Trevisio Post-Approval Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Trevisio Post-Approval Study (NCT04433520), a registered phase not stated study. The primary outcome is Effectiveness Endpoint: Rate of Technical Success.

2. Clinical Question

3. Trial Design

The Trevisio Post-Approval Study (NCT04433520) is listed as completed. It was a single-arm, non-randomized, multi-center clinical study sponsored by Abbott Medical Devices. Enrollment was 254. The study began on 2020-09-14, and primary completion was recorded on 2023-01-04. These dates describe the registry record; they do not by themselves explain how participants were recruited, followed, or analyzed.

The study evaluated the Amplatzer Trevisio Intravascular Delivery System when used to facilitate percutaneous, transcatheter implantation of Amplatzer occluder devices. The registry describes an ASD/PFO cohort and a VSD cohort. The first included participants indicated for ASD closure or PFO closure; the second included participants indicated for VSD closure with muscular or post-infarct muscular VSD occluders. The listed interventions reflect these different device uses.

Although the study has two named cohorts, it does not have a randomized control group. The cohorts differ in the conditions being treated and in the occluder devices used. They should not be read as interchangeable treatment arms, and the registry record does not describe allocation between them as a randomized process. The method by which participants entered either cohort is not reported in the registry record.

The primary endpoint was technical success, assessed at pre-hospital discharge or 7 days after the procedure. The endpoint analysis population was the Attempted Procedure population. A detailed analysis plan, including the handling of participants with an unsuccessful or unassessable procedure, is not reported in the registry record. The primary endpoint result is also not reported in the registry record, limiting interpretation of the study's effectiveness findings.

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 endpoint analysis was performed on the Attempted Procedure (AP) population

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 Effectiveness Endpoint: Rate of Technical Success, measured over at pre-hospital discharge or 7 days after the procedure.

The primary endpoint was the rate of technical success, with the unit described as participants. Technical success meant successful deployment and release of at least one device. The assessment time was pre-hospital discharge or 7 days after the procedure. The analysis population was the Attempted Procedure population.

This endpoint focuses on whether the delivery procedure reached a defined technical milestone. In general, a clearly defined procedural endpoint can describe whether the device-delivery process achieved a specified immediate objective. It is distinct from a longer-term clinical outcome: successful deployment and release alone does not establish what happened to participants after the stated assessment period.

The registry record does not report the number of participants who met the definition, the denominator used for the endpoint result, or an uncertainty interval. Consequently, an endpoint rate cannot be stated, and its precision cannot be evaluated. The enrollment figure does not substitute for the endpoint denominator, because the record identifies the Attempted Procedure population for the analysis but does not report its size.

The registry record lists two outcome measures and two analyses, but details beyond the described primary endpoint are not reported in the registry record. No additional endpoint findings should be inferred from the title or definition of technical success.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is binary at the participant level: a participant either meets the stated definition of technical success or does not. In general, binary outcomes are summarized by counts in each category and, when the denominator is known, by a proportion or rate. For this study, the definition is successful deployment and release of at least one device, assessed by pre-hospital discharge or 7 days after the procedure. The registry record does not report the success count or the endpoint denominator, so a rate cannot be interpreted.

What does a confidence interval add?

In general, a confidence interval expresses the statistical uncertainty around an estimate. A point estimate alone does not show how much the observed result might vary across repeated samples under the assumptions of the method. A narrower interval indicates greater precision, while a wider interval indicates less precision. The registry record does not report a confidence interval for technical success or for the listed safety counts, so precision cannot be assessed from the posted results. No interval should be reconstructed without the relevant result and analysis details.

What can a single-arm design estimate?

In general, a single-arm study can describe outcomes observed in the enrolled group. Without a concurrent randomized comparator, it does not isolate the difference attributable to one intervention compared with another. Participants in the ASD/PFO and VSD cohorts have different clinical indications and device uses. The cohorts therefore do not create a like-for-like comparison, and their counts should not be treated as if they arose from randomized treatment allocation. The registry record does not identify a comparative hypothesis or a control group.

How should the sample-size illustration be read?

The registry's planning illustration is described as using the observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It considers effects expressed as fractions of the observed effect. These are planning assumptions, not evidence that the trial itself used that design: the study is described as single-arm and non-randomized. The actual illustration values are not reported in the registry information available for interpretation, and the endpoint effect itself is not reported. Thus, no required sample size can be stated from these registry entries.

