Effect of Acute Statin Treatment in Patients Undergoing Percutaneous Coronary Intervention: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effect of Acute Statin Treatment in Patients Undergoing Percutaneous Coronary Intervention (NCT00588471), a randomized na study. The primary outcome is Change in Serum High Sensitivity C-Reactive Protein (hsCRP).

2. Clinical Question

The study was designed to examine a short-term response around the intervention. Its stated aims were to assess whether one dose of simvastatin would affect the inflammatory response to coronary intervention and whether it would affect endothelial function, measured using noninvasive peripheral arterial tonography. These are questions about measured biological outcomes; the registry record does not report an outcome estimate answering either question.

The record lists a randomized, parallel-group comparison and identifies simvastatin and placebo as the interventions. It reports that recruitment was insufficient and that the study was terminated early. Consequently, the posted record does not establish what the comparison showed. It does not report a primary-outcome estimate, an uncertainty interval, or a statistical test. The clinical question is therefore clear as a study objective, but the registry record does not contain results with which to assess the direction or precision of any difference.

3. Trial Design

The registry record describes a randomized, quadruple-masked, parallel-group trial. Participants were assigned to simvastatin or placebo. The simvastatin arm was scheduled to receive 80 mg, described as two pills, approximately one hour before percutaneous coronary intervention (PCI); the placebo arm was scheduled to receive two placebo pills at approximately the same time. The record does not identify which groups of people were masked or describe the randomization sequence, allocation concealment, or procedures for maintaining masking.

The listed primary outcome was change in serum high-sensitivity C-reactive protein (hsCRP), assessed at baseline and within 24 hours after PCI. Change in EndoPAT score after PCI was listed as a secondary outcome. The stated purpose was to investigate inflammation and peripheral arterial tone around coronary intervention. No detailed measurement schedule for the secondary outcome is reported in the registry record.

The registry lists enrollment of 57. That number is not an outcome-analysis sample size, and the record does not specify how many participants contributed data to either outcome. Adverse-event entries identify 28 participants at risk in the simvastatin group and 29 in the placebo group; those figures describe the safety entries, not necessarily the analysis populations for the primary outcome.

The record lists the study start as 2002-11 and primary completion as 2011-04. Its status is terminated, and the primary-outcome description states that the study ended early because not enough subjects could be recruited. The record names Mayo Clinic as sponsor. Phase is listed as NA. Details about the planned sample-size justification, recruitment targets, protocol amendments, or reasons beyond insufficient recruitment 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.

Before assignment: 66 subjects signed informed consent, but 9 subjects had to have the PCI procedure too quickly, and could not participate in the study.

Overall Study

Analysis population for the primary outcome, as defined in the registry: The study was terminated early because not enough subjects could be recruited.

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 Change in Serum High Sensitivity C-Reactive Protein (hsCRP), measured over baseline, within 24 hours post percutaneous coronary intervention.

The primary endpoint is change in serum high-sensitivity C-reactive protein (hsCRP). The registry describes hsCRP as a test evaluating vascular inflammation and identifies the measurement times as baseline and within 24 hours after percutaneous coronary intervention (PCI). The intended comparison is therefore about how this marker changes around the procedure in participants assigned to simvastatin versus placebo. The registry record does not state the endpoint unit, how change was calculated, or the exact analysis used to compare groups.

hsCRP is used in the study because it is a measurable marker related to inflammation. The registry description also gives risk categories attributed to the American Heart Association and U.S. Centers for Disease Control and Prevention: low risk is <1.0 mg/L, average risk is 1.0 to 3.0 mg/L, and high risk is >3.0 mg/L. These categories provide context for interpreting hsCRP values, but they are not reported as the trial’s outcome categories or as results for participants.

The endpoint is a laboratory measurement, not a direct measure of a clinical event. The record contains no posted group values, change estimates, confidence intervals, or statistical tests for hsCRP. It also does not report whether the marker was measured for all enrolled participants. Thus the biological rationale and timing are described, while the observed endpoint results and their precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, parallel-group study with quadruple masking. In general, random allocation is intended to make treatment groups comparable at the start of a trial, on average, including for factors that were not measured. A parallel-group design assigns participants to one group for the study comparison rather than having each participant receive both interventions. These design features describe the trial structure; they do not by themselves show how well the trial was carried out or what its results were.

What does randomization contribute?

In a randomized comparison, the main treatment contrast is ordinarily based on outcomes in the groups to which participants were assigned. Randomization can reduce systematic differences between groups, but it cannot guarantee balance in a small or incompletely recruited study. The registry record does not describe the sequence-generation method, allocation concealment, or any baseline characteristics. It also does not report the number of participants included in an outcome analysis. Thus the presence of randomization in the design does not permit reconstruction of the actual analysis.

What does masking mean in this record?

The record labels the study quadruple-masked. Masking is generally intended to limit the influence of knowing an assignment on participants’ experiences, clinical care, measurement, or interpretation. The record does not specify who was masked or how the masking was maintained. The simvastatin and placebo arms are described as receiving pills before PCI, but the registry does not provide enough detail to assess whether the intervention and placebo were indistinguishable or whether masking was successful.

