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 PROspective Multicenter Imaging Study for Evaluation of Chest Pain (NCT01174550), a randomized na study. The primary outcome is Time to Primary Endpoint.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01174550 |
| Phase | NA |
| Condition | Chest Pain |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 10003 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Duke University |
| Results posted | Yes |
2. Clinical Question
Population
People with symptoms concerning for coronary artery disease, as described in the registry summary. The condition listed is chest pain; further eligibility criteria and the characteristics of the enrolled participants are not reported in the registry record.
Intervention
An initial anatomic diagnostic strategy. The study summary describes coronary CT angiography (CTA), while the listed intervention and arm description identify coronary angiography. This inconsistency in the registry record makes the exact anatomic test strategy unclear.
Comparator
An initial functional testing strategy, described as usual care. The functional diagnostic tests listed are stress echocardiogram, nuclear stress test, and exercise electrocardiogram.
Primary question
Whether an initial anatomic imaging strategy, compared with an initial functional testing strategy, changes the time to a composite clinical endpoint. The registry describes the intended comparison but does not report the endpoint estimates needed to answer it.
The study is titled the PROspective Multicenter Imaging Study for Evaluation of Chest Pain, or PROMISE. Its stated objective was to compare clinical outcomes after the two initial testing strategies among people whose symptoms raised concern about coronary artery disease. The primary endpoint combines death, myocardial infarction, major complications from cardiovascular procedures or testing, and hospitalization for unstable angina. This composite is intended to capture several clinically important events within a common outcome framework.
The question is about the effect of choosing an initial diagnostic strategy, not a direct comparison of the individual functional tests with each other. The registry lists the functional options, but does not report how a particular functional test was selected for a participant. It also does not provide the primary endpoint results by group or the statistical comparison between groups. The record therefore identifies the research question, but cannot establish from the posted results whether the endpoint differed between strategies or how precisely any difference was estimated.
3. Trial Design
The registry describes a prospective, multicenter, randomized trial with a parallel-group model and no masking. It records enrollment of 10003. The status is completed; the start is listed as 2010-07 and primary completion as 2014-10. Duke University is identified as the sponsor, and the phase is recorded as NA.
Participants were assigned to an anatomic diagnostic test strategy or a functional diagnostic test strategy. The functional arm description lists stress echocardiogram, nuclear stress test, and exercise electrocardiogram. The anatomic arm description lists coronary angiography. However, the study summary describes the anatomic strategy as coronary CT angiography (CTA), while the intervention list names coronary angiography. These are different terms in the registry record, and the record does not resolve the discrepancy. The intended strategy should therefore be described with this qualification rather than treating the listed procedures as interchangeable.
Random allocation is relevant because, in general, randomization aims to make treatment groups comparable with respect to both measured and unmeasured characteristics at assignment. It does not guarantee that groups are identical, and its interpretation depends on how assignment, follow-up, and analysis were conducted. The registry record does not report the randomization procedure, concealment details, or the analysis population.
The listed primary outcome is time to the primary endpoint, expressed as the percentage of participants with an event. The stated time points are 90 days, 6 months, 12 months, 18 months, 24 months, 30 months, 36 months, and 42 months. The outcome description says Kaplan-Meier event rates were estimated for the anatomic and functional groups. Estimates for those time points, confidence intervals, and a direct between-group comparison are not reported in the registry record. The record lists secondary outcomes concerning other clinical events, procedure complications, catheterization findings, medical cost, and quality of life, but does not provide their results in the posted information.
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 | Functional Diagnostic Tests | Anatomic Diagnostic Test |
|---|---|---|
| STARTED | 5007 | 4996 |
| COMPLETED | 3737 | 4123 |
| NOT COMPLETED | 1270 | 873 |
Reasons for not completing this period:
| Reason | Functional Diagnostic Tests | Anatomic Diagnostic Test |
|---|---|---|
| Death | 75 | 74 |
| Lost to Follow-up | 652 | 510 |
| Withdrawal by Subject | 543 | 289 |
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 | Functional Diagnostic Tests | Anatomic Diagnostic Test | Total |
|---|---|---|---|---|
| Participants analysed | 5007 | 4996 | 10003 | |
| Age, Continuous | years | 60.9 (SD 8.3) | 60.7 (SD 8.3) | 60.8 (SD 8.3) |
| Sex: Female, Male: Female | Participants | 2675 | 2595 | 5270 |
| Sex: Female, Male: Male | Participants | 2332 | 2401 | 4733 |
6. Primary Endpoint
The registry lists the primary outcome as Time to Primary Endpoint, measured over 90 days, 6 months, 12 months, 18 months, 24 months, 30 months, 36 months, 42 months.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percentage of participants with an event |
| Endpoint classification | Binary Endpoint |
The primary endpoint is a composite of death, myocardial infarction (MI), major complications from cardiovascular (CV) procedures or testing, and unstable angina hospitalization. The registry describes it as time to the first qualifying primary endpoint event and expresses the result as the cumulative percentage of participants with an event. Estimates were intended at 90 days, 6 months, 12 months, 18 months, 24 months, 30 months, 36 months, and 42 months.
