A Clinical Trial to Assess the SYNERGY 48 mm Stent System for the Treatment of Atherosclerotic Lesion(s): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Clinical Trial to Assess the SYNERGY 48 mm Stent System for the Treatment of Atherosclerotic Lesion(s) (NCT03350542), a na phase 3 study. The primary outcome is Target Lesion Failure Rate at 12-months.

2. Clinical Question

3. Trial Design

EVOLVE 48 is a prospective, multicenter, open-label, single-arm phase 3 trial of the SYNERGY 48 mm everolimus-eluting platinum chromium coronary stent system. The registry lists an enrollment of 100 and identifies coronary artery disease as the condition under study. The trial is marked completed. Its recorded start date is 2018-04-12, and its primary completion date is 2020-01-16.

Because the trial has a single group, participants received the study system without a concurrent randomized control arm. Allocation is recorded as not applicable, and masking as none. These design features mean the trial can describe outcomes observed among its participants, but it cannot by itself separate the contribution of the device from other influences or establish a comparative treatment effect.

The study description focuses on a specific anatomical setting: atherosclerotic lesions longer than 34 mm and no more than 44 mm by visual estimate, in native coronary arteries with a visually estimated diameter from 2.5 mm to 4.0 mm. The results therefore pertain to the trial population and this stated setting; they should not be treated as direct evidence about other lesion lengths, vessel sizes, or clinical populations.

The primary endpoint is the target lesion failure rate at 12 months. The registry says the per-protocol and intention-to-treat populations are the same. It lists 14 outcome measures, including target lesion and target vessel revascularization, target vessel failure, myocardial infarction, and death outcomes. The registry record does not report the primary endpoint result, analysis details, or a statistical 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: The per-protocol and ITT populations are the same.

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 Target Lesion Failure Rate at 12-months, measured over 12-month.

Target lesion failure is a composite endpoint assessed at 12 months. The registry defines an event as any ischemia-driven revascularization of the target lesion, myocardial infarction related to the target vessel, or cardiac death. The endpoint is expressed as a percentage of participants.

Composite endpoints are used in clinical research to capture more than one clinically relevant type of outcome in a single measure. This can offer a broad summary of events related to the target lesion and vessel, but it also means the overall rate depends on the component events. A composite result alone does not show how much each component contributed. Component-specific results are needed to understand whether events were mainly revascularizations, infarctions, or cardiac deaths.

For a binary endpoint, each participant is classified according to whether an event occurred during the specified assessment period. The resulting proportion describes the observed frequency in the analyzed population; it does not, on its own, establish why an event occurred or whether the study system caused it. In this single-arm trial, there is no concurrent group to provide a direct comparison.

The registry record gives the endpoint definition and timeframe but does not report the observed target lesion failure rate, its component counts, or an uncertainty interval. It is therefore not possible to describe the endpoint’s observed frequency or precision from the registry information recorded.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Clinical trial results depend on the question, outcome definition, population, and analysis. EVOLVE 48 is recorded as a prospective, multicenter, open-label, single-arm study. Those design features determine what kinds of statistical interpretation are possible: the study can describe outcomes in its enrolled group, but it has no concurrent randomized group for a direct treatment comparison.

What does a binary percentage describe?

The primary outcome is a percentage of participants with target lesion failure by the 12-month assessment. In general, a binary outcome sorts participants into event and no-event categories over a defined period. A percentage is a summary of the observed event frequency in the population used for analysis. It does not describe the timing of each event, and it does not show which component of a composite endpoint occurred unless component results are also reported.

The target lesion failure definition combines ischemia-driven target lesion revascularization, target-vessel-related myocardial infarction, and cardiac death. For interpretation, a composite endpoint should be read alongside its definition and, when available, its separate components. Different components can have different clinical meanings and frequencies. The registry record does not report the observed composite result or component results, so neither can be characterized statistically from the recorded outcome information.

Why does a confidence interval matter?

General statistical explanation: a confidence interval conveys the uncertainty around an estimate under a specified statistical procedure. A narrower interval indicates greater precision under that procedure, while a wider interval indicates less precision. An interval does not remove limitations in the study design, and it does not make an uncontrolled result comparative. The registry record does not report a confidence interval for target lesion failure, so its precision cannot be assessed from the posted primary endpoint information.

What can a single-arm design estimate?

A single-arm study can report an observed proportion in its study group. Without a concurrent control group, it cannot directly estimate a randomized between-group difference. Historical or external comparisons would require additional information and assumptions; none are specified in the registry record. The study’s open-label status means masking is recorded as none. The registry record does not describe additional procedures for limiting ascertainment or analysis bias.

Allocation is listed as not applicable, consistent with the recorded single-group model. There is no evidence in the registry record of random assignment or of a control arm. Thus, comparative measures such as a risk difference, relative risk, or treatment effect between arms are not reported and cannot be inferred from the design description alone.

How should event counts be read?

