Regadenoson Stress-MRI to Identify Coronary Artery Disease in Atrial Fibrillation Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Regadenoson Stress-MRI to Identify Coronary Artery Disease in Atrial Fibrillation Patients (NCT01710254), a na phase 2 study. The primary outcome is Sensitivity of Regadenoson Stress-MRI for Detection of Coronary Artery Disease (CAD).

2. Clinical Question

3. Trial Design

This was a completed phase 2 study sponsored by the University of Utah. The registry records a start date of 2013-01 and primary completion in 2016-10. Enrollment was 30. The design is listed as single-group, with no allocation to multiple arms and no masking. Participants with atrial fibrillation received regadenoson stress MRI using gadobenate dimeglumine.

The study evaluated a diagnostic test rather than comparing assigned treatments. Its primary outcome was sensitivity of regadenoson stress MRI for detecting coronary artery disease, with x-ray angiography serving as the reference standard. The registry also lists accuracy of regadenoson stress MRI for coronary artery disease detection as a secondary outcome. It identifies three outcome measures in total, but numerical results for the outcomes are not reported in the registry record.

The primary outcome description says perfusion images were interpreted as normal or abnormal by three blinded readers, and that the majority result was reported. The registry's overall masking entry is NONE; the description of blinded image readers is a separate feature of the image-reading procedure. What information readers were blinded to, how disagreements were handled beyond using the majority result, and whether reader agreement was assessed are not reported in the registry record.

Because there was no randomized control arm, the design cannot provide a like-for-like comparison between regadenoson MRI and another assigned test or treatment. The comparison with x-ray angiography is instead part of the diagnostic accuracy assessment. The protocol, sample-size justification, and further details of the planned statistical analysis 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

Analysis population for the primary outcome, as defined in the registry: Results for 4 subjects are unevaluable due to delays in blinded reading of MRI scans and non-comparable due to personnel turnover in blinded MRI readers

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 Sensitivity of Regadenoson Stress-MRI for Detection of Coronary Artery Disease (CAD), measured over one MRI, up to 1 hour.

The primary endpoint was sensitivity of regadenoson stress MRI for detecting coronary artery disease. The registry defines the measure as the percentage of true positive cases and identifies a 95% confidence interval as the dispersion measure. The timeframe is one MRI, up to 1 hour.

In general, sensitivity describes how often a diagnostic test classifies disease as present among cases that have disease according to the chosen reference standard. Here, x-ray angiography was designated as that standard. The MRI perfusion images were classified as normal or abnormal by three blinded readers, with the majority reading reported. Thus, the outcome concerns the performance of the MRI classification against the angiography classification, not a treatment effect.

Sensitivity is useful for describing detection of disease, but it does not by itself describe how well a test classifies people without disease. Specificity addresses that complementary aspect, while accuracy combines classifications across disease-positive and disease-negative cases. The registry's stated objective mentions sensitivity and specificity, and a secondary outcome is accuracy; however, numerical results for these outcomes are not reported in the registry record. The sensitivity estimate and its confidence interval are also not reported, so the observed performance and its precision cannot be assessed from the registry entry.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Diagnostic accuracy is evaluated by comparing a test under study with a reference standard. In this study, the test was regadenoson stress MRI and the reference standard was x-ray angiography. For the primary endpoint, an MRI classification of abnormal in a case classified as having coronary artery disease by angiography contributes to sensitivity. An MRI classification of normal in a case classified as not having disease by angiography is relevant to specificity. These are general definitions; the registry does not report the underlying classification counts.

What does sensitivity describe?

In general, sensitivity is the proportion of reference-standard disease-positive cases that the test identifies as positive. It focuses on detection among people classified as having the condition by the reference standard. It does not reveal, by itself, how often a positive test occurs among people classified as disease-free. The primary endpoint is explicitly sensitivity, expressed as a percentage of true positive cases. The registry does not report its numerical value.

How does specificity differ?

In general, specificity is the proportion of reference-standard disease-negative cases that the test classifies as negative. Sensitivity and specificity describe different parts of diagnostic performance, so a sensitivity result alone cannot establish specificity. The study objective mentions both measures and states 90% sensitivity and 80% specificity as comparison benchmarks from meta-analyses of non-AF patients using adenosine. These are not reported findings from the study population. Numerical specificity results are not reported in the registry record.

What does accuracy add?

In general, accuracy describes the share of classifications that agree with the reference standard across both disease-positive and disease-negative cases. It can be influenced by the mix of participants with and without disease, so it should be interpreted alongside sensitivity and specificity and with an understanding of the study population. Accuracy is listed as a secondary outcome, but its numerical result and detailed calculation are not reported in the registry record.

