation, or detailed methods for the diameter-correlation analyses. The record also does not explain how treatment-strategy influence was assessed. The adverse-event listing lacks reported follow-up duration and event-ascertainment details. These omissions constrain assessment of both the diagnostic findings and safety counts.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Comparison of StentOptimizer With IntraVenous Ultrasound and 2D Quantitative Coronary Angiography — NCT00973921.
- Registry record last updated 2014-04-11; status last verified 2014-03.
- Results first posted 2014-04-11.
- 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.
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18. Record Summary
NCT00973921 is a completed observational study sponsored by Paieon Inc. It concerns StentOptimizer, an angiography-based software application for post-deployment stent analysis, and compares its decisions and diameter measurements with IVUS and QCA. The registry lists coronary artery disease as the condition and gives a study start of 2009-09 and primary completion of 2010-03.
The primary endpoint is the percentage of StentOptimizer post-dilatation decisions that agreed with IVUS, designated as the gold standard. The record describes 40 consecutive patients undergoing PCI with stent implantation; 31 had analyzable IVUS results. It also lists secondary diameter-correlation outcomes involving StentOptimizer, QCA, and IVUS.
The registry describes the analyses as retrospective and the study as observational. It does not report the primary accuracy value, secondary outcome results, or their uncertainty. The adverse-event listing records zero serious and zero other adverse events for the study group, with 40 at risk in each category.