Regadenoson Real Time Perfusion Imaging Trial-Optison: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Regadenoson Real Time Perfusion Imaging Trial-Optison (NCT01489176), a na phase 3 study. The primary outcome is Number of Participants With Coronary Stenosis.

2. Clinical Question

In practical terms, the study asks whether coronary stenosis meeting the specified angiographic threshold is identified among participants undergoing Regadenoson stress real-time myocardial perfusion echocardiography with Optison. The official title refers to feasibility and accuracy and mentions two different ultrasound contrast agents, while the listed intervention names Regadenoson and Optison. A second intervention group or a direct comparison is not described in the registry record. The single-group design can describe outcomes in the participants who received the listed intervention, but by itself it does not establish a contrast between that intervention and an alternative. The registry record does not report participant selection details, the echocardiographic classification results, or a comparison of those classifications with angiography. Consequently, the primary question can be stated from the registered endpoint, but the degree of diagnostic accuracy cannot be determined from the registry information available.

3. Trial Design

This is a phase 3, completed, single-group study sponsored by the University of Nebraska. The registry records enrollment of 50 participants and lists Regadenoson; Optison as the intervention. Its description specifies Regadenoson as the chemical stress agent and Optison as the contrast agent used during stress echocardiography. Allocation is recorded as not applicable, and masking is listed as none.

The study began on 2012-07-31, with primary completion recorded as 2014-04-01. The overall status is completed. These dates and status describe the study record; they do not establish when individual participants were assessed or how many completed each measurement. Those participant-level details are not reported in the registry record.

The single-group structure matters when interpreting the endpoint. No randomized or otherwise specified control group is identified, so the registered design does not support a like-for-like treatment comparison. The record lists a count of participants with coronary stenosis, rather than a comparative endpoint between intervention groups. It does not describe a separate group receiving another stress agent or contrast agent, nor does it report allocation procedures beyond the not-applicable designation.

The registry lists one outcome measure and no analysis entries. The analysis plan, eligibility criteria, recruitment setting, and sample-size justification are not reported in the registry record. The official title refers to two different contrast agents, but the intervention and arm description posted in the registry record identify only Regadenoson with Optison. The design information therefore supports describing a single-group study of this combination, but not inferring an unlisted comparison or protocol detail.

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

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 Number of Participants With Coronary Stenosis, measured over 1 year.

The primary endpoint is the number of participants with coronary stenosis greater than 50% in diameter, identified by quantitative cardiac angiography. Its stated timeframe is 1 year. This is a participant count: the endpoint concerns how many participants meet the specified angiographic criterion, not a change in a continuous measurement or a time-to-event outcome.

For an individual participant, the criterion amounts to classifying whether the angiographic finding meets the stated threshold. Aggregating those classifications produces a count. A count can describe how many participants had the finding, but its interpretation depends on knowing how many participants had the endpoint assessed. The registry record does not report the observed count, an assessed-participant denominator, or the result of the measurement.

The endpoint is relevant to the study’s stated interest in detecting coronary artery disease because it uses an angiographic finding to identify participants meeting a defined stenosis criterion. However, the count alone is not a complete measure of diagnostic accuracy. Assessing accuracy would also require the echocardiography-based classifications and their relationship to the angiographic findings. Those results are not reported in the registry record. The registered definition therefore establishes what was intended to be counted, but it does not establish how well the imaging approach identified stenosis.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical interpretation begins with the type of endpoint. The registry defines the primary outcome as a count of participants meeting an angiographic criterion. Although it is reported as a count, the underlying participant-level status is categorical: a participant either meets the stated stenosis criterion or does not. The registry record does not report the count or the number assessed, so neither an observed proportion nor its uncertainty can be described.

What does a count endpoint tell us?

A count communicates how many participants had the defined finding. To interpret a count as a rate or proportion, the relevant denominator must also be known. Enrollment is recorded as 50, but the registry record does not state whether every enrolled participant had the endpoint assessed or was included in its analysis. Therefore, enrollment should not automatically be used as the endpoint denominator. This distinction matters whenever participants can have unavailable measurements, be excluded from an analysis, or have follow-up that differs from the planned timeframe.

In general, a confidence interval expresses uncertainty around an estimate. For a binary participant-level outcome, an interval around a proportion can help readers judge how precisely the observed frequency has been estimated. An interval is not reported for this outcome in the registry record, and no result can be reconstructed from the information recorded. The same limitation applies to a p-value or other inferential statistic: none is reported, and the endpoint count alone would not establish one.

Why does the single-group design matter?

