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 Clinical Investigation Of The Mitroflow Aortic Pericardial Heart Valve (NCT00630916), a non-randomized na study. The primary outcome is Incidence Rate of Adverse Events and Mortality for the Mitroflow Aortic Heart Valve Repair.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00630916 |
| Phase | NA |
| Condition | Heart Valve Diseases |
| Allocation | Non-Randomized |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 756 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Sorin Group USA, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The investigation concerns people receiving a valve to replace a diseased or dysfunctional aortic valve or an aortic valve prosthesis. The registry lists Heart Valve Diseases as the condition and records enrollment of 756. Further eligibility details and the characteristics of participants are not reported in the registry record.
Intervention
The intervention is the Mitroflow Aortic Heart Valve, identified as a device. The stated purpose is to assess its safety and effectiveness when used for aortic valve replacement. Details about surgical procedures, device sizing, or other care are not reported in the registry record.
Comparator
There is no separate comparator group in this single-group investigation. Allocation is listed as non-randomized, and the registry record does not describe a control intervention. The study therefore does not provide a randomized, like-for-like comparison between the device and another treatment or device.
Primary question
The primary outcome asks about the incidence rate of adverse events and mortality after the early postoperative period. It is expressed as a percentage occurrence per patient-year, with the rate based on cumulative events and follow-up occurring >30 days after valve implantation. The primary numerical rate and its confidence interval are not reported in the registry record.
3. Trial Design
This was a completed, non-randomized investigation with a single group and no masking. The intervention was the Mitroflow Aortic Heart Valve. The registry lists the phase as NA and enrollment as 756. The study started in 2003-11, and primary completion was recorded as 2005-12. Sorin Group USA, Inc. is listed as the sponsor.
The stated aim was to demonstrate the safety and effectiveness of the valve when used to replace a diseased or dysfunctional aortic valve or aortic valve prosthesis. A single-group design can describe outcomes among people receiving the device, but it does not by itself estimate how those outcomes would compare with outcomes under another device or treatment. Because allocation was non-randomized and no comparator is recorded, differences from other populations or external reports would not be controlled comparisons.
The enrollment figure is not necessarily the number contributing to every outcome. The adverse-event record lists 699 people at risk for both serious and other adverse events, while the registry does not explain how that number relates to enrollment. The analysis population, follow-up completeness, and reasons for any exclusions are not reported in the registry record.
The primary outcome is defined for late postoperative follow-up, specifically cumulative follow-up occurring after day 30. A secondary outcome is Aortic Valve Regurgitation. The record lists four outcome measures, but detailed descriptions of all measures and a formal analysis count are not reported beyond the listed record information. The study protocol, prespecified analysis plan, and any interim analyses are not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Mitroflow Aortic Pericardial Valve |
|---|---|
| STARTED | 756 |
| Study Cohort | 699 |
| COMPLETED | 546 |
| NOT COMPLETED | 210 |
Reasons for not completing this period:
| Reason | Mitroflow Aortic Pericardial Valve |
|---|---|
| Death | 110 |
| Explant | 8 |
| Lost to Follow-up | 5 |
| Withdrawal by Subject | 30 |
| Protocol Violation | 7 |
| Physician Decision | 47 |
| Lack of Efficacy | 3 |
Analysis population for the primary outcome, as defined in the registry: Cumulative follow-up in years occurring post 30 days
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 | Mitroflow Aortic Pericardial Valve |
|---|---|---|
| Participants analysed | 699 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 96 |
| Age, Categorical: >=65 years | Participants | 603 |
| Age Continuous | years | 74.3 (SD 8.4) |
| Sex: Female, Male: Female | Participants | 302 |
| Sex: Female, Male: Male | Participants | 397 |
| Region of Enrollment: United States | participants | 556 |
| Region of Enrollment: Canada | participants | 143 |
6. Primary Endpoint
The registry lists the primary outcome as Incidence Rate of Adverse Events and Mortality for the Mitroflow Aortic Heart Valve Repair, measured over Late postoperative.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | Percent occurrence per patient-year |
| Endpoint classification | Event-Rate Endpoint |
The primary endpoint is titled as an incidence rate of adverse events and mortality. It is reported in the registry as a percentage occurrence per patient-year, with a 95% confidence interval. The description defines the rate as the number of adverse events divided by total follow-up in years, using cumulative events and follow-up occurring >30 days after valve implantation. The endpoint therefore relates events to accumulated time under follow-up rather than simply reporting the proportion of participants with an event.
In general, an exposure-based rate can be useful when participants contribute different amounts of follow-up: time at risk is incorporated into the denominator. Its interpretation depends on the event definition, how repeat events are handled, and how person-time is accumulated. Those details, beyond the stated cumulative-event calculation and post-30-day period, are not reported in the registry record.
