PROMUS PREMIER™ China Post-Approval Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for PROMUS PREMIER™ China Post-Approval Study (NCT03273023), a registered phase not stated study. The primary outcome is 12-month Major Adverse Cardiac Event (MACE) Rate.

2. Clinical Question

3. Trial Design

The PROMUS PREMIER China Post-Approval Study is a completed post-approval study of a coronary stent system. Its stated purpose was to compile real-world clinical outcome data for the PROMUS PREMIER everolimus-eluting platinum chromium coronary stent system in routine clinical practice in China. The condition listed is coronary artery disease. The registry records enrollment of 2059 participants and identifies Boston Scientific Corporation as the sponsor.

The study start date is 2018-01-11, and the primary completion date is 2020-12-28. The status is completed. These dates describe the study record; they do not specify the follow-up duration for every participant or establish when each participant's outcome data were collected.

The primary endpoint is the 12-month MACE rate, expressed as a count of participants. Its definition includes cardiac death, myocardial infarction, and target vessel revascularization. The registry also lists secondary outcomes of 12-month cardiac death, 12-month myocardial infarction, and 12-month TVR. Although the record indicates four outcome measures, further outcome details and the fourth measure are not reported in the registry record.

The stated ITT population includes all subjects who signed the written informed consent form and were enrolled, regardless of whether the study stent was implanted. This defines the intended analysis population, but the registry record does not report how many participants were included in each outcome analysis or how missing follow-up information was handled.

The record does not describe a randomized comparison; allocation is not stated. It cautions that any arms are not a like-for-like control comparison. Details such as the number of sites, eligibility criteria, blinding, follow-up procedures, and protocol deviations are not reported in the registry record. The available description therefore supports interpreting this as a post-approval, routine-practice data collection effort, not as a randomized efficacy comparison.

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: For the ITT analysis, all subjects who sign the written ICF and are enrolled in the study will be included in the analysis sample, regardless of whether the study stent was implanted.

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.

Population: For the ITT analysis, all subjects who sign the written ICF and are enrolled in the study will be included in the analysis sample, regardless of whether the study stent was implanted. For the per-protocol analysis, only enrolled subjects who received at least one study stent will be included in the analysis sample.

6. Primary Endpoint

The registry lists the primary outcome as 12-month Major Adverse Cardiac Event (MACE) Rate, measured over 12 months.

The primary endpoint is the 12-month major adverse cardiac event (MACE) rate, defined in the registry as cardiac death, myocardial infarction, or target vessel revascularization. The unit is participants, and the measure is a count of participants with an event. This is a binary outcome at the participant level: a participant either meets the stated event definition during the relevant follow-up or does not, according to the endpoint rules.

A composite endpoint combines multiple clinically important outcomes into a single measure. In general, this can capture a broader range of events than any component alone and may provide a useful overall summary. However, a composite result does not show which component accounts for most of the events. The components can also differ in frequency and clinical importance, so a MACE result should not be interpreted as though every component occurred equally often or had the same implications.

The 12-month timeframe identifies the endpoint's intended follow-up window. It does not, by itself, clarify how incomplete follow-up, events outside the window, or repeated events were handled. Those operational definitions are not reported in the registry record. The primary endpoint result is also not reported in the registry record, so its observed count, event frequency, and precision cannot be assessed from the available outcome information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What kind of outcome is MACE?

The primary endpoint is a participant count for a binary outcome. In general, a binary outcome classifies each participant according to whether a defined event occurred within a specified observation period. For this study, the event definition combines cardiac death, myocardial infarction, and target vessel revascularization, and the stated timeframe is 12 months. A count is not the same as a rate unless the relevant denominator and outcome ascertainment are also specified. The registry record does not report the primary count or an analysis denominator for it.

For a composite endpoint, a participant who experiences a qualifying component is generally counted as having the composite event, but the exact rules for overlapping or repeated events matter. The registry provides the component definition but does not report the detailed event-counting rules, adjudication process, or handling of repeated events. Component-specific results would help readers understand what contributed to any composite result; the listed secondary outcome results are not reported in the registry record.

What would an uncertainty estimate convey?

In general, an estimate based on observed participants is subject to sampling variability. A confidence interval communicates the uncertainty associated with an estimate under a specified statistical method and its assumptions. A narrower interval indicates greater precision under that method, while a wider interval indicates less precision. An interval does not address every source of uncertainty: for example, incomplete follow-up, selection into a study, measurement error, and differences in care can remain important.

The registry record does not report a confidence interval for MACE, a p-value, or an analysis result for the primary endpoint. Thus there is no posted inferential estimate to interpret. A p-value, in general, describes how compatible the data are with a specified null model under the analysis assumptions; it is not a measure of treatment benefit, clinical importance, or the probability that the null hypothesis is true. No such interpretation can be made for this endpoint without a reported analysis.

Why does the comparison structure matter?

Random allocation can help make treatment groups comparable at baseline, on average, by distributing measured and unmeasured prognostic factors across groups. An observational or post-approval study may instead describe outcomes among people treated in ordinary practice. That can be informative about the recorded setting, but treatment choice and participant characteristics may be related. A simple comparison between non-randomized groups can therefore reflect those differences as well as any treatment association.

