Revolution™ Peripheral Atherectomy System for Lower Extremity Peripheral Arterial Revascularization: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Revolution™ Peripheral Atherectomy System for Lower Extremity Peripheral Arterial Revascularization (NCT02961894), a na na study. The primary outcome is Safety Endpoint: Number of Participants With Freedom From Major Adverse Events.

2. Clinical Question

3. Trial Design

The registry record describes a completed, prospective device study with a single treatment arm. The intervention was the Revolution™ Peripheral Atherectomy System, and all eligible participating patients were assigned to receive it. Allocation is listed as NA, masking as NONE, and the model as SINGLE GROUP. The record lists Rex Medical as the sponsor and the phase as NA.

The stated aim was to evaluate safety and effectiveness in treating infrainguinal lower extremity peripheral arterial occlusive disease. The brief description specifies eligible patients with stenosis of at least 70% diameter reduction and says the study would evaluate change in stenosis after the procedure and major adverse events through 30 days. The primary safety timeframe is also listed as 30-Day.

Enrollment is reported as 121. The study start date is 2017-06-07, primary completion is listed as 2019-02-28, and status is COMPLETED. The record lists 15 outcome measures, including secondary outcomes concerning revascularization, stenosis change, procedural success, and components of safety. It does not report a concurrent control group, so the design cannot directly compare outcomes under the device with outcomes under an alternative treatment or no treatment.

Further details about recruitment, follow-up completeness, eligibility criteria beyond the stenosis threshold, or the statistical analysis plan are not reported in the registry record. A completed status indicates the study is recorded as completed; it does not itself provide the primary endpoint result or establish how completely each outcome was measured.

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

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 Safety Endpoint: Number of Participants With Freedom From Major Adverse Events, measured over 30-Day.

The primary endpoint counts participants who remained free from major adverse events during the 30-day timeframe. The composite includes all-cause mortality, clinically driven target lesion revascularization, major target limb amputation, major target vessel perforation requiring surgical or endovascular repair, and clinically significant distal embolization in the target limb. The registry description says events were to be adjudicated by an independent Clinical Events Committee.

A composite endpoint combines several clinically important event types into one summary. In general, this can capture a broader range of safety outcomes than any single component, but the components may differ in severity and frequency. A composite result alone would not show which component contributed most; interpretation benefits from component-level results as well.

For this study, the endpoint is framed as freedom from events, so its result would ordinarily be reported as a count or proportion of participants meeting that definition over the stated follow-up. However, the registry record does not report the observed primary endpoint count, proportion, or uncertainty interval. The adverse-event listings are not a substitute for that endpoint result: they do not provide a reported adjudicated summary of freedom from the full composite.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods describe how observations are turned into estimates and how uncertainty is represented. The registry record identifies a single-group study and a primary endpoint expressed as a count of participants free from major adverse events. It does not report the statistical analysis plan, the primary endpoint result, or an inferential analysis. The explanations below are general; they do not assert that any particular unreported method was used in this study.

What does a participant count represent?

A count of participants is a direct summary of how many people meet a defined outcome. For a safety endpoint, the outcome definition matters: a participant is classified according to whether the specified event criterion occurred during the stated observation period. The primary endpoint is freedom from a composite of specified major adverse events through 30 days. A count without a corresponding denominator or a clearly defined analysis population cannot fully communicate the frequency of the outcome. The primary endpoint count and its analysis denominator are not reported in the registry record.

Counts also differ from event totals. One participant can experience more than one event, while a participant-level endpoint may count that person once according to the endpoint rule. Event listings and participant counts are not automatically interchangeable. The record does not explain whether the separate adverse-event entries represent people, event episodes, or how overlapping events were handled. This is why the listed adverse-event numbers should not be combined to reconstruct the primary endpoint.

Why does the study design matter?

In general, a single-group study summarizes outcomes in participants receiving the intervention. Without a concurrent comparison group, it cannot separate the intervention’s contribution from other explanations for the observed outcomes. Examples of general considerations include participants’ underlying condition, other care received, and how outcomes are identified or followed. These are limitations of interpretation inherent to the design, not claims about what happened in this study.

Random allocation, when used in a comparative trial, is intended to make groups comparable on average with respect to measured and unmeasured factors. This study is listed as single-group, with allocation NA; the registry record does not identify a randomized comparison. As a result, no between-group treatment effect can be estimated from the posted design. Descriptive results can still characterize the treated group, but they answer a different question from a controlled comparison.

What does a confidence interval add?

In general, a confidence interval gives a range of values compatible with the data and the statistical method, reflecting sampling uncertainty. It helps readers judge how precisely an estimate has been measured. It does not correct bias from study design, incomplete follow-up, outcome misclassification, or other systematic problems. A precise estimate in a single-group study would still not provide a controlled estimate of comparative effect.

