Topera C-FIRM Registry: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Topera C-FIRM Registry (NCT02407249), a registered phase not stated study. The primary outcome is Number of Participants With Acute Success.

2. Clinical Question

3. Trial Design

The Topera C-FIRM Registry is described as a control registry to the E-FIRM registry. Its purpose was to track conventional atrial fibrillation procedures in routine clinical use, including handling and safety and effectiveness for treatment of symptomatic atrial fibrillation. Conventional ablation is defined in the record as pulmonary vein isolation and any additional ablation for atrial fibrillation according to the standard routine of each center.

The registry enrolled 73 participants and is marked completed. Its start is recorded as 2015-04, and its primary completion as 2017-05-31. The sponsor is Abbott Medical Devices. These administrative details do not establish how participants were selected, how many sites participated, or how procedures differed between sites; those details are not reported in the registry record.

The record does not describe a randomized comparison, and allocation is not stated. The registry’s role as a control to another registry should therefore not be read as proof of a randomized or otherwise balanced comparison. No parallel-arm outcomes or comparative estimates are reported in the information available for this analysis.

Five outcome measures are listed in the record, but no statistical analyses are listed. The primary outcome is an acute participant count measured on the day of procedure. Further details of follow-up, analysis populations beyond the primary endpoint’s “all treated patients” description, and the statistical plan are not reported in the registry record. The design is best understood as observational tracking of conventional procedures, with interpretation limited to what the registry reports rather than to causal effects.

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: All treated patients

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 population

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Acute Success, measured over day of procedure.

The primary endpoint is the number of participants with acute success, measured on the day of the procedure. The registry defines acute success as elimination, by ablation, of pulmonary vein triggers during the procedure. The stated population for this endpoint is all treated patients.

This kind of endpoint records whether a defined procedural event occurred for each participant, then reports a count of participants meeting that definition. It is a binary outcome at the participant level: a participant either meets the acute-success definition or does not. The count can describe how often the defined immediate procedural result was observed in the treated population, provided the number assessed and the number meeting the definition are both reported.

Its timing makes it a measure of acute procedural outcome, not a measure of longer-term atrial fibrillation status or later clinical events. The registry’s rationale for choosing this endpoint is not reported in the registry record. The primary endpoint result and the number of participants assessed for it are also not reported, so an observed acute-success count or rate cannot be described from this record. No inference about longer-term outcomes follows from the endpoint definition alone.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What kind of outcome is the primary endpoint?

The primary endpoint is a participant count for a binary outcome. Each treated participant can be classified according to whether pulmonary vein triggers were eliminated by ablation during the procedure. A count states how many participants met the definition; a rate would also require a clearly stated denominator. The registry identifies the endpoint population as all treated patients, but the number treated and the observed count are not reported in the registry record.

General statistical explanation: a binary outcome is often summarized by a count and a proportion. The count is easy to interpret, while a proportion relates the count to the population assessed. Both are needed for a complete descriptive result. If some participants have no assessable outcome, the denominator and the handling of those participants matter. Those details are not available for this endpoint in the registry record.

How would uncertainty be described?

General statistical explanation: a confidence interval expresses the uncertainty around an estimate under the assumptions of the statistical method. For a binary outcome, an interval around a proportion can show how compatible the data are with a range of underlying event frequencies. Its width depends on the information available and the method used. The registry record does not report an acute-success estimate or confidence interval, and it does not identify an interval method. No precision claim can therefore be made about the primary outcome.

A confidence interval is not a guarantee that the true value lies within its limits, nor does it resolve limitations in how participants were selected or outcomes recorded. Statistical precision and the validity of a comparison are separate questions. Even a precise estimate in a registry would not, on its own, establish a causal effect.

What does the analysis record establish?

The record lists five outcome measures and zero analyses. This means no analysis results are available in the information reported for this registry. It does not reveal whether analyses were planned but not posted, whether analyses were performed elsewhere, or what analytic choices might have been made. The statistical plan, including any adjustment variables, subgroup methods, interim analyses, and handling of missing outcomes, is not reported in the registry record.

General statistical explanation: an analysis plan matters because choices about the population, endpoint definition, missing data, and model can change the interpretation of results. A prespecified analysis can distinguish planned primary analyses from exploratory ones. Without a reported plan or analysis results, readers should not assume that a particular model, adjustment, or testing strategy was used.