In general, a composite endpoint combines several types of events into a shared outcome. This can make a trial outcome capture a wider range of clinically important experiences than a single event type alone. It also means that the composite should be interpreted as a whole: its components may differ in frequency and clinical meaning, and a result for the composite would not by itself show which component accounts for any observed pattern.
In general, a time-to-event measure accounts for when an event occurs, rather than simply classifying participants as having or not having an event by an unspecified point. The registry says Kaplan-Meier event rates were estimated. However, the actual rates and their uncertainty are not reported in the registry record. The record also does not report component-specific primary endpoint estimates or the statistical test used for the primary comparison, so the relative contribution of the composite components and the strength of evidence for a group difference cannot be assessed from the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record states the primary outcome definition and the times at which cumulative event rates were to be estimated. It does not report the rates for either diagnostic strategy, a difference between groups, a confidence interval, or a p-value for the primary endpoint. Consequently, the posted information does not allow a conclusion about the direction, size, or precision of the primary outcome comparison. The study’s stated hypothesis is not a result.
The endpoint is a composite that includes death, MI, major complications from CV procedures or testing, and unstable angina hospitalization. A composite result, if reported, would describe the combined outcome; it would not automatically show that every component changed in the same way. Component-specific results would be needed to understand which events contributed to the overall pattern. Such primary-component results are not reported in the registry record.
The listed primary outcome uses Kaplan-Meier cumulative event rates at multiple follow-up times. In general, those estimates describe the accumulated event probability over follow-up while accounting for incomplete observation through the method’s treatment of censored times. The registry does not report the estimates, the number of participants still under observation at each time, or the details of censoring and follow-up. Thus, the time-point schedule alone cannot indicate how event rates evolved or how much information remained at later times.
The serious adverse-event summaries report 161 affected participants in the Functional Diagnostic Tests group, with 5007 at risk, and 168 affected participants in the Anatomic Diagnostic Test group, with 4996 at risk. The other-event summaries report 16 affected participants in the Functional Diagnostic Tests group, with 5007 at risk, and 37 affected participants in the Anatomic Diagnostic Test group, with 4996 at risk. These are descriptive registry counts, not the primary endpoint results. No statistical comparison or uncertainty interval for these adverse-event counts is reported, so the counts alone do not establish a comparative effect.
The top serious-event terms include unstable angina hospitalization at 1.2%, myocardial infarction at 0.8%, death - non cardiovascular known cause at 0.7%, death - unknown cause at 0.5%, death- cardiovascular at 0.4%, and major bleeding at 0.1%. The record does not assign these term percentages to a specific randomized group in the listed summary. They should not be interpreted as a group comparison or as the primary composite endpoint’s cumulative rates.
Overall, the registry record documents a completed randomized study and describes its intended comparison, but the posted primary outcome estimates and statistical analysis are absent. Without those results, the treatment-strategy contrast cannot be quantified from this record. The distinction between an intended hypothesis and reported evidence is especially important when an outcome is defined over several event types and follow-up times.
9. Statistical Methods Explained
What does randomization contribute?
In general, randomization assigns participants to study groups by chance. Its purpose is to reduce systematic differences between groups at the point of assignment, including differences that investigators may not have measured. It does not ensure that every characteristic will be balanced, and it does not prevent differences arising after assignment, such as incomplete follow-up or departures from the assigned strategy. The record identifies the allocation as randomized, but details of sequence generation, allocation concealment, adherence, and analysis by assigned group are not reported in the registry record.
The trial is described as parallel, meaning the registry identifies separate groups assigned to the competing strategies. It is listed as unmasked. In general, lack of masking can matter for outcomes that depend on clinical decisions, reporting, or assessment, though the impact depends on the outcome and conduct of the study. The record does not describe measures used to limit possible bias in outcome assessment.
What does a time-to-event endpoint represent?
In general, time-to-event analysis uses both whether an event occurred and the time at which it occurred. It can also accommodate participants whose event status is not observed through the full follow-up period, using a censoring approach. Censoring means that the event time is only known to be later than the last observed time; it does not mean that an event definitely never occurred. The registry says Kaplan-Meier event rates were estimated, but does not report censoring rules, loss-to-follow-up information, or numbers under observation at the time points.
