Clinical Study for Safety and Acute Performance Evaluation of the THERMOCOOL SMARTTOUCH® SF-5D System Used With Fast Ablation Mode in Treatment of Patients With Paroxysmal Atrial Fibrillation.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Study for Safety and Acute Performance Evaluation of the THERMOCOOL SMARTTOUCH® SF-5D System Used With Fast Ablation Mode in Treatment of Patients With Paroxysmal Atrial Fibrillation. (NCT03459196), a na na study. The primary outcome is Number of Subjects Achieved Acute Procedural Success.

2. Clinical Question

The study was intended to assess safety and acute performance in the stated clinical setting. Because the design has one group, the central statistical question is descriptive: what outcomes were recorded among the participants in the effectiveness and safety populations? The registry entry does not report a comparative treatment effect, and its posted information cannot establish a difference relative to another approach.

3. Trial Design

The registry describes the QDOT-FAST study as a prospective, multicenter, non-randomized, interventional clinical study. It is listed as a single-group study with no masking. Allocation is listed as NA, and the phase is listed as NA. The sponsor is Biosense Webster, Inc. The device intervention is the THERMOCOOL SMARTTOUCH SF-5D Catheter, used with Fast Ablation Mode as described in the study title and treatment-group description.

The registry lists enrollment as 54. The study start date is 2018-04-02, the primary completion date is 2018-10-08, and the status is COMPLETED. The record describes the device and accompanying system as intended for pulmonary vein isolation in patients with paroxysmal atrial fibrillation. It does not describe an untreated control group or a second active-treatment group, so the design does not support a randomized head-to-head comparison.

The primary outcome is a count of participants who achieved acute procedural success, with a Day 1 timeframe. The effectiveness population is described in terms of device insertion and ablation with the study catheter used with QMode+ for pulmonary vein isolation. The record’s wording about exclusions from that population ends before the definition is complete; further detail is not reported in the registry record.

The record lists two outcome measures and zero analyses. It does not report the primary endpoint count, an estimate of uncertainty, or a statistical comparison. The enrollment figure should not be treated as the endpoint denominator: the record separately describes an effectiveness population and a safety group, and does not reconcile the enrollment figure with those populations. The statistical interpretation is therefore limited to the design, endpoint definition, and posted adverse-event figures.

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.

Before assignment: Subjects were screened carefully prior to enrollment in the study to ensure compliance with the inclusion and exclusion criteria. All subjects were screened using pre-procedure imaging for the presence of LA thrombus, which was intended to decrease the potential for thromboembolic complications.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Effectiveness population includes all subjects who have had the investigational device inserted and underwent ablation with the study catheter used in conjunction with QMode+ for pulmonary vein isolation (PVI). Subjects without any QMode+ application for PVI are excluded from the effectiveness 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 Number of Subjects Achieved Acute Procedural Success, measured over Day 1.

The primary endpoint is the number of participants who achieved acute procedural success, assessed on Day 1. Success was defined as confirmation of entrance block in all targeted pulmonary veins after an adenosine or isoproterenol challenge. This is an immediate procedural measure: it records whether the specified electrophysiologic result was confirmed at the time described by the registry, rather than measuring a later clinical outcome.

As a count of participants with an event, the endpoint can be presented descriptively as the number meeting the success definition in the stated effectiveness population. General statistical context: a proportion can help describe how often a binary outcome occurred in a defined group, while an interval estimate can express the uncertainty around that proportion. Neither the count nor an interval estimate for this endpoint is reported in the registry record, so its observed frequency and precision cannot be assessed from the posted results.

The endpoint definition also matters when interpreting the count. It requires confirmation of block in all targeted pulmonary veins and includes a challenge with adenosine or isoproterenol. It should not be treated as interchangeable with broader measures such as symptom improvement or longer-term freedom from arrhythmia. Those outcomes are not described as the primary endpoint in this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The available statistical information is limited. The registry identifies a single-group study and a binary primary endpoint expressed as a count of participants. It lists zero analyses and does not report the primary endpoint result, a confidence interval, a p-value, or an adjusted estimate. The statistical methods used for the sponsor’s primary analysis are not reported in the registry record.

What does a participant count mean?

For a binary endpoint, each participant is classified according to whether the defined event occurred. The primary outcome is the count meeting the acute procedural success definition. General statistical context: counts describe the number of observed participants meeting a criterion, while a proportion relates that count to the number assessed in a clearly defined analysis population. A count alone cannot give the proportion if the relevant denominator is not reported. In this record, the success count and its denominator are not given, so neither the observed proportion nor its uncertainty can be recovered from the posted results.

How should uncertainty be understood?