The confidence interval is intended to communicate uncertainty around the rate estimate. The numerical estimate and interval are not reported in the registry record, so the magnitude and precision of the primary endpoint cannot be assessed from the recorded outcome information. Although mortality is named in the endpoint title, a death count and a separate mortality estimate are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies an exposure-based primary outcome but does not report its numerical rate or 95% confidence interval. Consequently, the posted record does not establish the observed magnitude of the late postoperative adverse-event and mortality rate or how precisely that rate was estimated. The endpoint definition indicates that follow-up before or through the first 30 days after implantation is outside the stated rate calculation.
The adverse-event information does report 699 people at risk for serious events, of whom 351 are listed as affected. For other adverse events, 699 are listed at risk and 430 as affected. These counts describe the registry’s safety entries; they are not the primary patient-year rate, and they cannot be substituted for that estimate. The record does not state the exposure time associated with these figures, the event-counting rules, or whether participants could contribute to both categories.
The serious-event terms with the largest listed percentages are Heart failure at 8.4%, Respiratory failure / disorder at 5.0%, Respiratory infections at 5.0%, Miscellaneous infections at 4.9%, Miscellaneous GI disorders at 4.6%, and Musculo-skeletal disorders at 4.1%. The registry does not report the denominator, time period, or detailed coding basis for these percentages. They should therefore be read as listed descriptive figures, not as rates or comparative risks.
The study has no concurrent comparator group in the registry record. The event counts cannot show whether the frequency would have been different with another valve or treatment. Nor can the single-group design separate device-related effects from other influences on clinical outcomes. The record’s stated safety-and-effectiveness aim is not itself evidence of a comparative result.
Enrollment was 756, while the safety summaries use 699 at risk. The registry does not explain this difference or identify an analysis population for the primary endpoint. The primary result, participant follow-up distribution, and handling of missing observations are not reported in the registry record. Thus neither a complete endpoint interpretation nor a direct comparison with other studies can be made from these details alone.
9. Statistical Methods Explained
The primary outcome uses an event rate per unit of exposure. In general, an event rate divides counted events by accumulated time at risk. Here, the registry describes the denominator as total follow-up in years and restricts the calculation to cumulative events and follow-up occurring >30 days after implantation. The reported unit is percent occurrence per patient-year. The registry does not provide the numerical rate, the underlying event total, or the amount of accumulated follow-up, so the calculation cannot be independently examined from the record.
What does a patient-year rate express?
In general, a patient-year rate describes event occurrence relative to time under observation. It is different from a simple percentage of participants who experience at least one event: participants followed for different lengths of time may contribute different amounts to the exposure denominator. A rate is most interpretable when event definitions, censoring, follow-up time, and repeat-event handling are clearly described. Beyond the broad rate definition, those details are not reported in the registry record. The recorded affected counts alone do not supply the exposure-time information needed to reconstruct the primary rate.
What does the confidence interval add?
In general, a confidence interval gives a range of values compatible with the data under a specified statistical procedure. A narrower interval indicates greater precision under that procedure; a wider interval indicates more uncertainty. The primary outcome is described as having a 95% confidence interval, but neither its limits nor the rate estimate are reported in the registry record. The method used to calculate that interval is also not reported. It is therefore not possible to assess the precision of the primary result or whether the interval accounts for any particular event-rate distribution.
Why can event-rate data require care?
In general, event counts may vary more than a simple model expects, a feature called over-dispersion. This can arise in settings where event risk differs across participants or events recur, but whether either issue applies to this investigation is not reported in the registry record. When over-dispersion is present, methods that assume less variability can produce confidence intervals that are too narrow. This is a general statistical consideration, not a statement about the analysis used for this study. The registry does not describe a model, a variance adjustment, or handling of recurrent events.
What can a single-group design estimate?
A single-group design can describe outcomes observed among the people included in that group. It does not create a concurrent randomized comparison. In general, random allocation can help balance known and unknown prognostic factors between groups; without it, a comparison with another group may be affected by differences in participant mix, care, follow-up, or outcome ascertainment. No comparator group is recorded for this investigation, so the primary rate is not a comparative treatment effect. Adjustment methods, if any, are not reported in the registry record.
How should planning illustrations be understood?
In general, sample-size calculations are planning tools that describe how many participants or events a hypothetical study might need under specified assumptions. The planning illustrations associated with this record are based on fractions of an observed effect, use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. For time-to-event outcomes, the stated quantity is a total event count; for other outcomes, it is participants per arm. These are planning assumptions, not a description of this single-group trial’s design, and they are not observed power. The registry record does not report a protocol-based sample-size justification or the numerical planning outputs in the registry record for interpretation.
