Sentus QP - Extended CRT Evaluation With Quadripolar Left Ventricular Leads: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Sentus QP - Extended CRT Evaluation With Quadripolar Left Ventricular Leads (NCT02290028), a na na study. The primary outcome is Sentus QP Related Complication-free Rate Through 6 Months.

2. Clinical Question

The study concerns participants with heart failure who were implanted with a BIOTRONIK Sentus QP left ventricular lead. The primary question is whether participants in the defined pre-market cohort remained free of a Sentus QP-related complication through 6 months after implantation. The endpoint is expressed as a percentage of participants without a complication, with a 95% confidence interval specified as the measure of uncertainty.

This is a device-safety and performance question framed around a defined follow-up period, not a comparison of treatment effects between randomized groups. The record also lists secondary measures concerning pacing thresholds, sensed amplitude, impedance, complications, adverse events, and reprogramming. Their presence indicates additional areas of evaluation, but it does not establish what results were observed for them. The interpretation must remain limited to what the registry record reports.

3. Trial Design

NCT02290028 is an interventional device study titled “Sentus QP - Extended CRT Evaluation With Quadripolar Left Ventricular Leads.” The listed condition is heart failure, and the intervention is the Sentus QP left ventricular lead. The study uses a single-group model, with no randomized allocation and no masking. Participants in the described arm consented and were implanted with the lead. The record lists enrollment as 2226.

The study started on 2014-12-16, and the primary completion date is 2020-01-23. Its current registry status is terminated. The reason for termination is not reported in the registry record, so the status alone does not explain whether follow-up ended early, whether a planned transition occurred, or whether another circumstance led to termination.

The brief summary states that the study was designed to confirm safety and efficacy of the BIOTRONIK Sentus OTW QP left ventricular leads for regulatory approval in the United States. It also says the leads received FDA approval on May 4, 2017, and describes a continuing post-approval phase for long-term safety at US sites. The summary reports that a protocol update was implemented on September 6, 2019, transitioning long-term follow-up to a new EP PASSION real-world data methodology.

The record lists phase as NA. It does not report a randomized control group, allocation details, a blinding plan beyond masking listed as none, or a statistical analysis plan. The primary endpoint population is more specific than the full enrolled group: it comprises participants consented and implanted on or before January 29, 2016. The size and disposition of that cohort are not reported in the registry record. Therefore, the overall enrollment should not be assumed to be the primary endpoint denominator.

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: All participants in the Pre-Market cohort, defined as the study participants who were consented and implanted with a Sentus QP LV lead on or before January 29, 2016.

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: All participants consented with baseline data collection completed

6. Primary Endpoint

The registry lists the primary outcome as Sentus QP Related Complication-free Rate Through 6 Months, measured over 6 months.

The primary endpoint is the Sentus QP-related complication-free rate through 6 months. It is defined as the percentage of participants in the pre-market cohort who had no related complication during that period. The specified population consists of participants consented and implanted with a Sentus QP left ventricular lead on or before January 29, 2016. The registry identifies a 95% confidence interval as the accompanying measure of precision.

A complication-free endpoint provides a way to describe the frequency of participants without a specified device-related event over a defined follow-up period. It is a participant-level summary, rather than a count of every event: a participant’s status depends on whether a qualifying complication occurred. The attribution requirement also matters. The endpoint concerns complications related to Sentus QP, not necessarily every health event occurring after implantation.

The confidence interval is intended to communicate uncertainty around the estimated percentage. In general, it gives a range of values compatible with the observed data and the method used to calculate it; it does not guarantee that the true rate lies within that range. The registry record does not report the observed complication-free percentage, the confidence interval limits, the number of participants analyzed, or the detailed event-adjudication rules. As a result, the endpoint’s definition can be described, but its observed value and precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical interpretation depends first on distinguishing the endpoint definition from an endpoint result. The primary measure is a percentage of participants without a Sentus QP-related complication through 6 months. The record names the measure and its 95% confidence interval, but does not give the observed percentage or interval limits. Without those values, neither the estimated event-free experience nor its precision can be evaluated.

