This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Cardioband With Transfemoral Delivery System (NCT01841554), a na na study. The primary outcome is Number of Participants With Major Serious Adverse Events and Serious Adverse Device Effects.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01841554 |
| Phase | NA |
| Condition | Mitral Regurgitation |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 62 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Edwards Lifesciences |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes a study intended to evaluate repair of functional mitral regurgitation. The condition listed is mitral regurgitation. Further eligibility details and a fuller description of the enrolled population are not reported in the registry record.
Intervention
The intervention was the Cardioband Adjustable Annuloplasty System, identified in the record as Cardioband, a device. The stated purpose was to evaluate its performance and safety for repair of functional mitral regurgitation.
Comparator
This was a single-group study, with no comparator group listed. Allocation is recorded as NA, and the study was not a randomized comparison. There is therefore no concurrent control group in the record for a like-for-like comparison.
Primary question
The primary endpoint was the number of participants with major serious adverse events and serious adverse device effects during the stated 30-day timeframe. The description specifies overall assessment until hospital discharge and at post-operative 30 days. The record does not provide a separate comparative estimate of risk.
3. Trial Design
The registry record identifies NCT01841554 as a completed study of the Cardioband Adjustable Annuloplasty System for transcatheter repair of mitral valve regurgitation. The listed condition is mitral regurgitation, and the stated study purpose was to evaluate the device’s performance and safety for repair of functional mitral regurgitation. The intervention is Cardioband, classified as a device.
The design is recorded as single group, with enrollment of 62. There is no comparator group listed, and allocation is recorded as NA. The record indicates that this was not a randomized comparison. Masking is recorded as none. These features matter when interpreting observed outcomes: the reported events describe participants in the treated group, but the design does not provide a concurrent untreated or alternative-treatment group for a direct comparison.
The study began in 2011-09, reached primary completion in 2016-08, and is marked completed. The phase is recorded as NA. Further details about eligibility criteria, recruitment, treatment delivery, follow-up beyond the primary timeframe, or the number of sites are not reported in the registry record.
The primary endpoint concerns participants with major serious adverse events and serious adverse device effects, with a timeframe of 30 days. Its description refers to events until hospital discharge and at post-operative 30 days. Secondary outcomes are listed for the 6MWT, MLHFQ, and mitral regurgitation severity assessments, including an intra-subject comparison and a full analysis data set. Their numerical results and analysis details are not reported in the registry record.
Because this is a single-group study, its results are descriptive evidence about outcomes recorded among enrolled participants. The design does not itself establish what would have happened to comparable participants under another intervention or without the device.
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: Of 62 patients originally enrolled, 1 excluded from full analysis data set (N=61) but included in safety analysis data set (N=62). Patient had severe MR, right heart failure (RHF), and tricuspid regurgitation (TR); determined to be a significant deviation from intended use of device. Study protocol amended to exclude severe RHF and TR.
Overall Study
| Stage | Single |
|---|---|
| STARTED | 61 |
| Implanted | 60 |
| 1 Year Follow Up | 42 |
| COMPLETED | 42 |
| NOT COMPLETED | 19 |
Reasons for not completing this period:
| Reason | Single |
|---|---|
| Death | 7 |
| No Implantation | 1 |
| Discontinued Follow Up | 5 |
| Study exit due to secondary intervention | 6 |
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.
| Characteristic | Unit | Single |
|---|---|---|
| Participants analysed | 61 | |
| Age, Continuous | years | 72 (SD 7.5) |
| Sex: Female, Male: Female | Participants | 17 |
| Sex: Female, Male: Male | Participants | 44 |
| EuroSCORE II | Score | 7.3 (SD 6.3) |
| New York Heart Association (NYHA) Functional Class III or IV | Participants | 52 |
| Ischemic Etiology of Regurgitation | Participants | 37 |
| Left Ventricule Ejection Fraction (LVEF) | Percent Fraction | 33 (SD 11) |
| Previous Coronary Artery Bypass Graft (CABG) | Participants | 18 |
| Renal Insufficiency | Participants | 49 |
| Atrial Fibrillation | Participants | 46 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Major Serious Adverse Events and Serious Adverse Device Effects, measured over 30 days.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with major serious adverse events and serious adverse device effects. The registry gives a 30-day timeframe and describes an overall rate assessment through hospital discharge and at post-operative 30 days. It is a participant-count endpoint: its unit is people who meet the endpoint definition, rather than the total number of event episodes.
