Comparison of Pulmonary Vein Ablation With or Without Left Atrial Posterior Wall Ablation for Persistent AF (PIVoTAL): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparison of Pulmonary Vein Ablation With or Without Left Atrial Posterior Wall Ablation for Persistent AF (PIVoTAL) (NCT03057548), a randomized na study. The primary outcome is 1-year Freedom From Recurrent Atrial Arrhythmias.

2. Clinical Question

The trial addresses whether adding posterior left atrial wall ablation to pulmonary vein isolation is associated with a different one-year arrhythmia outcome than pulmonary vein isolation alone. Its clinical context is persistent or long-standing persistent atrial fibrillation, rather than a general population with any form of arrhythmia. The registry describes participants as undergoing their first ablation and identifies symptomatic disease.

The comparison is between treatment strategies, not between ablation and no ablation. Both arms receive pulmonary vein ablation; the distinguishing component is whether posterior left atrial wall ablation is also performed. Because the registry lists both cryoablation and radiofrequency approaches for pulmonary vein ablation, the comparison is not simply a test of one energy source against another.

The primary outcome is titled “1-year Freedom From Recurrent Atrial Arrhythmias.” The description says monitoring and electrocardiograms at scheduled follow-up points were used to document freedom from recurrent atrial fibrillation at one year. However, the posted group values and contrast are counts and risks that are lower in the combination arm, and the record does not explicitly clarify whether those counts represent freedom or recurrence. This makes careful attention to outcome coding essential when interpreting the direction of the contrast.

3. Trial Design

The registry describes PIVoTAL as a randomized, double-masked, parallel-group study. It lists an enrollment of 110 and a completed status. The phase is listed as not applicable. The record identifies persistent and chronic atrial fibrillation among the conditions studied, while the analyzed population description focuses on symptomatic persistent or long-standing persistent atrial fibrillation undergoing first-time ablation.

Participants were assigned to pulmonary vein isolation alone or pulmonary vein isolation combined with posterior left atrial wall ablation. In the isolation-only arm, pulmonary vein treatment could use cryoablation or radiofrequency ablation. In the combination arm, the posterior wall was also ablated using radiofrequency, while pulmonary vein ablation could use either listed method. The registry does not describe further allocation procedures or identify which people or roles were masked.

The primary endpoint was assessed at one year. Its description refers to 7-14 day ambulatory ECG monitoring and ECGs at 3, 6 and 12 months. The listed secondary outcome is overall complication rate, assessed during follow-up for an estimated total of one year. The record does not give further details about follow-up completion or how missing observations were handled.

The registry lists study start as 2017-02-24 and primary completion as 2020-05-13. Those dates describe the study record and do not, by themselves, establish when individual participants were enrolled or assessed. The sponsor is listed as Arash Aryana, MD. The registry does not report the trial’s original sample-size justification, a detailed statistical analysis plan, or further design assumptions. The planning illustrations associated with the observed result are not a record of the trial’s original design.

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: Study cohort consisted of patients undergoing first-time cryoballoon ablation for symptomatic persistent/long-standing persistent atrial ablation (55 subjects in the PVI isolation arm and 55 subjects in the PVI+PWI arm) were analyzed for freedom from recurrence of atrial fibrillation and all atrial arrhythmias at one-year post-study ablation.

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 1-year Freedom From Recurrent Atrial Arrhythmias, measured over One year.

The primary endpoint is titled “1-year Freedom From Recurrent Atrial Arrhythmias.” It concerns whether participants were free from recurrent arrhythmia at the one-year follow-up point after ablation. The registry says that 7-14 day ambulatory ECG monitoring and ECGs performed at 3, 6 and 12 months were used to document freedom from recurrent atrial fibrillation. Repeated monitoring can identify episodes that a single assessment might miss, while a defined follow-up point makes the outcome suitable for comparing the randomized strategies.

The posted results report 25 participants in the pulmonary vein isolation arm and 14 in the combined ablation arm, with 55 participants in each arm. The registry’s comparison expresses the corresponding risks as 0.455 and 0.255. Although the outcome title refers to freedom from recurrence, the record does not clearly state whether the posted counts represent freedom or recurrent events. The title and numerical direction should therefore not be treated as interchangeable descriptions of the same coding without clarification.

