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 Efficacy Study of Oral Nicorandil on Improving Microvascular Function in Female Non-obstructive Coronary Artery Disease (CAD) Participants (NCT03010423), a na phase 4 study. The primary outcome is Change From Baseline in Myocardial Blood Flow Reserve (MFR) by Stress Positron Emission Tomography (PET) at Week 12.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03010423 |
| Phase | Phase 4 |
| Condition | Non-obstructive Coronary Artery Disease |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 8 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Merck KGaA, Darmstadt, Germany |
| Results posted | Yes |
2. Clinical Question
Population
Female participants with non-obstructive coronary artery disease. The registry record lists enrollment of 8, but does not report how many participants had usable primary-outcome measurements.
Intervention
Oral nicorandil, assessed over a planned twelve-week treatment period. The dose and detailed administration schedule are not reported in the registry record.
Comparator
There was no separate comparator group. The study is described as a single-group intervention, so the intended assessment was change from baseline rather than a randomized comparison between treatments.
Primary question
What change from baseline in myocardial blood flow reserve, measured by stress positron emission tomography at Week 12, was observed during nicorandil treatment? The registry record reports no extractable data for this endpoint, so it does not provide an estimate of that change.
The primary question is framed around a within-participant change in myocardial blood flow reserve (MFR). MFR is described in the registry as a measure of endothelial function measured by positron emission tomography (PET). The listed assessment times are baseline and Week 12. The study summary describes the aim as evaluating whether microvascular function improved after twelve-week treatment, but an aim is not an outcome result. Because outcome data could not be extracted, the record does not establish the size or direction of any change, nor how precisely a change could be estimated.
There is also no untreated or active-control group against which to compare the observed course. Even if baseline and follow-up measurements had been available, a single-group change would describe participants' measurements over time during the study; by itself, it would not isolate the effect of nicorandil from other explanations. The registry record therefore supports a description of the study question and its missing result, not a comparative treatment-effect conclusion.
3. Trial Design
This was an interventional, single-center pilot study of oral nicorandil in female participants with non-obstructive coronary artery disease. The study is listed as Phase 4 and as a single-group design. The registry reports enrollment of 8. Allocation is listed as not applicable, and masking is listed as none. There is no separate control arm, so the design does not support a randomized, like-for-like comparison between nicorandil and another treatment or control condition.
The intervention was nicorandil, and the study summary describes a twelve-week treatment period. The primary outcome was change from baseline in MFR measured by stress PET at Week 12. Listed secondary outcomes cover rest and stress myocardial blood flow, ejection fraction, left ventricular end-systolic dimension, left ventricular wall thickness, the E/A ratio for cardiac diastolic function, and Seattle Angina Questionnaire score. These outcomes identify planned measurement domains; they do not show that measurements were obtained or analyzed.
The registry lists the study as terminated. The stated reason relevant to the missing result is that the study ended early and data could not be extracted because approval for data exportation from the Office of Human Genetic Resource Administration (OHGRA) China was lacking. The primary outcome record consequently contains no data for analysis. Although enrollment is recorded, the number with completed treatment, follow-up imaging, or an evaluable endpoint is not reported in the registry record.
The start date is 2016-11-30, and the primary completion date is 2019-07-09. Those dates provide registry context but do not establish when each participant entered, received treatment, or completed follow-up. The dose, detailed eligibility criteria, recruitment procedures, protocol deviations, and reasons for termination beyond the stated data-export limitation are not reported in the registry record. A sample-size justification and the trial's statistical analysis plan are also not reported in the registry record. The pilot label alone does not establish the intended precision or statistical power.
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 | Nicorandil |
|---|---|
| STARTED | 8 |
| COMPLETED | 0 |
| NOT COMPLETED | 8 |
Reasons for not completing this period:
| Reason | Nicorandil |
|---|---|
| Study termination | 8 |
Analysis population for the primary outcome, as defined in the registry: The study was terminated early and due to the lack of approval of data exportation from the Office of Human Genetic Resource Administration (OHGRA) China, the data could not be extracted. Therefore, no data available for the analyses.
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 | Nicorandil |
|---|---|---|
| Participants analysed | 8 | |
| Age, Customized: Between >=18 and <= 70 years | Participants | 8 |
| Sex: Female, Male: Female | Participants | 8 |
| Sex: Female, Male: Male | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 8 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Myocardial Blood Flow Reserve (MFR) by Stress Positron Emission Tomography (PET) at Week 12, measured over Baseline, Week 12.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is change from baseline in myocardial blood flow reserve (MFR) measured by stress positron emission tomography (PET) at Week 12. The registry describes MFR as a measure of endothelial function measured by PET. In general, an endpoint is selected to represent an outcome relevant to the research question; a baseline-to-follow-up measure can describe how that measurement changes during the observation period.