In general, a planning calculation asks how many participants a hypothetical study might need under specified assumptions. It is not a measure of the probability that the completed study produced a statistically significant result. A calculation anchored to an observed effect also depends on the effect estimate chosen. If that estimate is unavailable, the planning result cannot be checked or translated into a new design recommendation. Such planning figures must not be described as observed power.

Why does the outcome scale matter?

For a binary endpoint, the key information includes the number meeting the definition, the number not meeting it, and the denominator analyzed. Those counts allow an estimate of the event frequency and are needed for many standard uncertainty calculations. The Attempted Procedure population is identified for the primary analysis, but its size and the technical-success counts are not reported in the registry record. The overall enrollment figure cannot be assumed to be the endpoint denominator.

In general, statistical methods also depend on how observations are distributed and how participants are sampled. Over-dispersion is a concern for some count-data models when variability exceeds the model's assumptions; it is not a substitute for defining a binary participant endpoint. The registry entries describe the primary endpoint as a participant count and provide no model specification, dispersion estimate, or rationale for a particular statistical model. Those details are not reported in the registry record.

Likewise, the registry information does not state whether an adjusted analysis, a formal hypothesis test, or an interval method was used for technical success. Statistical significance, if it were reported, would not by itself convey the magnitude or precision of an effect. In this record, the primary result is absent, so neither statistical significance nor the size of the endpoint estimate can be evaluated. The supported interpretation is limited to the stated outcome definition and design, together with the safety counts that are reported.

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("ASD/PFO Cohort", "VSD Cohort")
n      <- c(251, 3)
events <- c(247, 3)
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  ASD/PFO Cohort  251  247  98.4  96.0  99.6  96.0  99.4  96.0  99.4
ARM  VSD Cohort  3  3  100.0  29.2  100.0  43.9  100.0  39.8  99.4

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists two outcome measures and two analyses, but does not describe the full set of analyses, identify all planned hypotheses, or state whether any multiplicity adjustment was used. When a study evaluates multiple outcomes or makes multiple statistical comparisons, the chance of at least one false-positive result can increase. In general, a prespecified strategy for handling multiple tests helps readers interpret inferential results. No such strategy is reported in the registry record, and the reported information does not establish that a multiplicity adjustment was necessary or performed.

The primary endpoint is assigned to the Attempted Procedure population. The record does not report the number of participants in that analysis population, how it was defined in operational terms, or whether participants were excluded from it. The number with an observed technical-success outcome and the number with missing endpoint data are not reported in the registry record.

Missing-data methods can affect an estimate when outcomes are unavailable. In general, readers need to know how much outcome information is missing, why it is missing, and how the analysis handled those observations. The registry record does not report the amount of missing primary endpoint data, any imputation approach, or a sensitivity analysis. It is therefore not possible to assess whether missing outcomes could have changed the endpoint interpretation.

The registry also does not report details of interim analyses, stopping rules, or a complete statistical analysis plan. These items are not assumed to have been absent; they are not reported in the registry record. The lack of a reported endpoint result further limits assessment of both multiplicity and analysis-population choices.

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: device embolization (0.4%).

The registry reports serious adverse-event counts separately for the ASD/PFO and VSD cohorts. The ASD/PFO cohort has 1 serious adverse event among 251 participants at risk; the VSD cohort has 0 among 3 at risk. For other adverse events, the reported counts are 7 among 251 at risk in the ASD/PFO cohort and 1 among 3 at risk in the VSD cohort. Deaths are recorded as 0 in both cohorts.

These figures are descriptive counts, not evidence from a randomized safety comparison. The cohorts differ in clinical indication and device use, and the VSD at-risk group is small. In general, a zero count means that no event was recorded in that observed group; it does not prove that the event cannot occur. Counts from groups of different sizes also have different levels of precision. The registry record does not report confidence intervals for these adverse-event results.

Device embolization is listed among the top serious terms at 0.4%. The corresponding term-specific count and further details are not reported in the registry record. These safety observations should be read as recorded events during the study, not as a complete characterization of risk beyond the recorded participants and reporting period.

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

The study's primary question concerns whether the Trevisio delivery system facilitated technical success, defined as successful deployment and release of at least one device by pre-hospital discharge or 7 days after the procedure. The registry record gives that definition and identifies the Attempted Procedure population, but does not report the number of participants with technical success or the endpoint rate. The primary effectiveness result therefore cannot be quantified from the reported information.

The safety information gives counts for serious and other adverse events, as well as deaths, in the ASD/PFO and VSD cohorts. Those counts describe events recorded among participants at risk. They do not establish that the cohorts have equal safety, nor do they provide a controlled comparison with another delivery system. The cohorts are not randomized control groups and differ by indication and device use.