The primary outcome is described as the cumulative percentage of participants with an event at 90 days, 6 months, 12 months, 18 months, 24 months, 30 months, 36 months, and 42 months. These are repeated estimates over a follow-up schedule, not separate randomized comparisons. In general, estimates at later times can be less precise when fewer participants remain under observation. The record does not report the estimates or their confidence intervals, so their precision cannot be assessed.
Why use a composite endpoint?
In general, a composite endpoint combines multiple event types into a shared measure. It may capture a broader range of important outcomes and can produce more events for analysis than a narrowly defined component, depending on the study. But a composite can be difficult to interpret if its components differ in severity or frequency. A change in the composite could be driven mainly by one component. For this trial, the listed components are death, MI, major complications from CV procedures or testing, and unstable angina hospitalization. Component-level primary outcome estimates are not reported in the registry record.
What can be said about the statistical comparison?
The registry describes group-specific Kaplan-Meier estimates, but does not report a primary statistical test, effect estimate contrasting the groups, confidence interval, or p-value. The type of model used to compare time-to-event outcomes, whether any adjustment was planned, and any assumptions used for inference are not reported in the registry record. In general, a confidence interval conveys the range of values compatible with an estimate under the statistical model; it helps assess precision, while a p-value addresses compatibility with a specified null hypothesis. Neither quantity is available for the primary comparison in the posted results.
In general, time-to-event comparisons may use methods that compare event experience over follow-up, but different methods answer somewhat different questions and rely on different assumptions. A hazard ratio, for example, would summarize a relative event rate over time under a model; it is not interchangeable with a difference between cumulative event percentages. The registry record does not identify a hazard-ratio analysis or any other model, so none should be inferred from the listed endpoint description.
What do the planning assumptions mean?
The record describes a planning illustration based on an observed effect, a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It says that the effect to detect is a stated fraction of the observed effect. In general, such calculations illustrate the participant count that might be needed under stated assumptions; they are not a measure of the trial’s observed power and do not replace the trial’s actual results. For time-to-event illustrations, the record specifies a total event count using the Schoenfeld method; other illustrations are described as participants per arm.
For this primary outcome, the registry notes that the outcome has several categories or time points and is not reduced to one comparison. Therefore, there is no single primary comparison in the posted record on which to base a simple planning interpretation. The calculation assumptions do not establish what was used in the original trial design. The sample-size justification and the statistical plan for the original study are not reported in the registry record.
How should the registry’s analysis fields be read?
The registry records zero analyses. This indicates that analyses are not captured in the registry’s posted analysis information; it does not establish that investigators performed no analyses. The record contains no inferential primary result for the endpoint. Any attempt to reconstruct a group comparison from the serious adverse-event counts would be a different, unadjusted calculation and would not substitute for the sponsor’s primary analysis. No such recalculation is reported, and the registry record does not include the sponsor’s analysis for the primary outcome.
10. Multiplicity, Missing Data and Analysis Populations
The primary endpoint is assessed at 90 days, 6 months, 12 months, 18 months, 24 months, 30 months, 36 months, and 42 months. The record also lists multiple secondary outcomes, including time to death or MI, procedure complications, catheterization findings, medical cost, and quality-of-life measures. Considering several outcomes or time points can raise a multiplicity question: in general, the chance of at least one apparently notable finding can increase when many statistical tests are considered. Methods such as prespecifying a primary comparison or adjusting inference can address aspects of multiplicity, but the statistical plan is not reported in the registry record.
The registry describes the primary outcome as a composite, but does not report component-specific primary results or explain how the multiple time-point estimates were handled inferentially. It does not identify a primary time point for a formal group comparison. No multiplicity adjustment, testing hierarchy, or interim-analysis plan is reported in the registry record. Their absence from the record should not be taken as evidence that no such procedures were used outside the registry.
Information about missing outcome data and analysis populations is also not reported in the registry record. The posted information does not describe losses to follow-up, withdrawals, censoring details, handling of missing covariates, or whether the main analysis followed assigned groups. In general, missingness can affect estimates when the probability of observing an outcome is related to participant characteristics or outcomes. Without details about follow-up completeness and analytic handling, the potential influence of missing data cannot be assessed.
The record identifies randomized allocation but does not provide a statistical analysis plan or the population included in the primary analysis. These omissions limit interpretation of how the intended randomized comparison was implemented and how uncertainty across outcomes and time points was controlled.
