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 Natriuretic Peptides - Predictors of In-hospital and Long-term Major Adverse Cardiac Events After Emergency Surgery? (NCT00942786), a registered phase not stated study. The primary outcome is Occurence of Adverse Cardiac Events.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00942786 |
| Phase | Phase not stated |
| Condition | Surgery |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 297 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Medical University of Graz |
| Results posted | Yes |
2. Clinical Question
Population
Consecutive patients undergoing emergency surgery. The registry record reports an enrollment of 297 participants; further demographic or clinical characteristics are not reported in the registry record.
Intervention
No assigned treatment is described. The study concerns perioperative natriuretic peptide levels as potential predictors, but the levels measured and their timing are not reported in the registry record.
Comparator
No comparison group is reported. The listed arm is labeled “No treatment,” and its description is consecutive patients undergoing emergency surgery. Allocation is not stated, so this is not a randomized treatment comparison.
Primary question
The stated hypothesis is that perioperative natriuretic peptide levels are associated with major adverse cardiac events during the postoperative period and long-term follow-up. The primary outcome is a composite of nonfatal myocardial infarction, acute heart failure, or death. The registry record does not report an analysis linking peptide levels to that composite.
The study’s official title describes a prospective evaluation of the predictive value of brain natriuretic peptides for long-term cardiac outcomes. Its brief summary states the investigators’ hypothesis about an association between perioperative natriuretic peptide levels and in-hospital and long-term events. These statements identify the intended clinical question, but they are not themselves evidence that a predictive relationship was observed.
To answer the question, a results record would need to report how peptide measurements relate to later events, with enough detail to assess the strength and uncertainty of that relationship. Such results, including the peptide measurements and a predictive analysis, are not reported in the registry record. The reported event count alone cannot establish whether peptide levels predict who experiences an event.
3. Trial Design
The registry identifies this as a prospective study and lists the Medical University of Graz as sponsor. The condition is surgery. The recorded study start is 2008-02, the primary completion is 2014-01, and the status is completed. Enrollment is 297.
One arm is listed, labeled “No treatment,” with a description of consecutive patients undergoing emergency surgery. The record does not describe a treatment being assigned or a second group used for comparison. Allocation is not stated. Accordingly, the listed design does not support a like-for-like comparison of treatments; the event count should be read as a result for the reported group, not as an estimate of a treatment contrast.
The primary outcome timeframe begins postoperatively at the index surgery and continues until a median follow-up of 34 months. The registry describes the primary outcome as the number of participants with adverse cardiac events. It also lists three outcome measures, but the details of the other measures are not included in the reported details.
The record reports no posted analyses. It does not report how peptide measurements were collected, how participants were followed, how events were adjudicated, or what statistical model was planned for evaluating prediction. The sample-size illustrations associated with the results are planning exercises based on an observed effect, not evidence of the study’s original design or its achieved power. The registry’s own sample-size justification is 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 | No Treatment |
|---|---|
| STARTED | 297 |
| COMPLETED | 297 |
| NOT COMPLETED | 0 |
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 | One Arm |
|---|---|---|
| Participants analysed | 297 | |
| Age, Continuous | years | 74 (51 to 103) |
| Sex: Female, Male: Female | Participants | 180 |
| Sex: Female, Male: Male | Participants | 117 |
6. Primary Endpoint
The registry lists the primary outcome as Occurence of Adverse Cardiac Events, measured over postoperatively (index surgery) until a median follow-up of 34 months.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the occurrence of major adverse cardiac events after the index emergency surgery, reported as a number of participants. It is a composite outcome: a participant is counted if they experience nonfatal myocardial infarction, acute heart failure, or death during the stated postoperative follow-up, which extends to a median of 34 months.
Combining events can capture more than one clinically important type of cardiac outcome in a single endpoint. It also means the overall count does not show how many participants experienced each component. Component-specific counts are not reported in the registry record. The definition of nonfatal myocardial infarction requires a typical rise and fall in troponin together with evidence of myocardial ischemia, such as ischemic symptoms, qualifying ECG changes, or imaging evidence of a new regional wall-motion abnormality. Acute heart failure is defined by clinical signs and symptoms, echocardiographic evidence of cardiac dysfunction, and a clinical response to treatment directed toward heart failure.
The endpoint is relevant to the stated question because the study aims to assess whether perioperative natriuretic peptide levels are associated with later cardiac events. However, the endpoint count alone does not show whether those levels distinguish participants who experience an event from those who do not. Peptide-level results and analyses relating them to the endpoint are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary result is a count of 91 participants with adverse cardiac events among the 297 participants in the reported group. The registry describes the outcome as a composite of nonfatal myocardial infarction, acute heart failure, or death, over follow-up from the index surgery to a median of 34 months. This is a descriptive result for the group; it is not a comparison between treatments or between levels of natriuretic peptides.