In general, serious-event endpoints are used to characterize important safety outcomes during a defined period. Combining major serious adverse events with serious adverse device effects can capture both serious clinical events and events considered device-related, but the record does not explain the operational definitions, adjudication process, or how the combined endpoint was constructed. It also does not separately report counts for the major serious adverse event component and the serious adverse device effect component.
The adverse-event listing records 44 participants in the serious-event affected count and 21 in the other-event affected count, with 62 at risk for each. These are adverse-event figures; the registry record does not give a separate estimate or analysis for the combined primary endpoint. A count alone does not indicate how events were distributed over time, whether participants experienced more than one event, or whether events were judged to be caused by the device.
The endpoint can describe the observed safety experience under the study’s follow-up, but without a comparator it cannot establish a relative safety difference. Further endpoint definitions and details about follow-up completeness are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a completed, single-group device study with enrollment of 62 and a primary safety endpoint covering 30 days. The adverse-event record lists 44 participants affected by serious events and 21 affected by other events; each group has 62 at risk. These are participant counts, not a comparison between treatment strategies. The record does not report a separate estimate for the combined primary endpoint of major serious adverse events and serious adverse device effects.
The serious-event terms listed most often include Cardiac Failure at 24.2%, Mitral Valve Disease at 6.5%, Renal Failure at 6.5%, Pericardial Effusion at 4.8%, Ventricular Tachycardia at 4.8%, and Air Embolism at 4.8%. The registry record does not specify the denominator or event attribution for each term in the listing, or whether a participant could contribute to more than one term. These percentages should therefore be read as registry-listed descriptors, not as mutually exclusive categories or as a basis for adding percentages together.
There is no concurrent control group, and the study was not a randomized comparison. As a result, the observed counts cannot by themselves show how the safety experience compares with another device, another procedure, or no intervention. Differences in participant characteristics, event ascertainment, follow-up, and other factors cannot be separated from treatment effects using this single-group record.
The number of participants affected is not the same as the number of event episodes. A participant may have had multiple events, but the record does not report event totals or the distribution of repeated events. Nor does the record provide a confidence interval or other uncertainty estimate for the primary endpoint. Without those details, precision cannot be quantified from the posted results.
The 30-day timeframe defines the endpoint’s stated observation window; it does not describe longer-term safety. The record does not report how many participants completed follow-up, whether all events were independently adjudicated, or how missing observations were handled. Deaths are not listed as a numerical count in the adverse-event record, so the absence of a death count should not be interpreted as evidence that no deaths occurred.
Overall, the registry supports a descriptive account of the adverse-event figures and listed serious-event terms for this single group. It does not support a causal conclusion about Cardioband’s effects, a comparison of risks, or a conclusion about longer-term outcomes.
9. Statistical Methods Explained
The registry record identifies a participant-count safety endpoint and a single-group design. Several statistical concepts help clarify what such results can and cannot convey; the general explanations below do not add analyses to the registry record.
What does a participant count represent?
A count of participants with an event records whether people met a specified event criterion during the defined follow-up. It is different from a count of event episodes: one participant may experience multiple episodes, while a participant-count endpoint generally counts that person once for the endpoint. The record’s adverse-event summary lists 44 participants affected by serious events and 21 affected by other events. It does not give episode totals, nor does it explain whether the primary endpoint uses the same counting rules as those adverse-event categories.
