MediGuide Registry: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for MediGuide Registry (NCT02470312), a registered phase not stated study. The primary outcome is Amount of Fluoroscopy Time.

2. Clinical Question

The registry describes its purpose as collecting information about the clinical utility of MediGuide in CRT implantation and EP procedures. Its primary outcome focuses on fluoroscopy exposure during the procedure, with the expected measurement time frame listed as day 1 of the study. The record does not state a specific target value, comparison against another system, or hypothesis about the size or direction of a difference.

Because this is an observational registry and allocation is not stated, the clinical question is descriptive rather than a randomized treatment-effect question. The CRT and EP groups undergo different procedures, so a direct comparison between their fluoroscopy times would not by itself isolate the effect of MediGuide. Actual mean fluoroscopy times, standard deviations, and analysis results are not reported in the registry record, so the magnitude and precision of the primary outcome cannot be described from this record.

3. Trial Design

The MediGuide Registry is described as a registry/observational study. Its stated goal was to collect data on the clinical utility of the MediGuide system in cardiac resynchronization therapy implantation and electrophysiology procedures. Abbott Medical Devices is listed as the sponsor. The record lists enrollment of 578 and a status of TERMINATED.

The study includes a CRT group, described as patients undergoing CRT implantation using the MediGuide system and tools, and an EP group, described as patients undergoing ablation procedures for Atrial Fibrillation, Atrial Flutter, and Ventricular Tachycardia using the system and tools. CRT implantation, MediGuide, and EP are listed as interventions, with procedure or device types identified in the record. These descriptions establish the settings in which information was collected; they do not establish that participants were randomly assigned to a device or procedure.

The start date is 2015-08-18, and the primary completion date is 2017-02-10. The record does not state why the study was terminated, so the status alone cannot establish whether termination was related to recruitment, logistics, safety, data quality, or another reason. The record also does not report a target enrollment rationale or whether the reported enrollment represents all participants who entered the registry.

The primary outcome is amount of fluoroscopy time during a CRT implant or EP procedure, expressed as a mean with standard deviation in minutes. The expected time frame is day 1 of the study. The record lists 2 outcome measures, but the available primary-outcome description does not include numerical results. It lists 0 analyses, so no statistical analysis results are recorded. Randomization, allocation procedures, comparator assignment, and a detailed analysis plan are not reported in the registry record.

The CRT and EP groups are not a like-for-like control comparison: they represent different clinical procedures and may differ in procedural context. The record does not describe a separate group receiving procedures without MediGuide. Consequently, the registry design supports a description of recorded procedures and outcomes, but the information in the record does not define a controlled estimate of the device's effect.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Amount of Fluoroscopy Time, measured over Expected time frame is day 1 of the study.

The primary endpoint is the amount of fluoroscopy time during a CRT implant or EP procedure. Fluoroscopy time is the duration for which fluoroscopic imaging is used during the procedure. The registry records the measure in minutes and specifies a mean with standard deviation. The expected measurement time frame is day 1 of the study, corresponding to the procedural setting described in the record.

As a continuous measure, fluoroscopy time can describe the typical duration of imaging use across recorded procedures, while the standard deviation describes how spread out individual observations are around the mean. Reporting both can give a more complete descriptive account than reporting the mean alone: similar means can occur alongside different amounts of participant-to-participant variation. The meaning of either statistic depends on which procedures and participants contributed observations and how missing measurements were handled; those details are not reported in the registry record.

Fluoroscopy time is relevant to this registry's stated goal because it measures one aspect of imaging use during CRT and EP procedures performed with MediGuide. However, the endpoint alone does not describe all aspects of clinical utility or procedural performance. The record does not specify additional interpretation criteria, a threshold for a clinically important value, or a comparison with a procedure conducted without MediGuide.