For a binary outcome, an event count and the number of participants assessed provide the basis for an observed proportion. The denominator matters: it indicates how many people contributed information to that outcome. The registry gives 100 as the enrollment and lists 100 at risk for each of the adverse-event categories reported. It does not give the primary endpoint event count or an analyzed denominator for that outcome. Enrollment alone should not be substituted for an endpoint-specific denominator if the analysis population or follow-up differs.

Adverse-event categories can overlap: one participant may experience more than one event type, and a participant may contribute to more than one category. Unless the registry explicitly states that categories are mutually exclusive, their counts or percentages should not be added to create a total. The safety information does not report enough detail to determine overlap or to attribute events to the device.

What does the planning information mean?

General statistical explanation: sample-size planning considers a target effect, variability or event frequency, allocation, and a chosen error criterion. A planning illustration based on an observed effect is not the original trial’s design justification and is not observed power. The registry record does not report the trial’s sample-size justification or its own planning assumptions. Any planning illustrations associated with this analysis are not evidence that a particular effect was detected, nor do they replace the missing primary endpoint estimate.

The stated illustration assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Those assumptions describe an illustrative calculation rather than EVOLVE 48’s design: the trial itself is single-arm, not an equal-allocation, two-arm comparison. The registry record contains no primary endpoint result from which to assess the observed effect in this discussion.

What can be concluded from the analysis record?

The registry lists 14 outcome measures and 0 analyses. It does not report a statistical analysis plan, an inferential result for the primary endpoint, or confidence intervals. In general, a p-value addresses compatibility between data and a specified statistical model or null hypothesis; it does not measure clinical importance or establish causation. No primary-endpoint p-value is reported in the registry record, and a statistical conclusion about that endpoint cannot be drawn from its definition alone.

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("SYNERGY 48 mm")
n      <- c(98)
events <- c(4)
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  SYNERGY 48 mm  98  4  4.1  1.1  10.1  1.6  10.0  1.7  10.0

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 14 outcome measures, including the primary target lesion failure endpoint and multiple secondary measures of revascularization, myocardial infarction, vessel failure, and death. When a study examines several outcomes, multiplicity can matter: conducting multiple statistical tests can increase the chance of at least one apparently notable finding under a set of null hypotheses. General statistical practice may address this through prespecified outcome hierarchies, adjustment procedures, or careful descriptive interpretation. The registry record does not report a multiplicity strategy, testing hierarchy, or statistical analysis plan.

The registry records 0 analyses. It does not provide an inferential analysis of the primary endpoint or the listed secondary outcomes. In particular, there are no reported primary outcome estimates, confidence intervals, or p-values in the registry record. The presence of an outcome in the registry is not evidence that a result was statistically significant or that the outcome was analyzed as planned.

Missing-data handling is also not reported in the registry record. It does not describe how missing visits, incomplete follow-up, withdrawals, or unavailable endpoint assessments were handled. The registry states that the per-protocol and intention-to-treat populations are the same, but does not give further population definitions or explain how that equality was implemented in the analysis.

General statistical explanation: missing outcome information can affect an estimated event proportion, and the direction of any resulting bias depends on why information is missing and how it is handled. Without the number of participants assessed for the primary endpoint, details of follow-up, and the missing-data procedure, the impact cannot be evaluated. The enrollment figure should not be treated as proof that every participant contributed a complete 12-month outcome.

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 1% 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 dissection (8.0%), acute kidney injury (4.0%), angina pectoris (4.0%), plaque shift (3.0%), carotid artery stenosis (2.0%).

The registry lists one SYNERGY 48 mm group with 100 participants at risk for both serious and other adverse events. It records 31 participants with serious adverse events, 4 with other adverse events, and 5 deaths. These are descriptive counts from the safety record; the registry information does not establish that the study system caused these events.

The listed serious adverse-event terms include coronary artery dissection at 8.0%, acute kidney injury at 4.0%, angina pectoris at 4.0%, plaque shift at 3.0%, carotid artery stenosis at 2.0%, and acute coronary syndrome at 2.0%. These percentages describe the recorded terms, not necessarily distinct participants. A person may experience more than one event type, so the percentages should not be added together as though they represented mutually exclusive groups.

Counts of participants with events are different from counts of all events if an individual can experience repeated events. The registry information does not explain whether the serious-event figures represent unique participants, repeated events, or both in every detail. Nor does it provide event timing, outcome severity beyond the serious classification, or a causal assessment for each term. The 5 deaths are listed separately; the record does not provide a breakdown by cause in the safety figures.

Without a concurrent control group, these figures cannot estimate a comparative safety difference. They describe the recorded safety experience in this study group and should be interpreted with the trial’s design and the limitations of the registry entries in mind.

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

EVOLVE 48 addresses a defined question: the 12-month target lesion failure rate after use of the SYNERGY 48 mm stent system in a specified group of people with long atherosclerotic lesions in native coronary arteries. The registry provides the endpoint definition, the single-arm study design, and an enrollment of 100. It also provides selected safety counts and event terms.