General statistical context: a confidence interval is a range of values compatible with the observed data under a specified statistical method. It communicates precision, not certainty that a particular value is true. With a binary endpoint, the interval is tied to the event count and the number of participants assessed. Since neither the primary success count nor a confidence interval is reported, no statement about the endpoint’s precision is justified from this record. The same limitation applies to inferential interpretation of the adverse-event counts, for which no intervals are reported.

What can a single-group design estimate?

A single-group study can describe outcomes observed among participants who received the intervention. It cannot provide a randomized estimate of the contrast between the intervention and a comparator when no comparator group is included. General statistical context: comparisons across separate studies or against an assumed benchmark may be affected by differences in participant selection, outcome definitions, follow-up, and clinical practice. The registry does not report a prespecified benchmark or a comparative analysis. The result should therefore be framed descriptively, and the absence of a posted primary count further limits that description.

What do the sample-size illustrations represent?

The record’s sample-size assumptions describe planning illustrations based on an observed effect, not the trial’s own design. They specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. These are hypothetical planning assumptions, not evidence that the study used those methods or had a particular statistical power. The actual study is listed as single-group, so equal allocation between two arms does not describe its stated design. Sample-size planning illustrations are not observed power and do not supply a missing endpoint result.

Why does over-dispersion matter in general?

General statistical context: over-dispersion occurs when observed variability is greater than a statistical model assumes. If a model does not account for that extra variability, its uncertainty estimates can be too narrow and its inferential conclusions too confident. Whether over-dispersion is relevant depends on the outcome and analysis model. The registry record does not report a model for the primary endpoint or an assessment of over-dispersion, so no claim about its presence or handling can be made for this study.

In general, an analysis plan may specify the analysis population, outcome definitions, handling of missing observations, model, and multiplicity approach before results are examined. Those details help distinguish prespecified analyses from exploratory ones. The registry record does not report such a statistical plan, nor does it describe interim analyses. The posted material therefore does not support assumptions about how the sponsor intended to analyze the primary outcome or address uncertainty.

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("THERMOCOOL SMARTTOUCH SF-5D Catheter")
n      <- c(52)
events <- c(52)
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  THERMOCOOL SMARTTOUCH SF-5D Catheter  52  52  100.0  93.2  100.0  93.1  100.0  93.3  100.0

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures, but does not provide the full analysis details needed to determine how multiple outcomes were handled. A multiplicity strategy, such as a prespecified hierarchy or adjustment to control the chance of false-positive findings across several tests, is not reported in the registry record. Because the record lists zero analyses and does not report the primary endpoint result, no conclusion about multiplicity-adjusted inference can be drawn.

The primary outcome population is described as an effectiveness population that includes subjects who had the investigational device inserted and underwent ablation with the study catheter used with QMode+ for pulmonary vein isolation. The record also says subjects without any QMode+ application for pulmonary vein isolation are excluded, but the population description ends before the wording is complete. Additional eligibility rules and the number of participants in the effectiveness population are not reported in the registry record.

The registry lists enrollment as 54 and describes a safety group with 52 participants at risk. It does not explain the difference between these figures. The enrollment figure should not be substituted for the denominator of the primary endpoint or used to infer why participants were absent from a particular analysis population.

Missing-data rules, the number of missing primary outcome observations, and any sensitivity analyses are not reported in the registry record. The record also does not describe interim analyses or a statistical analysis plan. These omissions prevent assessment of whether missing outcomes could have affected the primary endpoint estimate or whether analyses were defined before the results were known.

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: oesophageal ulcer haemorrhage (1.9%), vascular pseudoaneurysm (1.9%), atrial flutter (1.9%), syncope (1.9%).

The safety group for the THERMOCOOL SMARTTOUCH SF-5D Catheter lists 52 participants at risk for serious adverse events and 4 affected. For other adverse events, 52 participants were at risk and 32 were affected. Deaths are listed as 0. These figures describe the posted safety results; they are not a comparison with another treatment group.

The registry lists Oesophageal ulcer haemorrhage, Vascular pseudoaneurysm, Atrial flutter, and Syncope among the serious adverse-event terms, each at 1.9%. Those percentages are individual listed figures. The record does not state whether the terms correspond to different participants, so they should not be added or interpreted as a combined percentage.

General statistical context: adverse-event counts depend on the event definitions, follow-up period, and completeness of collection. The record does not report detailed follow-up duration, event attribution methods, or uncertainty intervals for these figures. The counts also do not establish that an event was caused by the catheter, procedure, or another factor. They should be read as descriptive registry data rather than as comparative or causal estimates.