No numerical mean, standard deviation, or other primary-endpoint result is reported in the registry record. Thus, the endpoint's definition can be described, but its observed level, variability, and precision cannot be assessed from the recorded results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a continuous measure: fluoroscopy time in minutes. The registry specifies the mean as the summary measure and standard deviation as the measure of dispersion. In general, a mean represents the arithmetic average of observed values, and a standard deviation describes their spread around that average. Together they convey the central level and variability of a continuous outcome, but they do not show the full shape of its distribution.

A mean and standard deviation are most informative when the observations and the analysis population are clearly defined. For this registry, the outcome description identifies fluoroscopy time during a CRT implant or EP procedure, with an expected time frame of day 1 of the study. The record does not report whether the mean was calculated separately for CRT and EP, whether any pooled estimate was intended, or which participants were included. It also does not report observed values, so no numerical descriptive interpretation is possible.

In general, an estimate can be accompanied by a confidence interval to show its statistical precision. A narrower interval indicates greater precision under the model and assumptions used; a wider interval indicates more uncertainty. An interval is not reported for the primary endpoint in the registry record. Without an estimate and its uncertainty, readers cannot assess whether the available observations would distinguish among a range of plausible fluoroscopy times.

For a comparison between groups, a statistical analysis would need to define the contrast, the populations being compared, and any adjustment for differences that could influence the outcome. That is especially important when the groups represent different kinds of procedures. Here, the CRT and EP groups are described separately, allocation is not stated, and the record says the arms are not a like-for-like control comparison. A difference in group means, if reported, would be descriptive unless the design and analysis justified a causal interpretation. No such comparison or adjustment strategy is reported.

Random allocation, in general, can help balance measured and unmeasured characteristics between comparison groups, while observational group membership may reflect clinical or procedural factors. The registry is observational, and allocation is not stated. The record therefore does not describe a randomization process or establish an exchangeable comparison. It also does not state whether a no-MediGuide comparison was included.

Dispersion matters because averaging can hide heterogeneity. In general, a standard deviation indicates how much measurements differ across observations, but it can be sensitive to unusually high or low values and does not describe skewness on its own. Other summaries or distributional plots can sometimes help, but no distributional results for fluoroscopy time are reported in the registry record. The record does not state whether values were checked for skew, outliers, or other features that could affect the suitability of a mean-based analysis.

Over-dispersion is a general issue for outcomes whose variability exceeds what a chosen statistical model assumes. It can make standard errors and confidence intervals too optimistic if the model does not account for the extra variability. For this continuous endpoint, the registry record does not describe a model, variance assumptions, or any assessment of dispersion. There is no basis to assert that over-dispersion was present or addressed; the relevant model details are not reported in the registry record.

The record lists 0 analyses. It does not report a test statistic, p-value, confidence interval, adjusted estimate, or model specification for the primary outcome. A non-significant result, if one were reported, would not by itself establish equivalence or absence of a meaningful difference; it could also reflect imprecision. In this record, even that distinction cannot be made because no primary-outcome analysis result is recorded.

The registry's stated sample-size assumptions describe a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. For non-time-to-event outcomes, the intended quantity is participants per arm, and the effect is framed as a stated fraction of the observed effect. These are planning assumptions, not evidence of the registry's original design or analysis plan. The registry record does not report a sample-size justification, and no numerical observed effect or planning estimate is reported there. Such illustrations are not observed power and do not establish what the study was designed to detect.

In general, power is a property of a specified design and assumed effect, variability, significance level, and analysis. It is not a measure of whether an observed result is true, and post hoc calculations based on an observed effect do not replace the uncertainty interval around that effect. Any sample-size illustration should be read as a hypothetical planning exercise under its stated assumptions, not as a finding about the registry. The actual analysis plan, including any interim analyses or multiplicity procedure, is not reported in the registry record.

