5 Year Observation of Patients With PORTICO Valves: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for 5 Year Observation of Patients With PORTICO Valves (NCT01802788), a registered phase not stated study. The primary outcome is Percentage of Participants With All-cause Mortality.

2. Clinical Question

The study is titled as a 5 Year Observation of Patients With PORTICO Valves, and its official title describes international long-term follow-up of patients implanted with a Portico valve. The primary endpoint is all-cause mortality, while the listed secondary outcomes cover all-cause, cardiovascular and non-cardiovascular mortality, as well as myocardial infarction. Some secondary outcomes are specified for Cohort A as percentages and others for Cohort B as participant counts across follow-up windows.

The registry describes observational follow-up rather than a randomized treatment comparison. It therefore addresses outcomes among people who received the valve, not a causal contrast between valve implantation and an alternative treatment. The record does not report a numerical primary endpoint estimate, so the question can be identified but its answer cannot be quantified from the posted results.

3. Trial Design

This completed registry record concerns long-term observation of patients implanted with the Portico valve. The study start date is 2013-04-16, primary completion is listed as 2018-09-25, and overall enrollment is 1032. The stated purpose is to further assess the performance and safety profile of the commercially available Portico TAVI System in patients with severe symptomatic aortic stenosis. The condition listed is aortic valve stenosis.

The record describes two cohorts with different histories. Cohort A includes patients implanted with a Portico valve after CE mark. Cohort B includes patients implanted in previous SJM-sponsored premarket studies. These cohort descriptions do not establish that the groups were assigned to different treatments or enrolled under the same conditions. The record specifically notes that this is not a randomized comparison, allocation is not stated, and the arms are not a like-for-like control comparison. Comparisons between their outcomes would therefore need to be interpreted cautiously.

The intervention entries name the St Jude Medical Portico replacement aortic valve and the transcatheter aortic valve implant procedure. The registry lists 50 outcome measures. Secondary outcomes include mortality classifications and myocardial infarction, with some outcomes described as percentages in Cohort A and others as counts in Cohort B. Several Cohort B outcomes have specified follow-up windows extending from 30 days through 5 years.

The primary endpoint is all-cause mortality at 1 year post implant. Its population description refers to Cohort B subjects in the Portico I study scheduled for follow-up starting with the 2 year visit. The record does not explain this scheduling description or provide an endpoint result. It also lists 0 analyses. Details of participant selection, follow-up completeness, analysis populations, and the statistical analysis plan 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.

Before assignment: The first subject was enrolled on April 16, 2013 and the last subject was enrolled on June 28, 2017. Among the 973 subjects who were screened initially in Cohort A, 32 were excluded due to screen failures or exit without a Portico implant attempt. Hence only 941 subjects from Cohort A and 59 from Cohort B were considered for baseline, endpoint and safety analyses.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Cohort B subjects in the Portico I study scheduled follow-up visit starting with the 2 year follow-up.

5. Baseline Characteristics

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

Population: Of the 973 subjects who were screened in Cohort A, 32 subjects did not undergo an implant attempt with Portico THV. Hence only 941 subjects from Cohort A and 59 from Cohort B were considered for baseline, endpoint and safety analyses.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With All-cause Mortality, measured over 1 year post implant.

The primary endpoint is the percentage of participants who died for any reason at 1 year after implantation. All-cause mortality combines deaths regardless of their attributed cause, making it a broad endpoint that does not depend on distinguishing cardiovascular from non-cardiovascular deaths. The registry separately lists cause-specific mortality outcomes among its secondary measures.

The stated population is Cohort B subjects in the Portico I study scheduled for a follow-up visit starting with the 2 year follow-up. That wording is part of the endpoint description; the registry record does not explain how this scheduled-visit population relates to the 1 year post-implant assessment. It also does not report the number of participants included in the primary endpoint analysis, the observed percentage, or the stated 95% confidence interval.