For this record, allocation is not stated and the registry cautions that arms are not a like-for-like control comparison. No adjustment model or comparative analysis is reported. Any apparent contrast between groups should therefore not be interpreted as a randomized treatment effect. The record does not report whether an adjusted analysis was planned or conducted.

How should the planning illustration be understood?

The planning illustration is described as a calculation based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes a planning scenario, not the design justification for this post-approval study. The registry record does not report the trial's sample-size justification or indicate that the illustration's assumptions were used to enroll participants.

In general, a sample-size calculation asks how many participants would be needed under chosen assumptions to detect a specified effect with a chosen probability, often called power. Its result depends on the assumed effect, outcome frequency or variability, significance level, allocation, and analysis method. Changing the assumed effect changes the planning requirement. Such a calculation is not observed power and does not show that a completed study had adequate precision. The planning figures are illustrations, not observed outcomes, and should not be treated as evidence that the primary endpoint was or was not detected.

The record describes the effect to detect as a stated fraction of the observed effect, but the relevant plotted planning outputs are not included in the registry record details. No planning participant counts can therefore be stated from the record. For binary outcomes, the record says the planning figures refer to participants per arm; the available study itself is not reported as a randomized comparison with equal allocation.

What does over-dispersion mean in general?

Over-dispersion occurs when observed variation is greater than a statistical model assumes. It matters because a model that understates variability can produce confidence intervals that are too narrow and tests that appear more informative than warranted. The primary measure in this record is a binary participant count, and its dispersion is not reported. The registry record does not identify an over-dispersion adjustment or a model for the primary endpoint. A discussion of over-dispersion is therefore general statistical context, not a description of an analysis reported for this study.

More broadly, an analysis plan should specify the estimand, analysis population, event definitions, missing-data approach, model, and any adjustment for multiple testing. These elements determine what an estimate means and how its uncertainty is calculated. Several of these details are not reported in the registry record, and the record lists no analyses. Interpretations should therefore remain confined to the descriptive information and endpoint definitions that are recorded.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("PROMUS PREMIER Group")
n      <- c(2059)
events <- c(41)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  PROMUS PREMIER Group  2059  41  2.0  1.4  2.7  1.5  2.7  1.5  2.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists the primary 12-month MACE endpoint and secondary outcomes of cardiac death, myocardial infarction, and TVR. It does not report a multiplicity strategy, such as a hierarchy for testing outcomes or an adjustment for testing several outcomes. In general, when multiple hypotheses are tested, the chance of at least one false-positive result can increase unless the analysis plan accounts for the testing structure. That general issue cannot be resolved for this study from the registry record, and no outcome tests are reported.

The registry record lists no analyses. It also does not report outcome results for the primary endpoint or the listed secondary outcomes. No missing-data method, imputation approach, censoring rule, or sensitivity analysis is reported in the registry record. These omissions matter because incomplete follow-up can affect the denominator and the interpretation of a 12-month outcome. The record's enrollment count does not establish how many participants had complete endpoint ascertainment.

The stated ITT analysis population comprises all subjects who sign the written informed consent form and are enrolled, regardless of whether the study stent was implanted. This is the record's stated population definition. It does not establish that every enrolled participant was included in every analysis, particularly since analysis-specific counts are not reported. Details about exclusions, protocol deviations, withdrawals, and follow-up completeness are not reported in the registry record.

Without the analysis population counts and missing-data rules, readers cannot assess how closely an outcome analysis followed the stated ITT definition or whether incomplete follow-up could have influenced the result. Because no primary or secondary analysis result is posted in the record, there is also no basis for evaluating multiplicity-adjusted or unadjusted statistical evidence.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 2.8% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: cardiac disorders (1.9%), general disorders (0.3%), injury, poisoning and procedural complications (0.0%), nervous system disorders (0.0%).

The serious adverse-event summary for the PROMUS PREMIER Group lists 2059 at risk and 48 affected participants. The separate other adverse-event summary lists 2059 at risk and 58 affected participants. The record also lists 30 deaths. These are registry summaries; the record does not report the event collection timeframe, detailed definitions, or whether the adverse-event categories overlap. The counts should not be added together or treated as separate, mutually exclusive groups of people.

The leading serious-event terms are listed with percentages: Cardiac disorders, 1.9%; General disorders, 0.3%; Injury, poisoning and procedural complications, 0.0%; and Nervous system disorders, 0.0%. The record does not explain in this summary how these category percentages were calculated or provide term-specific participant counts. Percentages rounded to 0.0% do not establish that no events occurred.

These summaries do not provide a randomized comparison or establish that the device caused or prevented the listed events. They are also distinct from the primary MACE endpoint, which combines cardiac death, myocardial infarction, and TVR. The primary MACE result is not reported in the registry record. Safety interpretation is limited by the absence of further definitions, timing, ascertainment details, and comparative analyses.

