Post Approval Registry of Corox OTW, Endocardial, Left Ventricular Steroid Lead, Bipolar: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Post Approval Registry of Corox OTW, Endocardial, Left Ventricular Steroid Lead, Bipolar (NCT00810264), a registered phase not stated study. The primary outcome is Percentage of Subjects Who Are Free of Complications Related to the Corox LV Lead.

2. Clinical Question

The registry was intended to document post-approval clinical experience and confirm long-term safety and reliability. Its primary endpoint focuses on a specific category of complication: an event must be serious, related to the lead, and require additional invasive intervention to resolve. That definition is narrower than a count of all serious adverse events and differs from a measure of lead performance such as pacing threshold, sensing, or impedance.

The record identifies the endpoint and its timeframe, but does not report the primary endpoint estimate, the number of subjects in the evaluable population, or the stated confidence interval. The broader safety figures therefore cannot be treated as the answer to the primary question. Without a comparison group, the registry can describe reported experience in the enrolled group, but it cannot establish how that experience compares with an alternative lead or care strategy.

3. Trial Design

CELESTIAL is a post-approval registry of the Corox OTW BP endocardial left ventricular steroid lead. The record describes its purpose as confirming long-term safety and reliability and documenting post-approval clinical experience, as required by the FDA as a condition of approval. Enrollment was 2499. The listed condition is congestive heart failure, and the intervention is CRT therapy with the left ventricular lead.

The registry record identifies a data collection group rather than a randomized treatment allocation. Allocation is not stated, and no like-for-like control group is described. Accordingly, the study should be read as a registry record of clinical experience, not as a randomized comparison of competing treatments. Details of recruitment, eligibility criteria, clinical site procedures, and how follow-up was organized are not reported in the registry record.

The primary endpoint timeframe is 5 years. The listed primary completion date is 2018-11-02, the study start is 2008-12, and the status is COMPLETED. The endpoint population is defined as the sum of subjects who completed the 5-year follow-up and/or experienced a primary endpoint adverse event. The number meeting that definition and the handling of overlap between those categories are not reported in the registry record.

Other listed outcomes include successful biventricular pacing at the 5 Year in-office Visit, serious adverse events excluded from the primary safety endpoint, and lead pacing threshold, sensing, and impedance measurements, including measures by lead model. The record lists 12 outcome measures. The analysis methods for those outcomes, beyond the single analysis indicated in the record, are not reported in the registry record. A detailed protocol, statistical analysis plan, and sample-size justification are not reported in the registry record.

4. Participant Flow and Accounting

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

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The evaluable subject population is the sum of the total unique subjects who completed the 5-year follow-up and/or who experienced a primary endpoint adverse event.

5. Baseline Characteristics

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

Population: Baseline characteristics are provided when available, subjects without available baseline characteristics are not included in the number of participants analyzed in this section.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Subjects Who Are Free of Complications Related to the Corox LV Lead, measured over 5 years.

The primary endpoint is the percentage of subjects free of complications related to the Corox LV lead. The endpoint description narrows this to the overall incidence of serious adverse events that both relate to the Corox BP LV leads implanted with BIOTRONIK CRT-P or CRT-D devices and require additional invasive intervention to resolve. It is evaluated as a serious adverse event-free rate over 5 years.

This endpoint is used to capture serious complications with a clinical consequence requiring an invasive response, rather than treating every reported adverse event as a primary endpoint event. The distinction matters: a serious adverse event may not be lead-related, may not require additional invasive intervention, or may fail both criteria. The listed serious adverse event counts therefore cannot substitute for the primary endpoint result.

The stated endpoint unit is percentage of subjects, and the record identifies a 95% confidence interval as its dispersion measure. However, the primary endpoint estimate, its confidence interval, and the number of subjects in the evaluable population are not reported in the registry record. The endpoint definition is available, but its numerical result and precision cannot be assessed from the registry record.

The definition of the evaluable population includes subjects completing the 5-year follow-up and/or experiencing a primary endpoint adverse event. The record does not report how many subjects qualified through each route or how subjects with both characteristics were counted. Those details would help readers understand the population underlying the endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods help clarify what a registry endpoint can establish and what remains uncertain when key results are absent. In this record, the primary measure is a percentage of subjects who are free of a narrowly defined complication over 5 years. The record specifies a 95% confidence interval as the dispersion measure, but does not report the estimate or interval. The methods concepts below are general explanations; the specific analysis procedures used are not reported in the registry record.