This endpoint is clinically relevant to the trial question because it concerns the arrhythmia outcome the investigators sought to compare after ablation. It is also a binary participant-level measure: each participant is counted according to whether the defined outcome is recorded. The registry does not provide an operational definition of every qualifying arrhythmia, nor does it explain how unavailable monitoring or incomplete follow-up affected endpoint classification. Those details matter when interpreting what a recorded count means.

7. Results Posted in the Registry

• PVI & Posterior Left Atrial Ablation: 25.5% (14/55) versus 45.5% (25/55) on control; risk difference -20.0 percentage points (95% CI -37.5 to -2.5), risk ratio 0.56 (0.33–0.96); unadjusted two-proportion z-test p = 0.028.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Overall Complication Rate

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • PVI & Posterior Left Atrial Ablation: 5.5% (3/55) versus 5.5% (3/55) on control; risk difference 0.0 percentage points (95% CI -8.5 to 8.5), risk ratio 1.00 (0.21–4.74); unadjusted two-proportion z-test p = 1.000.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between PVI & Posterior Left Atrial Ablation and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists one secondary outcome, overall complication rate. Its posted point estimates are equal across arms, and the interval around the risk difference is compatible with effects in either direction. The secondary result therefore does not provide a precise basis for ruling out a difference in complications. It also does not directly clarify the primary endpoint’s coding ambiguity, because it concerns a different outcome.

The secondary outcome complements the primary result by describing a safety-related aspect of the comparison alongside the arrhythmia endpoint. It should not be treated as confirmation of the primary finding or as a counterweight that cancels it. The outcomes address distinct questions, and the registry does not report a combined benefit-risk analysis or a prespecified way to balance them.

The secondary contrast is labeled unadjusted. When multiple outcomes or analyses are considered, the chance of at least one apparently unusual result can increase if no multiplicity strategy is used. The registry record does not report a multiplicity adjustment or a hierarchy for interpreting outcomes. This makes an isolated unadjusted secondary p-value less decisive than a result interpreted within a documented analysis plan. The result remains descriptive evidence about the posted complication counts, but it should not be used to assert equivalence or to make a broad safety comparison.

The record lists no additional posted secondary analyses. It also does not describe whether the secondary endpoint was defined before analysis or how missing data were handled. Interpretation should therefore focus on the reported pattern while recognizing that the analysis context needed for stronger confirmatory claims is not reported in the registry record.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Overall Complication Rate

9. Statistical Interpretation

10. Statistical Methods Explained

The primary result compares a binary participant outcome between two randomized arms. Each participant is classified according to whether the endpoint is counted, and the reported group risks are the proportions associated with those counts. A risk difference subtracts the comparator-arm risk from the intervention-arm risk. It is expressed on the risk scale, so zero represents equal recorded risks, a negative value means a lower risk in the intervention arm, and a positive value means a higher risk in that arm. That direction describes the coded outcome, not necessarily the clinical meaning when the registry’s endpoint label and count coding are unclear.

What does a confidence interval add?

A confidence interval describes the uncertainty around an estimated contrast under the statistical model. It is not a range guaranteed to contain the true value, and it does not show the probability that a particular treatment effect is true. An interval that includes zero is compatible with no risk difference as well as with effects in either direction represented by the interval. An interval wholly on one side of zero indicates that the values most compatible with the data under that procedure do not include zero. These interpretations assume the analysis and its underlying conditions are appropriate.

The primary contrast also includes a risk ratio and an odds ratio. A risk ratio compares the risk in one arm with the risk in the other, with one indicating equal risks. An odds ratio compares odds rather than risks; an odds ratio of one also indicates equal odds. These measures answer related but different questions, and their values should not be substituted for the risk difference. In particular, an odds ratio is not generally the same as a risk ratio. The registry’s principal reported contrast is the risk difference, so it is the clearest scale for describing the absolute separation between the posted risks.

How should the p-value be understood?

The primary unadjusted p-value is 0.028. A p-value measures how unusual data at least as discrepant as those observed would be under a specified null hypothesis and the assumptions of the test. It is not the probability that the null hypothesis is true, nor is it a measure of clinical importance. The record labels the value unadjusted. It does not describe any correction for testing multiple outcomes or analyses, so the value should not be interpreted as multiplicity-adjusted evidence.

