Post-Approval Study Protocol of the St. Jude Medical Trifecta Valve: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Post-Approval Study Protocol of the St. Jude Medical Trifecta Valve (NCT01514162), a na na study. The primary outcome is Late Adverse Event Incidence.

2. Clinical Question

3. Trial Design

This was a completed, single-group post-approval study protocol for the St. Jude Medical Trifecta Valve. The registry record lists Abbott Medical Devices as the sponsor, a study start of 2012-02, and primary completion in 2014-10. Enrollment is listed as 245. The study is marked as completed, and its phase is recorded as not applicable.

The model is single group, with one listed group: subjects implanted with a Trifecta valve. Allocation is not applicable, and masking is listed as none. These design features mean that the posted results describe observations within the device group; they do not form a randomized comparison or a blinded comparison. No comparator group is listed, so differences between treatment groups cannot be estimated from this study record.

The stated purpose was to further evaluate the long-term clinical safety and effectiveness of the Trifecta valve. The primary outcome is Late Adverse Event Incidence, with a timeframe of 5 years. The secondary outcomes are to characterize patient NYHA Functional Classification Status and report the hemodynamic performance of the valve. The registry lists 3 outcome measures, but detailed numerical results for these outcomes are not included in the information.

The record does not report further design details such as eligibility criteria, how follow-up was conducted beyond the primary endpoint definition, or the planned statistical analysis. Those omissions limit how specifically the study population, measurement process, and analysis can be assessed. The posted safety summaries can be described, but they should not be treated as a controlled estimate of the valve’s effect.

4. Participant Flow and Accounting

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

Overall Study

5. Baseline Characteristics

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

6. Primary Endpoint

The registry lists the primary outcome as Late Adverse Event Incidence, measured over 5 years.

The primary endpoint is titled Late Adverse Event Incidence. It is expressed in events per 100 patient-years and has a timeframe of 5 years. The registry describes late patient-years as time accumulated from 31 days after implantation until the last follow-up visit or contact, or until an adverse event. Its stated calculation is the number of late adverse events divided by the sum of late patient-years, multiplied by 100.

In general, an incidence rate uses person-time to account for different amounts of observation across participants. A participant followed for a longer period contributes more time at risk than one with shorter follow-up. This can make a rate more informative than a simple count when follow-up time varies, although its interpretation depends on the event definition and the accuracy and completeness of follow-up.

The endpoint is useful for summarizing the frequency of late adverse events relative to accumulated follow-up. However, the registry record does not report the numerical rate, the event count used in that calculation, or the total late patient-years. It also does not report a confidence interval or other uncertainty estimate. As a result, the endpoint definition can be explained, but the magnitude and precision of the primary result cannot be assessed from the posted record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The study is described as single group, with one group of subjects implanted with a Trifecta valve. Allocation is not applicable, and masking is listed as none. These are descriptive design details, not evidence of a randomized treatment comparison. In general, random allocation can help balance measured and unmeasured characteristics across groups, while masking can reduce some forms of assessment or reporting bias. Neither a randomized comparator nor masking is part of the design, so conclusions should remain focused on the observations in this group.

How to understand the primary rate

The primary endpoint is Late Adverse Event Incidence, reported in events per 100 patient-years. The record defines the late observation period as starting 31 days post-implant and ending at the last follow-up visit or contact, or an adverse event. The stated rate calculation divides the number of late adverse events by the sum of late patient-years, then multiplies by 100. The registry record does not report the numerator, the accumulated patient-years, or the resulting rate.

In general, patient-years combine the amount of observation contributed by participants. A rate can account for varying follow-up duration, but it depends on clear event definitions and reliable follow-up. Interpretation also depends on what happens after an event and how repeat events are handled. Those details are not reported in the registry record. The endpoint description identifies a calculation, but does not establish all of the operational choices needed to reproduce it.

Counts, rates, and uncertainty

A count tells how many events or participants were recorded, while a rate relates events to observed time. They answer different descriptive questions. The adverse-event summary lists participants affected by serious and other events, whereas the primary endpoint is defined as an incidence rate. The participant counts cannot be used to reconstruct that rate because the required late event count and total late patient-years are not reported.

In general, a point estimate is more informative when accompanied by an uncertainty interval. A confidence interval reflects sampling uncertainty under a specified statistical model; it does not remove limitations arising from incomplete follow-up, measurement error, or study design. No primary point estimate or confidence interval is reported in the registry record. Consequently, neither the magnitude nor the statistical precision of the primary endpoint can be evaluated.

