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 Safety and Performance Study of the Harpoon Mitral Valve Repair System (NCT03285724), a na na study. The primary outcome is Number of Subjects With Procedural Success During the First 30 Days.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03285724 |
| Phase | NA |
| Condition | Mitral Valve Regurgitation, Mitral Valve Prolapse, Mitral Valve Insufficiency |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Edwards Lifesciences |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients with degenerative mitral regurgitation. The listed conditions include mitral valve regurgitation, mitral valve prolapse, and mitral valve insufficiency. The arm description identifies the study as an early feasibility evaluation in patients, while the primary outcome population field contains the phrase Subject was not implanted with study Device. That wording does not clearly describe the intended patient population and should be read as a registry-record inconsistency rather than a complete eligibility description.
Intervention
The intervention is Harpoon Artificial ePTFE Chords, delivered using the Harpoon Medical Transapical device TSD-5. The stated procedural aim is to implant one or more artificial cords on the anterior leaflet, posterior leaflet, or both leaflets of the mitral valve through a small left thoracotomy on the beating heart.
Comparator
There is no control group. The registry describes a prospective, single-arm, nonrandomized study, so the recorded experience is not a randomized comparison with another procedure or with usual care. A treatment contrast between groups is therefore not the study question addressed by this design.
Primary question
The primary question is whether the device performs as designed in the procedural setting and whether the recorded criteria for success are met during the procedure and through 30 days. Success is defined in terms of implanting at least one artificial cord and reducing mitral regurgitation from severe to no more than moderate at the conclusion of the procedure and at 30 days. The registry record does not report the primary endpoint result, so it does not establish whether those criteria were met.
3. Trial Design
The registry describes a prospective, single-arm, nonrandomized, early feasibility study of the Harpoon Medical Device. It lists no masking and no randomized allocation. The phase field is recorded as NA. The sponsor is Edwards Lifesciences, and the listed intervention is Harpoon Artificial ePTFE Chords using the Harpoon Medical Transapical device TSD-5.
The registry lists an enrollment of 1. The study start date is 2017-05-16, and the primary completion date is 2017-06-16. Its status is TERMINATED. The registry record does not report why the study was terminated, so no reason for that status can be inferred from these details.
A single-arm design can describe what occurred among participants receiving the study device, but it does not directly estimate a difference from a concurrent control group. The record also does not describe a randomized allocation process or a masking procedure. The stated primary objective is to evaluate safety and performance, with procedural success defined by device implantation and a specified reduction in mitral regurgitation during the procedure and at 30 days.
The registry lists two secondary outcome topics: mitral regurgitation severity over time and freedom from serious adverse events over time. It records 4 outcome measures in total, but the registry record does not list any analyses. The primary endpoint result is not reported in the registry record. As a result, the design and intended measurement can be described, but the available record does not support a conclusion about the primary endpoint outcome.
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
| Stage | Harpoon Medical Device |
|---|---|
| STARTED | 1 |
| COMPLETED | 1 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Subject was not implanted with study Device
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 | Harpoon Medical Device |
|---|---|---|
| Participants analysed | 1 | |
| Age, Customized: Age | years | 70 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 0 |
| Race and Ethnicity Not Collected | Participants | — |
6. Primary Endpoint
The registry lists the primary outcome as Number of Subjects With Procedural Success During the First 30 Days, measured over Procedure, discharge, and 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 procedural success during the first 30 days. Its timeframe is the procedure, discharge, and 30 days. The description defines success through both a technical and a clinical measurement: implantation of one or more ePTFE artificial cords on the anterior leaflet, posterior leaflet, or both, and reduction of mitral regurgitation from severe to less than or equal to moderate at the end of the procedure and at 30 days.
A combined endpoint of this kind is intended to capture whether the device can be placed as intended and whether the specified valve-regurgitation threshold is reached during the stated follow-up period. The endpoint therefore addresses procedural performance as well as the measured degree of regurgitation. The registry record does not report the observed endpoint count or an analysis of the result.