The registry lists zero analyses. The particular statistical procedures used for the primary endpoint, the confidence interval, any adjustment for covariates, and any prespecified analysis plan are not reported in the registry record. These gaps limit assessment of the analysis, but do not change the basic distinction between an exposure-based rate and a comparative treatment effect.
10. Multiplicity, Missing Data and Analysis Populations
The record lists four outcome measures and identifies Aortic Valve Regurgitation as a secondary outcome. It does not provide a detailed account of all outcome definitions, their analysis time points, or which outcomes were treated as primary in the analysis beyond the stated primary endpoint. A formal multiplicity strategy is not reported in the registry record.
In general, evaluating multiple outcomes can increase the chance that at least one result appears notable by chance, especially when many statistical tests are performed. Prespecified outcome priorities and a plan for interpreting multiple tests help readers understand how results were selected and how uncertainty should be considered. The registry lists zero analyses, and does not report test results, p-values, or adjustments for multiple comparisons. It is therefore not possible to assess how multiplicity was handled in any analysis.
Information about missing outcome data, loss to follow-up, exclusions, and analysis populations is not reported in the registry record. Enrollment was 756, whereas the safety summaries list 699 at risk for each event category; the record does not explain the difference. It also does not state whether everyone at risk contributed the same follow-up or whether missing observations were handled by a particular method. These omissions matter because missingness and follow-up differences can affect both event counts and exposure-based estimates.
The record does not describe interim analyses, stopping rules, or a prespecified statistical analysis plan. Those items should not be inferred from the completed status or from the endpoint description.
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 |
|---|---|---|---|
| Mitroflow Aortic Pericardial Valve | 351 | 699 | 50.2% |
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 |
|---|---|
| Mitroflow Aortic Pericardial Valve | 430 of 699 |
Most frequent serious adverse event terms
| Event term | Organ system | Mitroflow Aortic Pericardial Valve |
|---|---|---|
| Heart failure | Cardiac disorders | 59 of 699 |
| Respiratory failure / disorder | Respiratory, thoracic and mediastinal disorders | 35 of 699 |
| Respiratory infections | Respiratory, thoracic and mediastinal disorders | 35 of 699 |
| Miscellaneous infections | Infections and infestations | 34 of 699 |
| Miscellaneous GI disorders | Gastrointestinal disorders | 32 of 699 |
| Musculo-skeletal disorders | Musculoskeletal and connective tissue disorders | 29 of 699 |
| Sepsis / bacteremia | Infections and infestations | 29 of 699 |
| Renal failure / insufficiency | Renal and urinary disorders | 28 of 699 |
| Pleural effusion | Respiratory, thoracic and mediastinal disorders | 26 of 699 |
| Cardiac arrhythmias | Cardiac disorders | 24 of 699 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Mitroflow Aortic Pericardial Valve |
|---|---|---|
| Atrial fibrillation | Cardiac disorders | 156 of 699 |
| Urinary tract infection | Renal and urinary disorders | 67 of 699 |
| Pleural effusion | Respiratory, thoracic and mediastinal disorders | 60 of 699 |
| Miscellaneous infections | Infections and infestations | 53 of 699 |
| Respiratory infections | Respiratory, thoracic and mediastinal disorders | 45 of 699 |
| Renal failure / insufficiency | Renal and urinary disorders | 40 of 699 |
| Arrhythmias | Cardiac disorders | 36 of 699 |
| Heart failure | Cardiac disorders | 35 of 699 |
Serious events with the highest arm-level rate: heart failure (8.4%), respiratory failure / disorder (5.0%), respiratory infections (5.0%), miscellaneous infections (4.9%), miscellaneous gi disorders (4.6%).
The registry lists 699 people at risk for serious adverse events and 351 affected. It also lists 699 at risk for other adverse events and 430 affected. These are counts in separate registry categories; they do not indicate the number of events per patient-year, and the record does not explain whether a person could appear in both categories. The follow-up period and event-counting rules for these figures are not reported in the registry record.
The listed serious-event terms and percentages are Heart failure, 8.4%; Respiratory failure / disorder, 5.0%; Respiratory infections, 5.0%; Miscellaneous infections, 4.9%; Miscellaneous GI disorders, 4.6%; and Musculo-skeletal disorders, 4.1%. The registry does not report the denominator or time period for these term-specific percentages, so they should not be interpreted as patient-year rates or compared directly with the affected counts.
Although mortality is included in the primary endpoint title, a death count is not reported in the registry record. The safety entries are descriptive and do not establish that the device caused any listed event.
