RESOLUTE Japan - The Clinical Evaluation of the MDT-4107 Drug-Eluting Coronary Stent: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for RESOLUTE Japan - The Clinical Evaluation of the MDT-4107 Drug-Eluting Coronary Stent (NCT00927940), a na na study. The primary outcome is In-stent Late Lumen Loss (LLL).

2. Clinical Question

3. Trial Design

RESOLUTE Japan (NCT00927940) is recorded as a completed, single-group device study sponsored by Medtronic Vascular. The registry lists enrollment of 100. The study start is recorded as 2009-03 and primary completion as 2010-12. Phase is listed as NA, allocation as NA, and masking as none. These entries describe the registry classification; they do not supply additional details about how participants were recruited, treated, or followed.

All patients in the described group received the drug-eluting stent. The arm description permits one or two treated lesions, with two lesions only when located in separate coronary arteries, and specifies stent diameters from 2.5mm to 3.5mm. No randomized or concurrent control arm is listed. The record therefore supports describing outcomes in a treated cohort, but not estimating a treatment contrast against a control group.

The primary outcome was in-stent late lumen loss, a continuous measure reported as a mean with standard deviation, with the stated timeframe of post procedure and 8 months. The record lists four outcome measures and names secondary outcomes covering target lesion failure, device, lesion and procedure success, major adverse cardiac events, target vessel failure, stent thrombosis, incomplete stent apposition, neointimal hyperplastic volume, and percent volume obstruction. It lists no analysis entries. Details of the protocol, sample-size justification, follow-up schedule beyond the endpoint timeframe, and statistical analysis plan are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Actually a patient was excluded from this analysis because of death before 30 days follow up.

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 In-stent Late Lumen Loss (LLL), measured over Post procedure, 8 Months.

In-stent late lumen loss (LLL) is the primary endpoint. The registry defines it as the difference between minimal lumen diameter measured immediately after the procedure and minimal lumen diameter at follow-up angiography. The measure is expressed in millimeters and specified as a mean with standard deviation, with measurements after the procedure and at 8 months.

General explanation: A lumen-diameter change measure can describe how the treated vessel’s measured inner opening differs between the immediate post-procedure assessment and later imaging. Late lumen loss is used in stent studies as a quantitative imaging endpoint relevant to narrowing within the stented segment. It is a surrogate anatomical measurement; by itself, it is not a count of clinical events and does not directly establish how patients feel or function.

The registry record does not report the mean, standard deviation, number analyzed, confidence interval, or a test result for this endpoint. It also notes that a patient was excluded from this analysis because of death before 30 days of follow-up. The available description therefore identifies what was intended to be measured but does not give the numerical endpoint result or enough information to reconstruct it.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General statistical explanation: The endpoint is continuous: each analyzed participant can have a measured amount of late lumen loss, and the registry specifies summarizing that measure with a mean and standard deviation. A mean describes the cohort’s average observed value. A standard deviation describes how spread out individual measurements are around that average. These quantities answer different questions: the mean locates the center of the observed measurements, while the standard deviation describes their variability.

What would an uncertainty interval tell a reader?

General: A confidence interval gives a range of values compatible with the data and the method used to calculate it. It helps readers assess the precision of an estimate; a narrower interval indicates greater precision under that method, while a wider interval indicates less. It is not a guarantee that the true value lies within the particular interval. No confidence interval for late lumen loss is reported in the registry record, so its precision cannot be evaluated from the posted information.

What does a single-group estimate represent?

General: In a single-group study, a mean describes the measured outcome among participants in that group. A treatment contrast requires a comparison with another group or another defined counterfactual, together with suitable design and analysis assumptions. The recorded study model is single group, and allocation is listed as NA. Thus, even if a cohort mean were available, it would not by itself quantify a difference attributable to the stent compared with an alternative.

Why can variability and measurement details matter?

General: Continuous imaging measurements can vary between participants, and measurement procedures can also affect observed values. A standard deviation is one way to describe participant-level spread, but it does not explain the sources of that spread or establish that measurement was consistent. The endpoint description names minimal lumen diameter at immediate post-procedure and follow-up angiography. Further details on image reading, measurement procedures, quality control, or reader blinding are not reported in the registry record.

How should analysis populations be considered?

General: The number enrolled and the number contributing to a particular endpoint need not be the same. A clear report typically identifies who was included in each analysis and how unavailable measurements were handled. Here, the registry lists enrollment of 100 and says one patient was excluded from the primary analysis because of death before 30 days of follow-up. The number actually analyzed and rules for any other incomplete data are not reported in the registry record. The enrollment count should therefore not be treated as the endpoint denominator.