No confidence interval for the primary endpoint is reported in the registry record. Since the primary endpoint estimate itself is also not reported, readers cannot assess its precision. The serious-event entries include counts and listed percentages for selected terms, but no uncertainty intervals are given in the registry record. Those listings therefore do not support a formal assessment of precision.

Why can event data require specialized methods?

In general, the appropriate method depends on the form of the outcome. Binary outcomes classify participants according to whether an event or condition occurred; counts record numbers of participants or events; and time-to-event outcomes incorporate when an event occurred and may account for participants with incomplete observation. A method intended for one outcome type cannot automatically be applied to another. The primary endpoint is described as a participant count, and no time-to-event analysis is reported.

For event counts, over-dispersion is a general concern when observed variability is greater than a simple model assumes. Ignoring it can make uncertainty estimates too small. Whether that issue applies depends on the outcome structure and data; the registry record does not report a model or enough detail to assess it. No model should be attributed to this study based on the endpoint description alone.

What can planning calculations establish?

In general, a sample-size calculation is a planning exercise: it estimates the amount of information a proposed study would need to detect a specified effect under stated assumptions. It is not an observed result and does not show whether the completed study achieved a particular level of power. The record’s planning description refers to an illustration based on an observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. It also distinguishes participant-per-arm planning for most outcomes from total-event planning for time-to-event outcomes.

Those assumptions describe an illustration, not the design of this single-group trial. The registry record does not report the trial’s own sample-size justification. A two-arm illustration should not be interpreted as evidence that the study had two arms, and its assumed allocation should not be mistaken for the actual study design. Planning values, where presented, are not observed power and do not replace an analysis of the endpoint.

What remains unreported?

The registry record does not report the statistical plan, the method used for the primary endpoint, confidence intervals, p-values, interim analyses, or a sample-size justification. It also does not report details needed to assess follow-up completeness or analysis-set definitions. Without those details and the endpoint result, statistical interpretation should remain limited to the documented design and descriptive entries rather than implying an unreported analysis.

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("Revolution Treatment Arm")
n      <- c(113)
events <- c(110)
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  Revolution Treatment Arm  113  110  97.3  92.4  99.4  92.5  99.1  92.5  99.0

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 15 outcome measures, covering the primary safety endpoint and secondary measures such as target lesion revascularization, change in stenosis, procedural success, and other safety or revascularization outcomes. It lists no analyses. The record does not report a multiplicity plan describing whether or how inference across several outcomes was controlled.

In general, when researchers test or estimate many outcomes, the chance of at least one apparently notable finding can increase if each result is interpreted separately. A prespecified hierarchy, adjustment, or other strategy can help define how findings should be interpreted. The registry record does not say whether any such strategy was planned or used. No conclusion about statistical significance across outcomes can be drawn from the outcome list alone.

Missing-data handling and follow-up completeness are also not reported in the registry record. The primary endpoint is defined over 30 days, but the record does not give the number of participants with complete endpoint follow-up, explain how missing outcome status was handled, or describe any imputation or sensitivity analysis. It does not identify analysis populations such as an intention-to-treat or per-protocol set. These omissions matter because the denominator and handling of participants without observed endpoint status can affect the interpretation of a participant count or proportion.

The adverse-event listings report participants at risk and participants with events for serious and other events, but they do not establish the primary endpoint analysis population or missing-data procedure. In general, readers should distinguish a reported count from a complete analysis when follow-up and handling rules are unclear. Here, the primary endpoint result and those supporting details are not reported in the registry record.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: clinically driven tlr (13.2%), perforation of target vessel (3.3%), all-cause mortality (2.5%), major target limb amputation (1.7%), distal embolization (0.8%).

The registry lists the Revolution Treatment Arm with 121 participants at risk for serious events and 26 participants with serious events. For other events, it lists 121 at risk and 78 participants with events. It also lists 3 deaths. These are descriptive safety entries; the record does not report a comparative safety analysis against a control group.

The listed serious-event terms and percentages are Clinically Driven TLR (13.2%), Perforation of target vessel (3.3%), All-cause mortality (2.5%), Major target limb amputation (1.7%), and Distal embolization (0.8%). The record does not explain whether these terms overlap, how their percentages were calculated, or whether they count participants or events. They should not be added together or treated as components with mutually exclusive categories.

These listings are also distinct from the primary endpoint result. The primary endpoint is freedom from a defined composite through 30 days, with events adjudicated by an independent Clinical Events Committee. The registry record does not report the number meeting that endpoint. The serious-event count and term listings alone do not establish that primary count or its precision.