The primary outcome population field says Subject was not implanted with study Device. That wording does not align clearly with the endpoint description, which defines success partly through device implantation. The registry record does not clarify this inconsistency. It is therefore not possible to determine from the record how that population phrase was applied when assessing the endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes an early feasibility study with a single arm and an enrollment of 1. It does not report the number of participants who met the primary definition of procedural success. The endpoint description is available, but the result needed to determine whether the defined criteria were met is not reported in the registry record. The recorded enrollment should not be treated as the primary endpoint result.
The safety record lists 1 participant at risk for serious adverse events and 1 with a serious adverse event recorded as related. It also lists 1 participant at risk for other adverse events and 0 with other adverse events recorded as related. The death count is 0. The leading serious-event term is Implantation cord failure, mitral ring damage, with 100.0% listed. These entries describe the registry's reported safety counts; they do not provide a complete account of event timing, severity detail, or clinical course.
Because the record describes a single arm without a control group, it cannot estimate a comparative effect against another procedure or care strategy. There is no random allocation that could support a randomized between-group interpretation. The posted data therefore concern the limited experience recorded for this study, rather than a comparison of treatment outcomes.
The enrollment is too limited to characterize how frequently procedural success or adverse events might occur in a broader patient population. More generally, small samples yield imprecise estimates, and a single observed participant cannot characterize the range of possible outcomes. No confidence interval or inferential analysis is reported in the registry record. The absence of a reported endpoint result also means that no conclusion about the primary measure can be drawn from the stated endpoint definition alone.
The status is TERMINATED, but the reason is not reported in the registry record. Termination does not by itself explain whether the study ended for operational, safety, recruitment, or other reasons. Likewise, the registry record does not report whether any planned follow-up was completed beyond the primary completion date. Interpretation should stay within the recorded enrollment, endpoint definitions, safety counts, and omissions.
9. Statistical Methods Explained
What kind of outcome is the primary endpoint?
The primary endpoint is a count of participants meeting a binary definition: each participant either meets the stated procedural-success criteria or does not. The registry labels the measure as a count of participants and gives the timeframe as the procedure, discharge, and 30 days. The criteria combine a device-implantation requirement with a specified reduction in mitral regurgitation. Combining multiple conditions can make an endpoint clinically focused on the whole intended performance target, but it also means the endpoint result depends on how each condition is defined and assessed.
The registry record does not report the observed count for this endpoint, nor does it list an analysis of that count. The endpoint definition alone is not an outcome. In particular, enrollment does not reveal whether the participant met the success definition. The population wording in the outcome record, Subject was not implanted with study Device, also appears difficult to reconcile with a success definition that includes implantation. The registry record does not explain how that wording was used.
What can a single-arm design estimate?
In general, a single-arm study can describe outcomes among participants who receive the intervention. Without a concurrent comparison group, it does not directly estimate how outcomes would differ under another treatment or under no intervention. Nonrandomized allocation also means there is no randomized treatment assignment to support a causal comparison. These points matter even when the endpoint is recorded clearly: a descriptive account of one group and an estimate of comparative treatment effect answer different questions.
Here, the registry identifies a prospective, single-arm, nonrandomized early feasibility study, with no masking and an enrollment of 1. The record does not report an inferential analysis, confidence interval, or statistical analysis plan. A confidence interval is, in general, a way to express uncertainty around an estimate under specified assumptions. It does not remove limitations caused by a very small sample or by the absence of a comparator. No interval estimate is reported for this study in the registry record.
How should the sample-size illustrations be understood?
The sample-size assumptions describe planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They describe detecting a stated fraction of the observed effect. These are planning assumptions, not observed trial findings and not observed power. The registry describes this study as single-arm, so the equal-allocation, two-arm assumptions do not describe its enrolled design. Any such illustration should be understood as a hypothetical planning scenario rather than a feature of the actual study design.
For binary outcomes, sample-size planning generally depends on the event rates being compared, the effect targeted for detection, the significance level, the desired power, and the allocation between groups. In general, a smaller effect is harder to distinguish from random variation and requires more information. The registry record does not report the underlying observed primary endpoint result or the numerical sample-size outputs. The record also does not report a protocol-based sample-size justification. The planning illustrations therefore do not establish what enrollment the investigators originally intended or what assumptions informed the study's design.