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 |
|---|---|---|---|
| Functional Diagnostic Tests | 161 | 5007 | 3.2% |
| Anatomic Diagnostic Test | 168 | 4996 | 3.4% |
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 |
|---|---|
| Functional Diagnostic Tests | 16 of 5007 |
| Anatomic Diagnostic Test | 37 of 4996 |
Most frequent serious adverse event terms
| Event term | Organ system | Functional Diagnostic Tests | Anatomic Diagnostic Test |
|---|---|---|---|
| Unstable Angina Hospitalization | Cardiac disorders | 41 of 5007 | 61 of 4996 |
| Myocardial Infarction | Cardiac disorders | 40 of 5007 | 30 of 4996 |
| Death - Non cardiovascular known cause | General disorders | 27 of 5007 | 33 of 4996 |
| Death - unknown cause | General disorders | 27 of 5007 | 27 of 4996 |
| Death- Cardiovascular | Cardiac disorders | 21 of 5007 | 14 of 4996 |
| Major Bleeding | Cardiac disorders | 3 of 5007 | 3 of 4996 |
| Stroke | Cardiac disorders | 2 of 5007 | 1 of 4996 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Functional Diagnostic Tests | Anatomic Diagnostic Test |
|---|---|---|---|
| Mild Contrast Reaction (rash or hives) | Skin and subcutaneous tissue disorders | 0 of 5007 | 22 of 4996 |
| Extravasion of Contrast Into Surrounding Tissue | Skin and subcutaneous tissue disorders | 0 of 5007 | 12 of 4996 |
| Exercise Induced Hypotension | Cardiac disorders | 6 of 5007 | 0 of 4996 |
| Hemodynamic Instability | Cardiac disorders | 2 of 5007 | 3 of 4996 |
| Hospital Admission Not In The Primary Endpoint | General disorders | 5 of 5007 | 0 of 4996 |
| Any Event Potentially Related to Vasodilators | Cardiac disorders | 5 of 5007 | 0 of 4996 |
| Stress Induced Symptoms Related to Functional Testing | Cardiac disorders | 4 of 5007 | 0 of 4996 |
| Ventricular Tachycardia | Cardiac disorders | 4 of 5007 | 0 of 4996 |
Serious events with the highest arm-level rate: unstable angina hospitalization (1.2%), myocardial infarction (0.8%), death - non cardiovascular known cause (0.7%), death - unknown cause (0.5%), death- cardiovascular (0.4%).
The serious adverse-event summary lists 5007 at risk and 161 affected in the Functional Diagnostic Tests group, and 4996 at risk and 168 affected in the Anatomic Diagnostic Test group. The other-event summary lists 5007 at risk and 16 affected in the Functional Diagnostic Tests group, and 4996 at risk and 37 affected in the Anatomic Diagnostic Test group. These are the registry’s group-level counts. The record does not provide confidence intervals, p-values, or a statistical comparison for these summaries.
The top serious-event terms and percentages are unstable angina hospitalization at 1.2%, myocardial infarction at 0.8%, death - non cardiovascular known cause at 0.7%, death - unknown cause at 0.5%, death- cardiovascular at 0.4%, and major bleeding at 0.1%. The record does not state that these percentages are specific to either randomized group, so they should not be used to compare the strategies. Nor does the summary establish whether the listed terms overlap with one another or with the primary endpoint.
In general, adverse-event counts describe reported events or affected participants according to the registry’s definitions; they do not by themselves show that a strategy caused an event. The group summaries list deaths as not reported, while death-related terms appear in the top serious-event list. The record does not explain this difference in presentation. The adverse-event summaries are distinct from the primary endpoint estimates, which are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The registry record establishes that PROMISE was a completed, randomized, parallel-group study comparing initial diagnostic strategies for people with symptoms concerning for coronary artery disease. It states a clinically oriented objective and defines a composite primary endpoint over multiple follow-up times. It also records serious adverse-event summaries and lists secondary outcomes. Those details describe the planned question and selected registry results, but they do not supply the primary outcome estimates required to judge the randomized comparison.
The posted information does not show whether cumulative primary endpoint rates differed between the anatomic and functional strategies, how large any difference was, or how precisely it was estimated. It does not include a confidence interval or p-value for the primary endpoint. The study hypothesis that an initial anatomic strategy would provide superior long-term outcomes is a stated hypothesis, not evidence that the hypothesis was supported.
The serious adverse-event counts can be read as descriptive summaries for the named groups. Without a reported statistical comparison, uncertainty intervals, or details of event definitions and follow-up, they do not establish a causal difference. The top serious-event percentages also lack a group-specific label in the posted summary. They therefore cannot be interpreted as a direct comparison between assigned strategies.
