Isthmus Ablation With Gold Electrode for Treatment of Atrial Flutter (AURUM 8): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Isthmus Ablation With Gold Electrode for Treatment of Atrial Flutter (AURUM 8) (NCT00326001), a randomized phase 4 study. The primary outcome is Duration of Energy Application.

2. Clinical Question

The registry describes the study purpose as demonstrating an advantage for the gold-alloy tip over the platinum-iridium tip. The primary measure is procedural rather than a direct measure of long-term treatment success: it records cumulative time when current flowed through the catheter tip while the cavotricuspid isthmus in the right atrium was ablated.

Other registered outcomes broaden the question beyond energy-application time. They address success with the first catheter, treatment success at 6 months after ablation, and charred catheter tips. These outcomes describe different aspects of the procedure and follow-up, so they should not be treated as interchangeable measures of one underlying effect.

3. Trial Design

AURUM 8 is listed as a phase 4 randomized trial with a parallel-group model. The registry reports enrollment of 463 and a completed status. The record lists a start of 2004-06 and primary completion of 2008-03. It identifies Biotronik SE & Co. KG as the sponsor and atrial flutter as the condition.

Participants were assigned to a gold tip catheter or a platinum-iridium tip catheter. Allocation is listed as randomized, and masking is listed as none. The record therefore indicates random assignment but does not report masking of participants, clinical staff, or outcome assessors. Details of the randomization procedure, allocation concealment, and any stratification are not reported in the registry record.

The primary outcome is duration of energy application during the ablation procedure, expressed as a mean with standard deviation. Its stated analysis population is per protocol. The arm counts posted for this primary measure are 229 for the gold tip catheter and 219 for the Pt-Ir tip catheter. The registry also lists three secondary outcomes: first-catheter ablation success, long-term treatment success at 6 months after ablation, and patients with charred catheter tips.

The record does not describe the trial's original sample-size justification, recruitment targets by arm, or protocol for handling deviations from assigned treatment. It also does not report specific eligibility criteria or the numbers assessed for eligibility. These omissions limit how fully the randomized design and the relationship between enrollment and the analyzed populations can be reconstructed from the registry record alone.

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: No exclusion before assignment

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Per protocol

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 Duration of Energy Application, measured over ablation procedure.

The primary endpoint, duration of energy application, measures the cumulative amount of time during which radiofrequency current flows through the catheter tip in the ablation procedure. It is reported in minutes as a mean and standard deviation, for the per-protocol population. The measure focuses on procedural energy delivery rather than a clinical event occurring after the procedure.

Such a measure can be used to compare the amount of time spent applying energy under the two catheter approaches. As a continuous endpoint, it retains more gradation than a simple success/failure outcome: participants can have different energy-application times rather than being grouped only by whether an event occurred. The mean gives a central summary, while the standard deviation describes how dispersed participant-level times are around that mean.

The endpoint does not, by itself, establish whether an ablation was successful, whether treatment remained successful over time, or whether complications occurred. Those questions are represented separately by the registered secondary outcomes. Duration is therefore best interpreted as one procedural comparison, not as a stand-alone summary of overall treatment outcome.

The endpoint's timeframe is the ablation procedure. The record does not report a more detailed measurement protocol, such as the precise timing rules used to start and stop the energy-application clock, or whether any special handling was applied to repeated applications.

7. Results Posted in the Registry

• Pt-Ir Tip Catheter: mean 10.90 versus 10.20 on control; difference 0.70 (95% CI -0.58 to 1.98), standardized effect d = 0.10; z-test p = 0.283.

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.

Ablation Success With the First Catheter

• 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:
  • Pt-Ir Tip Catheter: 89.0% (195/219) versus 94.3% (216/229) on control; risk difference -5.3 percentage points (95% CI -10.4 to -0.2), risk ratio 0.94 (0.89–1.00); unadjusted two-proportion z-test p = 0.042.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for Pt-Ir Tip Catheter than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Number of Patients With Long-term Treatment Success

• 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:
  • Pt-Ir Tip Catheter: 97.3% (213/219) versus 98.3% (225/229) on control; risk difference -1.0 percentage points (95% CI -3.7 to 1.8), risk ratio 0.99 (0.96–1.02); unadjusted two-proportion z-test p = 0.477.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pt-Ir Tip Catheter and the control. The interval gives the range of effects that remain compatible with the data.