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

The record establishes that a completed, single-group study evaluated the Revolution™ Peripheral Atherectomy System in participants with peripheral arterial disease. It defines a primary safety endpoint based on freedom from a composite of major adverse events through 30 days and describes the intervention and intended assessment of stenosis change. It also records selected adverse-event information for the treatment arm.

What the record does not establish is the observed result for the primary endpoint. It does not report the count or proportion of participants who were free from the composite, nor an uncertainty interval around such an estimate. The listed serious events and deaths provide descriptive information, but they are not a substitute for the adjudicated primary endpoint result. Without a result, the safety question cannot be answered quantitatively from the registry record.

The single-group design also limits what can be inferred about comparative effectiveness or safety. Any observed outcome among treated participants would describe that group; without a concurrent comparator, it would not show what would have occurred under another treatment. The registry record does not provide a comparative treatment effect.

In general, statistical evidence should be read in light of the outcome definition, the analysis population, completeness of follow-up, study design, and uncertainty. Important details about analysis methods, missing data, and analysis populations are not reported in the registry record. Consequently, the registry entries support a description of the study’s stated question and selected safety listings, but not a conclusion that the device did or did not achieve a particular clinical result.

14. Why This Trial Matters Statistically

This trial is statistically notable because its central question is framed as a participant-level safety endpoint in a single-group device study. The design determines the scope of the answer: it can describe safety outcomes recorded among treated participants, but it does not provide a randomized, like-for-like comparison. Keeping that distinction clear prevents descriptive event counts from being mistaken for estimates of comparative effect.

The primary outcome is a composite. In general, combining multiple event types can make an endpoint cover a broader range of safety concerns, while also making it important to examine the separate components. Components may differ in clinical severity and frequency, so a single composite summary can obscure which events contributed to it. In this registry record, the endpoint definition is available, but the adjudicated result and its component-level interpretation are not reported.

The adverse-event entries illustrate why denominators, event definitions, and overlap rules matter. The registry lists participants at risk, participants with serious or other events, deaths, and selected serious-event terms. Those entries should be read as distinct reported descriptions unless the record clarifies how they relate. They cannot be combined into a reconstructed primary endpoint.

The record also lists multiple outcome measures but no analyses and does not report how missing outcomes, multiplicity, or analysis populations were handled. These details affect how confidently estimates can be interpreted. The main statistical lesson is that a clearly defined endpoint and a completed study status do not replace an outcome estimate, its uncertainty, and transparent analysis details. Here, those elements are not reported for the primary safety result.

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 is that the registry record does not report the observed result for the primary safety endpoint. Although it defines freedom from major adverse events through 30 days, it gives no endpoint count or proportion and no confidence interval. The principal safety question therefore cannot be quantified from the record.

The single-group design has no concurrent comparator, and allocation is listed as NA. This means the study description does not support a controlled estimate of the intervention’s effect relative to another treatment. The record does not provide a like-for-like control comparison.

The adverse-event entries offer some descriptive information, but the relationship between serious events, other events, deaths, selected terms, and the primary composite is not explained. Whether categories overlap, how listed percentages were calculated, and whether entries represent participants or event episodes are not reported in the registry record. These gaps prevent reliable reconstruction of the primary endpoint from the safety listings.

Other limitations include the absence of reported details about statistical methods, missing-data handling, follow-up completeness, analysis populations, multiplicity, and the study’s own sample-size justification. The record lists 15 outcome measures and no analyses, but does not explain how findings across outcomes were to be interpreted. These are reporting gaps in the registry record; they do not demonstrate that a particular method was or was not used outside the posted information.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Revolution™ Peripheral Atherectomy System for Lower Extremity Peripheral Arterial Revascularization — NCT02961894.
• Registry record last updated 2020-11-02; status last verified 2020-10.
• Results first posted 2020-11-02.
• 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 registry record describes a completed, single-group study sponsored by Rex Medical, evaluating the Revolution™ Peripheral Atherectomy System for infrainguinal lower extremity peripheral arterial occlusive disease. Enrollment is listed as 121; the study began on 2017-06-07, primary completion is listed as 2019-02-28, and status is COMPLETED.

The primary endpoint is the count of participants free from a composite of major adverse events through 30 days, with adjudication by an independent Clinical Events Committee. The registry record does not report the primary endpoint result. It lists 15 outcome measures and no analyses.

For the treatment arm, the record lists 26 participants with serious events and 78 with other events, each among 121 at risk, and 3 deaths. Selected serious-event terms and percentages are also listed. These entries are descriptive and do not replace the unreported primary endpoint result or provide a controlled comparison.