What does a confidence interval communicate?

In general, a confidence interval describes uncertainty around an estimate under a specified statistical method. A narrower interval indicates greater precision under that method, while a wider interval indicates less precision. The interval does not show the range of outcomes for individual participants and is not a guarantee about the true value. For this study, the 95% confidence interval is named, but the method used to calculate it and the resulting limits are not reported in the registry record.

Why does the analysis population matter?

The primary endpoint applies to a defined pre-market cohort: participants consented and implanted on or before January 29, 2016. This is not necessarily the same population as everyone enrolled. The overall enrollment is 2226, but the number of participants eligible for the primary endpoint, the number followed through the endpoint period, and the number included in the analysis are not reported in the registry record. Those counts matter because the estimate’s denominator determines whose experience it represents. If follow-up is incomplete, the way incomplete observations are handled can also affect the interpretation.

What can a single-group design estimate?

In general, a single-group study can describe observed outcomes in the participants who received the intervention. Without a concurrent comparison group, it cannot directly estimate how outcomes would have differed under another intervention. Randomization is one method for balancing both measured and unmeasured characteristics between groups; this registry describes no randomized comparison. The design therefore does not support a randomized treatment-effect contrast. The absence of masking may also be relevant to outcome assessment, particularly when deciding whether an event is related to the device, but the record does not describe the adjudication process.

How should event attribution be understood?

The primary endpoint is limited to complications judged related to Sentus QP. General clinical events and device-related complications are not interchangeable categories. Attribution involves deciding whether an event is associated with the device or procedure, and the decision rules can influence which events enter the endpoint. The registry record does not report the detailed criteria, review process, or adjudication arrangements used for this endpoint. The listed adverse-event terms should therefore be read as registry-reported descriptions, not as a complete account of how primary-endpoint events were classified.

Why are descriptive safety counts not comparative estimates?

In general, a count of participants with events can summarize what was recorded in a group, but a count alone does not measure comparative risk. Interpretation also depends on the denominator, follow-up duration, definitions, handling of recurrent events, and the presence of a suitable comparison. Here, the adverse-event record lists an at-risk count of 2226 for both serious and other event categories, affected counts of 290 and 711 respectively, and 217 deaths. These are descriptive entries. They do not establish causation, and the registry record does not describe whether a participant could be represented in more than one event category or how repeated events were counted.

The event-term percentages should likewise be treated as reported descriptors. The record lists LV lead related lead dislodgement at 2.7%, RA lead related lead dislodgement at 1.4%, Implant procedure related infection at 1.0%, RV lead related lead dislodgement at 1.0%, Hematoma at 0.8%, and Pneumothorax at 0.7%. The denominators and calculation details for those term-specific percentages are not reported in the registry record. They should not be used to infer a comparative effect or a participant-level primary endpoint result.

What can be said about statistical planning?

The registry record does not report a sample-size justification for the primary endpoint, a power calculation tied to a prespecified target, or the assumptions used to plan enrollment. It also does not report a statistical analysis plan, the confidence-interval calculation method, or interim analyses. General sample-size illustrations based on an observed effect are planning exercises, not evidence that a trial had a particular observed power. In the absence of the trial’s own documented planning rationale and the primary result, such illustrations cannot fill the reporting gaps.

Finally, the study summary describes a protocol update on September 6, 2019, changing the long-term follow-up approach to a new EP PASSION real-world data methodology. That detail is relevant to the follow-up context, but the statistical consequences of the transition, including how pre-transition and later data were handled, are not reported in the registry record. The registry status is terminated, but the reason and implications for analysis are not reported. These limitations leave the primary endpoint’s numerical result and its statistical precision unresolved.