What are the planning assumptions?

The registry information describes a planning illustration based on an observed effect, rather than the trial’s own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is described as a stated fraction of the observed effect. These are planning assumptions, not observed findings and not evidence that this registry used a randomized two-arm design.

No numerical planning results or observed effect estimate are reported in the registry record available for this analysis. A planning illustration estimates the number of participants that might be needed under specified assumptions. It is not an observed result, does not show the probability that a treatment works, and must not be described as observed power. The record does not provide enough information to assess the underlying effect estimate or independently interpret a numerical planning result.

General statistical explanation: power calculations depend on assumptions about the outcome frequency or effect size, variability, allocation, significance level, and analysis method. If the effect used for planning is uncertain, the resulting sample-size estimate is also uncertain. For a binary outcome, assumptions about the event frequency can be especially important because they affect the amount of information contributed by each participant. These general principles do not supply missing details about this registry’s own design.

Why does the registry structure matter?

This registry tracks routine conventional procedures and serves as a control registry to E-FIRM. It is not described as a randomized comparison, and allocation is not stated. General statistical explanation: in nonrandomized comparisons, differences in who receives or appears in each group can be associated with outcome differences. This can complicate causal interpretation, even when the outcome is measured consistently. The record does not describe a comparative analysis or methods to address such differences.

Accordingly, the strongest statistical reading is descriptive: the record defines an acute outcome and gives some safety counts, while leaving the primary endpoint value and comparative estimates unreported. No treatment effect, precision estimate, or inference about the relative performance of procedures can be recovered from the registry description 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("Analysis Population")
n      <- c(60)
events <- c(53)
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  Analysis Population  60  53  88.3  77.4  95.2  77.8  94.2  77.8  94.2

11. Multiplicity, Missing Data and Analysis Populations

The record lists five outcome measures, but the primary endpoint is the number of participants with acute success on the day of procedure. No statistical analyses are listed. A multiplicity strategy—such as how several endpoints or comparisons would be handled when drawing inferential conclusions—is not reported in the registry record. Without analysis results or an inferential plan, there is no basis for describing adjusted or unadjusted significance findings.

The missing-data approach is also not reported in the registry record. The endpoint population is described as all treated patients, but the number treated, the number with an assessed outcome, and the handling of any unavailable assessments are not stated. The enrollment count of 73 should not automatically be treated as the denominator for the primary endpoint.

The registry identifies all treated patients as the primary endpoint population, but other analysis populations—such as populations defined by protocol adherence or evaluable outcomes—are not reported in the registry record. The record also does not state whether the endpoint definition or analysis population changed, or whether any participants were excluded from analyses.

These omissions affect interpretation rather than establishing that a particular analytic problem occurred. Without a denominator and missing-data account, an outcome rate cannot be checked. Without a multiplicity plan or reported analyses, there is no basis to assess how multiple outcomes were incorporated into statistical conclusions. The endpoint count itself is not reported, so these questions cannot be resolved using the posted results.

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 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: amaurosis fugax / volatile blindness right eye (1.4%), strong hematoma left groin/knee (1.4%), ventricular extrasystole ablatiion (1.4%).

The enrolled-population safety figures report 3 participants affected by serious adverse events among 73, 0 participants affected by other adverse events among 73, and 0 deaths. The listed serious-event terms are “Amaurosis fugax / volatile blindness right eye,” “Strong hematoma left groin/knee,” and “Ventricular extrasystole ablatiion”; each is reported as 1.4%. The registry’s spelling is retained in the last term.

These are registry safety counts and listed terms, not measures of the primary acute-success endpoint. The record does not report the timing of each event, whether events were considered related to the procedure, how seriousness was defined, or the extent of safety follow-up. The three listed terms should not be used to infer additional details about clinical course or causality.

Zero reported deaths means the registry lists none in this safety summary; it does not resolve the completeness or duration of follow-up. Likewise, zero participants affected by other adverse events is what the record reports and should not be expanded into a claim that no events occurred outside the record’s reporting framework. These figures describe the posted safety information, not comparative safety relative to another registry.

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

The record establishes that the registry enrolled 73 participants to track conventional atrial fibrillation procedures and defines acute success as elimination of pulmonary vein triggers by ablation during the procedure. It also reports safety counts for the enrolled population. These registry entries describe the registry and the outcomes it intended to track.

