Cardiovalve Transfemoral Mitral Valve System: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Cardiovalve Transfemoral Mitral Valve System (NCT03813524), a na na study. The primary outcome is Number of Participants With Cardiovalve Technical Success.

2. Clinical Question

This is an early feasibility question, focused on whether the device and delivery procedure can meet a set of technical and safety conditions in the study participant. The registry summary also describes collection of 30-day safety and performance data and long-term clinical outcomes over a follow-up of 5 years. That stated follow-up plan does not establish that those data were collected or reported. The record gives no primary endpoint result, so the number of participants who met the technical-success definition is not reported in the registry record. The terminated status and enrollment of 1 are important context for interpreting the limited results available.

3. Trial Design

The registry describes an early feasibility study of the Cardiovalve Transfemoral Mitral Valve System. Its phase is recorded as NA, allocation is recorded as NA, masking is listed as none, and the model is single-group. The intervention is the replacement valve delivered through transfemoral access and a transseptal approach. No comparator arm is listed, so the design does not support a direct comparison with another treatment or a control group.

The registry record lists 1 participant enrolled. The study start date is 2019-03-26, the primary completion date is 2020-03-31, and the status is terminated. A reason for termination is not reported in the registry record. Nor does the record give a date for termination, so the listed dates should not be taken as an explanation of why the study stopped or what follow-up was completed.

The stated purpose was to evaluate safety and technical performance of the device and its associated procedure, with the aim of minimizing mitral regurgitation. The registry summary describes 30-day safety and performance data for the device and delivery system, as well as long-term clinical outcomes over a follow-up of 5 years. The status and the small enrollment do not themselves establish the amount of follow-up available; completion of the planned follow-up is not reported in the registry record.

The primary outcome is a count of participants with technical success at 30 days. The registry lists 2 outcome measures and no statistical analyses. Further details about the protocol, eligibility criteria, recruitment, planned sample size, study procedures, or statistical analysis plan are not reported in the registry record. In particular, the record does not explain how the enrollment target was chosen or why the study has a single participant.

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.

Population: Enrolled and treated

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Cardiovalve Technical Success, measured over 30 Days.

The primary endpoint counts participants with Cardiovalve technical success at 30 days. It uses a combined definition: successful access, delivery and retrieval of the delivery system; successful deployment and correct positioning of the first intended implant; and freedom from emergency surgery or reintervention related to the device or access procedure. The participant must also be free of procedural mortality, stroke and specified device dysfunction at the 30-day follow-up.

Device dysfunction is defined in the registry using criteria that include Central MR grade > 1 or moderate or severe paravalvular leak, mean mitral gradient > 6 mm Hg, or LVOT obstruction with a gradient increase of at least 10 mm Hg. These conditions make the endpoint broader than a measure of whether the implant was deployed: the definition also includes procedural events and specified clinical or device findings.

As a general statistical concept, a combined endpoint can capture several ways a procedure or device may fail to meet a study’s success criteria. Its interpretation depends on the components and thresholds specified in the definition. A count of participants meeting the full definition is not interchangeable with a separate count for any one component. The registry record does not report the observed primary endpoint count, so whether the participant met the combined definition is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical information in the registry record is limited. It identifies a participant-count primary outcome, lists 2 outcome measures, and records no statistical analyses. The record does not report a statistical analysis plan, confidence intervals, hypothesis tests, or adjusted estimates. The explanations below describe general statistical concepts, not methods confirmed to have been used for this study.

What does a participant count represent?

The primary outcome is the number of participants who meet the technical-success definition at 30 days. For a binary endpoint, each assessed participant is classified as either meeting or not meeting the stated criterion. A count describes the number in a category; interpreting it as a proportion also requires knowing the relevant denominator and whether the outcome was assessed for everyone in that denominator. The registry record does not report the primary endpoint count or an analysis population for that outcome.

The endpoint combines multiple requirements. General interpretation of a combined endpoint should begin with its full definition: a participant must meet all required success conditions and avoid the specified events. A combined count cannot by itself show which individual component drove the result. Component-level results are not reported in the registry record.

What can a confidence interval tell a reader?

In general, a confidence interval conveys the statistical uncertainty around an estimate under the assumptions of the method used. A narrow interval indicates greater precision than a wide interval, while a wide interval indicates substantial uncertainty. An interval does not correct for limitations in the study design or make a small, uncontrolled study representative of a broader population. No confidence interval for the primary endpoint is reported in the registry record, and the available information does not specify an interval method.