Why is the confidence interval relevant?

A confidence interval expresses uncertainty around an estimated quantity under the assumptions of the statistical method. The registry specifies a 95% confidence interval for the primary sensitivity outcome, but does not report its bounds or the sensitivity estimate. Without those values, readers cannot judge the precision of the estimate or whether a range of plausible values is narrow or broad. A confidence interval is not a guarantee that the true value lies within the interval; it is a statistical summary interpreted under the method's assumptions.

What does reader blinding and majority interpretation mean?

The outcome description says three blinded readers classified perfusion images as normal or abnormal, and the majority result was reported. In general, blinding can reduce the influence of information outside the image interpretation on a reader's classification. A majority rule provides a way to produce one classification when several readers assess an image. The registry does not state what information was concealed from readers, whether readings were independent, whether disagreements were reviewed, or whether agreement among readers was quantified. The registry also lists study masking as NONE, so the reader-blinding description should be understood as a feature of image reading rather than as evidence that the entire study was masked.

What can planning calculations establish?

In general, sample-size calculations estimate how many observations might be needed under specified assumptions to detect a chosen effect with a chosen level of statistical power. The planning framework described for this study is an illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. These calculations are planning illustrations, not evidence of observed power and not the trial's own design justification. This study is listed as a single-group study, and its protocol and sample-size justification are not reported in the registry record. No planning count or observed effect value is reported in the registry record.

More broadly, diagnostic estimates depend on the enrolled population, the reference standard, and how the test classifications are obtained. In general, imprecise classification or differences in reader interpretation can add uncertainty. The registry describes the reference standard and majority interpretation but does not report additional validation procedures, reader agreement, or detailed statistical methods. Those omissions limit how fully the analysis can be independently evaluated.

10. Multiplicity, Missing Data and Analysis Populations

The registry identifies three outcome measures: the primary sensitivity outcome and a secondary accuracy outcome are named, while the remaining outcome is not specified in the record. It lists no analyses. The analysis plan, any hierarchy among outcomes beyond the primary designation, and any adjustment for testing multiple outcomes are not reported in the registry record. In general, when several outcomes are examined, the chance of a chance-positive finding can increase if each is tested without accounting for multiplicity. Whether that issue arose, or how it was handled, cannot be determined from the registry entry.

The registry says results for 4 subjects are unevaluable because of delays in blinded MRI reading and non-comparability associated with turnover among blinded MRI readers. It does not report the primary analysis population, participant-level outcome availability, or whether any missing or unevaluable results were included, excluded, or handled through another method. The number analyzed for each outcome is not reported in the registry record.

In general, missing outcome information can affect both precision and the interpretation of an estimate, particularly if the availability of results is related to participant characteristics or test findings. The registry does not report enough information to assess whether the unevaluable cases differed from those with evaluable results or whether the missingness could have influenced the estimate. The record also does not report an intention-to-diagnose population, a per-protocol population, or another defined analysis population. Consequently, the handling and potential impact of unavailable results remain unclear.

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 5% reporting threshold.

Most frequent non-serious adverse event terms

The registry lists 30 participants at risk for serious adverse events and records 0 participants affected. It lists 30 participants at risk for other adverse events and records 15 affected. It also records 0 deaths. No serious adverse-event terms are listed.

These figures describe the counts recorded in the registry; they do not establish that an intervention caused or did not cause an event. The record does not report event details, severity categories for the other adverse events, timing, follow-up duration, or an assessment of relatedness. It also does not explain in this entry how adverse events were defined or collected. The absence of listed serious-event terms should therefore be read as the registry's reported serious-event tally, not as proof that no safety issues of any kind occurred. The 15 participants recorded with other adverse events are a count, not a description of their nature or clinical significance.

Because this was a single-group study, these counts do not provide a randomized safety comparison with another group. The adverse-event figures should be interpreted separately from diagnostic performance: they do not indicate whether MRI classifications agreed with angiography.

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

The registry record establishes that a completed phase 2, single-group study enrolled 30 participants with atrial fibrillation and evaluated regadenoson stress MRI for coronary artery disease detection. It specifies x-ray angiography as the reference standard for the primary sensitivity outcome and describes a majority interpretation of images by three blinded readers. It also documents that results for 4 subjects were unevaluable, citing delays in blinded reading and non-comparability associated with reader personnel turnover.

Those design details explain what the study intended to measure, but the registry does not report numerical sensitivity, specificity, accuracy, or confidence interval results. It therefore does not show how well MRI classifications matched angiography classifications in the analyzed participants, how precise any estimate was, or whether performance was comparable to the stated benchmarks. The benchmarks of 90% sensitivity and 80% specificity are part of the objective, not the study's reported outcome values.