These general principles explain how continuous-outcome analyses are commonly interpreted; they do not fill gaps in this record. The outcome definition is available, but the numerical outcome summaries and analytic details needed to evaluate the statistical result are not reported.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("CRT Group", "EP Group")
n   <- c(142, 419)
m   <- c(9.5, 6)
sp  <- c(8, 9.9)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  CRT Group  142  9.500  8.000  8.173  10.827
CARM  EP Group  419  6.000  9.900  5.049  6.951

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 2 outcome measures, but the primary-outcome description available for interpretation concerns fluoroscopy time. The other outcome measure's identity and results are not reported in the registry record. The record lists 0 analyses and does not describe a multiplicity procedure. It is therefore not possible to determine whether multiple outcomes or comparisons were tested, or whether any adjustment was planned.

In general, multiplicity arises when several outcomes, groups, time points, or statistical comparisons are examined. Without appropriate planning or interpretation, repeated testing can increase the chance of finding an apparently notable result by chance. This is a general statistical concern, not a claim that such testing occurred in this registry. The analysis plan and any interim analyses are not reported in the registry record.

The record does not state how missing fluoroscopy-time values were handled, how many values were missing, or whether the primary outcome was available for all enrolled participants. It also does not identify an intention-to-treat or other analysis population. Missing-data methods can affect an estimate when participants with observed outcomes differ from those without observed outcomes; the direction and size of any effect depend on the circumstances and assumptions. Those circumstances and methods are not reported in the registry record.

Because the primary outcome results are absent, readers cannot check whether the analyzed population matches the enrolled population or whether sensitivity analyses tested the impact of missing values. The registry record also does not report a prespecified hierarchy of outcomes or a plan for handling multiple comparisons. These omissions limit assessment of selective reporting and the robustness of any statistical conclusions.

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: pseudoaneurysm (0.7%), arrhyrhmia (0.7%), bleeding (non-hematoma) (0.7%), cardiac perforation (0.7%), coronary sinus perforation (0.7%).

The safety information lists serious adverse events by group. In the CRT Group, 142 participants are listed as at risk and 5 as affected by a serious adverse event; 142 are listed as at risk for other adverse events and 0 as affected. In the EP Group, 419 are listed as at risk for serious adverse events and 12 as affected; for other adverse events, 11 are listed as at risk and 11 as affected. Deaths are listed as 0 in each group.

These are registry counts with group-specific denominators, not comparative risk estimates. The denominator listed for other adverse events in the EP Group is 11, while the serious-event denominator is 419; the record does not explain the difference. These figures should therefore be read with their specific listed denominators rather than assumed to cover the same analysis population or observation period. The record does not report event timing, exposure duration, event adjudication, or a statistical comparison between groups.

The serious-event terms listed at 0.7% each are Pseudoaneurysm, Arrhyrhmia, Bleeding (non-hematoma), Cardiac Perforation, Coronary Sinus Perforation, and Phrenic Nerve/Diaphragmatic Stimulation. The registry record does not provide enough detail in these listings to determine whether terms overlap within participants or how they relate to the group-level affected counts. These counts and listed terms describe recorded safety information; they do not establish a causal relationship to the device or procedure.

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

The registry provides a description of its intended use: collecting information about MediGuide during CRT implantation and EP procedures. It identifies fluoroscopy time as the primary endpoint and gives the unit, summary measure, dispersion measure, and expected time frame. It also records group descriptions, enrollment, status, dates, and selected adverse-event counts. These details help define the scope of the registry.

What the record does not provide is the numerical result for the primary endpoint. There is no reported mean fluoroscopy time, standard deviation, confidence interval, or analysis result. Consequently, the record does not establish what fluoroscopy times were observed or how precise any estimate may be. The outcome definition alone cannot support a conclusion about the magnitude of fluoroscopy use.

The record also does not establish a comparative effect of MediGuide. It describes an observational registry, does not state allocation, and identifies the CRT and EP groups as not being a like-for-like control comparison. Those groups differ by procedure type, and the record does not describe a comparator group without the system. Any raw contrast between CRT and EP would not, by itself, identify an effect attributable to MediGuide.

Nor does the record explain why the study was terminated or provide a sample-size justification, analysis plan, or missing-data method. The status TERMINATED should not be read as a conclusion about efficacy, safety, or feasibility. The adverse-event counts are descriptive and do not establish causation or comparative risk. Their interpretation is limited by the denominators and additional details not reported in the registry record.