Number of Patients With Charred Catheter Tips

• 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:
  • Pt-Ir Tip Catheter: 37.9% (83/219) versus 4.8% (11/229) on control; risk difference 33.1 percentage points (95% CI 26.1 to 40.1), risk ratio 7.89 (4.33–14.39); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Pt-Ir Tip Catheter than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary outcomes cover distinct stages and features: an immediate procedural measure, treatment success at follow-up, and catheter-tip charring during ablation. Together, they offer context beyond energy-application duration, but they do not form a single composite result. The pattern across these outcomes is not uniform: some comparisons show clearer separation between the groups than others, while the follow-up success comparison is less decisive.

These secondary findings relate to the primary result by describing other aspects of the catheter comparison, not by directly validating or disproving the mean-duration result. A procedural outcome may reflect a different mechanism or definition from cumulative energy-application time, and a follow-up endpoint addresses a different timeframe. Therefore, agreement or disagreement between their directions does not establish what caused the primary result.

The secondary p-values are unadjusted, and the registry lists multiple secondary outcomes. When many comparisons are examined, an isolated small p-value can arise by chance more readily than when only one comparison is made. The registry does not report a multiplicity strategy or identify which secondary outcome, if any, was designated as a key confirmatory endpoint. This makes the secondary findings more appropriately interpreted as supportive or hypothesis-generating than as independent confirmation of a broad superiority claim.

Outcome definitions and analysis populations also matter. The record gives the measure names, timeframes, arm counts, and reported chi-squared methods, but does not provide detailed event adjudication procedures or a complete account of missing follow-up data. Without those details, the comparisons can be described as posted, but the reasons for any outcome differences and their robustness cannot be determined from the registry record alone.

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

• Ablation Success With the First Catheter
• Number of Patients With Long-term Treatment Success
• Number of Patients With Charred Catheter Tips

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is continuous: each participant contributes a duration, measured in minutes, and the group result is summarized by a mean and standard deviation. The registry's posted method is a two-sided t-test. A t-test assesses whether the observed difference between group means is large relative to the variability and sample sizes. The two-sided form considers departures in either direction, rather than testing only whether one catheter produces longer application time.

What the mean difference represents

The re-calculated mean difference is defined as the Pt-Ir group mean minus the gold tip group mean. The estimate is 0.7 minutes, so the observed group means place the Pt-Ir group higher on this measure. This is a difference between group averages, not a statement that every participant in one group had a longer duration than every participant in the other. The standard deviation of 6.9 minutes in each group indicates considerable participant-to-participant spread relative to the difference between the means.

A p-value describes how compatible the observed data are with a statistical model in which the groups have no difference in their underlying means. It is not the probability that the null hypothesis is true, nor does it measure clinical importance. A p-value also does not show whether an effect is large enough to matter. In this case, the registry reports p = 0.25 for its two-sided t-test, while the simple unadjusted re-calculation gives p = 0.283. Neither figure alone establishes equivalence or rules out effects that may be relevant under a separately specified clinical criterion.

Why variability matters

Standard deviations describe the spread of individual observations, whereas standard errors describe the uncertainty in an estimated group mean. The posted standard deviations are 6.9 minutes in both groups; the re-calculated standard errors of the group means are 0.456 and 0.466. These quantities answer different questions. A standard deviation characterizes variation among measured durations, while a standard error reflects the precision of a mean estimate given the data and sample size.

A mean and standard deviation are useful summaries when a continuous outcome is represented by a central value and dispersion. However, a mean-based comparison can be affected by skewness or unusually extreme observations. The registry record does not provide participant-level distributions, diagnostics, or details about how departures from t-test assumptions were assessed. It is therefore not possible to determine from the posted summaries whether the duration distribution was symmetric or whether outliers influenced the mean.

How to read the confidence interval

A confidence interval expresses uncertainty around an estimated effect. In repeated applications of the same method under its assumptions, intervals constructed at a stated confidence level would cover the underlying effect at that rate. For an individual trial, the interval gives a range of effect estimates reasonably compatible with the data and model; it is not a guarantee that the true effect lies within that particular interval.