The primary outcome result is not reported in the registry record. Therefore, the record does not show how many treated participants met the acute-success definition, what proportion did so, or how precise such an estimate would be. It also does not provide a statistical comparison against E-FIRM or another group. No conclusion about relative effectiveness can be drawn from the control-registry label.

The endpoint is acute and procedural. Even if its value were reported, it would answer a question about the defined event during the procedure, not by itself establish longer-term outcomes. The record does not provide a basis for extending the endpoint to outcomes beyond its stated timeframe.

The reported safety counts likewise have limits. They do not establish event relatedness, provide a comparative safety estimate, or describe the completeness and duration of follow-up. No deaths are listed in the safety summary, but this should be read as a report about the registry data, not as a broad claim beyond the recorded population and follow-up.

Absence of an outcome or analysis result in the registry record is not evidence that the outcome was zero, that there was no difference between groups, or that a procedure did or did not have an effect. It means the posted information is insufficient to answer those questions. The appropriate interpretation is descriptive and limited to the registry entries and counts actually reported.

14. Why This Trial Matters Statistically

This registry illustrates a basic distinction in clinical statistics: a well-defined endpoint is not the same as a reported endpoint result. The record specifies what acute success means and when it is assessed, but does not report the number of participants meeting that definition. Without the result and the number assessed, neither an outcome rate nor its precision can be interpreted.

It also illustrates why design labels need careful reading. A control registry can provide context about routine procedures, but the label alone does not establish randomization, balanced groups, or a valid causal comparison. Allocation is not stated, and no comparative statistical analysis is listed. The distinction between descriptive registry information and comparative evidence is therefore central to interpretation.

The safety information is another useful statistical example: event counts, participant counts, and percentages are not interchangeable descriptions. The record reports counts for the enrolled population and percentages for the listed serious-event terms. Readers should retain those stated quantities and avoid inferring unreported timing, relatedness, or follow-up details.

Finally, the record separates planning assumptions from observed outcomes. A planning illustration based on an observed effect is not a result from the registry and is not observed power. General statistical practice treats planning calculations as conditional on their assumptions, while conclusions about outcomes require actual observed data and a suitable analysis. Here, the primary outcome value and analyses are not reported, so planning assumptions cannot substitute for evidence about the registry’s observed outcomes.

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 endpoint result is not reported in the registry record. Although the endpoint definition, timeframe, and intended population are stated, the number of treated participants assessed and the number meeting the definition are absent. This prevents interpretation of the outcome frequency and its precision.

The registry is described as a control registry to E-FIRM, but allocation is not stated and the information does not describe a randomized comparison. No comparative estimates or analysis results are listed. The record does not report methods for accounting for differences among participants or participating centers, so a causal interpretation or like-for-like comparison is unsupported.

The registry description says that data items were to be collected when available, consistent with and applicable to routine and standard clinical care at each site. This indicates that data collection was linked to routine care, but the record does not detail which data were unavailable, how missing observations were handled, or whether sites collected the same items. These details limit assessment of outcome completeness and consistency.

Additional limitations are that the statistical plan, outcome-specific analysis populations, multiplicity handling, and any interim analyses are not reported in the registry record. Follow-up details beyond the primary endpoint’s day-of-procedure timeframe are not specified in the available information. Safety-event timing and relatedness are also not stated. These omissions do not establish that any particular bias or analytic issue occurred; they limit what can be evaluated from the posted record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Topera C-FIRM Registry — NCT02407249.
• Registry record last updated 2019-10-16; status last verified 2019-10.
• Results first posted 2019-10-16.
• 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

The Topera C-FIRM Registry is a completed control registry to the E-FIRM registry, sponsored by Abbott Medical Devices. It tracked conventional atrial fibrillation procedures, defined as pulmonary vein isolation and any additional ablation for atrial fibrillation according to each center’s standard routine. The registry enrolled 73 participants.

The primary endpoint was the number of treated participants with acute success on the day of procedure, defined as elimination of pulmonary vein triggers by ablation. Its observed result is not reported in the registry record. Five outcome measures are listed, and no analyses are listed.

The enrolled-population safety summary reports 3 participants affected by serious adverse events among 73, 0 affected by other adverse events among 73, and 0 deaths. The record does not state allocation or report a comparative analysis. Accordingly, the available information supports description of the registry design, endpoint definition, and reported safety counts, but not a numerical conclusion about acute success or a comparative effect.