The posted result is a comparison of participant counts, not a time-to-event estimate. Although the outcome is assessed at one year and the description refers to monitoring across follow-up, the registry reports counts and risks rather than a hazard ratio or a survival curve. A count-based contrast does not convey the timing of recurrences within follow-up. The registry record does not report a time-to-event analysis for this endpoint.

Why does outcome coding matter?

The endpoint title describes freedom from recurrent arrhythmias, while the record lists counts of 25 and 14 and risks of 0.455 and 0.255. The risk difference is -0.2 for the combination arm relative to the isolation-only arm. These figures can be described as a lower recorded risk under the comparison’s coding. But if the counts represent recurrence, a lower risk has a different clinical interpretation than if they represent freedom from recurrence. The registry does not explicitly resolve this point. Statistical summaries cannot repair an unclear definition: the analysis needs a clear statement of which event is counted before the direction is assigned a clinical label.

For the secondary complication outcome, the risk difference is 0.0 and the unadjusted p-value is 1.0. The risk ratio and odds ratio are also reported, with estimates of 1.0. These point estimates describe equal observed risks in the posted data, but interval estimates remain important because the observed number of events is small. Lack of a statistically distinguishable contrast is not evidence that the risks are exactly equal.

Randomization supports an intention-to-compare the assigned strategies, but the registry does not report whether the analyses followed an intention-to-treat principle, whether participants crossed over, or how protocol deviations were handled. Nor does it specify the statistical test used to produce each p-value, whether the reported estimates were adjusted for any covariates, or how missing endpoint data were treated. Those omissions limit independent assessment of the analysis assumptions. General statistical interpretation should therefore remain tied to the posted summaries rather than imply undocumented procedures.

11. Confidence Intervals and Precision

Precision concerns how narrowly the data locate the contrast. The primary risk difference is -0.2, with a reported interval entirely below zero. In practical terms, the interval indicates uncertainty around the estimated lower recorded risk in the combination arm, rather than a single exact effect. The posted interval does not include zero, but the registry’s unclear coding of the endpoint means its clinical direction remains uncertain even though the statistical direction of the coded contrast is clear.

The risk ratio and odds ratio provide alternative relative scales for the same primary comparison. Their intervals are broad enough to indicate meaningful uncertainty about the magnitude. Relative measures can also be harder to interpret without the underlying risks, so the reported risks and risk difference provide useful context. None of these measures should be described as a precise estimate of a treatment benefit when the endpoint coding is unresolved.

For overall complications, the risk difference estimate is 0.0, but the reported interval extends to both sides of zero. The data therefore remain compatible with lower or higher complication risk for the combination arm, as well as no difference. The equal point estimates do not establish equivalence, and the registry does not report an equivalence or non-inferiority framework.

Confidence intervals quantify sampling uncertainty under the analysis procedure; they do not capture every source of uncertainty. They cannot account for potential outcome misclassification, missing follow-up, departures from randomized assignment, or unreported analysis choices. Those aspects are not sufficiently described in the registry record. Statistical precision should therefore be considered alongside these limitations, not as a substitute for them.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size illustrations use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. They use the observed effect as a planning reference and show scenarios based on detecting 100%, 75% or 50% of that observed effect. These are planning illustrations, not the trial’s original design assumptions; the original sample-size justification is not reported in the registry record.

For this binary participant outcome, the figures are participants per arm, not total events. The 80% power column describes the planned number of participants per arm that would give an 80% chance of detecting the specified effect under the listed assumptions, if that effect and the assumptions were correct. The 90% power column describes the corresponding planning target for a 90% chance. Neither column is an estimate of the chance that the completed trial detected a real effect.