For the primary mean difference, the re-calculated 95% confidence interval spans zero. Zero represents no mean difference under the chosen contrast. Because the interval includes values on both sides of zero, the data do not precisely locate the direction of the underlying mean difference. The width also matters: an interval can include zero yet still allow effects that are meaningfully different from zero. Whether any such value is important depends on a clinical threshold, which is not reported in the registry record.

Binary outcomes and unadjusted comparisons

The secondary endpoints are binary counts: whether first-catheter ablation success occurred, whether long-term treatment success was recorded, and whether a catheter tip was charred. The registry reports chi-squared tests for these outcomes. A chi-squared test compares the observed event distribution between groups with the distribution expected under no association between assigned group and outcome. A risk difference expresses the difference between event proportions; its sign depends on the order in which groups are contrasted.

The re-calculated secondary comparisons are unadjusted. When several outcomes are tested, the chance of obtaining at least one apparently unusual result can increase if no multiplicity procedure is used. A small p-value for an individual secondary outcome therefore needs cautious interpretation alongside the number of outcomes, their prespecified status, and any adjustment plan. The registry record does not report a multiplicity adjustment plan.

Why over-dispersion can matter

In general, over-dispersion occurs when observed variability is greater than assumed by a statistical model. If a model understates variability, standard errors can be too small and confidence intervals too narrow, leading to overstated precision. This is a general consideration for statistical modeling, not a reported finding in this trial. The registry does not report an over-dispersion assessment for the primary endpoint, and the continuous primary analysis is described as a t-test rather than a model with a stated dispersion parameter.

The re-calculations use posted summary statistics and are simple, unadjusted checks. They cannot reproduce adjustments for baseline covariates, stratification, or participant-level features that are not contained in the registry summaries. The registry's own analysis method and p-value should therefore be distinguished from the additional summary-statistic calculations.

11. Confidence Intervals and Precision

Precision is reflected in the range of effects compatible with the data, not just in the point estimate or p-value. For the primary mean difference, the re-calculated 95% confidence interval spans zero. This indicates uncertainty about whether the mean duration is higher in the gold tip group or the Pt-Ir group, and the interval also allows differences away from zero. The registry does not report a threshold for a clinically important difference in energy-application time, so the practical meaning of the interval cannot be judged against a prespecified margin.

The group standard deviations are 6.9 minutes, while the difference between the posted means is 0.7 minutes. These summaries show that participant-level durations vary substantially around their group averages, relative to the separation of those averages. They do not establish whether the uncertainty is acceptable for a clinical decision, because that would require a decision threshold and a fuller account of the endpoint's relevance.

For the secondary comparisons, the recalculated intervals for first-catheter success and catheter-tip charring exclude zero, whereas the interval for long-term treatment success spans zero. These intervals quantify uncertainty around each respective risk difference. They should be considered in light of the unadjusted multiple-outcome context and the fact that the registry does not report a multiplicity plan.

Confidence intervals are not measures of the probability that a treatment is beneficial, and they do not establish that all plausible values are equally likely. Their interpretation depends on the analysis assumptions and the way the data were collected. The registry record does not provide participant-level data, detailed missing-data handling, or a clinical margin that would allow a more complete assessment of precision.

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 planning figures are illustrations based on the observed effect, not the trial's original design calculation. They assume a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each scenario uses the stated fraction of the observed effect as the effect to detect. The trial's own original sample-size assumptions and justification are not reported in the registry record.

For these continuous and binary outcomes, the figures are participants per arm, not a total across both arms and not a total number of events. The planning columns for 80% and 90% power indicate the participants per arm estimated to give the specified probability of detecting the assumed effect under the planning model, if the model assumptions hold. They are not guarantees that a study of that size will produce a particular p-value or result.

For the primary endpoint, planning for 100% of the observed effect gives 1,526 participants per arm for 80% power and 2,042 participants per arm for 90% power. Planning for 75% of the observed effect gives 2,712 participants per arm for 80% power and 3,630 participants per arm for 90% power; planning for 50% gives 6,101 and 8,168 participants per arm, respectively. The pattern illustrates that smaller effects require more participants to detect under the same assumptions.

These figures are planning illustrations, not observed power. Observed power is not a useful substitute for interpreting the effect estimate and its confidence interval; the planning numbers instead show how design requirements change under specified effect assumptions.