The study's single-arm, non-randomized design also limits causal interpretation. In general, observations in a single group cannot separate the contribution of the intervention from other influences on outcomes. The reported design does not support a randomized estimate of what would have happened under an alternative device or procedure. The registry record does not report a comparator or a comparative effect estimate.

The posted information does not establish longer-term outcomes, because the stated primary endpoint is assessed by pre-hospital discharge or 7 days after the procedure. It also does not report a confidence interval for technical success or the listed adverse events, the amount of missing outcome data, or the statistical plan. These absences limit assessment of precision and robustness. The appropriate reading is descriptive: the record specifies the technical endpoint and provides selected safety counts, while leaving the primary endpoint result and several analysis details not reported in the registry record.

14. Why This Trial Matters Statistically

This study is statistically notable because it combines a clearly stated procedural endpoint with a design that is descriptive rather than comparative. Technical success is defined as successful deployment and release of at least one device, which identifies a specific procedural milestone. The endpoint is assessed within a defined short-term timeframe. Those features clarify what the outcome is intended to capture, but they do not supply the observed endpoint result.

The two cohorts also illustrate why grouping labels should not be mistaken for treatment arms in a controlled trial. ASD/PFO and VSD participants have different indications and use different occluder-device groups. A comparison between their outcomes would mix differences in the clinical conditions and device use with any differences in observed events. The registry identifies the study as single-arm and non-randomized, so there is no basis for treating cohort comparisons as randomized evidence.

For biostatistical interpretation, the missing primary endpoint count is consequential. A definition alone cannot yield an estimated rate, and without a denominator or uncertainty measure, readers cannot evaluate either the magnitude or precision of the result. This is a useful reminder that a named outcome and an analysis population are not substitutes for a posted estimate.

The safety record similarly highlights the importance of denominators and cohort size. The reported counts are informative as descriptions of recorded events, but the cohorts have different at-risk counts, and the registry record provides no precision intervals. The smaller VSD cohort makes cautious interpretation especially important; a zero recorded count should not be read as proof of no underlying risk.

Finally, the planning assumptions described in the record should be distinguished from the study's actual design. A hypothetical two-arm planning illustration is not evidence that the completed study had random allocation or a comparator. Keeping design, estimation, uncertainty, and planning separate is central to interpreting post-approval registry results responsibly.

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 statistical interpretation is that the registry record does not report the technical-success result. The endpoint definition, assessment time, and analysis population are stated, but the success count, denominator, rate, and confidence interval are not reported in the registry record. The main effectiveness question therefore cannot be answered from the posted results.

The design is single-arm and non-randomized, with cohorts based on different indications and device uses. There is no like-for-like randomized control group, so the study information does not support a causal comparison with another treatment or delivery system. Any comparison between the ASD/PFO and VSD cohorts would be descriptive rather than a randomized contrast.

The reported safety counts have different at-risk denominators across cohorts, and no confidence intervals are reported. The VSD cohort includes 3 participants at risk, so its event counts have limited scope for characterizing uncommon outcomes. The record does not provide event-level detail for the device embolization term beyond its reported 0.4% value.

Further limitations arise from missing reporting details. The registry record does not report the primary endpoint's missing-data amount or handling, a full statistical analysis plan, multiplicity methods, or details of interim analyses. The specific method used to calculate uncertainty for the outcome measures is also not reported in the registry record. These gaps prevent assessment of the robustness of the endpoint estimate even apart from the absent result.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Trevisio Post-Approval Study — NCT04433520.
• Registry record last updated 2026-03-16; status last verified 2026-02.
• Results first posted 2026-03-16.
• 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

NCT04433520, the Trevisio Post-Approval Study, is listed as completed and sponsored by Abbott Medical Devices. It enrolled 254 participants and is described as a single-arm, non-randomized, multi-center study of the Amplatzer Trevisio Intravascular Delivery System used with occluder devices. The registry lists ASD/PFO and VSD cohorts.

The primary endpoint was technical success, defined as successful deployment and release of at least one device by pre-hospital discharge or 7 days after the procedure. The analysis population was the Attempted Procedure population. The endpoint result is not reported in the registry record.

Reported safety counts include serious adverse events of 1 among 251 at risk in the ASD/PFO cohort and 0 among 3 at risk in the VSD cohort. Other adverse events are 7 among 251 and 1 among 3, respectively; deaths are 0 in each cohort. Device embolization is listed at 0.4% among the top serious terms.