What can be inferred from the analysis listing?

The registry lists no analysis entries. It does not report a model, hypothesis test, confidence-interval method, adjustment variables, or analysis population definition for the primary endpoint. These details cannot be inferred from the fact that a mean and standard deviation were specified as the summary. A planned summary statistic does not establish which inferential method was used or whether an inferential analysis was conducted.

How do planning illustrations differ from observed results?

General: A sample-size calculation is a planning exercise based on assumed design features and a target effect; it is not an observed outcome and is not a substitute for reporting the estimate and its uncertainty. The registry’s planning assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with a target effect expressed as a fraction of an observed effect. Those are assumptions for a planning illustration, not a description of this single-group study’s allocation. Numerical planning outputs and the trial’s own sample-size justification are not reported in the registry record. No planning illustration should be read as observed power or as evidence about the trial’s results.

Over-dispersion is a general issue for count outcomes when observed variation exceeds what a model’s assumed distribution allows; accounting for it can affect standard errors and interval estimates. That concept does not establish that over-dispersion was present or that a particular model was used in this study. The primary endpoint is continuous, and the registry record does not identify any model used for it.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Zotarolimus Eluting Stent")
n   <- c(99)
m   <- c(0.13)
sp  <- c(0.22)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Zotarolimus Eluting Stent  99  0.130  0.220  0.086  0.174

11. Multiplicity, Missing Data and Analysis Populations

The registry names a primary endpoint and several categories of secondary outcomes, but it does not report how testing across these outcomes was handled. Multiplicity arises when multiple hypotheses are tested: without an appropriate strategy, the chance of at least one apparently notable result can increase. General explanation: A statistical plan may designate a limited set of confirmatory tests or adjust interpretation for multiple comparisons. No such strategy is reported in the registry record, so it is not possible to determine whether secondary analyses were adjusted, ordered, or treated as exploratory.

The record lists four outcome measures, including in-stent late lumen loss as the primary measure and secondary descriptions covering target lesion failure; success measures and cardiovascular events; and imaging measures. It also lists no analysis entries. The registry record does not report an interim-analysis plan, stopping rules, or a prespecified hierarchy for endpoints.

For the primary analysis, the record states that one patient was excluded because of death before 30 days of follow-up. It does not give the endpoint analysis denominator, describe other missing measurements, or specify whether any imputation or sensitivity analysis was used. General explanation: Excluding participants with unavailable outcomes can affect both the size and composition of the analyzed group. The direction and magnitude of any effect cannot be determined without the data and the missing-data process. The available record does not establish whether the stated exclusion was the only missing-data issue, nor does it describe the analysis population for secondary outcomes.

12. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: coronary artery restenosis (5.0%), miocardial infarction (4.0%), coronary artery stenosis (3.0%), abdominal pain (2.0%), gastric ulcer (2.0%).

The registry lists 100 participants at risk for serious adverse events and 35 affected participants. It separately lists 100 at risk for other adverse events and 58 affected participants. These are participant counts recorded in the safety entry; the record does not explain whether a participant could appear in both categories, so the counts should not be added to create a total number of distinct participants. Deaths are not reported in the safety entry.

The most frequent serious-event terms listed are CORONARY ARTERY RESTENOSIS at 5.0%, MIOCARDIAL INFARCTION at 4.0%, CORONARY ARTERY STENOSIS at 3.0%, ABDOMINAL PAIN at 2.0%, GASTRIC ULCER at 2.0%, and LOWER GASTROINTESTINAL HEAMORRAGE at 2.0%. The registry uses these terms and spellings. The listed percentages describe the reported terms; the record does not provide additional context about event severity beyond the serious-event classification, timing, relatedness, or whether terms can overlap within participants.

General explanation: Adverse-event counts describe events recorded during a study and are not, on their own, proof that the device caused them. Interpretation also depends on definitions, follow-up, comparison data, and attribution procedures, details that are not reported in the registry record.

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

The record establishes that RESOLUTE Japan was a completed, single-group evaluation of the MDT-4107 drug-eluting coronary stent, with an enrollment of 100 and in-stent late lumen loss specified as the primary endpoint. It also defines the endpoint’s measurement and lists safety and secondary-outcome categories. These features clarify what the study set out to examine and what kinds of outcomes it tracked.