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, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 0.700; pooled standard deviation σ = 6.900.
2. n = 2 × (1.96 + 0.842)² × 6.900² / 0.700² = 1,525.2, rounded up to 1,526 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
delta <- 0.700000000000001                      # observed difference in means
sigma <- 6.9                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^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 (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(326001)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 1,526 (80% power), 2,042 (90% power)
 75% of observed effect: n per arm = 2,712 (80% power), 3,630 (90% power)
 50% of observed effect: n per arm = 6,101 (80% power), 8,168 (90% power)
power.t.test: 1526.2 
Simulated power at n = 1,526 per arm: 0.797 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-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. Analyses Reported by the Sponsor

The registry reports the sponsor's primary analysis as a two-sided t-test with p = 0.25. A simple unadjusted re-calculation from the posted group summaries estimates a mean difference of 0.7 minutes, with a 95% confidence interval that spans zero, and gives p = 0.283. Both analyses therefore present limited evidence of a difference in mean duration, although their p-values are not identical.

The re-calculation uses the posted means, standard deviations, and group sizes. It is not a reproduction of an analysis using participant-level observations, and it may not capture analysis details that are not reported in the registry. The sponsor's reported test is the registry's own analysis and should be kept distinct from the summary-statistic re-calculation. The registry record does not provide the sponsor's test statistic, degrees of freedom, or participant-level data needed to investigate the small difference between the reported and recalculated p-values.

The comparison does not show that the catheter groups are equivalent. No equivalence margin is reported, and the confidence interval remains compatible with differences in either direction. Interpretation should focus on the estimated mean difference, its uncertainty, and the endpoint's procedural meaning, rather than treating either p-value as a measure of the probability that one catheter is superior.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and three secondary outcomes. It reports a two-sided t-test for the primary comparison and chi-squared tests for the secondary comparisons. A plan for controlling the overall type I error across multiple outcomes is not reported in the registry record. The posted secondary comparisons are therefore best read as individual comparisons rather than as a documented family of tests with a stated multiplicity adjustment.

The original statistical analysis plan, including whether outcomes were hierarchically ordered or whether any secondary measure was confirmatory, is not reported in the registry record. The registry does not report interim analyses, stopping rules, or the original sample-size justification. The planning illustration uses a two-sided significance level of 0.05, but that is not evidence of the trial's own prespecified testing threshold or design assumptions.

The primary analysis population is identified as per protocol. The registry does not report the criteria for inclusion in that population, the handling of protocol deviations, or whether an intention-to-treat analysis was also performed. The analysis populations for the secondary endpoints are not reported in the registry record in the same detail. This makes it difficult to assess whether all outcomes use comparable sets of participants.

Missing-data handling is not reported in the registry record. The record does not explain how absent endpoint measurements, incomplete follow-up, or withdrawal were handled, nor does it describe sensitivity analyses for missing data. The difference between overall enrollment and the posted arm counts for the primary per-protocol analysis should not be attributed to a specific cause without those details.

These omissions do not negate the posted results, but they limit assessment of prespecification, selective reporting, and robustness. A full protocol or statistical analysis plan would be needed to evaluate those issues more completely.

16. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

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: hospitalization (7.9%), death (0.9%).

The registry reports serious adverse events affecting 20 participants in the gold tip group, with 229 at risk, and 12 participants in the Pt-Ir group, with 219 at risk. It reports zero other adverse events affecting participants in each group. Death counts by group are not reported in the registry record.

The registry also lists hospitalization at 7.9% and death at 0.9% among the top serious adverse event terms. The record does not clarify in this summary how those percentages relate to the arm-specific serious-event counts or give an arm-specific breakdown for those terms. They should not be assigned to one catheter group or treated as a direct comparison without that information.

Serious adverse event counts are descriptive safety data. They do not, on their own, establish that an event was caused by the catheter or that the groups differ in safety. The registry summary does not report event-level descriptions, severity criteria, timing, relatedness assessments, or statistical comparisons for these figures. Accordingly, the counts can be read as the reported numbers affected, with important details about attribution and comparative interpretation not reported in the registry record.

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

The primary result describes mean energy-application duration during ablation. The posted means were 10.2 minutes for the gold tip catheter and 10.9 minutes for the Pt-Ir tip catheter, and the recalculated mean difference was 0.7 minutes with the Pt-Ir group higher. The sponsor's two-sided test reported p = 0.25; the simple recalculation gave p = 0.283. The 95% confidence interval for the recalculated difference spans zero, so the estimate is not precise enough to establish a clear direction of difference.