A single-group study describes outcomes among participants who receive the listed intervention. It does not, without a suitable comparison group, isolate differences that might be attributed to one intervention rather than another. Here, allocation is listed as not applicable, masking is listed as none, and the study model is single-group. No separate comparator is described. Thus, a between-group treatment effect is not defined by the registered design details.

The study’s stated interest in detection and accuracy raises a different statistical question from a treatment comparison. Diagnostic accuracy generally requires knowing how the test classifies participants and how those classifications correspond to a reference assessment. In this record, quantitative cardiac angiography defines the stenosis endpoint, but the echocardiography classifications and their cross-classification with angiography are not reported. Sensitivity, specificity, agreement, and related measures therefore cannot be interpreted from the registry record. This is a general distinction between counting a condition and evaluating a test’s ability to identify it.

How should the planning illustrations be read?

The sample-size material is described as a planning illustration computed from the observed effect, not as the trial’s own design. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. The registry study itself is single-group, so those two-arm assumptions do not mirror its recorded design. A planning illustration describes sample sizes under its assumptions. It is not the number enrolled, an observed outcome, or observed power.

Sample-size calculations are conditional on an assumed effect and a specified analysis. If the effect estimate used as the basis is not available in the registry record, the illustration cannot be independently interpreted as a trial-specific design rationale. The trial’s own sample-size justification is not reported in the registry record. The calculations should therefore be understood only as planning scenarios, not as evidence that the completed study had a particular probability of detecting an effect.

In general, over-dispersion means that observed variability is greater than a model assumes. When a count model is used, ignoring over-dispersion can make uncertainty appear too small. This concept is not a reported feature of this trial’s analysis: the endpoint is specified as a participant count, and no model, dispersion estimate, or analysis is reported in the registry record. It would be inappropriate to assert that over-dispersion occurred or that a particular count model was used.

What analysis details are available?

The registry lists one outcome measure and no analysis entries. It does not report the statistical test, model, confidence interval method, covariate adjustment, missing-data method, or analysis population. Those omissions prevent a detailed reconstruction of how the endpoint was analyzed. General statistical concepts can clarify what such methods would ordinarily address, but they cannot fill in the unreported analysis plan for this study.

For diagnostic evaluation, the relationship between the imaging result and angiography would usually be central to assessing classification performance. For estimation of a participant-level frequency, the denominator and uncertainty around the estimate would be central. These are general methodological considerations, not claims that the registry reports those analyses. Since the relevant result details are not reported in the registry record, the most defensible statistical reading is to separate the clearly defined endpoint from unreported estimates and methods.

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("Regadenoson; Optison")
n      <- c(50)
events <- c(50)
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  Regadenoson; Optison  50  50  100.0  92.9  100.0  92.9  100.0  93.0  100.0

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and no analysis entries. It does not report how many comparisons, subgroups, or outcome analyses were planned beyond the listed measure, nor does it describe any multiplicity adjustment. A listed primary outcome helps identify the main registered measure, but does not establish that no additional analyses were conducted. The analysis plan is not reported in the registry record.

Missing-data information is also absent. The record does not state how many participants had angiography, whether any primary endpoint assessments were unavailable, how missing observations were handled, or whether participants were excluded from an analysis. Enrollment of 50 is recorded, but this is not enough to determine the denominator for the primary endpoint. No analysis population, such as all enrolled participants or only those with evaluable measurements, is specified in the registry record.

These omissions limit interpretation in distinct ways. Multiplicity concerns how to interpret results when several hypotheses or analyses are considered; missingness concerns which observations contribute to an estimate and whether the available observations represent the enrolled group. Without the analysis plan and participant flow information, readers cannot assess either issue for this study. The registry record also does not report a primary endpoint result or uncertainty estimate, so there is no reported finding on which to evaluate the effects of multiplicity or missing data.

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 non-serious adverse event terms

The registry lists 50 participants at risk for serious adverse events and records 0 participants affected in that category. It records 0 deaths. For the separate other-adverse-event category, 50 participants are listed at risk and 50 are recorded as affected. These are the safety figures entered in the registry; they should be read as recorded counts, not as descriptions of the particular events experienced.

The registry does not list serious adverse-event terms, and the specific other adverse events are not described in the record. It also does not provide details about event timing, duration, severity within the other category, attribution, or whether participants experienced more than one event. The figures alone therefore do not identify the types of events or explain their clinical context.

The at-risk count is the denominator recorded for each category. It should not be confused with the primary endpoint assessment population, which is not reported. These safety entries are descriptive registry data and do not establish a comparison with another group, since no comparator group is described. They also do not, by themselves, establish a causal relationship between the intervention and any event.

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

The registry record establishes what the study set out to measure: the number of participants with coronary stenosis greater than 50% in diameter by quantitative cardiac angiography within a timeframe of 1 year. It also records enrollment of 50 participants in a completed, single-group study of Regadenoson with Optison. Those details describe the study’s design and intended endpoint, not its observed diagnostic result.