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("Sentus QP Left Ventricular Lead")
n      <- c(279)
events <- c(271)
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  Sentus QP Left Ventricular Lead  279  271  97.1  94.4  98.8  94.4  98.5  94.4  98.5

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures and 3 analyses. The secondary outcomes cover pacing thresholds, R-wave sensed amplitude, pacing impedance, time to complication, complication-free rates by lead model, adverse-event rates, and successful reprogramming to address phrenic nerve stimulation or high pacing threshold. The record does not report how these outcomes were prioritized for statistical testing or whether adjustments were made for multiple comparisons.

In general, evaluating many outcomes can increase the chance that at least one result appears unusual by chance. Multiplicity procedures are sometimes used to control that risk, or outcomes may be designated as descriptive or exploratory. The registry record does not report which approach was used. The number of listed outcomes alone does not establish that all were tested as confirmatory hypotheses.

Missing-data methods are also not reported in the registry record. It does not describe how participants with incomplete follow-up, unknown complication status, or unavailable measurements were handled. The primary cohort is defined by consent and implantation on or before January 29, 2016, but the cohort size, analyzed denominator, follow-up completeness, and reasons for missing observations are not reported. These details are important when interpreting a percentage, because the estimate depends on which participants have evaluable data and on the assumptions used for missing outcomes.

The record does not report whether analyses followed a prespecified protocol, whether any interim analyses were conducted, or how the 2019 transition to a new long-term follow-up methodology affected analysis populations. It also does not report sensitivity analyses examining alternative assumptions about incomplete data. These omissions prevent assessment of how robust the endpoint estimate would be to missingness or analytical choices; in this case, the endpoint estimate itself is not reported.

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 related lead dislodgement (2.7%), ra lead related lead dislodgement (1.4%), implant procedure related infection (1.0%), rv lead related lead dislodgement (1.0%), hematoma (0.8%).

The registry lists the Sentus QP Left Ventricular Lead group with 2226 at risk in the serious-event category and 2226 at risk in the other-event category. The serious-event affected field is 290, the other-event affected field is 711, and deaths are listed as 217. These entries are descriptive counts, not a comparison with another group. They should not be interpreted as proof that the device caused the events.

The record also lists selected event terms with percentages: LV lead related lead dislodgement, 2.7%; RA lead related lead dislodgement, 1.4%; Implant procedure related infection, 1.0%; RV lead related lead dislodgement, 1.0%; Hematoma, 0.8%; and Pneumothorax, 0.7%. The registry record does not report the denominator or calculation details for each term-specific percentage, or whether the entries count participants, events, or both. The listed terms therefore provide a descriptive safety profile, not a complete event analysis.

In general, serious-event summaries depend on definitions, follow-up, attribution, and rules for counting repeated events. The registry record does not report these details, nor does it clarify the relationship between the serious-event, other-event, and death entries. The counts should be read as recorded safety information rather than as estimates of comparative risk or as a substitute for the unreported primary endpoint result.

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

The registry record establishes the study’s purpose and primary endpoint definition: evaluating the Sentus QP-related complication-free rate through 6 months in a defined pre-market cohort. It also documents a single-group device study, its overall enrollment, selected adverse-event counts, and a transition in long-term follow-up methodology. These details describe the scope and context of the evaluation.

They do not establish the observed primary complication-free rate. The registry names a 95% confidence interval but does not report its limits, the endpoint estimate, or the analyzed cohort size. Consequently, the magnitude and precision of the primary result cannot be described. The record also does not report enough information to assess missing follow-up, event adjudication, or the statistical approach used for the endpoint.

Because there is no randomized comparator, the study cannot provide a randomized comparison of outcomes between the Sentus QP lead and an alternative. Outcomes in a single implanted group may describe what was observed among participants, but they do not isolate the effect of the device from other influences. The safety counts and term-specific percentages are descriptive and do not establish causation or comparative safety.

The brief summary reports FDA approval on May 4, 2017, and a later transition of long-term follow-up to an EP PASSION real-world data methodology. Those statements supply regulatory and follow-up context; they do not replace the missing endpoint estimate or establish how the statistical analyses were conducted. The terminated status also does not, by itself, indicate why the study ended or what conclusions were reached.