What the analysis record establishes

The registry lists 0 analyses. This means that no analysis results are posted in the record; it does not show that no analysis was ever conducted outside the registry. The statistical analysis plan, model specifications, covariate adjustments, handling of repeat events, and approach to censoring are not reported in the registry record. Readers should not infer a particular method from the endpoint title or calculation description alone.

The posted results do include serious and other adverse-event summaries. Such summaries can describe observed events, but they do not by themselves provide a causal estimate. In general, a causal comparison requires a credible counterfactual: a way to estimate what would have happened to comparable participants under an alternative. This single-group record has no listed comparator, so it does not supply that comparison.

Planning illustrations are not study findings

The sample-size section presents planning illustrations, not observed power. The assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined as a stated fraction of the observed effect. Time-to-event illustrations use a total event count; other illustrations use participants per arm. These are general planning assumptions for hypothetical comparisons, not a description of the study’s single-group design.

In general, sample-size planning asks how much information a future study might need to detect an effect under specified assumptions. It does not show that the current study had a particular probability of finding a result, and it does not establish the validity of an observed effect. The sample-size illustrations should therefore be read separately from the registry results. The record does not report its own sample-size justification, so the planning section cannot be taken as the original design rationale.

Over-dispersion is a general statistical issue that arises when variability is greater than a model assumes. If present, a model that ignores it may understate uncertainty. The registry record does not report a model for the primary outcome or information that would allow over-dispersion to be assessed. Accordingly, no claim about whether it affected this analysis can be made.

Overall, the available methodological information supports a careful description of the study structure and endpoint definition, but not a reconstruction of the primary analysis. The absence of a reported estimate, uncertainty interval, and analysis details leaves key questions about magnitude, precision, and analytic choices unanswered.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 3 outcome measures: the primary Late Adverse Event Incidence endpoint and secondary outcomes concerning NYHA Functional Classification Status and valve hemodynamic performance. It does not report numerical results for those secondary outcomes. The registry also lists 0 analyses. The statistical plan, including whether and how multiple outcomes or analyses were handled, is not reported in the registry record.

In general, multiplicity arises when several outcomes, time points, subgroups, or statistical tests are examined. If many tests are performed, the chance of obtaining at least one apparently unusual result can increase. Statistical approaches can address this, but the appropriate method depends on the analysis plan and the questions being asked. There is not enough information to determine whether multiplicity adjustments were planned or used, so no adjustment should be assumed.

Missing-data methods are also not reported. The primary endpoint definition refers to follow-up through the last visit or contact, but does not explain how incomplete follow-up, missed visits, or unavailable outcome information were handled. In general, missingness can affect interpretation if participants with incomplete data differ from those with complete data. Without the number and pattern of missing observations and the analysis approach, the direction or size of any potential impact cannot be assessed.

The analysis populations are not described beyond the group of subjects implanted with the valve and the enrollment of 245. The registry record does not report whether all enrolled participants were included in each outcome analysis or whether any exclusions occurred. These omissions limit assessment of the population represented by the posted summaries. They do not establish that missing data or exclusions occurred; they mean that the relevant details are not reported in the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

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

Serious events with the highest arm-level rate: major bleed (9.8%), thromboembolism (3.7%), structural deterioration (1.6%), reoperation (0.8%), valve thrombosis (0.0%).

The safety summary lists a Trifecta Valve Group with 245 participants at risk for serious events and 39 affected. For other events, it lists 245 at risk and 0 affected. The record also gives selected serious-event percentages: Major bleed, 9.8%; Thromboembolism, 3.7%; Structural deterioration, 1.6%; Reoperation, 0.8%; Valve thrombosis, 0.0%; and Nonstructural dysfunction, 0.0%. These figures are presented as posted, and no additional calculations are needed to describe them.

These summaries should be read as descriptive safety information for one group, not as comparative effects. The record does not identify a control group, and the event percentages alone do not establish whether the device caused an event. The serious-event entries also do not provide the primary late incidence rate, which is defined using late events and accumulated patient-years. That rate and its uncertainty are not reported in the registry record.

The death field is not reported in the registry record. The summaries do not provide further detail about event timing, recurrence, adjudication, or how the listed terms relate to the overall count of participants affected. The percentages should therefore be understood as the values listed for the event terms, not as a complete account of safety over time.