As the effect used for planning becomes smaller, more participants are needed to distinguish it from random variation at the same significance level and target power. The illustrations show that pattern across the stated fractions of the observed effect. They should be read as hypothetical design scenarios, not as evidence that the trial was adequately or inadequately powered for its original question. This is not observed power.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.455; treatment proportion p₁ = 0.255; average p̄ = 0.355.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6765 = 1.3260.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6616 = 0.5568.
4. n = (1.3260 + 0.5568)² / (-0.2000)² = 88.6, rounded up to 89 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.454545454545455                          # control proportion
p1 <- 0.254545454545455                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(3057548)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 89 (80% power), 119 (90% power)
 75% of observed effect: n per arm = 164 (80% power), 218 (90% power)
 50% of observed effect: n per arm = 377 (80% power), 505 (90% power)
power.prop.test: 88.6 
Simulated power at n = 89 per arm: 0.806 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry record does not report a statistical analysis plan specifying a primary testing hierarchy, a multiplicity adjustment, or how secondary outcomes were intended to affect the main conclusion. The primary p-value is unadjusted, and the secondary comparison is also reported without adjustment. If multiple hypotheses are tested, unadjusted p-values do not account for the increased opportunity to observe a small p-value by chance. The number and structure of all analyses planned by investigators are not reported, so the extent of any multiplicity cannot be established.

The record lists the one-year arrhythmia outcome as primary and overall complication rate as a secondary outcome. That distinction helps identify the principal question, but it does not tell readers whether other analyses were planned, whether subgroup analyses were conducted, or whether any analysis choices were made after examining results. Those details are not reported in the registry record.

Missing-data methods are also not reported. The primary description says participants were analyzed, but it does not state how many had complete monitoring at each assessment, whether unavailable ECG data were imputed, or how participants without a one-year classification were treated. The record does not specify whether analysis was based on assignment, treatment received, or a defined evaluable population. Consequently, it is not possible to confirm from the registry whether the posted comparison preserves the full benefits of randomization or how sensitive it may be to missing outcomes.

The registry’s population description identifies participants undergoing first-time ablation and gives group counts, but it does not provide a complete account of eligibility, exclusions after randomization, adherence, or crossover. Nor does it report an adjusted analysis. These omissions do not invalidate the numerical summaries, but they limit assessment of their robustness and of the population to which they apply.

15. 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

Serious events with the highest arm-level rate: cardiac failure (1.8%), pericarditis (1.8%), pericardial effusion (1.8%), persistent phrenic nerve palsy (1.8%), bradycardia (1.8%).

The registry lists 3 participants with a serious adverse event in each arm. It lists 0 participants with other adverse events in each arm and 0 deaths in each arm. These are counts as reported in the safety record; they should not be combined into an overall event total, since the record does not clarify overlap or provide further event-level detail.

The serious-event terms listed include Cardiac Failure, Pericarditis, Pericardial Effusion, Persistent Phrenic Nerve Palsy, Bradycardia, and Groin Vascular Complication. Each term is paired with 1.8% in the registry. The record does not specify the group assignment for each term in this list, so they should not be attributed to a particular arm based on the available information.

These safety counts are descriptive. The similar counts do not establish that the strategies have identical safety profiles, especially because the number of reported events is limited and no formal safety comparison or adjusted analysis is posted. The registry does not give event timing, severity grading beyond the serious-event classification, or a detailed account of how adverse events were collected. No treatment advice follows from these figures.

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

The posted results describe a randomized comparison of pulmonary vein isolation alone with pulmonary vein isolation plus posterior left atrial wall ablation. The primary numerical contrast is a lower recorded risk in the combination arm, with a risk difference of -0.2 and an unadjusted p-value of 0.028. That is a statistical description of the registry’s outcome coding, not a stand-alone conclusion about clinical benefit.

The endpoint title says freedom from recurrent atrial arrhythmias, but the registry does not explicitly state whether the group counts represent participants free of recurrence or participants with recurrence. The numerical direction therefore cannot safely be translated into a statement that one arm had more freedom or fewer recurrences without clarification. The record’s stated endpoint description and its posted count coding need to be read together rather than treating the title as a complete definition.

The secondary complication result has equal point estimates, but its interval permits differences in either direction. The safety record lists serious adverse events in both arms and no deaths. These data describe what was recorded, but do not demonstrate that the strategies are equivalent in either efficacy or safety. Equivalence would require an appropriate design and analysis, neither of which is reported.

The trial’s randomized design is relevant because it aims to make the comparison of assigned strategies fair. Still, the registry does not report all details needed to evaluate missing data, adherence, analysis populations, or multiplicity. The posted results also do not establish how well they generalize beyond the described population of symptomatic persistent or long-standing persistent atrial fibrillation undergoing first-time ablation.