Stress PET is the specified measurement approach for the primary endpoint. The record also lists rest and stress myocardial blood flow as secondary outcomes, but these are distinct from the stated primary endpoint of MFR. The endpoint's unit, numerical parameter definition, and measure of dispersion are not reported in the registry record. Without those details and an analysis dataset, the magnitude and precision of any change cannot be assessed.
The registry's outcome description gives baseline and Week 12 as the assessment times. The primary result itself is unavailable: the record says that the study was terminated early and that data could not be extracted because data-export approval from OHGRA China was lacking. No baseline value, follow-up value, change estimate, confidence interval, or test result is reported in the registry record. Accordingly, the endpoint's intended role can be explained, but its observed behavior cannot be described.
In general, a confidence interval communicates the range of estimates compatible with the data and the method used; it would help convey precision alongside an estimated change. No such interval can be interpreted for this endpoint because no estimate or outcome data are reported. The endpoint's purpose does not substitute for its result, and describing MFR as a measure of endothelial function does not imply that this study demonstrated a change in endothelial function.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record states that no primary-outcome data were available for analysis. Its explanation is that the study was terminated early and that data could not be extracted because approval for data exportation from OHGRA China was lacking. As a result, there is no reported MFR change from baseline to Week 12, and no numerical estimate of the primary outcome can be interpreted.
The record also reports no analyses. It therefore provides no estimate, standard error, confidence interval, or hypothesis-test result for the primary endpoint. The direction of change is unknown from the registry record, as are its magnitude and precision. It would not be justified to describe the endpoint as improved, unchanged, or worsened based on the available record. The stated study objective is not evidence that the intended change occurred.
Enrollment of 8 is a study-level count, not a reported count of participants with analyzable endpoint data. The registry does not state how many participants completed the planned treatment period, had Week 12 imaging, or contributed to an endpoint analysis. It is not possible to infer an analysis sample from enrollment alone. Nor can the absence of an outcome estimate be interpreted as an estimate of no effect: an unavailable result and a measured result near no change are different situations.
The study used a single-group design without a separate comparator. General statistical context: a within-group change can describe how participants' measurements differ over time, but it does not by itself distinguish a treatment-associated change from other changes over the same period. A concurrent comparison can help address that question, depending on its design and analysis. This study's design, as recorded, does not offer that contrast.
The registry lists no adverse events at risk or affected in the Nicorandil group, with zero participants listed in each of those counts. Because the record lists zero at risk, these entries do not establish that adverse events were assessed in an evaluable group or that none occurred among treated participants. The number of participants assessed for safety and the method of adverse-event collection are not reported in the registry record. The adverse-event fields therefore cannot support a safety-rate interpretation.
Overall, the record permits interpretation of the study's question, design, and reason for unavailable outcome data, but not of efficacy, precision, or safety results. Any quantitative conclusion about the primary endpoint would require results that are not reported in the registry record.
9. Statistical Methods Explained
The registry describes a single-group intervention, with change from baseline as the primary outcome. It does not report analyses. The statistical methods used to estimate the change, account for repeated measurements, handle incomplete observations, or quantify uncertainty are not reported in the registry record. The following concepts explain how such methods are generally considered; they are not claims about procedures used in this study.
What does a baseline-to-follow-up analysis estimate?
General statistical context: a change analysis compares a participant's measurement at follow-up with that participant's baseline measurement, then summarizes those changes across participants with usable measurements. A mean change can describe the average direction and size of change, while a measure of spread indicates how much participants' changes differ. The choice of summary depends on the endpoint's scale and distribution. The registry record does not specify the numerical definition or unit for MFR, the summary measure, or the method used to estimate a change.
Repeated measurements from the same participant are related, rather than independent observations. General statistical context: an analysis should account for that within-participant relationship when estimating uncertainty. A paired analysis is one possible approach when baseline and follow-up data are available, but the registry record does not say whether such an analysis was planned or performed. Because the primary endpoint data were not extractable, no approach can be evaluated against an observed estimate.
How should uncertainty be expressed?
General statistical context: a point estimate gives a single summary of an effect, while a confidence interval expresses uncertainty around that estimate under a stated statistical method. A narrow interval generally indicates greater precision than a wide interval, but precision depends on both the amount of information and variability in the observations. Neither an estimate nor an interval is reported for MFR in this record. There is consequently no trial-specific uncertainty to interpret.