For a binary outcome, each participant is classified as having or not having the specified outcome within the relevant period. A proportion can be estimated from a participant count and its denominator, but the registry record does not report a separately calculated primary-endpoint estimate or an uncertainty interval. No new proportion is calculated in this interpretation.
What does a confidence interval add?
In general, a confidence interval expresses the statistical uncertainty around an estimate under a stated model and sampling framework. A narrower interval indicates greater precision under those assumptions; a wider interval indicates less precision. It does not resolve design limitations such as the absence of a comparison group, and it does not establish that an observed event was caused by the intervention. The registry record does not report a confidence interval for the primary endpoint, so its precision cannot be assessed from an interval estimate.
Why does the single-group design matter?
A comparative treatment effect requires a contrast between outcomes under different strategies. This study has one listed group and no randomized comparator. Its counts describe outcomes recorded in that group, but they do not estimate a difference between Cardioband and another treatment. In general, comparison with an external population can be difficult to interpret because the groups may differ in their characteristics, observation periods, event definitions, or care. The registry record does not report an external comparison or an adjusted comparative analysis.
Masking is recorded as none. In general, lack of masking can matter when decisions about event classification or reporting involve judgment, although the record does not describe how events were identified, reviewed, or adjudicated. It would therefore be inappropriate to infer either that outcome assessment was biased or that it was protected from bias.
What does the planning convention mean?
The stated sample-size assumptions describe a planning illustration based on a fraction of the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The stated convention specifies participants per arm for non-time-to-event outcomes; time-to-event illustrations use total events. These are planning assumptions, not evidence about how the trial was designed. The actual trial is single-group, and the registry record does not report its sample-size justification or state that these hypothetical planning assumptions governed enrollment.
A planning illustration asks what sample size might be needed under specified assumptions for a future comparison. It is not observed power, and it does not change the uncertainty of this trial’s actual findings. Any such illustration depends on its assumed effect and statistical model; the record does not report the trial’s own design justification or a comparative effect estimate for the primary endpoint.
Why can over-dispersion matter?
In general, over-dispersion means that observed variation in counts is greater than a model expects. It can arise when participants have different underlying event risks or when events cluster. A model that ignores such extra variation can produce uncertainty estimates that are too small. This concept is most relevant to event-count analyses; the primary endpoint is described as a count of participants with events, and the registry record does not report a model-based recurrent-event analysis or an over-dispersion assessment.
Which analyses are documented?
The registry record lists zero analyses. It does not report a hypothesis test, an adjusted model, a confidence interval, or a prespecified statistical analysis plan for the primary endpoint. The outcomes and their descriptions do not, on their own, establish which analysis population was used or how missing measurements were treated. Consequently, interpretation should remain with the recorded design, outcome definitions, and descriptive event counts, without attributing unreported inferential methods to the study.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists eight outcome measures, including the primary safety outcome and secondary performance outcomes involving the 6MWT, MLHFQ, and mitral regurgitation severity. The record does not report a multiplicity strategy, such as a planned adjustment for evaluating multiple outcomes or repeated comparisons. Without such information, the chance of false-positive findings across a collection of tests cannot be assessed. The registry lists zero analyses, so no set of inferential results or testing hierarchy is documented.
Missing-data handling is not reported in the registry record. The record does not state how incomplete follow-up, unavailable measurements, withdrawal, or other missing observations were addressed. It also does not report outcome-specific analysis populations or the number of participants contributing data to each secondary outcome. The primary endpoint description names a 30-day timeframe but does not establish whether every participant had complete event ascertainment through that period.
The primary endpoint population field is blank, and the registry does not identify an intention-to-treat, per-protocol, or other analysis population. It is therefore not possible to determine from this record which participants were included in any particular analysis or how exclusions were handled.