12. What the Result Does, and Does Not, Mean
The registry record documents a completed, single-group investigation of the Mitroflow Aortic Heart Valve and describes a primary outcome intended to quantify adverse events and mortality during late postoperative follow-up. It also records affected counts for serious and other adverse events and lists several serious-event terms with percentages. These details describe what the record contains; they do not supply the numerical primary rate or its confidence interval.
Without that primary estimate, its interval, and the exposure-time information, the late postoperative rate and its precision cannot be characterized. Without a concurrent comparator, the observed safety counts cannot establish how outcomes compare with another valve or approach. The design also cannot, on its own, determine whether an event was caused by the device. The registry’s stated aim of demonstrating safety and effectiveness should be distinguished from evidence that would quantify a comparative benefit or harm.
The data do not establish that the valve works or does not work. The registry describes its intended use and the outcomes it sought to assess, but the primary numerical result, analysis methods, and population details needed for a fuller assessment are not reported in the registry record. The secondary outcome Aortic Valve Regurgitation is named, but its result is not reported in the registry record.
Accordingly, the most defensible reading is descriptive: the record identifies a device investigation, defines a post-30-day event-rate endpoint, and reports adverse-event counts and selected terms. It does not provide enough statistical detail to judge the primary endpoint’s magnitude and precision or to make causal and comparative conclusions.
13. Why This Trial Matters Statistically
This investigation illustrates why the type of outcome measure matters. A count of people affected and an event rate per patient-year answer different descriptive questions. The count indicates how many people are listed as affected within the registry’s safety categories; the rate relates counted events to accumulated follow-up. The primary endpoint is explicitly exposure-based, but its numerical estimate and the exposure total are not reported in the registry record. Without those details, the rate cannot be interpreted alongside the affected counts.
It also illustrates the distinction between a safety description and a comparative treatment estimate. A single-group, non-randomized investigation can record outcomes after device use, but it has no concurrent randomized comparator in the registry record. The counts therefore do not provide a like-for-like estimate of what would have occurred under another intervention. This is a general design limitation, not a judgment about the quality of care or the device.
Finally, precision and transparency depend on more than naming an endpoint. The record gives a rate definition and specifies a 95% confidence interval, but does not report the numerical estimate, interval limits, analytic procedure, or exposure details. The discrepancy between enrollment of 756 and 699 at risk in the safety summaries is also unexplained. These gaps show why outcome definitions, analysis populations, follow-up, and uncertainty estimates are essential for interpreting clinical trial results.
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 main trial-specific limitation is that the registry record does not report the numerical primary rate or its 95% confidence interval. It defines the rate as adverse events divided by follow-up in years for the period occurring >30 days after implantation, but does not report the event total, accumulated follow-up, or calculation details needed to assess the result.
The study is non-randomized and single-group, with no comparator described. As a result, the registry record does not support a direct comparison with another device or treatment. The record also does not report participant characteristics, eligibility criteria, outcome ascertainment procedures, or details of the intervention beyond the device name and intended replacement use.
The safety summaries list 699 at risk in each category, compared with enrollment of 756, but the relationship between these numbers is not explained. Follow-up completeness, missing data, and analysis populations are not reported in the registry record. The serious-event term percentages lack a reported denominator and time period. A death count is not reported, despite mortality appearing in the primary endpoint title.
The registry lists a secondary outcome and four outcome measures, but detailed results and a multiplicity plan are not reported. Nor are the statistical analysis plan, interval calculation method, handling of repeat events, or interim analyses reported in the registry record. These limitations constrain interpretation of both the outcome definitions and the strength of any conclusions.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Clinical Investigation Of The Mitroflow Aortic Pericardial Heart Valve — NCT00630916.
- Registry record last updated 2011-09-22; status last verified 2011-09.
- Results first posted 2011-09-20.
- 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 record describes NCT00630916, titled Clinical Investigation Of The Mitroflow Aortic Pericardial Heart Valve. It lists Sorin Group USA, Inc. as sponsor, enrollment of 756, a non-randomized allocation, no masking, a single-group model, and completed status. The study started in 2003-11, with primary completion in 2005-12.
The stated purpose was to assess safety and effectiveness when the Mitroflow Aortic Heart Valve is used to replace a diseased or dysfunctional aortic valve or aortic valve prosthesis. The primary outcome is an adverse-event and mortality rate per patient-year for follow-up occurring >30 days after implantation, with a stated 95% confidence interval. Aortic Valve Regurgitation is listed as a secondary outcome.
The primary numerical rate and interval, analysis population details, and a comparative group are not reported in the registry record. Safety entries list 699 at risk for serious events and 699 at risk for other events, with 351 and 430 affected, respectively.