In general, diagnostic performance in a study population does not automatically transfer to other populations or settings. Interpretation depends on the participants studied, the reference standard, and the way images are read. Here, the registry record does not provide enough outcome or analysis information to assess performance or its uncertainty. The single-group diagnostic design also does not estimate a treatment effect or establish a comparison with another assigned strategy.

The safety entry records 0 serious adverse events among 30 at risk, 15 participants with other adverse events among 30 at risk, and 0 deaths. These counts do not by themselves establish causation, and event descriptions and follow-up details are not reported. Taken together, the record describes a diagnostic evaluation and a limited set of safety counts; it does not provide the numerical outcome evidence needed to draw conclusions about diagnostic accuracy.

13. Why This Trial Matters Statistically

This trial is statistically notable for asking a diagnostic-accuracy question in a population identified by the registry as having atrial fibrillation, rather than testing a treatment effect between randomized groups. That distinction determines what the primary estimate would mean: sensitivity relative to angiography, not a difference in outcomes between interventions. It also explains why a diagnostic reference standard and a clearly specified image-reading process are central to interpretation.

The registry describes three blinded readers and a majority classification, which makes reader procedure part of the measurement method. In general, a diagnostic test result can depend on how images are interpreted, so reader procedures matter when judging reproducibility and potential sources of variation. The reported turnover among blinded MRI readers and the designation of 4 subjects' results as unevaluable make the availability and comparability of readings especially relevant. The registry does not provide enough detail to quantify the effect of these issues.

The study objective gives sensitivity and specificity benchmarks from meta-analyses of non-AF patients using adenosine. Such a benchmark can frame a research question, but it is not a substitute for outcome estimates in the population under study. The registry does not report the sensitivity, specificity, accuracy, or confidence interval results needed to evaluate the objective statistically.

More generally, the record illustrates why design, endpoint definition, analysis population, precision, and missing-result handling must be considered together. Enrollment alone does not reveal the precision of a diagnostic estimate, and a confidence interval cannot be interpreted without its reported bounds. Because this entry does not report numerical outcome results or key analysis details, it documents the question and methods more fully than it documents the statistical evidence answering that question.

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 numerical results for the primary and secondary outcomes are not reported in the registry record. The primary sensitivity estimate and its 95% confidence interval are absent, as are numerical results for accuracy and any reported specificity. Without outcome counts or estimates, diagnostic performance and statistical precision cannot be assessed.

The record identifies results for 4 subjects as unevaluable, citing delays in blinded MRI reading and non-comparability associated with turnover among blinded MRI readers. It does not report the number included in each outcome analysis, the handling of these cases, or whether evaluable and unevaluable participants differed. This prevents assessment of the potential influence of unavailable results.

Further details of the statistical analysis are not reported in the registry record. These include the analysis population, the method used to form the confidence interval, any treatment of multiple outcomes, and any sensitivity analyses. The registry describes x-ray angiography as the reference standard and a majority result from three blinded readers, but does not report reader agreement, the exact information concealed from readers, or additional image-adjudication procedures.

The single-group design has no randomized control arm, so it does not support a direct randomized comparison of interventions. The registry's stated benchmarks are from non-AF patients using adenosine and are not study findings. The record also does not report the protocol or sample-size justification. These limitations restrict conclusions about both the observed diagnostic performance and how broadly any findings might apply.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Regadenoson Stress-MRI to Identify Coronary Artery Disease in Atrial Fibrillation Patients — NCT01710254.
• Registry record last updated 2017-12-13; status last verified 2017-11.
• Results first posted 2017-11-07.
• 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

NCT01710254 is a completed phase 2, single-group study sponsored by the University of Utah, with enrollment of 30. It evaluated regadenoson stress MRI using gadobenate dimeglumine in participants with atrial fibrillation. The primary outcome was sensitivity for detecting coronary artery disease against x-ray angiography, with a 95% confidence interval specified and a timeframe of one MRI, up to 1 hour. Three blinded readers classified perfusion images as normal or abnormal, and the majority result was reported.

The registry also lists accuracy as a secondary outcome and states an objective of comparing sensitivity and specificity with 90% and 80% benchmarks, respectively. These are objective benchmarks, not reported study results. Numerical outcome estimates and confidence interval bounds are not reported in the registry record. Results for 4 subjects are described as unevaluable. Safety counts list 0 serious adverse events, 15 participants with other adverse events, and 0 deaths.