These omissions limit interpretation of both the safety count and secondary outcomes. They do not demonstrate that missing data or multiplicity affected the findings; they mean that the registry record does not provide enough information to assess those issues. No assumptions about the analysis plan or missing-data procedures should be substituted for the absent details.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Single | 44 | 62 | 71.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Single | 21 of 62 |
Most frequent serious adverse event terms
| Event term | Organ system | Single |
|---|---|---|
| Cardiac Failure | Cardiac disorders | 15 of 62 |
| Mitral Valve Disease | Cardiac disorders | 4 of 62 |
| Renal Failure | Renal and urinary disorders | 4 of 62 |
| Pericardial Effusion | Cardiac disorders | 3 of 62 |
| Ventricular Tachycardia | Cardiac disorders | 3 of 62 |
| Air Embolism | Vascular disorders | 3 of 62 |
| Atrial Fibrillation | Cardiac disorders | 2 of 62 |
| Bundle Branch Block Left | Cardiac disorders | 2 of 62 |
| Cardiac Arrest | Cardiac disorders | 2 of 62 |
| Myocardial Infarction | Cardiac disorders | 2 of 62 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Single |
|---|---|---|
| Atrial Fibrillation | Cardiac disorders | 6 of 62 |
| Renal Failure | Renal and urinary disorders | 5 of 62 |
| Device Fastener Issue | General disorders | 4 of 62 |
| Post Procedural Haemorrhage | Injury, poisoning and procedural complications | 4 of 62 |
| Haemoglobin Decreased | Investigations | 4 of 62 |
Serious events with the highest arm-level rate: cardiac failure (24.2%), mitral valve disease (6.5%), renal failure (6.5%), pericardial effusion (4.8%), ventricular tachycardia (4.8%).
The adverse-event record lists 44 participants with serious events and 21 with other events, with 62 at risk in each category. These are participant counts, not counts of individual event episodes, and the two affected counts should not be combined: the record does not state whether the categories overlap or how participants were classified across them.
The listed serious-event terms and percentages are Cardiac Failure, 24.2%; Mitral Valve Disease, 6.5%; Renal Failure, 6.5%; Pericardial Effusion, 4.8%; Ventricular Tachycardia, 4.8%; and Air Embolism, 4.8%. The record does not provide enough detail to determine whether these categories are mutually exclusive, how the percentages were calculated, or whether every event was considered related to the device. They should not be read as device-caused event rates.
The primary endpoint refers to major serious adverse events and serious adverse device effects through hospital discharge and at post-operative 30 days. Separate counts for these components are not reported in the registry record. A death count is also not reported; this is not evidence that no deaths occurred. The figures describe recorded safety events in a single group and do not provide a comparative estimate.
12. What the Result Does, and Does Not, Mean
The results describe a single group enrolled in a study of Cardioband for functional mitral regurgitation. The registry records 62 enrolled and reports adverse-event affected counts of 44 for serious events and 21 for other events. It also lists selected serious-event terms and their percentages. These details provide a descriptive account of events recorded in the study, not a controlled estimate of the effect of treatment.
The primary safety question concerns major serious adverse events and serious adverse device effects within the 30-day timeframe. Although the record defines this endpoint in words, it does not provide a separate numerical result for the combined endpoint or separate counts for its components. It also does not report an uncertainty interval. The precision of the primary endpoint estimate therefore cannot be evaluated from the registry record.
The study has no comparator and was not randomized. The reported counts cannot show whether the event experience was higher or lower than it would have been under another treatment or without the device. They also cannot establish that Cardioband caused any listed event. Attribution, event definitions, and adjudication procedures are not reported in sufficient detail to make such judgments from the registry record.
The secondary outcomes indicate that performance was assessed using the 6MWT, MLHFQ, and mitral regurgitation severity measures. Numerical secondary results and their analyses are not reported in the registry record, so no conclusion about changes in those measures can be drawn from the listed outcome names alone.