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

This study documents a post-approval evaluation of the Trifecta valve in a single group. The registry record describes an enrollment of 245, a completed study, a primary endpoint focused on late adverse-event incidence, and secondary outcomes concerning functional classification and hemodynamic performance. It also posts selected safety summaries. These registry entries show what the study set out to assess and what information is available in the record.

The record does not report a numerical result for the primary incidence endpoint, its uncertainty, or numerical results for the named secondary outcomes. It therefore does not support a quantitative conclusion about the primary rate or how precisely it was estimated. The safety summaries are descriptive and have no listed comparator. They cannot establish how the observed event pattern differs from an alternative treatment or what would have occurred without the device.

In general, a single-group study can describe the experience of participants who received an intervention. Without a comparison group, it cannot isolate the intervention’s effect from other explanations for observed outcomes. The lack of a posted analysis also means the statistical methods used to summarize outcomes cannot be assessed from this registry record. These limits concern what can be concluded from the posted information; they do not imply that no additional analyses or follow-up exist elsewhere.

The study’s stated goal was to further evaluate long-term clinical safety and effectiveness. A stated goal is not itself evidence of a particular outcome. The endpoint definitions and safety entries should be separated from a claim of benefit or harm, especially when the main rate and comparative results are unavailable. The appropriate reading is that the record describes a study and selected observations, while leaving the magnitude, precision, and comparative meaning of its primary outcome unresolved.

13. Why This Trial Matters Statistically

This record is statistically informative in part because it makes the distinction between an outcome definition and an outcome result visible. The primary endpoint is described with a time-based rate definition, but its numerical value and uncertainty are not reported. That distinction matters: knowing how a measure was intended to be calculated does not tell readers what value was observed or how precise it was.

The design also matters. A single group can provide descriptive information, but the absence of a comparator limits what can be learned about differences between treatment strategies. The posted safety figures characterize events in the Trifecta Valve Group; they do not provide a controlled estimate of an intervention effect. This is important when interpreting post-approval studies, where observational descriptions and comparative evidence answer different questions.

The endpoint uses patient-years, which in general can account for differing follow-up time. Yet a rate requires both event information and accumulated observation time. With neither the primary numerical estimate nor its components, readers cannot inspect the rate or its precision. The secondary outcomes are named, but their numerical results are not reported either.

Finally, the planning illustrations on the page are not the study’s observed power or proof of a design rationale. They use hypothetical two-arm planning assumptions, while this record describes a single group. Keeping those purposes separate helps avoid treating planning scenarios as trial findings. The record is therefore a useful example of why design, endpoint definition, analysis reporting, and result reporting all need to be considered together.

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 central limitation for interpreting this record is that the numerical primary endpoint result is not reported in the registry record. The underlying late event count and sum of late patient-years are also not reported, and no confidence interval is available. As a result, the primary incidence rate’s magnitude and precision cannot be assessed.

The study has one group and no listed comparator. The safety summaries therefore describe the Trifecta Valve Group without offering a like-for-like control comparison. They cannot establish that the device caused the events listed or quantify how outcomes compare with an alternative. Masking is listed as none, and allocation is not applicable.

Important analysis details are not reported in the registry record. These include the statistical analysis plan, methods for incomplete follow-up or missing data, analysis populations, handling of repeat events, and any approach to multiplicity. The record also does not report further participant characteristics or additional details of outcome ascertainment. These omissions restrict assessment of the analyses and the population represented by the results.

Although the registry names NYHA Functional Classification Status and valve hemodynamic performance as secondary outcomes, their numerical findings are not reported. The death field is also not reported in the registry record. The listed serious-event percentages and affected-participant counts do not resolve these gaps or replace the primary rate. These limitations describe what can be evaluated from the registry record; they do not establish whether further information exists outside it.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Post-Approval Study Protocol of the St. Jude Medical Trifecta Valve — NCT01514162.
• Registry record last updated 2019-02-15; status last verified 2019-01.
• Results first posted 2017-05-31.
• 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.

18. Record Summary

This is a completed, single-group post-approval study of the Trifecta valve, sponsored by Abbott Medical Devices. The record lists enrollment of 245, a study start of 2012-02, and primary completion in 2014-10. It describes the primary outcome as Late Adverse Event Incidence, expressed per 100 patient-years over a 5 years timeframe.

The record also lists secondary outcomes concerning NYHA Functional Classification Status and valve hemodynamic performance, along with selected adverse-event summaries. A numerical primary endpoint result, its uncertainty, and numerical secondary outcome results are not reported in the registry record. No analyses are listed. The single-group design provides descriptive information but no comparator-based estimate.