The primary endpoint result is not reported in the registry record. Nor are the echocardiographic classifications or their relationship to angiography reported. As a result, the record does not establish how many participants met the stenosis criterion, how many were assessed, or how accurately stress echocardiography identified the finding. The title and stated purpose express the study’s topic, but do not supply evidence of a diagnostic result.

The single-group design also limits comparative conclusions. No like-for-like control group is described, so the registry does not provide a between-group estimate of differences in diagnostic performance or outcomes. No estimate with uncertainty is reported. Without those results, the data in the registry cannot be used to judge the size or precision of an effect.

These limits do not mean that the procedure succeeded or failed; neither conclusion follows from the information recorded. They mean that the registered design and endpoint can be described, while the outcome and diagnostic evidence needed to evaluate the stated accuracy question are not reported in the registry record. The safety counts are also descriptive and do not supply a comparison or causal assessment.

14. Why This Trial Matters Statistically

This trial is statistically notable because its stated interest is diagnostic detection, while its registered primary outcome is a count of participants meeting an angiographic stenosis threshold. Those are related but not interchangeable questions. A count describes how many participants had the specified finding; evaluating detection accuracy requires information about how the imaging assessment classified participants relative to angiography. The latter information is not reported in the registry record.

The single-group design is another important feature. Without a separate comparator, the record does not define a direct comparison of Regadenoson with Optison against another approach. This affects what kinds of estimates can be supported: descriptive findings in a single group are different from comparative evidence. The registry records no analysis entries, so it does not clarify whether or how the stated diagnostic question was analyzed.

The case also illustrates why denominator and missing-data details matter for count outcomes. Enrollment is recorded as 50, but the registry does not state how many participants contributed an endpoint assessment. A count cannot be interpreted as a participant-level frequency without knowing the number assessed. An estimate’s precision likewise cannot be judged without a result and its uncertainty.

Finally, planning illustrations should be kept separate from the study’s actual design and findings. The stated illustration assumptions include equal allocation between two arms, whereas the registered trial is single-group. Reading those assumptions as if they described the completed study would blur the difference between a hypothetical planning scenario and an observed analysis. The registry record’s design, outcome definition, and missing result together make this distinction particularly important.

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.

The registry record leaves several trial-specific details unavailable. It does not report eligibility criteria, participant characteristics, recruitment setting, or how many enrolled participants completed the endpoint assessment. The recorded enrollment of 50 therefore cannot be assumed to be the number included in the primary outcome analysis. The handling of missing measurements and the definition of the analysis population are not reported in the registry record.

The endpoint itself is described, but its result is not. The record does not give the observed number of participants meeting the angiographic criterion, an assessed-participant denominator, or an uncertainty estimate. It also does not report the echocardiography classifications needed to evaluate diagnostic accuracy against angiography. Although the official title refers to two different contrast agents, the listed intervention and arm description specify Regadenoson with Optison; a second intervention group is not described in the registry record.

The design is single-group, allocation is recorded as not applicable, and masking is listed as none. No comparator is described, limiting what can be concluded from the design about differences between approaches. The statistical analysis plan, the trial’s own sample-size justification, and any approach to multiplicity are not reported in the registry record. Sample-size illustrations with two-arm assumptions should not be mistaken for the registered design or the trial’s original plan.

The safety record gives counts but does not provide event terms or further context. Taken together, these limitations mean that the registry supports a clear description of the intended endpoint and the recorded design, but not a complete evaluation of diagnostic performance, precision, participant flow, or comparative safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Regadenoson Real Time Perfusion Imaging Trial-Optison — NCT01489176.
• Registry record last updated 2024-10-08; status last verified 2024-10.
• Results first posted 2022-12-30.
• 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

NCT01489176 is a completed phase 3, single-group study sponsored by the University of Nebraska. The registry records enrollment of 50 participants, no masking, and allocation as not applicable. The listed intervention is Regadenoson with Optison during stress echocardiography.

The primary outcome is the count of participants with coronary stenosis greater than 50% in diameter by quantitative cardiac angiography, with a timeframe of 1 year. The registry record lists one outcome measure and no analysis entries, but does not report the primary outcome result, its denominator, or diagnostic accuracy estimates. Serious adverse events were recorded for 0 of 50 participants at risk, other adverse events for 50 of 50, and deaths for 0. Event details are not reported in the registry record.

The study began on 2012-07-31 and reached primary completion on 2014-04-01. The registered design and endpoint are identifiable, but the outcome and analysis information needed to assess the stated accuracy question are not reported in the registry record.