What does the endpoint percentage represent?

In general, a percentage expresses the share of a defined population meeting a stated condition. For this endpoint, the condition is being free of serious adverse events related to the lead that require additional invasive intervention to resolve. The population definition is not simply everyone enrolled: it refers to subjects who completed the 5-year follow-up and/or experienced a primary endpoint adverse event. The size of that evaluable population is not reported. Without its denominator and endpoint estimate, the percentage cannot be independently understood or checked from the posted information.

The endpoint is also a composite definition in the practical sense that an event must satisfy several criteria: it must be serious, related to the lead, and require additional invasive intervention to resolve. A broad adverse-event count does not identify which records met all these conditions. General statistical interpretation depends on clear event definitions and consistent classification; the adjudication approach is not reported in the registry record.

How should a confidence interval be understood?

In general, a confidence interval communicates uncertainty around an estimate. It reflects how compatible the observed data are with a range of underlying values under the assumptions of the analysis. A narrower interval indicates greater statistical precision than a wider interval, but neither width nor location alone resolves possible bias from missing follow-up, measurement, or event classification. Here, the registry identifies a 95% confidence interval but does not report its bounds. The precision of the primary endpoint therefore cannot be evaluated.

A confidence interval is not a guarantee that the true value lies within its bounds, and it does not address every source of uncertainty. It does not by itself establish that the registry population represents other populations, that events were classified without error, or that an observed outcome was caused by the lead. Those questions require design and process information as well as an estimate.

Why does the comparison structure matter?

General comparative inference relies on a clearly defined contrast between groups. The record lists a data collection group, does not state allocation, and does not describe a like-for-like control. The study is not a randomized comparison. It can therefore report clinical experience, but a difference attributable to the device cannot be estimated against an alternative from the registry information. In an uncontrolled registry, patient characteristics, clinical decisions, follow-up practices, and other factors may affect recorded outcomes. Their effects cannot be separated from device-related experience without appropriate comparative data and methods.

A reported event rate in a registry is descriptive of the recorded group under its definitions and follow-up. It is not automatically a causal effect or a benchmark against another device. General methods for causal comparisons require explicit comparison groups and attention to how subjects enter each group and remain under observation. Such details are not reported in the registry record.

What can the serious adverse event counts tell readers?

Counts describe the number of subjects or events recorded under a particular category, depending on the definition. The registry lists 281 serious adverse event-affected subjects, 83 other adverse event-affected subjects, and 641 deaths, with the reported at-risk figures. These categories are not interchangeable with the primary endpoint. In general, a serious adverse event count may include events unrelated to the device or events that did not require additional invasive intervention. The record does not provide a cross-tabulation connecting the broad safety counts to the primary endpoint criteria.

The listed event-term percentages give descriptive information about selected serious-event terms. They should be interpreted according to the record’s definitions, population, and reporting process. The registry does not report the selection rule for the listed terms, whether terms can overlap, or an event adjudication method. Those omissions limit interpretation of the event categories as a complete account of safety.

What is not available about the analysis?

For a full statistical appraisal, readers would need the primary estimate, its confidence interval, the evaluable population size, a transparent account of missing follow-up, and the analysis method. Details such as censoring or time-to-event methods, handling of repeated events, and prespecified sensitivity analyses are not reported in the registry record. These are examples of general considerations, not claims that the registry used any particular method.

The record describes additional measures of biventricular pacing, pacing threshold, sensing, and impedance. It does not report the analysis approach for those outcomes in the information available. Multiple outcomes can create multiplicity concerns in general, especially if many results are tested and selectively emphasized. Whether any multiplicity adjustment or hierarchy was prespecified is not reported in the registry record. Without the methods and full outcome results, readers cannot determine the role of chance or selection in any secondary finding.

The sample-size assumptions describe a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They are planning assumptions, not observed power. The registry itself is not described as a two-arm randomized comparison, and no trial-specific sample-size justification is reported in the registry record. The assumptions should therefore not be mistaken for the registry’s design or for evidence about the precision of its primary result.