Why does the single-group design matter?

In general, an intervention-versus-control comparison can help distinguish differences between groups from outcomes that might occur without the intervention. A single-group study has no such internal control. Its observations can describe the enrolled participant’s experience, but do not estimate a comparative treatment effect. The record lists allocation as NA, no masking, and a single-group model. Its accompanying note explicitly indicates that the arms are not a like-for-like control comparison.

Statistical adjustment cannot create a valid control group when none is present. Likewise, a numerical difference between outcomes from unlike groups would not by itself establish that the intervention caused the difference. No comparative analysis is listed in the registry record.

What is over-dispersion, and is it relevant?

In general, over-dispersion describes count data that vary more than a chosen statistical model expects. It can make standard errors too small if the model assumes less variability than the data contain. A model that allows extra variability may be considered when there are enough observations and the data structure warrants it. The registry record does not report an over-dispersion assessment or a count model. Given that the primary endpoint is a participant count and enrollment is 1, there is not a reported dataset from which to assess population-level variation.

How should the planning illustration be understood?

The record describes a sample-size planning illustration based on a fraction of an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It specifies that the effect to detect is a stated fraction of the observed effect. For time-to-event outcomes, the illustration is described as giving total events; other illustrations are described as participants per arm.

These are planning assumptions, not a report of the trial’s design rationale or its observed evidence. The study itself is single-group, while the illustration’s assumptions include equal allocation between two arms. The record does not report a sample-size justification or the calculations’ resulting participant counts. Any planning values should therefore be read as hypothetical illustrations, not as the study’s enrollment target, actual enrollment by arm, or observed power. The observed primary effect needed to interpret an effect-based planning scenario is not reported in the registry record.

As a general concept, power calculations concern the chance that a planned analysis will detect a specified effect under stated assumptions. They do not measure the probability that a result is true, and a post hoc calculation based on observed data is not a substitute for an analysis plan. The record does not report an observed-power analysis or enough primary-outcome results to reconstruct one.

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("Cardiovalve Transfemoral Mitral Valve")
n      <- c(1)
events <- c(1)
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  Cardiovalve Transfemoral Mitral Valve  1  1  100.0  2.5  100.0  20.7  100.0  15.8  98.7

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 2 outcome measures but no statistical analyses. It does not report a hierarchy of outcomes, a multiplicity adjustment, or a plan for controlling the chance of false-positive findings across multiple tests. In general, when several hypotheses are tested, the chance of at least one false-positive result can increase unless the analysis plan addresses multiple testing. That general concern does not establish that the study conducted multiple tests; no analyses are listed.

The registry record does not describe how missing outcome data were handled. It does not report whether the primary endpoint was assessed, whether there were missing observations, or whether any imputation or sensitivity analysis was used. These details are not reported in the registry record. The stated 30-day timeframe is part of the endpoint definition, but it does not by itself confirm completion of the assessment.

The analysis population is also not reported in the registry record. There is no description of an intention-to-treat, per-protocol, safety, or other defined analysis set. The record lists 1 participant enrolled, but does not state which participants were included in each outcome analysis. Since no statistical analyses are listed, there are no reported analysis-set denominators to interpret.

In general, missing-data methods and analysis populations matter because they determine which observations contribute to an estimate and what assumptions are being made about unavailable outcomes. Without those details and the primary endpoint result, readers cannot assess how incomplete data might have affected the reported 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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: acute respiratory failure (100.0%), fever (100.0%), urinary retention (100.0%), gout (100.0%), elevated mitral mean gradient (100.0%).

The registry lists 1 participant at risk and 1 affected for serious adverse events. It also lists 1 participant at risk and 1 affected for other adverse events, with 1 death recorded. Six serious adverse-event terms are listed: Acute Respiratory Failure, Fever, Urinary Retention, Gout, Elevated Mitral Mean Gradient, and Worsening Heart Failure. Each term is marked 100.0%.

These figures describe a cohort with 1 participant at risk. The percentages should not be read as precise estimates of how often these events would occur in a larger population. The registry does not explain whether the listed terms occurred in the same participant, whether each term represents a distinct event, or how the death relates to the adverse-event terms. A count of deaths does not, on its own, establish cause or relationship to the device or procedure.

Whether an adverse event was judged related to the intervention, how events were collected, and the applicable reporting period are not reported in the registry record. The listed safety figures therefore document what the record reports, but do not establish causation or characterize risk beyond this study cohort.