Why does over-dispersion matter in general?
For count outcomes, over-dispersion means that observed variability is greater than a model assumes. If a count model underestimates variability, its uncertainty estimates can be too narrow and its statistical tests can be misleading. This is a general consideration for count-data methods, not a description of an analysis reported for this study. The primary endpoint is expressed as a participant count, but the registry record does not report a count model or any analysis that would permit an assessment of over-dispersion.
What is missing from the analysis record?
The registry lists 4 outcome measures and 0 analyses. It names secondary topics concerning mitral regurgitation severity over time and freedom from serious adverse events over time, but the registry record does not report results for those measures. It also does not report the statistical methods used to analyze the primary endpoint, any adjustment for multiple testing, or the handling of missing observations. No interim analysis plan is reported in the registry record. These absences limit the ability to assess how outcomes were intended to be summarized or how uncertainty was handled.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 4 outcome measures, including the primary procedural-success measure and secondary topics covering mitral regurgitation severity over time and freedom from serious adverse events over time. It lists 0 analyses. The registry record does not report a multiplicity strategy, such as a method for controlling the chance of false-positive findings when several outcomes are assessed. In general, assessing multiple outcomes can increase the chance that at least one result appears noteworthy by chance; an analysis plan can specify how to interpret that issue. No such plan is reported.
The registry record does not report how missing outcome data were handled, whether any participants were excluded from particular analyses, or which analysis populations were used. The record lists an enrollment of 1, but enrollment alone does not establish whether every scheduled assessment was available or how an analysis would treat unavailable measurements. The primary outcome population wording, Subject was not implanted with study Device, is not clearly reconciled with the endpoint definition. The registry record does not clarify the intended population or the treatment of this wording.
No interim analysis plan or statistical analysis plan is reported in the registry record. These omissions do not establish that no procedures were used; they mean those procedures cannot be described from the registry entry. The primary endpoint result and secondary outcome results are also not reported, so the available information does not support an assessment of multiplicity-adjusted findings or missing-data sensitivity.
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 |
|---|---|---|---|
| Harpoon Medical Device | 1 | 1 | 100.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Harpoon Medical Device | 0 of 1 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Harpoon Medical Device | 0 of 1 |
Most frequent serious adverse event terms
| Event term | Organ system | Harpoon Medical Device |
|---|---|---|
| Implantation cord failure, mitral ring damage | Cardiac disorders | 1 of 1 |
Serious events with the highest arm-level rate: implantation cord failure, mitral ring damage (100.0%).
The registry safety record lists 1 participant at risk for serious adverse events and 1 with a serious adverse event recorded as related to the device. For other adverse events, it lists 1 participant at risk and 0 with events recorded as related. The death count is 0. The leading serious-event term is Implantation cord failure, mitral ring damage, and the registry lists 100.0% for that term.
The 100.0% entry should be read as the percentage recorded for the listed serious-event term, not as an estimate of risk in a broader population. The registry record does not report the denominator or calculation details for that percentage. It also does not provide further event-level information such as timing, duration, management, or outcome. The summary counts are therefore a limited description of reported safety entries, not a complete account of the participant's clinical course.
With an enrollment of 1, these figures are descriptive of the recorded study experience and do not precisely characterize event frequency beyond it. They should not be interpreted as a comparative safety estimate because the study has no control group.
12. What the Result Does, and Does Not, Mean
The record establishes the study's intended question and some details of the enrolled study. It describes an early feasibility evaluation of a device intended to implant artificial cords and reduce mitral regurgitation to no more than moderate by the end of the procedure and at 30 days. It also records an enrollment of 1, a TERMINATED status, and limited safety counts.
The record does not report the primary endpoint result. It therefore does not show whether the participant met the procedural-success definition. The safety entries record 1 serious adverse event as related, 0 other adverse events as related, and 0 deaths, but the record does not provide enough event-level context to characterize the full safety experience. The event counts should not be extended beyond the study's recorded experience.