In general, an observational registry can describe outcomes in the settings where information was collected and may help identify questions for further study. The strength of any inference depends on the completeness of outcome data, the comparison design, and the analysis. In this record, the descriptive framework is present, but primary-outcome results and details needed for comparative interpretation are not reported. The record therefore supports a clear account of what was intended to be measured, not a conclusion about the measured result.

14. Why This Trial Matters Statistically

This registry raises a central statistical distinction: defining an outcome is not the same as reporting its result. The record specifies fluoroscopy time in minutes, summarized by a mean and standard deviation, but does not include those numerical summaries. Without an estimate, readers cannot assess the endpoint's observed level or variability. Without an uncertainty measure, they cannot judge the precision of an estimate.

Its observational structure also matters for interpretation. The registry includes CRT and EP procedure groups, but they are not described as randomized or as a like-for-like control comparison. A numerical difference between distinct procedure groups, even if one were reported, could reflect the procedures or other group differences rather than the use of MediGuide. Good statistical interpretation begins by asking what contrast the design can support, not only which summary statistic was selected.

The safety listings illustrate a related issue: denominators are part of the result. The listed at-risk counts differ between event categories in the EP Group, and the record does not explain why. Readers need the population and observation context attached to each count before treating figures as comparable. Counts alone are not causal estimates.

Finally, the registry record leaves key analytic details unreported, including the analysis population, missing-data handling, and multiplicity approach. These omissions do not demonstrate that the methods were inadequate; they mean the record does not allow those methods to be evaluated. Statistically, distinguishing between an unreported result and a null result is essential. Here, the primary endpoint's numerical result is not reported, so no conclusion about its direction, size, or statistical significance is supported.

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 principal trial-specific limitation is that the registry record defines the primary endpoint but does not report its numerical results. Mean fluoroscopy time, standard deviation, and a confidence interval are not reported, and the record lists 0 analyses. The endpoint therefore cannot be evaluated for magnitude, variability, or precision using the registry information.

The study is described as observational, with allocation not stated. Its CRT and EP groups involve different procedures and are not a like-for-like control comparison. The record does not describe a group undergoing comparable procedures without MediGuide, so a device-specific contrast cannot be identified from the design information available.

Enrollment is listed as 578, but the record does not explain how many participants contributed to the primary endpoint or whether outcome data were missing. It does not describe an analysis population, missing-data approach, or sensitivity analysis. The group-specific safety denominators do not resolve the primary-outcome denominator question.

The record lists 2 outcome measures but does not provide the identity and results of the other measure in the available outcome description. It does not report a multiplicity plan, detailed statistical methods, interim analyses, or a sample-size justification. The planning assumptions described for a sample-size illustration do not establish the registry's original design rationale or actual analysis.

The status is TERMINATED, but the reason is not reported. The record also does not describe event timing or the basis for the listed safety counts. These limitations are about what can be evaluated from the registry record; they do not establish that unreported procedures or analyses did not occur outside it.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: MediGuide Registry — NCT02470312.
• Registry record last updated 2019-02-04; status last verified 2019-01.
• Results first posted 2019-01-11.
• 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 MediGuide Registry is an observational study sponsored by Abbott Medical Devices, with a stated goal of collecting data on the clinical utility of the MediGuide system in CRT implantation and EP procedures. It lists enrollment of 578, status TERMINATED, a start date of 2015-08-18, and a primary completion date of 2017-02-10.

The primary endpoint is mean fluoroscopy time in minutes, with standard deviation, during a CRT implant or EP procedure; the expected time frame is day 1 of the study. The record does not report numerical primary-outcome results and lists 0 analyses. It describes CRT and EP groups but does not state allocation, and the groups are not a like-for-like control comparison.

Safety counts and serious-event terms are listed, but the record does not provide the detail needed for a causal or comparative safety interpretation. The reason for termination, missing-data methods, analysis population, and statistical plan are not reported in the registry record.