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

The registry record establishes that an early feasibility study of the Cardiovalve Transfemoral Mitral Valve System was conducted as a single-group study, enrolled 1 participant, and was later listed as terminated. It provides a detailed definition of technical success at 30 days and lists adverse-event information. It does not report the primary endpoint result or statistical analyses.

That absence matters: the endpoint definition is not itself evidence that technical success was achieved. The number of participants meeting the definition, and the component-level outcomes, are not reported in the registry record. The reader therefore cannot determine the study’s observed technical-success result from the information described.

Even if an endpoint result were available, a single-group feasibility study would not establish a comparative effect. There is no listed control group against which to assess the outcome. General statistical interpretation also requires caution because enrollment was 1; results from this cohort cannot precisely describe outcome frequency or variability in a larger population.

The adverse-event listings should be understood as descriptive information for the enrolled cohort. The listed 100.0% values arise in a record with 1 participant at risk and do not provide precise estimates of how frequently these events may occur elsewhere. The relationship of the recorded death and adverse events to the device or procedure is not reported in the registry record.

The registry summary states that data collection was intended to include 30-day safety and performance and long-term clinical outcomes over a follow-up of 5 years. It does not establish that the follow-up was completed or that those outcomes were reported. The record also does not explain why the study was terminated. The defensible conclusion is therefore limited: the registry documents the study’s intended question, design, enrollment and endpoint criteria, while its primary result and key follow-up details are not reported in the registry record.

14. Why This Trial Matters Statistically

Early feasibility studies address practical questions about a device and its associated procedure. This study’s primary endpoint reflects that focus by combining delivery-system access and retrieval, implant deployment and positioning, freedom from certain reinterventions, and absence of specified procedural or device problems. Such a definition makes explicit what the study considered technical success at 30 days.

Statistically, the record also illustrates the difference between a clearly defined endpoint and a reported result. A detailed definition allows readers to understand what would count as success, but it cannot substitute for the observed endpoint count. The primary result is not reported in the registry record, and no statistical analyses are listed.

The design and enrollment shape what conclusions can be drawn. The study is single-group, has no listed comparator, and enrolled 1 participant. These features mean the record does not provide a controlled comparison or a precise estimate of outcome frequency across a broader population. The safety percentages should be read in that same context.

Finally, the stated plans for 30-day data and long-term follow-up over 5 years are distinct from evidence that those data were collected and reported. The status is terminated, but the reason and the completion of planned follow-up are not reported in the registry record. For statistical readers, these distinctions help separate the study’s intended aims, design features, available observations and unanswered 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 main trial-specific limitation is the enrollment of 1 participant. That leaves little basis for describing variation across participants, and the registry record does not report a primary endpoint result from which to assess technical success. No confidence interval or statistical analysis is listed.

The single-group design offers no like-for-like control comparison. Allocation is recorded as NA and masking as none. As a result, the design described in the record cannot establish a comparative outcome or separate an observed course from outcomes that might occur without the intervention.

The status is terminated, but the reason for termination is not reported in the registry record. The record gives a primary completion date of 2020-03-31, but does not explain how this relates to termination or whether planned follow-up was completed. The summary describes long-term clinical outcomes over a follow-up of 5 years; actual follow-up results are not reported in the registry record.

The registry lists adverse events and a death, but does not report their relationship to the device or procedure, how the event terms relate to one another, or the cause of death. Eligibility details, participant characteristics, missing-data handling, analysis populations, and a statistical analysis plan are also not reported in the registry record. These gaps constrain interpretation of both the endpoint and safety information.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Cardiovalve Transfemoral Mitral Valve System — NCT03813524.
• Registry record last updated 2026-06-25; status last verified 2026-06.
• Results first posted 2026-06-02.
• 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 an early feasibility study of the Cardiovalve Transfemoral Mitral Valve System for mitral regurgitation. It is listed as single-group, with allocation recorded as NA and no masking. The study enrolled 1 participant and is listed as terminated. The start date is 2019-03-26 and the primary completion date is 2020-03-31.

The primary endpoint is the count of participants with Cardiovalve technical success at 30 days, defined by technical, procedural and device-related criteria. The registry lists 2 outcome measures and no statistical analyses. The primary endpoint result, reason for termination, analysis populations, missing-data methods, and completion of planned long-term follow-up are not reported in the registry record. The adverse-event listing includes 1 death and six serious-event terms marked 100.0%, in a cohort with 1 participant at risk.