The study is not a randomized comparison and has no control group. Its record cannot show how outcomes compare with another procedure or with usual care. Nor can the limited enrollment establish how frequently success or adverse events would occur in a larger group. Statistical precision is inherently limited when the experience is restricted to 1 participant; no confidence interval or inferential analysis is reported.
The status TERMINATED does not explain why the study ended, because a reason is not reported in the registry record. It also does not establish that a particular outcome occurred. The endpoint's population wording is unclear, and the record does not resolve the inconsistency between that wording and the implantation component of the success definition.
Overall, the registry entry documents a proposed performance and safety evaluation and a small amount of recorded safety information. It does not provide the primary result or analyses needed to draw a conclusion about the endpoint.
13. Why This Trial Matters Statistically
Early feasibility studies ask whether a device can be evaluated in its intended procedural setting and whether the proposed measurements can be recorded. Statistical interpretation must separate that descriptive purpose from evidence of comparative benefit or risk. This registry describes a prospective, single-arm, nonrandomized study, so its design does not estimate a randomized contrast with another procedure.
The enrollment of 1 is especially important when reading the endpoint and safety entries. A result from such limited experience cannot characterize the distribution of outcomes across a broader population with useful precision. General statistical reasoning also cautions that a small sample can produce highly uncertain estimates, even when a count or percentage appears simple to read. No confidence interval or analysis is reported in the registry record.
It also matters that the primary endpoint result is not reported. An endpoint definition explains what investigators intended to measure; it does not establish the observed outcome. The mismatch between the population wording and the implantation-based success criteria further complicates interpretation. The registry record does not explain how that wording was applied.
Finally, the record's sample-size assumptions describe two-arm planning illustrations, while the study itself is listed as single-arm. Recognizing that distinction prevents a planning scenario from being mistaken for the actual design or for evidence of study power. These statistical features determine how narrowly the recorded experience can be interpreted.
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.
Several limitations are specific to this record. First, the listed enrollment is 1, which provides little information about the range or frequency of outcomes in a wider population. Second, the study is single-arm and nonrandomized, with no control group. Its recorded outcomes therefore do not provide a direct comparison with another procedure.
The registry status is TERMINATED, but the reason is not reported in the registry record. The primary endpoint result is also not reported, despite a detailed endpoint definition. Although safety counts are listed, the record does not provide event timing, duration, clinical course, or further detail about the 100.0% serious-event term.
The outcome population field says Subject was not implanted with study Device, while the primary endpoint definition includes successful implantation. The registry record does not reconcile these descriptions. It also lists 4 outcome measures and 0 analyses, without reporting a statistical analysis plan, missing-data handling, analysis populations, or a multiplicity approach. The record does not report whether planned follow-up was completed.
The sample-size assumptions describe two-arm planning illustrations, which do not match the listed single-arm design. The registry record does not report a protocol-based sample-size justification or the numerical planning outputs. These limitations prevent a detailed reconstruction of the intended analysis and restrict interpretation to the design description and the limited reported counts.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Performance Study of the Harpoon Mitral Valve Repair System — NCT03285724.
- Registry record last updated 2019-11-19; status last verified 2019-11.
- Results first posted 2019-10-14.
- 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.
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18. Record Summary
The registry describes a prospective, single-arm, nonrandomized early feasibility study of the Harpoon Medical Device in degenerative mitral regurgitation. The listed sponsor is Edwards Lifesciences. The study status is TERMINATED, with a start date of 2017-05-16 and a primary completion date of 2017-06-16. Enrollment is 1, masking is NONE, and phase and allocation are recorded as NA.
The primary endpoint is the number of participants with procedural success during the first 30 days, defined through device implantation and reduction of mitral regurgitation from severe to no more than moderate. The primary result is not reported in the registry record. Safety entries list 1 serious adverse event as related, 0 other adverse events as related, and 0 deaths. The record lists 4 outcome measures and 0 analyses. It does not report the reason for termination, a statistical analysis plan, or an explanation of the endpoint population wording.