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

The registry record gives a clear description of the acute procedural success criterion: confirmation of entrance block in all targeted pulmonary veins after adenosine or isoproterenol challenge, assessed on Day 1. However, it does not report the number of participants who met this criterion. The available record therefore does not show the observed primary endpoint result or how precisely it was estimated.

The safety information reports serious adverse events in 4 of 52 participants at risk and other adverse events in 32 of 52 participants at risk, with 0 deaths. It also lists four serious adverse-event terms at 1.9% each. These figures describe what was posted for the study group. They do not provide a comparison with another device or treatment, and they do not by themselves establish that the intervention caused or prevented an event.

The non-randomized, single-group design limits what can be attributed to the catheter and accompanying system. Without a comparator group, outcomes cannot be contrasted under randomized conditions. The record also does not give the primary endpoint count, statistical analyses, confidence intervals, a complete analysis-population definition, or details of missing-data handling. Those omissions limit assessment of both the magnitude and the precision of the primary result.

Accordingly, the record supports a description of the study design, endpoint definition, and posted safety counts. It does not support a quantified conclusion about acute procedural success, a comparative treatment effect, or a causal claim about adverse events. The planning assumptions for sample-size illustrations are not observed outcomes and are not evidence of achieved power.

14. Why This Trial Matters Statistically

This study illustrates why a clearly defined endpoint and a reported endpoint result are both necessary for statistical interpretation. The registry specifies an acute procedural success criterion, its Day 1 timeframe, and the challenge used to confirm entrance block. That definition clarifies what success means operationally, but without the participant count and analysis denominator, the outcome cannot be quantified from the posted record.

The design also matters. A prospective, multicenter study can collect observations across sites, but this registry record describes one non-randomized group. The design is therefore descriptive rather than a randomized comparison. Readers should distinguish an observed outcome in a treatment group from evidence that the intervention differs from an alternative; the latter requires a relevant comparative design or other explicitly described analysis.

The adverse-event figures provide a limited safety description, including the numbers affected and several listed serious-event terms. Their interpretation depends on the population at risk and on information about follow-up and event ascertainment. Because the record does not provide detailed methods or comparative data, these counts cannot alone establish causal attribution or comparative safety.

Finally, the sample-size planning assumptions should not be mistaken for the study’s actual design or for observed power. The record describes hypothetical two-arm planning assumptions, while the study itself is listed as single-group. Keeping design, planning, observed outcomes, and inferential analyses distinct is essential to avoid drawing conclusions that the registry data do not support.

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 important limitation of the registry entry is that it defines the primary endpoint but does not report the number of participants who achieved acute procedural success. It also does not report the denominator for that outcome, an effect estimate, a confidence interval, or a p-value. The primary result’s magnitude and precision therefore cannot be assessed from the posted information.

The single-group, non-randomized design has no comparator arm. The study can describe outcomes in its treated group, but the record does not provide a randomized contrast that would help separate intervention-related outcomes from other influences. The registry also lists allocation as NA and masking as NONE.

The effectiveness population description is incomplete, and the record does not report the size of that population or explain how it relates to the enrollment figure of 54. The safety group lists 52 participants at risk, but the record does not reconcile this with enrollment. Missing-data rules and the number of missing primary endpoint observations are not reported.

Further limitations include the absence of a reported statistical analysis plan, multiplicity approach, interim-analysis information, and detailed follow-up or adverse-event ascertainment methods. The posted adverse-event figures are descriptive and do not include uncertainty intervals or a comparator. These gaps limit interpretation of both efficacy-related and safety findings; they do not imply that unreported procedures or analyses were or were not conducted.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Clinical Study for Safety and Acute Performance Evaluation of the THERMOCOOL SMARTTOUCH® SF-5D System Used With Fast Ablation Mode in Treatment of Patients With Paroxysmal Atrial Fibrillation. — NCT03459196.
• Registry record last updated 2025-06-29; status last verified 2025-06.
• Results first posted 2019-11-06.
• 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

NCT03459196 is listed as a completed, prospective, multicenter, non-randomized, interventional, single-group study sponsored by Biosense Webster, Inc. It evaluated the THERMOCOOL SMARTTOUCH SF-5D Catheter with Fast Ablation Mode in patients with paroxysmal atrial fibrillation. Enrollment is listed as 54; the study start date is 2018-04-02 and the primary completion date is 2018-10-08.

The primary endpoint was the count of participants achieving acute procedural success on Day 1, defined by confirmation of entrance block in all targeted pulmonary veins after an adenosine or isoproterenol challenge. The endpoint count and statistical analyses are not reported in the registry record. The safety group lists 4 of 52 participants with serious adverse events, 32 of 52 with other adverse events, and 0 deaths. The record does not report a comparator or a statistical analysis plan.