A hypothesis test, if performed, would address compatibility between the observed data and a specified null hypothesis under the chosen model. A p-value alone would not quantify the size or clinical importance of a change. No p-value, test statistic, or null hypothesis is reported in the registry record. It is therefore not possible to assess statistical evidence from a test or to infer that a test was or was not conducted beyond the record's statement that no analyses are reported.
What role would a comparison group play?
General statistical context: a single-group change analysis describes the observed course of a group, but cannot separate treatment effects from other influences on measurements over time. Examples of general sources of change include measurement variation, natural fluctuation, and changes in care or behavior; these are possibilities in general, not documented explanations for this study. A well-designed comparison can provide information about what might have happened over the same period without the intervention. This study has no separate comparator, and the registry identifies it as not being a randomized comparison.
The registry's planning assumptions describe 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. They are planning assumptions, not evidence that the study used those methods. Since the primary outcome data are unavailable, there is no observed effect on which to base an effect-scaled illustration. Equal allocation between two arms also does not describe the recorded single-group design. No trial-specific sample-size justification is reported in the registry record, and any planning calculation should not be interpreted as observed power.
How do outcome selection and multiplicity matter?
General statistical context: a study may measure several outcomes, and drawing confirmatory conclusions from many separate tests can increase the chance of finding an apparently notable result by chance. A prespecified primary endpoint helps identify the principal question; adjustment or a hierarchical testing plan may be used in some studies to address multiple testing. The registry lists one primary endpoint and several secondary outcomes, but does not report a multiplicity strategy or analysis plan. Since no outcome analyses are reported, there are no trial-specific estimates or tests to compare across endpoints.
Over-dispersion is a general issue for outcomes whose variability is greater than a model assumes; ignoring it can lead to uncertainty estimates that are too small. Whether over-dispersion is relevant depends on the outcome and the statistical model. The record does not identify a model or provide outcome data, so no claim about over-dispersion or its handling can be made for this trial.
Can the posted safety counts be treated as rates?
General statistical context: interpreting an event count requires knowing the population observed and the duration or opportunity for event ascertainment. The registry lists zero participants at risk and zero affected for the Nicorandil group, and lists zero deaths. These entries do not provide an evaluable denominator. The number of participants monitored for adverse events and the collection procedures are not reported in the registry record. The entries cannot be converted into, or interpreted as, an event rate.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies MFR change at Week 12 as the primary outcome and lists several secondary outcomes: rest and stress myocardial blood flow, ejection fraction, left ventricular end-systolic dimension, left ventricular wall thickness, the E/A ratio, and Seattle Angina Questionnaire score. However, the record reports no analyses and no extractable outcome data. It gives no estimates or test results for either the primary or secondary outcomes.
The registry does not report a plan for handling multiplicity, such as an adjustment across outcomes or a prespecified order for testing them. General statistical context: when multiple outcomes are tested, interpreting each result as if it were the only test can overstate the strength of evidence. A stated analysis plan helps clarify how confirmatory claims would be made. In the absence of results and a reported plan, no trial-specific multiplicity assessment is possible.
The reason given for the missing primary outcome is that the study was terminated early and data could not be extracted because approval for data exportation from OHGRA China was lacking. The record does not report how many participants had baseline or Week 12 measurements, whether any measurements were missing for other reasons, or whether an analysis population was defined. It also does not describe imputation, exclusion, sensitivity analysis, or other missing-data procedures.
General statistical context: missingness can affect an estimate when participants with unavailable measurements differ from those with usable measurements. The direction and scale of any such effect depend on information about missingness and the analysis. Here, there is no primary-outcome dataset or reported analysis with which to assess that issue. Enrollment of 8 does not establish the number included in an outcome analysis, and the record does not identify an intention-to-treat, per-protocol, or other analysis population.
11. What the Result Does, and Does Not, Mean
The record documents a pilot study designed to examine change in MFR during oral nicorandil treatment in female participants with non-obstructive coronary artery disease. It also documents that the study was terminated and that primary-outcome data were unavailable because data could not be extracted without approval for exportation from OHGRA China. These registry entries describe the research question and the limit on what can be concluded from the posted results.
The record does not report an observed MFR change. It therefore cannot establish the direction, magnitude, or precision of a change between baseline and Week 12. No numerical primary-outcome estimate, confidence interval, or analysis result is available. The absence of these results should not be mistaken for evidence of no change: an unobserved or unavailable estimate is not the same as a measured estimate indicating little or no change.