In general, the result of a diagnostic-strategy trial concerns the strategies as implemented in the study context. It should not automatically be read as a comparison of every individual test, or as an assessment of all possible diagnostic pathways. Here, the registry’s description of the anatomic strategy is internally inconsistent: the study summary refers to coronary CT angiography (CTA), while the arm and intervention listings refer to coronary angiography. The record does not resolve which description best characterizes the assigned strategy.
The registry’s information is therefore useful for identifying the study question, design, endpoint, and selected safety summaries. It is insufficient for a conclusion about the primary clinical outcome or the precision of a comparative effect. The missing statistical plan, outcome estimates, and analysis details also prevent assessment of how the primary comparison was conducted.
13. Why This Trial Matters Statistically
Statistically, PROMISE illustrates why a clear endpoint definition and a reported group comparison are both essential. The registry defines a composite outcome spanning death, MI, major complications from CV procedures or testing, and unstable angina hospitalization. It also identifies multiple follow-up times. Those choices determine what the primary outcome represents and what estimates would be needed to interpret it. Without the actual event-rate estimates and their uncertainty, the endpoint description alone cannot answer the trial’s comparative question.
The study’s randomized, parallel design is relevant because random allocation is intended to support a comparison between assigned strategies. But the value of that design for inference depends on complete reporting of outcomes, follow-up, and analysis. The registry identifies the randomized structure but does not report the primary estimates, the statistical test, the analysis population, or the handling of missing observations. Thus, the record offers design information without the inferential results needed to assess the main comparison.
The composite outcome also illustrates a central interpretive issue: an overall result can combine events that differ in character. In general, component-level summaries help show whether a composite pattern is broad or driven by particular event types. The registry does not report primary component results. Its listed serious-event terms should not be treated as a substitute, because they are not presented as a group-specific decomposition of the primary endpoint.
Finally, the discrepancy between coronary CT angiography in the study summary and coronary angiography in the listed intervention and arm description highlights the importance of consistent intervention reporting. A reader needs a clear account of the strategy being compared to interpret the target of the estimand. Without that clarification and the primary analysis, the registry record can identify the intended design but cannot establish the trial’s outcome-based conclusion.
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 registry record does not report the primary endpoint estimates for either group, the between-group effect, confidence intervals, or p-values. It therefore does not permit assessment of the direction, magnitude, or precision of the main outcome comparison. Although the outcome description identifies Kaplan-Meier estimates at 90 days, 6 months, 12 months, 18 months, 24 months, 30 months, 36 months, and 42 months, none of those rates is included in the posted results.
The intervention description is inconsistent: the study summary identifies coronary CT angiography (CTA), while the listed anatomic arm and intervention identify coronary angiography. The record does not explain whether these refer to the same assigned strategy or which term is correct. This limits certainty about what intervention the anatomic group received.
Other important details are not reported in the registry record, including eligibility criteria, baseline participant characteristics, the randomization procedure, follow-up completeness, censoring details, and the analysis population. The statistical analysis plan, primary comparison, handling of the multiple time points, multiplicity procedures, and missing-data methods are also not reported. These omissions make it difficult to assess risks of bias or reproduce the intended analysis.
The serious adverse-event counts and listed term percentages are descriptive. No comparative uncertainty estimates or testing results are reported, and the record does not clarify how the term percentages relate to the randomized groups. These summaries cannot fill the gap left by the absent primary outcome analysis. The record also does not provide the results for the listed secondary outcomes.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: PROspective Multicenter Imaging Study for Evaluation of Chest Pain — NCT01174550.
- Registry record last updated 2016-02-29; status last verified 2016-01.
- Results first posted 2016-02-29.
- 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
The registry record describes NCT01174550, the PROspective Multicenter Imaging Study for Evaluation of Chest Pain, also titled the PROMISE Trial. It lists Duke University as sponsor, randomized allocation, a parallel model, no masking, enrollment of 10003, and completed status. The start is recorded as 2010-07 and primary completion as 2014-10.
The stated objective was to compare an initial anatomic diagnostic strategy with an initial functional testing strategy for people with symptoms concerning for coronary artery disease. The primary endpoint is time to a composite of death, MI, major complications from CV procedures or testing, and unstable angina hospitalization, with estimates intended across 90 days through 42 months. The anatomic-test description is inconsistent within the record.
Serious and other adverse-event counts are listed by group, alongside selected serious-event terms and percentages. However, the primary endpoint estimates, comparative statistical analysis, and details of missing data and analysis populations are not reported in the registry record.