Overall, the registry supports cautious description of the reported contrasts and their uncertainty. It does not justify an unqualified claim that either strategy works or does not work, nor does it supply a basis for individual medical decisions. The meaning of the primary result depends in part on clarifying what event the reported counts represent.

17. Why This Trial Matters Statistically

This trial raises a central issue in clinical biostatistics: an apparently clear numerical contrast can still be difficult to interpret if the event definition and coding are not explicit. The endpoint title concerns freedom from recurrent arrhythmias, while the reported counts and contrast are not clearly labeled as freedom or recurrence. The statistical calculation can summarize the recorded data, but interpretation depends on knowing exactly what was counted.

The example also illustrates why effect estimates and uncertainty should be read together. The primary risk difference and its interval communicate both the observed separation and the range of values compatible with the analysis. The secondary point estimate is equal between arms, yet its interval allows differences in either direction. A point estimate alone can make uncertainty easy to overlook.

Another important lesson is the distinction between a trial’s observed result and planning calculations based on that result. The sample-size illustrations examine hypothetical future designs under stated assumptions; they do not establish the trial’s original design rationale or its power after completion. Treating planning scenarios as properties of the completed study would confuse design calculations with inference from observed data.

Finally, the registry highlights the value of reporting analysis populations, missing-data procedures, multiplicity plans, and endpoint definitions. Without those details, readers can describe the posted results but cannot fully assess how robust they are to analysis choices. Transparent reporting is part of statistical interpretation, not a technical afterthought.

18. 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.

A trial-specific limitation is the uncertainty about the meaning of the primary count. The outcome label refers to freedom from recurrent atrial arrhythmias, while the registry does not state explicitly whether the reported group counts represent freedom or recurrence. This prevents a confident clinical interpretation of the direction, even though the numerical contrast is clear under the recorded coding.

The analyzed population description is narrow: participants undergoing first-time ablation for symptomatic persistent or long-standing persistent atrial fibrillation. The results should not automatically be extended to people with other arrhythmia patterns or prior ablation. The registry does not provide further subgroup results that would show whether the comparison differs across patient characteristics.

The record lists both cryoablation and radiofrequency approaches for pulmonary vein isolation, while the combination arm also includes posterior wall radiofrequency ablation. It does not report how many participants received each pulmonary vein technique or provide technique-specific results. The overall comparison therefore does not isolate the effect of a single energy method.

The registry does not report detailed adherence, crossover, missing endpoint data, or analysis-population rules. The outcome description lists monitoring at several follow-up points, but the record does not say how incomplete monitoring was addressed. It also does not report the original sample-size justification or a full analysis plan, including any multiplicity strategy. These reporting gaps limit assessment of bias, robustness, and precision beyond the estimates themselves.

Finally, the secondary complication information is sparse. The recorded serious-event counts and listed terms do not provide event timing, participant-level overlap, or a detailed comparison by arm for each term. The results are therefore useful as descriptive registry findings, but they do not offer a comprehensive account of comparative safety.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Comparison of Pulmonary Vein Ablation With or Without Left Atrial Posterior Wall Ablation for Persistent AF (PIVoTAL) — NCT03057548.
• Registry record last updated 2025-11-05; status last verified 2025-10.
• Results first posted 2025-11-05.
• 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.

22. Record Summary

The registry describes a completed randomized, double-masked, parallel-group study of pulmonary vein isolation alone versus pulmonary vein isolation with posterior left atrial wall ablation. It lists an enrollment of 110 and an analyzed cohort of 55 participants in each arm. The primary endpoint concerns freedom from recurrent atrial arrhythmias at one year, assessed using ambulatory monitoring and ECGs during follow-up.

The posted primary contrast is a risk difference of -0.2 for the combination arm, with an unadjusted p-value of 0.028. Because the record does not explicitly clarify whether the reported counts represent freedom from recurrence or recurrence itself, the clinical direction remains uncertain. The secondary complication point estimates are equal, with limited precision. Missing-data procedures, multiplicity plans, original sample-size justification, and detailed analysis-population rules are not reported in the registry record.