The registry record does not report the observed primary endpoint rate, its event count, component outcomes, or an uncertainty interval. As a result, the posted primary outcome information cannot establish how frequently target lesion failure occurred or how precisely that frequency was estimated. The absence of a reported result is not evidence that no events occurred; it means the result is not reported in the registry record.

The design also limits what the trial can say comparatively. With no concurrent randomized control group, observed outcomes cannot be interpreted as a direct estimate of the difference between the stent system and another treatment. The study does not by itself establish that the system caused a particular outcome or that an outcome would differ under another approach.

The safety figures describe events recorded among participants in the study group. They do not, by themselves, show that events were caused by the device, and the available details do not clarify the relation of each event to the study system. The death count is reported without a cause-specific breakdown in the safety information described in the registry.

Statistical significance, clinical importance, and causal interpretation are distinct questions. A statistical test, if reported, would address a specified model and hypothesis; clinical importance requires interpretation of the outcome and its context; causal claims require a design and assumptions that support them. The registry record does not report a primary endpoint analysis or a comparative estimate. The appropriate reading is therefore limited to the stated design, endpoint definition, and descriptive safety information.

14. Why This Trial Matters Statistically

EVOLVE 48 is statistically informative as an example of how a single-arm device study frames an outcome question without a concurrent randomized comparator. Its prospective, multicenter design, specified lesion characteristics, and 12-month composite endpoint define the intended setting and outcome. These details matter because an event rate is interpretable only in relation to the population, endpoint definition, and assessment period to which it applies.

The trial’s primary endpoint combines revascularization of the target lesion, target-vessel-related myocardial infarction, and cardiac death. This construction can summarize several event types, but it also makes component-level reporting important. Without the composite estimate and component results, readers cannot assess the event frequency or identify which type of event contributed to it. The registry record does not report those results.

The single-arm design makes clear the distinction between describing outcomes and estimating comparative effects. An observed rate in one group can characterize that group, but it cannot supply a randomized estimate of how outcomes would differ under another treatment. That distinction is particularly important when interpreting device studies, where a numerical result may otherwise be mistaken for evidence of comparative benefit or harm.

The record also illustrates why results reporting and methods reporting both matter. The registry identifies 14 outcome measures but records 0 analyses, and does not report the primary endpoint estimate, its precision, missing-data handling, multiplicity strategy, or sample-size justification. Those omissions constrain statistical interpretation even though the design and endpoint are clearly described.

Finally, the safety figures show why descriptive counts need context. Counts and percentages convey recorded events in the study group, but not causation, comparative risk, or necessarily the number of unique event episodes. Clearer analysis details and outcome reporting would be needed to answer those further questions.

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 most direct limitation of the registry record is that it does not report the primary endpoint result. Although target lesion failure at 12 months is defined, no observed percentage, event count, component breakdown, confidence interval, or p-value is reported. The primary statistical question therefore cannot be answered from the recorded results.

The single-arm design has no concurrent randomized comparator. It can describe outcomes in the study group, but it does not provide a direct estimate of comparative efficacy or safety. Open-label status is recorded, with masking listed as none. The registry does not describe procedures that might address outcome-assessment or analytic bias.

The study population is narrowly described by lesion length and native-vessel diameter, both assessed by visual estimate. The record does not establish how results would apply to people outside those stated anatomical criteria. The enrollment is listed as 100, but the registry information does not report the endpoint-specific analyzed denominator or completeness of 12-month follow-up.

Several analysis details are absent. The registry does not report the sample-size justification, statistical analysis plan, multiplicity strategy, missing-data handling, or inferential analyses. It states that per-protocol and intention-to-treat populations are the same, but does not give further detail about their definition or application.

Safety interpretation is also limited. The registry lists adverse-event counts and selected serious-event terms, but the information does not establish causality, clarify all event overlap, or give a cause-specific breakdown of deaths. These omissions restrict conclusions about comparative risk and event patterns.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Clinical Trial to Assess the SYNERGY 48 mm Stent System for the Treatment of Atherosclerotic Lesion(s) — NCT03350542.
• Registry record last updated 2021-05-14; status last verified 2021-04.
• Results first posted 2021-02-05.
• 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

EVOLVE 48 (NCT03350542) is a completed, prospective, multicenter, open-label, single-arm phase 3 trial of the SYNERGY 48 mm everolimus-eluting platinum chromium coronary stent system. The registry lists an enrollment of 100 and describes treatment of atherosclerotic lesions longer than 34 mm and no more than 44 mm by visual estimate in native coronary arteries with a visually estimated diameter from 2.5 mm to 4.0 mm.

The primary endpoint is the 12-month target lesion failure rate, defined as ischemia-driven target lesion revascularization, target-vessel-related myocardial infarction, or cardiac death. The per-protocol and intention-to-treat populations are recorded as the same. The registry lists 14 outcome measures and 0 analyses.

The primary endpoint result and its statistical uncertainty are not reported in the registry record. Descriptive safety information lists 31 participants with serious adverse events, 4 with other adverse events, and 5 deaths among 100 at risk. The single-arm design does not provide a concurrent randomized comparison.