They do not establish a numerical primary result. The mean late lumen loss, standard deviation, confidence interval, and analysis denominator are not reported in the registry record. In the absence of those results, the direction, magnitude, and precision of the observed imaging outcome cannot be assessed from the posted information. The stated study objective is not a result and should not be interpreted as a conclusion that safety or efficacy was demonstrated.

The single-group design also means the registry record does not provide a randomized comparison with another treatment. It cannot, by itself, show how outcomes would differ under an alternative device or treatment strategy. This is a design limitation on causal interpretation, separate from the absence of numerical outcome results.

The safety entry gives counts of participants with serious and other adverse events and lists several serious-event terms with percentages. Those entries describe reported events in the cohort, but do not establish causation or provide a comparison against another group. The record does not report event timing, attribution, or the full context needed to interpret those listings comparatively.

General interpretation: A complete assessment of a clinical study usually considers the estimate, its uncertainty, the population analyzed, missing data, and the design’s ability to support comparisons. For this study, several of these details are not reported in the registry record. The appropriate reading is therefore limited: the entry describes the study and some safety information, while leaving the primary endpoint’s numerical result and its precision unavailable.

14. Why This Trial Matters Statistically

This study is statistically notable because its primary endpoint is a continuous imaging measure in a single-group device evaluation. Such a design can describe the observed distribution of a measurement in the treated cohort, provided the result and analysis population are reported. It cannot by itself estimate a treatment difference against a concurrent control. Distinguishing descriptive evidence from comparative evidence is central to interpreting device studies.

The endpoint definition also makes timing important: it compares an immediate post-procedure measurement with follow-up angiography at 8 months. A clear account of the mean, variability, number analyzed, and uncertainty would help readers judge what the cohort measurements show. Those numerical details are not reported in the registry record, leaving the principal quantitative question unresolved in the posted entry.

The record further illustrates why enrollment and endpoint analysis size should not be assumed to be identical. Although enrollment is listed as 100, one patient was excluded from the primary analysis because of death before 30 days of follow-up, and the final analysis denominator is not reported. Transparent reporting of exclusions and missing measurements is important for understanding which participants contribute to an estimate and how representative that estimate may be.

Finally, the entry lists multiple secondary outcomes and safety categories, but no analysis entries or multiplicity approach. Statistical interpretation depends not only on which outcomes are named, but also on how results were analyzed and how uncertainty across multiple assessments was considered. The registry record supplies a study framework, but not the primary numerical results or enough analysis detail for a full quantitative appraisal.

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 main limitation of the registry record for statistical interpretation is that it does not report a numerical result for the primary endpoint. The mean in-stent late lumen loss, standard deviation, confidence interval, and test result are absent. The analysis denominator is also not reported, so the enrollment of 100 cannot be assumed to be the number contributing to that endpoint.

The primary analysis excludes one patient because of death before 30 days of follow-up. The registry record does not explain whether other participants lacked follow-up angiography, how any incomplete measurements were handled, or whether sensitivity analyses were conducted. The stated exclusion is therefore relevant, but does not fully describe the endpoint’s missing-data process.

The recorded single-group model and absence of a randomized allocation mean there is no concurrent control comparison in the registry description. This limits interpretation to the treated cohort and does not support an estimate of a comparative treatment effect. The record also lists no analysis entries; details such as the inferential method, model specification, and multiplicity strategy are not reported in the registry record.

Additional study details—including protocol-level eligibility criteria, the rationale for sample size, interim analyses, and procedures for measuring or reviewing angiographic images—are not reported in the registry record. The safety information lists participant counts and selected event terms, but does not report event timing, relatedness, or whether individual participants experienced multiple listed terms. These gaps constrain interpretation without establishing that any particular method or procedure was or was not used.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: RESOLUTE Japan - The Clinical Evaluation of the MDT-4107 Drug-Eluting Coronary Stent — NCT00927940.
• Registry record last updated 2015-05-05; status last verified 2015-04.
• Results first posted 2012-07-09.
• 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

RESOLUTE Japan (NCT00927940) is a completed, single-group study sponsored by Medtronic Vascular, with enrollment of 100. It evaluated the MDT-4107 Drug Eluting Stent for de novo lesions in native coronary arteries. The registry lists masking as none and phase and allocation as NA.

The primary endpoint is mean in-stent late lumen loss in millimeters, measured from immediate post-procedure to 8-month follow-up angiography. One patient was excluded from that analysis because of death before 30 days of follow-up. The numerical endpoint result, its variability and precision, and the endpoint analysis denominator are not reported in the registry record. The entry lists safety counts and secondary-outcome categories, but no analysis entries. Because the design is single group, the record does not provide a randomized treatment comparison.