In general, a well-defined endpoint and transparent reporting of its estimate, uncertainty, analysis population, and missing-data handling are needed to assess what the data support. The registry record describes the endpoint but leaves these result-level details unreported. Therefore, the most defensible interpretation is a description of the study design and recorded safety entries, without a numerical conclusion about the primary endpoint.

14. Why This Trial Matters Statistically

This study illustrates why a clearly stated endpoint is not the same as a reported result. The primary measure is defined in terms of participants without a Sentus QP-related complication through 6 months, and a 95% confidence interval is specified. Yet the estimate, its interval limits, and the analyzed denominator are not reported in the registry record. Without them, readers cannot assess either the observed rate or its precision.

It also illustrates the importance of the analysis population. The overall enrollment is 2226, while the primary endpoint applies to a cohort defined by implantation on or before January 29, 2016. If those populations are conflated, readers may assume a denominator that the primary endpoint does not necessarily use. Clear reporting of the cohort size and participant flow would help show how the endpoint population relates to enrollment and follow-up.

The single-group design highlights the difference between describing outcomes and comparing outcomes. A device study may collect useful safety and performance information without a randomized control group, but the resulting description cannot be interpreted as a randomized estimate of benefit or comparative risk. That distinction is especially important when registry summaries include event counts and percentages alongside a complication-free endpoint.

Finally, the record describes a transition in long-term follow-up methodology. Such changes make transparent reporting of analysis populations, endpoint definitions, and data handling particularly important. The registry record does not report how the transition affected statistical analysis. The case therefore underscores how design details, endpoint reporting, and analysis documentation jointly determine what readers can conclude from clinical-trial data.

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 for statistical interpretation is the absence of the primary endpoint estimate, its 95% confidence interval, and the number of participants included in that analysis. The pre-market cohort is defined by an implantation cutoff, but its size and completeness of follow-up are not reported in the registry record. Overall enrollment cannot fill that gap because it is not necessarily the primary endpoint denominator.

The single-group model and lack of random allocation mean there is no randomized comparator for estimating relative outcomes. Masking is listed as none. The registry record does not report the process for determining whether complications were related to the lead, the criteria for event adjudication, or the statistical methods used to calculate the primary endpoint and confidence interval.

Several further analysis details are not reported in the registry record: the sample-size justification, statistical analysis plan, interim analyses, multiplicity approach, missing-data handling, and sensitivity analyses. Although the record lists 11 outcome measures and 3 analyses, it does not explain how confirmatory and descriptive outcomes were distinguished or how multiple testing was addressed.

The safety entries also have limits. The record lists event counts and selected term-specific percentages, but does not give calculation details for those percentages or explain how repeated events and overlapping categories were handled. The reason for termination is not reported. The summary describes a transition to a new long-term follow-up methodology, but the statistical implications of that transition are not reported in the registry record. These gaps restrict interpretation to the study description and the safety entries that are explicitly listed.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Sentus QP - Extended CRT Evaluation With Quadripolar Left Ventricular Leads — NCT02290028.
• Registry record last updated 2021-03-24; status last verified 2020-01.
• Results first posted 2021-03-24.
• 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

NCT02290028 is a single-group, unmasked interventional device study of the Sentus QP left ventricular lead in participants with heart failure. The record lists enrollment of 2226, status as terminated, and phase as NA. The primary endpoint is the related complication-free rate through 6 months in participants consented and implanted on or before January 29, 2016.

The registry record specifies a 95% confidence interval for the primary endpoint but does not report the endpoint estimate, interval limits, or analyzed cohort size. It lists 11 outcome measures and 3 analyses, as well as descriptive adverse-event counts and selected event-term percentages. A randomized comparator is not reported. The brief summary describes FDA approval on May 4, 2017, and a September 6, 2019 protocol update transitioning long-term follow-up to a new EP PASSION real-world data methodology.