This result does not demonstrate that the catheters are equivalent. Equivalence requires a prespecified margin and an analysis designed to test whether the full plausible range lies within that margin; neither is reported in the registry record. Nor does the primary outcome alone determine procedural success, long-term treatment success, or safety. Those are separate outcomes with their own definitions and uncertainties.

The trial is randomized, but its primary endpoint is reported for a per-protocol population, and the criteria for that population are not described. The record also lists no masking. These features should be considered when interpreting how directly the posted analysis estimates the effect of assignment under routine trial conditions.

Statistical interpretation is not a treatment recommendation. The posted summaries describe comparisons within this trial and do not establish how an individual patient should be treated. A broader judgment would require clinical context, full outcome definitions, complete safety information, and evidence beyond the registry record.

18. Why This Trial Matters Statistically

This trial illustrates why an endpoint's meaning matters as much as its p-value. Duration of energy application is a continuous procedural measure, while first-catheter success, follow-up success, and catheter-tip charring are binary outcomes. Each captures a different aspect of the intervention. A result on one scale cannot automatically substitute for a result on another.

It also shows the distinction between an estimate and its precision. The primary group means differ by 0.7 minutes in the posted summaries, but the recalculated 95% confidence interval spans zero. Reporting the estimate with its uncertainty is more informative than treating a single p-value as a yes-or-no verdict. The standard deviations further describe how much participant-level duration varies around each group mean.

Randomization is an important design feature for comparing assigned interventions, but interpretation still depends on the analysis population and reporting detail. Here, the primary outcome is identified as per protocol, while the protocol criteria and missing-data methods are not reported in the registry record. Such information is needed to judge how the analyzed population relates to the randomized comparison.

Finally, the secondary endpoints and safety counts demonstrate why multiplicity and outcome definitions deserve attention. Multiple findings can add context, but unadjusted comparisons should not be treated as if each were a single prespecified primary test. The registry record supports a careful description of the posted results while leaving key questions about design and analysis procedures unanswered.

19. 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 registry record does not report detailed eligibility criteria, the randomization procedure, allocation concealment, or the protocol for masking. It lists no masking, which leaves open the possibility that knowledge of assigned catheter could have affected procedural decisions or outcome assessment; the record does not describe safeguards against such effects.

The primary endpoint uses a per-protocol population, but the definition of adherence and the handling of protocol deviations are not reported. Missing-data methods, reasons for unavailable observations, and sensitivity analyses are also not reported in the registry record. Consequently, the relationship between the analyzed participants and all randomized participants cannot be fully assessed from the posted summary.

The registry does not provide participant-level data, baseline characteristics, detailed distributional information for energy-application duration, or diagnostic checks for the t-test. It also does not report a clinically important difference for the primary measure. These gaps limit interpretation of whether the observed mean difference is practically important and how robust the summary analysis is to distributional features.

For secondary outcomes, the record reports chi-squared tests but does not report a multiplicity adjustment plan or detailed endpoint adjudication procedures. The adverse-event summary provides affected counts and selected terms but not event-level timing, relatedness, or arm-specific term breakdowns. The sponsor's full analysis details and the original sample-size justification are not reported in the registry record.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Isthmus Ablation With Gold Electrode for Treatment of Atrial Flutter (AURUM 8) — NCT00326001.
• Registry record last updated 2010-02-18; status last verified 2009-08.
• Results first posted 2010-02-04.
• 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.

23. Record Summary

AURUM 8 is a completed phase 4 randomized, parallel-group study of gold-alloy and platinum-iridium tip catheters for cavotricuspid isthmus ablation in patients with atrial flutter. The registry lists enrollment of 463 and no masking. The primary outcome is per-protocol mean duration of energy application during the ablation procedure.

The sponsor-reported two-sided t-test for the primary endpoint has p = 0.25. The unadjusted summary-statistic re-calculation estimates a mean difference of 0.7 minutes and gives p = 0.283; its 95% confidence interval spans zero. Three secondary outcomes and serious adverse event counts are also posted. Important details about the original design assumptions, missing-data handling, multiplicity, and analysis populations are not reported in the registry record.