How should the primary outcome be understood?

The primary outcome is change in serum hsCRP, measured at baseline and within 24 hours after PCI. A change outcome uses measurements at more than one time point to describe movement in a marker over time. A comparison of change between randomized groups is one general way to evaluate whether the groups followed different patterns. Other approaches may adjust for baseline values or use a different model. The specific approach used for this trial is not reported in the registry record, and no group values or estimates are posted.

In general, a treatment-effect estimate summarizes the contrast being studied, while a confidence interval communicates uncertainty around that estimate. A confidence interval is not a guarantee that the true value lies within a particular interval; its interpretation depends on the statistical procedure and assumptions. A p-value, when reported, addresses compatibility between data and a specified null hypothesis under a model. It does not measure the size or importance of an effect. The registry record does not report a confidence interval, p-value, or effect estimate for hsCRP, so these concepts cannot be applied to a trial result from this record.

What can be said about the secondary outcome?

Change in EndoPAT score after PCI is listed as a secondary outcome. The registry’s summary describes peripheral arterial tonography as a noninvasive measure related to endothelial function, or artery activity. A secondary outcome can add information beyond the primary endpoint, but its interpretation depends on how it was measured, when it was assessed, and how it was analyzed. Those details and any numerical result for EndoPAT are not reported in the registry record.

Why does early termination matter?

The record states that recruitment was insufficient and that the study was terminated early. In general, fewer available observations can make estimates less precise, although the actual precision depends on the amount and variability of the outcome data. The registry lists enrollment of 57, but does not state how many participants completed each measurement or entered an analysis. It is therefore not possible to infer the precision of an outcome estimate from the listed enrollment alone.

Sample-size planning and observed results serve different purposes. A planning calculation uses assumptions about a target effect, variability, significance level, allocation, and statistical method to illustrate the number of participants that might be needed. Such a calculation is not a result from the trial and does not measure observed power. The record’s planning description states assumptions of a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect expressed as a fraction of the observed effect. The trial’s own sample-size justification is not reported in the registry record. No planning illustration can substitute for the missing outcome estimates or establish the trial’s actual statistical power.

Other model choices can matter as well. In general, over-dispersion occurs when observed variability exceeds what a statistical model assumes; if ignored, uncertainty can be understated. This trial’s primary outcome is described as a continuous laboratory marker, but the registry does not report the model used or evidence of over-dispersion. There is no basis in the record to assert that a particular model, correction, or diagnostic was applied.

Overall, the design provides a framework for a comparison, but the registry record does not disclose the statistical plan or analyses. The treatment contrast, handling of repeated measurements, assumptions, uncertainty, and robustness of the findings cannot be evaluated without those details and the underlying results.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary outcome, change in serum hsCRP, and a secondary outcome, change in EndoPAT score after PCI. Considering more than one outcome can raise a multiplicity issue: in general, the chance of at least one apparently notable finding can increase when several statistical tests are conducted. Study plans may address this through a hierarchy of outcomes, an adjustment to testing, or other prespecified procedures. The registry record does not report whether any such approach was planned or used, and it contains no outcome analyses to interpret.

The record identifies the primary outcome measurement times as baseline and within 24 hours after PCI. It does not report the number of participants with measurements at either time, how missing measurements were handled, or whether any imputation or sensitivity analysis was performed. Missing-data methods can affect estimates when outcome availability differs across participants or groups. Without the relevant counts and methods, the extent and potential influence of missing data cannot be assessed.

The analysis populations are also not reported in the registry record. It does not say whether analyses were based on all randomized participants, participants who received assigned treatment, or those with available outcome measurements. The record lists enrollment of 57, while the safety entries list 28 and 29 participants at risk in the two arms; these figures do not establish who was included in the primary or secondary outcome analyses.

Details about protocol deviations, exclusions, analysis models, prespecified contrasts, and handling of multiple measurements are not reported in the registry record. Consequently, neither the multiplicity strategy nor the consequences of missing data and analysis-population choices can be evaluated from the posted information.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry’s adverse-event entries list serious adverse events for each treatment group. In the simvastatin group, 0 of 28 participants listed at risk had a serious adverse event. In the placebo group, 0 of 29 participants listed at risk had a serious adverse event. These are the counts recorded in the registry, not evidence that the underlying risk is exactly zero. With no serious events recorded in these groups, the entries do not provide a precise estimate of how often such events might occur in a broader population.

For other adverse events, the registry lists 1 of 28 participants at risk in the simvastatin group and 0 of 29 in the placebo group. The record does not give the event description, severity details, timing, or relationship to treatment. It also does not provide an adverse-event follow-up period or explain how events were collected.

Deaths are not reported in the registry record. The safety entries should be read as descriptive counts with the listed participants at risk, not as a formal comparison between groups. They do not establish that one assignment is safer than the other, and they do not replace the missing outcome analyses.