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("BIOTRONIK Corox BP LV Lead")
n      <- c(946)
events <- c(891)
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  BIOTRONIK Corox BP LV Lead  946  891  94.2  92.5  95.6  92.5  95.5  92.5  95.5

11. Multiplicity, Missing Data and Analysis Populations

The record lists 12 outcome measures, including the primary safety endpoint and measures of biventricular pacing, adverse events, pacing threshold, sensing, and impedance. In general, examining multiple outcomes can increase the chance of highlighting a result that appears notable by chance, particularly when analyses are selected after reviewing results. Whether the registry specified an outcome hierarchy, adjusted for multiplicity, or prespecified the reported analyses is not reported in the registry record. The record indicates one analysis, but does not provide enough detail to establish the full analysis plan or its relationship to the listed outcomes.

Missing data are especially relevant to a 5-year registry endpoint. The primary population is defined as subjects who completed the 5-year follow-up and/or experienced a primary endpoint adverse event. The number in that population, the number completing follow-up, and the extent or pattern of missing outcome information are not reported in the registry record. The method for handling subjects without complete follow-up is also not reported. In general, incomplete follow-up can affect estimates if those lost differ in outcome risk from those retained.

The record does not report whether event review was blinded, whether events were adjudicated, or how relatedness to the lead and the need for invasive intervention were determined. These details matter because classification determines whether an event meets the primary endpoint definition. The available information does not support an assessment of classification consistency, sensitivity analyses, or the impact of missing data on the primary estimate.

The stated evaluable-population definition includes subjects with a primary endpoint event even if they did not complete follow-up. How overlapping categories were handled and how the endpoint calculation used that population are not reported in the registry record. The primary estimate and confidence interval are also absent, preventing direct evaluation of precision and analysis completeness.

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: lv lead dislodgement (2.4%), icd lead dislodgement (1.4%), ra lead dislodgement (1.2%), implant procedure related infection (0.8%), icd lead impedance out of range, high impedance, potential conductor fracture (0.6%).

The registry lists 281 subjects affected by serious adverse events among 2499 at risk. It separately lists 83 subjects affected by other adverse events among 2499 at risk, and 641 deaths. These are broad safety figures; the record does not explain their relationship to one another or to the primary endpoint. In particular, they should not be added together or treated as mutually exclusive categories.

The primary endpoint has a narrower definition than a broad serious adverse event count. It concerns serious events related to the Corox BP LV lead that require additional invasive intervention to resolve. The broad serious adverse event count does not establish how many events met all of those criteria. The primary endpoint estimate and its 95% confidence interval are not reported in the registry record.

The listed serious-event terms include LV lead dislodgement at 2.4%, ICD lead dislodgement at 1.4%, RA lead dislodgement at 1.2%, implant procedure related infection at 0.8%, ICD lead impedance out of range, high impedance, potential conductor fracture at 0.6%, and secondary infection at 0.6%. The record does not report whether categories overlap or how these terms were selected. These descriptive figures are not, by themselves, evidence that an event was caused by the lead or met the primary endpoint definition.

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

The registry’s objective was to document post-approval clinical experience and assess long-term safety and reliability of the Corox OTW BP left ventricular pacing lead. The recorded enrollment was 2499, and the primary endpoint was defined over 5 years. The posted safety information includes counts of subjects affected by serious and other adverse events, deaths, and selected serious-event terms. These data describe the information recorded in the registry, subject to its definitions and follow-up.

The primary endpoint result itself is not reported in the registry record. Neither its percentage nor its 95% confidence interval is available, and the evaluable population size is not reported. Therefore, readers cannot determine the observed serious adverse event-free rate, quantify its statistical precision, or assess the reported result against a particular threshold. The broad safety counts cannot fill this gap because they do not identify the subset of serious events that were lead-related and required additional invasive intervention.

The registry also does not provide a like-for-like control group. Allocation is not stated, and the record identifies a data collection group. Consequently, the registry information does not estimate a comparative effect against another lead, device strategy, or an untreated counterfactual. A descriptive safety record should not be interpreted as proof of benefit, harm, equivalence, or absence of risk relative to an alternative.

The result also cannot be generalized automatically to people, settings, or devices not represented by the registry. Information about eligibility, participant characteristics, follow-up completeness, event adjudication, and analysis handling is not reported in the registry record. Those details influence how representative and complete a registry estimate may be.