General statistical context: a percentage expresses the share of an analyzed group with the event of interest. A confidence interval conveys uncertainty around an estimated percentage; it is not a guarantee that the true value lies within the interval. The record names a 95% confidence interval as the measure of dispersion for the primary endpoint, but does not post the estimate or interval. Without those results and the analysis denominator, the precision of the primary mortality estimate cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a binary event at the participant level: death from any cause by the specified 1 year post-implant assessment. General statistical context: a binary outcome records whether each participant experienced the event, rather than how many times an event occurred or how long until it occurred. A percentage summarizes the proportion with the event in the analysis population. To interpret that percentage, readers need both its numerator and the number of participants assessed. The registry record does not post the primary endpoint percentage or its analysis denominator.

What the confidence interval would convey

The primary endpoint lists a 95% confidence interval as its dispersion measure. General statistical context: a confidence interval communicates uncertainty around an estimate, reflecting that an observed result from a group of participants may not equal the value that would be seen in a wider population. A narrower interval indicates greater precision than a wider interval, when constructed using comparable methods. An interval does not establish that the result is clinically important, and it does not remove biases arising from study design or incomplete follow-up. The interval limits are not reported in the registry record, so the precision of the endpoint estimate cannot be evaluated.

Why the cohort structure matters

Cohort A and Cohort B are described by different implantation histories: post-CE-mark implantation for Cohort A and implantation in previous SJM-sponsored premarket studies for Cohort B. The registry states that the study is not a randomized comparison, allocation is not stated, and the arms are not a like-for-like control comparison. General statistical context: random assignment can help balance measured and unmeasured participant characteristics between treatment groups. Without it, group differences may reflect factors related to who entered each cohort, when or under what study setting implantation occurred, follow-up practices, or other characteristics. The registry record does not report enough detail to assess those factors, and cohort contrasts should not be read as causal effects.

Counts, percentages, and follow-up windows

The listed secondary outcomes use different forms of summary. Some are percentages of participants, while other outcomes are participant counts at named time windows. General statistical context: counts and percentages answer different descriptive questions, and a count alone cannot be interpreted as a risk without knowing the relevant group size and period of observation. For outcomes measured at successive follow-up windows, the number at risk or assessed can change over time. The registry lists windows for several Cohort B mortality outcomes, but the available record does not provide the outcome values for those measures. The primary endpoint population description refers to follow-up scheduling beginning at the 2 year visit, while the endpoint itself is specified at 1 year post implant; no further explanation is reported.

What the posted event counts do and do not show

The safety summary gives participants at risk and counts with serious events, other events, and deaths for each cohort. Those entries are descriptive counts. General statistical context: an event count does not, on its own, show when events occurred, how long participants were followed, whether the same person contributed to more than one event category, or how event rates compare across groups with different follow-up. Those details are not reported alongside the figures in the registry record. The listed term percentages likewise lack a stated denominator and an explanation of whether terms are mutually exclusive.

Analyses and planning

The registry lists 0 analyses. It therefore does not report an adjusted model, a hypothesis test, or an analysis-specific estimate for the primary outcome in this record. No statistical analysis plan, sample-size justification, interim analysis approach, or missing-data procedure is reported in the registry record. General statistical context: a planning sample size and an observed result serve different purposes. A planning calculation describes assumptions for a future study and is not an observed treatment effect or observed power. The registry’s stated planning assumptions describe a general illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation; the effect to detect is a stated fraction of the observed effect. The record does not report numerical planning results in the registry record for this interpretation, and those assumptions should not be mistaken for the trial’s own design or analysis.

In short, the registry identifies the outcome type, the intended confidence-interval summary, cohort definitions, and some descriptive event counts. It does not give the primary estimate, its confidence interval, the analyzed population size, or the methods needed to judge how missing follow-up and potential differences between cohorts were handled.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Cohort A")
n      <- c(941)
events <- c(114)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Cohort A  941  114  12.1  10.1  14.4  10.2  14.4  10.2  14.4

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 50 outcome measures, including primary and secondary outcomes, and 0 analyses. The listed secondary outcomes span all-cause mortality, cardiovascular mortality, non-cardiovascular mortality, and myocardial infarction. Some are described as percentages in Cohort A, while others are counts in Cohort B across specified follow-up windows. The registry record does not report a multiplicity strategy, such as whether testing was prioritized, adjusted, or treated as descriptive. Without that information and without posted analysis results, statistical significance across multiple outcomes cannot be assessed.