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

The registry record documents a randomized comparison of a single pre-PCI dose of simvastatin with placebo, focused on short-term hsCRP change and a secondary EndoPAT outcome. It also records that recruitment was insufficient and the study was terminated early. These registry entries describe the trial’s question, planned comparison, and completion status.

What the record does not contain is the information needed to determine the observed treatment contrast. There are no posted group-level hsCRP values, change estimates, confidence intervals, or statistical tests. No results are posted for the EndoPAT outcome. Consequently, the record cannot show whether the outcomes differed between groups, how large any difference was, or how uncertain an estimate might be. A missing result must not be interpreted as a finding of no difference.

The listed enrollment of 57 does not tell how many participants had measurements available or contributed to an analysis. The safety counts are reported separately and cannot be treated as the primary-outcome analysis population. The reason for termination is described as insufficient recruitment, but the record does not provide details on the number or timing of missing measurements, or on the planned analysis.

More generally, a short-term change in a biological marker is not the same as a demonstrated change in clinical outcomes. The study’s endpoint and stated rationale concern inflammation and arterial function around PCI; the registry record does not report clinical outcome findings. The listed hsCRP risk categories provide context for interpreting hsCRP levels, but do not supply trial-specific outcome data.

The appropriate interpretation is therefore limited: the registry documents the study design and its early termination, but does not provide results that answer the primary or secondary research questions. No treatment recommendation or conclusion about clinical benefit or harm follows from the information recorded.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of the distinction between a planned randomized comparison and a reportable result. Randomization and masking are important design features, but they do not ensure that an interpretable estimate will be available. Recruitment stopped early because not enough subjects could be recruited, according to the registry record, and outcome analyses are not posted. Without those analyses, readers cannot evaluate the direction, magnitude, or precision of the treatment comparison.

The record also illustrates why enrollment and analysis counts should not be treated as interchangeable. Enrollment is listed as 57, while the safety entries give the numbers at risk for adverse-event reporting. The registry does not state the numbers contributing to the hsCRP or EndoPAT analyses. Outcome-specific denominators, missingness, and the analysis population are essential for judging how much information a result contains.

The distinction between a biomarker outcome and a clinical outcome matters as well. hsCRP and EndoPAT are the listed measures, with the study’s rationale centered on inflammation and peripheral arterial tone. Even a reported change in a marker would need to be interpreted as a marker result, rather than automatically as evidence about clinical events. In this record, even those marker results are absent.

Finally, the record’s methodological gaps are a reminder that labels such as randomized and quadruple-masked do not reveal the full statistical plan. Details of allocation, outcome availability, missing-data handling, analysis populations, and multiplicity are not reported. Statistical interpretation depends on both design and transparent reporting of results and methods. Here, the record supports a description of the intended study, but not an estimate of its outcomes.

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 most important trial-specific limitation in interpreting the registry record is that it reports no outcome analyses. The primary endpoint is identified, but no hsCRP results, effect estimates, uncertainty intervals, or tests are posted. The secondary EndoPAT outcome is also listed without a result. The clinical questions therefore remain unanswered by the information in the record.

The study was terminated early because of insufficient recruitment, as stated in the primary-outcome description. The registry lists enrollment of 57, but does not report outcome-specific analysis counts or the extent of missing measurements. The completeness of follow-up and the number of participants with measurements at both stated hsCRP time points are not reported in the registry record.

Several design and analysis details are absent. The record does not describe the randomization method, which people were masked, the statistical analysis plan, the analysis populations, or methods for handling missing data. It does not report whether the planned outcome hierarchy or any multiplicity approach was specified. These omissions limit assessment of how the trial was conducted and how an analysis, if posted elsewhere, should be interpreted.

The endpoint description does not state the unit used for hsCRP results, the formula for calculating change, or additional measurement details. The secondary-outcome description does not give a detailed measurement schedule. The adverse-event record lacks event descriptions and a follow-up period, and deaths are not reported in the registry record. These limitations concern what can be learned from this record; they should not be taken as evidence that the unreported procedures or data did not exist.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Effect of Acute Statin Treatment in Patients Undergoing Percutaneous Coronary Intervention — NCT00588471.
• Registry record last updated 2012-11-08; status last verified 2012-10.
• Results first posted 2012-11-08.
• 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

The registry record describes a randomized, quadruple-masked, parallel-group study of simvastatin versus placebo in patients undergoing percutaneous coronary intervention. The simvastatin arm was scheduled to receive 80 mg, described as two pills, approximately one hour before the procedure; the placebo arm was scheduled to receive two placebo pills at approximately the same time. The listed primary outcome is change in serum hsCRP from baseline to within 24 hours after PCI. Change in EndoPAT score after PCI is listed as a secondary outcome.

The record lists enrollment of 57, names Mayo Clinic as sponsor, and gives the study start as 2002-11 and primary completion as 2011-04. The study status is terminated; the primary-outcome description attributes early termination to insufficient recruitment. The registry record does not report primary or secondary outcome analyses, analysis populations, missing-data methods, or a statistical analysis plan. Serious adverse-event counts are 0 in each group; one other adverse event is listed in the simvastatin group and none in the placebo group. Deaths are not reported in the registry record.