In general, a registry can be useful for collecting long-term clinical experience after approval, particularly for outcomes that may arise during routine use. Its value depends on complete follow-up, clear outcome definitions, reliable classification, and transparent reporting of estimates and uncertainty. For this record, the objective and endpoint definition are stated, but the missing primary result and analysis details limit what can be concluded from the posted information.

14. Why This Trial Matters Statistically

Post-approval registries address a different statistical question from a randomized comparison. They can document clinical experience over time in the setting where a device is used, but their descriptive findings depend on the completeness and quality of follow-up and event recording. CELESTIAL was intended to document post-approval experience with the Corox OTW BP left ventricular lead and assess long-term safety and reliability.

The registry’s primary endpoint is narrowly defined: subjects are counted as free of complications only in relation to serious adverse events attributed to the lead and requiring additional invasive intervention to resolve. This specificity can make an endpoint more clinically focused than a broad adverse-event count, but it also makes transparent classification and reporting essential. Without the primary estimate and confidence interval, readers cannot assess the outcome the registry was designed to describe.

The record also illustrates why denominator definitions matter. The endpoint population includes subjects who completed the 5-year follow-up and/or experienced a primary endpoint adverse event. The size of that population and the treatment of incomplete follow-up are not reported. A clear population definition is a necessary starting point, but it does not by itself show how many participants contributed information or how missing outcomes affected the estimate.

Statistically, the absence of a control group also defines the limits of interpretation. The registry can provide descriptive observations, but it cannot establish a comparative effect from the recorded structure. This distinction is important when interpreting safety data: counts and event-term percentages are not equivalent to a causal comparison or to the primary endpoint.

The registry is therefore informative as a record of the intended post-approval safety question and the broad categories collected, while also showing why complete outcome reporting and analysis details are needed for precision and interpretation. The study objective, endpoint definition, and reported safety counts do not replace the missing primary estimate, confidence interval, and evaluable-population information.

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 main limitation is that the primary endpoint estimate and its 95% confidence interval are not reported in the registry record. The endpoint’s evaluable population is defined, but its size is not reported. This prevents readers from assessing the observed serious adverse event-free rate, its precision, or the population contributing to that result.

No like-for-like control group is described, and allocation is not stated. The registry therefore does not support a randomized comparative interpretation. The information can describe reported experience, but cannot determine whether outcomes differ from those under an alternative device or strategy.

Follow-up completeness and missing-data handling are not reported. This is important for a 5-year endpoint, because incomplete follow-up can affect a descriptive estimate if subjects with missing information have different outcomes. The registry also does not report how the evaluable-population definition was implemented, including how subjects who both completed follow-up and had an event were handled.

Additional limitations concern event definition and classification. The primary endpoint requires seriousness, lead relatedness, and additional invasive intervention, while the broad safety figures do not separate events by those criteria. Methods for adjudication, determining relatedness, and selecting the displayed serious-event terms are not reported. The record also does not explain whether event categories overlap.

Participant characteristics, eligibility details, analysis methods for secondary outcomes, and a detailed statistical analysis plan are not reported in the registry record. These omissions restrict assessment of generalizability, potential selection effects, multiplicity, and the robustness of the findings. The listed sample-size assumptions are planning illustrations and do not supply a trial-specific justification or the missing endpoint precision.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Post Approval Registry of Corox OTW, Endocardial, Left Ventricular Steroid Lead, Bipolar — NCT00810264.
• Registry record last updated 2019-11-29; status last verified 2019-11.
• Results first posted 2019-11-29.
• 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

NCT00810264 is the CELESTIAL Post Approval Registry of the Corox OTW BP left ventricular steroid lead. The record lists congestive heart failure as the condition, enrollment of 2499, a study start of 2008-12, primary completion on 2018-11-02, and status COMPLETED. Its stated purpose was to document post-approval experience and confirm long-term safety and reliability.

The primary endpoint is the percentage of subjects free of serious lead-related adverse events requiring additional invasive intervention to resolve over 5 years. The record describes a data collection group, does not state allocation, and does not report a like-for-like comparator. Although broad adverse event figures and selected event terms are listed, the primary estimate, its 95% confidence interval, and the evaluable population size are not reported in the registry record. These omissions limit assessment of the central endpoint and its statistical precision.