The primary outcome specifies a 95% confidence interval, but its limits and the corresponding estimate are not reported. The number of participants included in that analysis is also not reported in the registry record. Overall enrollment of 1032 does not establish how many participants had an evaluable primary endpoint. The endpoint description refers to Cohort B subjects in the Portico I study scheduled for follow-up starting with the 2 year visit, but the record does not explain the relation between that scheduling criterion and the 1 year post-implant endpoint.

Missing-data handling, loss to follow-up, censoring, and the definition of each analysis population are not reported in the registry record. No interim-analysis plan or statistical analysis plan is reported. These omissions limit assessment of the completeness and comparability of follow-up, as well as the reliability of any unposted estimate. General statistical context: when outcome availability differs across participants, the analyzed group may not represent everyone enrolled; the consequences depend on why information is missing and how the analysis handles it. The registry does not provide enough information to evaluate those issues for this study.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: other (63.4%), arrhythmia / conduction abnormality (27.2%), pacemaker implantation (21.7%), major bleeding (7.9%), clinical significant bleeding (7.1%).

The registry lists serious adverse event information separately for the two cohorts. For Cohort A, 941 participants are listed as at risk, 754 as affected by a serious event, 526 as affected by another event, and 382 deaths are recorded. For Cohort B, the corresponding entries are 59 at risk, 40 with a serious event, 22 with another event, and 18 deaths. These are descriptive registry counts; the record does not state a time window for these group-level figures in the available information.

The listed serious-event terms and percentages are Other at 63.4%, Arrhythmia / Conduction abnormality at 27.2%, Pacemaker implantation at 21.7%, Major bleeding at 7.9%, Clinical significant bleeding at 7.1%, and Major vascular complications at 6.9%. The registry does not state the denominator for these term percentages or whether one participant could be represented in more than one term. They should therefore be read as listed term frequencies, not as mutually exclusive categories or as rates over a known period.

General statistical context: event counts are influenced by the size of the group observed and by how long participants are followed. The cohorts have different listed at-risk counts and different study histories, and the registry cautions that they are not a like-for-like control comparison. These safety figures do not establish a causal difference between cohorts. The record does not provide further detail about event adjudication, timing, or the relationship between the term percentages and the cohort-level counts.

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

The registry describes a completed long-term observation study of patients implanted with a Portico valve. It identifies all-cause mortality at 1 year post implant as the primary endpoint and lists a 95% confidence interval as its dispersion measure. The record does not report the numerical primary outcome, its confidence interval, or the number of participants included in the analysis. Consequently, the posted information cannot establish the observed magnitude or precision of that endpoint.

The record does provide overall enrollment and cohort-level safety counts, as well as a list of serious-event terms with percentages. Those figures are descriptive, but their interpretation is limited by the absence of a stated time window for the cohort-level counts and by missing details about the denominators and overlap of event terms. They should not be treated as a complete account of event timing or as directly comparable rates between cohorts.

The study does not describe a randomized treatment comparison. Cohort A and Cohort B differ in their stated implantation settings, and the registry explicitly says the arms are not a like-for-like control comparison. General statistical context: outcomes observed in an implanted group describe what happened among the people followed; they do not alone show what would have happened to the same people under another treatment or without the intervention. Differences between these cohorts, if considered, could reflect differences in participant histories or study settings as well as other factors.

The record’s completion status and long-term follow-up purpose do not substitute for posted outcome estimates or detailed methods. No adjusted analyses, missing-data procedures, or multiplicity strategy are reported. The defensible interpretation is therefore limited to the study purpose, cohort descriptions, endpoint definition, enrollment, and listed safety summaries. The available registry information does not support a conclusion about the size of the primary mortality outcome, comparative treatment effects, or the precision of any such effect.