The single-group design also limits causal interpretation. General statistical context: when a group is measured before and after an intervention without a separate comparator, the observed difference can reflect several influences in addition to the intervention. A within-group change, even if reported, would not alone provide the same evidence as a comparison designed to estimate what would have happened under another condition. No such between-group contrast is part of this recorded design.
Enrollment of 8 is reported, but the number with analyzable outcomes is not reported in the registry record. The absence of reported analyses and participant-level outcome availability prevents an assessment of statistical precision or the contribution of individual observations. The listed secondary outcomes do not fill this gap because the record contains no results for them either.
The safety entries likewise do not establish that adverse events were absent. The record lists zero participants at risk and zero affected, without describing an evaluable safety population or ascertainment method. The study record can therefore be used to understand the intended assessment and the missing-result context, but not to make a treatment-effect or safety conclusion.
12. Why This Trial Matters Statistically
This study illustrates why a clearly stated endpoint and an available endpoint result are both necessary for statistical interpretation. The registry identifies a specific primary question: change in MFR from baseline to Week 12 measured by stress PET. Yet the record states that data could not be extracted because data-export approval was lacking. Without the actual measurements or an analysis, the endpoint definition cannot yield an estimate of change or its uncertainty.
The distinction between enrollment and analysis is also important. The registry reports enrollment of 8, but does not report how many participants had usable baseline and follow-up measurements. A count of enrolled participants describes recruitment, not the information available for estimating the primary endpoint. This matters especially in a pilot study, where the number of usable observations and their variability would be central to understanding how precisely an estimate could be made.
The single-group design provides another statistical lesson. A baseline-to-follow-up comparison can characterize change over time, but without a separate comparator it cannot by itself distinguish intervention-related change from other influences. The limitation is inherent in the contrast available, rather than a consequence of a particular numerical result. In this record, no change estimate is available in any case.
Finally, the record shows why missing results should not be interpreted as null findings. No reported estimate is not equivalent to an estimate near no change, and the zero-at-risk adverse-event entries do not establish an absence of harm. Statistical interpretation depends on knowing which participants contributed data, how outcomes were measured, how missing observations were handled, and what uncertainty surrounds the estimates. Those elements are not available for this study's reported outcomes.
13. 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 principal trial-specific limitation is that the primary endpoint data were not extractable. The registry attributes this to early termination and lack of approval for data exportation from OHGRA China. With no reported outcome data or analyses, the primary question cannot be answered from the registry record. The reason for termination beyond this stated data-export limitation is not reported in the registry record.
The study enrolled 8 participants and used a single-group design. There is no separate comparator, and allocation is listed as not applicable. Even if a within-group change estimate were available, the design would not provide a randomized contrast with another treatment or control condition. The record also does not report the number who completed Week 12 or contributed usable endpoint data, so the analytic sample and follow-up completeness cannot be assessed.
The registry describes a twelve-week treatment period but does not report the nicorandil dose, detailed eligibility criteria, participant characteristics, or the measurement and analysis procedures beyond identifying PET for the primary endpoint. The endpoint unit, parameter definition, and dispersion measure are not reported in the registry record. The statistical analysis plan, sample-size justification, multiplicity approach, missing-data procedures, and analysis populations are also not reported in the registry record.
Several secondary outcomes are listed, but no results are available for them. The adverse-event entries list zero at risk and zero affected, without an evaluable safety denominator or ascertainment details. Consequently, neither outcome breadth nor safety entries compensate for the missing primary analysis. These limitations concern what can be learned from the registry record; they do not establish what measurements may exist outside it.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Efficacy Study of Oral Nicorandil on Improving Microvascular Function in Female Non-obstructive Coronary Artery Disease (CAD) Participants — NCT03010423.
- Registry record last updated 2020-07-07; status last verified 2020-06.
- Results first posted 2020-07-07.
- 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.
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17. Record Summary
The registry describes NCT03010423 as a Phase 4, single-center, interventional pilot study of oral nicorandil in female participants with non-obstructive coronary artery disease. It lists a single-group design, no masking, and enrollment of 8. The study's primary outcome was change from baseline in MFR by stress PET at Week 12, with additional secondary outcomes related to myocardial blood flow, cardiac measures, and angina questionnaire score.
The registry lists a start date of 2016-11-30, a primary completion date of 2019-07-09, and a terminated status. It states that the study ended early and that outcome data could not be extracted because approval for data exportation from OHGRA China was lacking. No analyses or primary-outcome results are reported. The record therefore supports description of the study design and missing-result reason, but not an estimate of change, its precision, or a safety conclusion.