Finally, the primary endpoint has a defined short-term observation window, and the record does not provide longer-term safety results. Details about follow-up completeness, missing data, analysis populations, and the statistical analysis plan are also not reported. The appropriate interpretation is therefore limited to the registry’s descriptive record and should not be extended to comparative effectiveness, causality, or outcomes beyond the stated timeframe.
13. Why This Trial Matters Statistically
This trial is statistically informative in part because it makes clear the distinction between describing outcomes and estimating a treatment effect. A single-group record can document the observed safety experience among enrolled participants, but it cannot by itself supply the counterfactual comparison needed to determine how outcomes would differ under another strategy. That distinction is central when interpreting any device study without a concurrent comparator.
The primary endpoint is framed as a participant count within a defined 30-day period. That framing highlights a useful measurement choice: counting affected participants gives a different account from counting all event episodes. The registry’s adverse-event counts are participant counts, while the number and pattern of repeated episodes are not reported. Readers should not treat those two kinds of information as interchangeable.
The record also shows why outcome definitions and analysis details matter. The endpoint names major serious adverse events and serious adverse device effects, but separate component results, adjudication details, and a statistical analysis are not reported. Without those details, even a clearly stated endpoint title cannot answer every question about how events were classified or how precisely the result was estimated.
Finally, the study’s listed secondary outcomes span performance measures and assessments of mitral regurgitation severity, but their numerical results are not reported in the registry record. The presence of outcome names is not a substitute for results. Taken together, these features make the study a useful example of how design, endpoint construction, uncertainty, and completeness of reporting shape the conclusions that can reasonably be drawn from a clinical trial record.
14. 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 single-group design is the main trial-specific limitation for comparative interpretation. Allocation is recorded as NA, and no control arm is listed. The study was not a randomized comparison, so observed event counts cannot establish a relative difference between Cardioband and another treatment or no intervention. Masking is recorded as none; how outcomes were assessed and adjudicated is not reported in the registry record.
The primary endpoint is described as the number of participants with major serious adverse events and serious adverse device effects, but a separate numerical result for that combined endpoint is not reported. Nor are the component counts reported separately. The adverse-event summary contains affected counts for serious and other events, but the record does not explain whether these categories overlap with the primary endpoint or with each other.
Further limitations arise from incomplete statistical and follow-up details. The registry lists zero analyses and does not report confidence intervals, a statistical analysis plan, missing-data procedures, outcome-specific populations, or the completeness of follow-up. The stated 30-day timeframe does not provide information about later safety. Although secondary outcomes are listed, their numerical results are not reported in the registry record.
Eligibility criteria and fuller descriptions of the enrolled population are also not reported. These omissions limit assessment of how broadly the findings might apply. They do not prove that a particular bias occurred, but they prevent readers from evaluating several important sources of uncertainty using the registry record alone.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Cardioband With Transfemoral Delivery System — NCT01841554.
- Registry record last updated 2020-11-30; status last verified 2020-11.
- Results first posted 2020-03-11.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT01841554 is a completed, single-group study of the Cardioband Adjustable Annuloplasty System for transcatheter repair of mitral valve regurgitation. The registry lists mitral regurgitation as the condition, enrollment of 62, and a device intervention. The study began in 2011-09 and reached primary completion in 2016-08. Allocation is recorded as NA, masking as none, and phase as NA.
The primary outcome is the number of participants with major serious adverse events and serious adverse device effects, with a 30-day timeframe and a description covering hospital discharge and post-operative 30 days. The adverse-event record lists 44 participants affected by serious events and 21 by other events, with 62 at risk in each category. A separate numerical result for the combined primary endpoint is not reported.
Secondary outcomes include 6MWT, MLHFQ, and mitral regurgitation severity assessments. Their numerical results, the analysis plan, missing-data handling, and outcome-specific analysis populations are not reported in the registry record. The absence of a comparator limits the findings to descriptive interpretation.