14. Why This Trial Matters Statistically

This study is statistically informative as an example of how a long-term registry record can identify a clinically relevant endpoint without posting the result needed to quantify it. All-cause mortality at 1 year post implant is clearly named, and the record specifies a 95% confidence interval as the intended dispersion measure. Yet the estimate, interval, and analysis denominator are not reported in the registry record. Readers can identify the planned question but cannot assess its observed magnitude or precision.

The two cohort descriptions also matter for interpretation. Cohort A comprises post-CE-mark implantations, while Cohort B comprises patients implanted in previous SJM-sponsored premarket studies. The registry states that allocation is not stated, the study is not a randomized comparison, and the arms are not a like-for-like control comparison. This cautions against treating cohort contrasts as if they isolate an effect of the valve or procedure.

The record further illustrates why safety counts need context. It lists participants at risk, serious-event counts, other-event counts, and deaths by cohort, alongside term percentages. But a time window, term denominators, and possible overlap between terms are not reported in the available information. Without such context, counts and percentages cannot be interpreted as fully specified rates or compared as equivalent measures.

Finally, the registry lists 50 outcome measures and 0 analyses. The absence of reported analysis details leaves uncertainty about how outcomes were summarized, how missing follow-up was handled, and whether multiplicity was considered. For clinical researchers and biostatisticians, these gaps distinguish a useful description of study intent and available safety information from a complete statistical account of outcome evidence.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

Several limitations arise from details not reported in the registry record. The primary endpoint is defined as all-cause mortality at 1 year post implant, but the numerical percentage, confidence interval, and analysis denominator are absent. The population description refers to Cohort B subjects in the Portico I study scheduled for follow-up beginning with the 2 year visit. The record does not explain how that visit schedule relates to the 1 year endpoint.

The overall enrollment of 1032 does not indicate how many participants contributed to each outcome or remained under observation at each follow-up window. The registry does not report participant flow, loss to follow-up, missing-data methods, or analysis-population definitions. These omissions prevent assessment of whether outcome availability was complete or comparable over time.

The study is not described as randomized, allocation is not stated, and the two cohorts are explicitly not a like-for-like control comparison. Their different stated study histories and implantation settings limit causal interpretation of any cohort contrast. Details that would help characterize participant comparability and potential confounding are not reported in the registry record.

The safety summary does not specify the time period represented by the cohort-level counts in the available information. The denominators and overlap rules for the listed serious-event term percentages are also not reported. In addition, the registry lists 50 outcome measures but does not report a multiplicity strategy, statistical analysis plan, or interim-analysis approach. It lists 0 analyses and does not post adjusted estimates or tests. These gaps constrain interpretation to the descriptive information explicitly recorded.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: 5 Year Observation of Patients With PORTICO Valves — NCT01802788.
• Registry record last updated 2025-02-11; status last verified 2025-02.
• Results first posted 2022-01-24.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

NCT01802788 is a completed international follow-up study titled 5 Year Observation of Patients With PORTICO Valves. Its official title describes long-term follow-up of patients implanted with a Portico valve. The study began on 2013-04-16, primary completion is listed as 2018-09-25, and enrollment is 1032. Abbott Medical Devices is the listed sponsor.

The study concerns aortic valve stenosis and aims to assess the performance and safety profile of the commercially available Portico TAVI System in patients with severe symptomatic aortic stenosis. Cohort A includes patients implanted after CE mark; Cohort B includes patients implanted in previous SJM-sponsored premarket studies. The registry states that the study is not a randomized comparison and that the cohorts are not a like-for-like control comparison.

The primary endpoint is the percentage of participants with all-cause mortality at 1 year post implant. The registry lists 50 outcome measures and 0 analyses. A numerical primary endpoint result and its confidence interval are not reported in the registry record.