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

The record describes a completed study intended to collect real-world clinical outcome data for the PROMUS PREMIER stent system in routine clinical practice in China. It defines a 12-month MACE endpoint and states an ITT population that includes enrolled subjects regardless of whether the study stent was implanted. It also records enrollment, study dates, a study group, and limited adverse-event summaries. These registry entries describe the study's scope and registry information; they are not themselves evidence of a particular clinical outcome.

The primary MACE result is not reported in the registry record. Therefore, the record cannot show how many participants met the endpoint, the estimated frequency of MACE, or the precision of an estimate. The listed secondary outcomes likewise have no reported results. Neither the enrollment figure nor the safety counts can be used to fill in those missing endpoint results.

The record does not describe a randomized comparison, and allocation is not stated. It explicitly warns that the arms are not a like-for-like control comparison. Consequently, it cannot support a causal comparison between the device and a control based on random allocation. A post-approval study can provide descriptive information about outcomes in its recorded practice setting, but the absence of comparative analysis and details about participant selection and follow-up limits broader interpretation.

The serious-event figures and category percentages should be read as registry summaries, not as proof that the device caused an event or that an event was absent. The record does not provide the detail needed to evaluate overlap, timing, ascertainment, or an appropriate comparison. It also does not report a statistical analysis or confidence interval for these summaries.

In short, the registry record establishes the study's stated purpose, endpoint definition, analysis-population definition, completion status, and some safety counts. It does not report the primary outcome result, secondary outcome results, or comparative evidence. Statistical claims about event frequency, precision, or treatment effect would go beyond what the record reports.

14. Why This Trial Matters Statistically

Post-approval studies address a different statistical question from randomized comparisons. Their aim may be to describe outcomes under routine practice conditions, where patient selection, treatment decisions, and follow-up reflect the study setting. Such information can complement controlled evidence by documenting what was collected in a practice context. Its value depends on transparent reporting of who was enrolled, which outcomes were observed, how completely they were followed, and how analyses were conducted.

This record makes several useful elements explicit: the intended real-world purpose, the 12-month MACE definition, the named secondary outcomes, and the ITT population definition. It also identifies a completed study and gives the enrollment and study dates. These details help frame what the study set out to collect and what its primary outcome was intended to represent.

At the same time, the record illustrates why outcome definitions and results must be read separately. Defining a composite endpoint does not report its observed frequency, and enrollment does not establish endpoint completeness. Because the primary result and analyses are not reported, readers cannot assess statistical precision or the contribution of the component outcomes. The registry's warning about the absence of a like-for-like control comparison also matters: descriptive data should not be mistaken for a randomized estimate of a treatment effect.

The record's safety counts offer limited descriptive information, while their interpretation remains constrained by missing details about time, definitions, overlap, and analysis. More complete reporting of results and methods would be needed for stronger statistical evaluation. The central statistical lesson is that a study's registration, stated objective, and endpoint definition are not substitutes for reported outcome estimates and their uncertainty.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The primary limitation for interpreting outcomes is that the registry record does not report the primary MACE result or results for the listed secondary outcomes. It provides no outcome estimate, confidence interval, or p-value for the primary endpoint. The endpoint is defined, but the observed participant count and analysis denominator are not available in the record.

The design description is limited. The study is not described as a randomized comparison, allocation is not stated, and the record warns that arms are not a like-for-like control comparison. No comparator details, adjustment strategy, or comparative analysis are reported. The study's stated real-world purpose provides context, but does not remove the limitations of an uncontrolled or non-comparable contrast.

Important clinical and operational details are not reported in the registry record, including eligibility criteria, participant characteristics, site information, follow-up completeness, event adjudication, and detailed endpoint rules. The ITT population is defined, but analysis-specific population counts and handling of withdrawals or missing outcomes are not reported. Consequently, adherence to the stated analysis population and the potential effects of missing follow-up cannot be assessed.

The adverse-event summary lacks detail about event timing, definitions, overlap, and the calculation basis for category percentages. The record does not present analyses that would connect these summaries to the primary endpoint or support causal attribution. The planning illustration is not the study's own design justification, and its assumptions do not establish the precision of the completed study. Overall, the registry record supports a description of the study's stated aims and limited posted data, but not a full assessment of outcome frequency, statistical uncertainty, or comparative effect.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: PROMUS PREMIER™ China Post-Approval Study — NCT03273023.
• Registry record last updated 2026-07-22; status last verified 2026-07.
• Results first posted 2026-07-22.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The PROMUS PREMIER China Post-Approval Study (NCT03273023) is listed as completed, with enrollment of 2059. The study aimed to compile real-world clinical outcome data for the PROMUS PREMIER everolimus-eluting platinum chromium coronary stent system in routine clinical practice in China. The recorded start date is 2018-01-11, and the primary completion date is 2020-12-28.

The primary endpoint is the 12-month MACE participant count, defined as cardiac death, myocardial infarction, or target vessel revascularization. The stated ITT population includes enrolled subjects who signed written informed consent, whether or not the study stent was implanted. The registry record does not report the primary or secondary outcome results, and it lists no analyses. Allocation is not stated; the record cautions that arms are not a like-for-like control comparison. Adverse-event summaries list 48 serious-event affected participants, 58 affected participants in the other summary, and 30 deaths, with limited category percentages and no detailed analysis.