The record’s stated hypothesis concerns an association between perioperative natriuretic peptide levels and in-hospital and long-term events. Yet no peptide measurements, groupings by peptide level, effect estimate, confidence interval, or statistical test for that association is reported in the registry record. Therefore, the posted event count cannot answer whether peptide levels were associated with events, how strong any association was, or how precisely it was estimated. Nor can it establish predictive performance, which would require information about how predictions corresponded to observed outcomes.
A confidence interval, in general, expresses statistical uncertainty around an estimated quantity. No confidence interval for the primary event result or for a peptide-outcome relationship is reported in the registry record. Without an interval or an equivalent uncertainty measure, the precision of the reported association cannot be assessed. The event count is informative about the number recorded in this group, but it does not fill that gap.
The absence of a comparator also matters. A single group can describe the frequency of observed events, but it cannot by itself estimate a difference attributable to a treatment. The “No treatment” label does not create a control group, and the record states that allocation is not stated. The record should therefore not be read as a randomized trial result.
The registry lists three outcome measures and reports zero posted analyses. This means the record does not present an analysis result for the proposed predictive question; it does not establish that investigators performed no analyses outside the registry. The status is completed, but completion status is not a substitute for a posted statistical result. Taken together, the record documents the study’s objective, design description, follow-up timeframe, and event count, while leaving the central biomarker-prediction result unreported.
9. Statistical Methods Explained
The central statistical question is whether a measurement made before or around surgery is associated with a later outcome. In general, an association analysis compares outcome patterns across measurement values or estimates how outcome probability changes with the measurement. A predictive analysis asks whether the measurement helps distinguish participants who will experience an event from those who will not. Those are related but distinct questions: an association does not, by itself, demonstrate useful prediction. The registry record does not report peptide values, a model, or either type of analysis.
What does the event count represent?
The primary outcome is binary at the participant level: a participant either experienced at least one event in the composite or did not, as captured by the registry. The posted result gives a count of 91 affected participants out of 297 in the reported group. This count describes observed outcomes during the stated follow-up; it does not convey the timing of each event or identify which component occurred. Component counts and a time-to-event analysis are not reported in the registry record.
For a binary endpoint, statistical methods may estimate an event probability or compare probabilities between groups. In this record there is only one listed group and no reported comparator, so a between-group treatment effect cannot be obtained from the posted result. In general, a count can be accompanied by an uncertainty interval to show how much the estimated event frequency might vary due to sampling. Such an interval for this result is not reported in the registry record.
Why does follow-up matter?
The endpoint timeframe runs from the index surgery through a median follow-up of 34 months. In general, participants may have different lengths of observation, and an analysis that accounts for event timing can use information about when events occur and how long participants remain under observation. A simple count does not reveal that timing or whether every participant had the same observation period. The registry record does not report individual follow-up durations, censoring information, or a time-to-event analysis. The median follow-up gives a summary of the observation period, but does not supply those missing details.
What would a predictive analysis need to show?
In general, evaluating a biomarker’s predictive value requires a defined measurement and outcome, a model or other prediction method, and results that describe both the estimated relationship and how well predictions correspond to outcomes. Assessment may also consider calibration, meaning agreement between predicted and observed risks, and discrimination, meaning how well the method separates participants with and without events. These are general concepts, not reported results for this study. The registry record does not report peptide concentrations, a prediction model, calibration, discrimination, an effect estimate, or uncertainty around a prediction result.
The timing and handling of the peptide measurement are also important to interpretation. Measurements made at different perioperative times may answer different questions, and any categorization of a continuous measurement can affect the analysis. The measurement schedule, assay details, and any cut points are not reported in the registry record. No assumptions about them can be drawn from the study title or stated hypothesis.
How should sample-size illustrations be read?
In general, a sample-size calculation describes how many participants might be needed under stated assumptions to detect a chosen effect with a specified statistical approach. The illustrations associated with this record use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; their target effect is expressed as a fraction of the observed effect. These are planning illustrations computed from the observed effect, not the study’s own design justification and not observed power. The record’s study itself lists one group, so the equal-allocation assumption in such an illustration should not be mistaken for the study’s actual enrollment structure. The registry’s original sample-size justification is not reported in the registry record.
For time-to-event illustrations, the stated method concerns a total number of events; other illustrations are expressed as participants per arm. These conventions describe planning calculations, not the outcomes of this study. A planning estimate cannot recover missing information about peptide measurements, follow-up, or the statistical analysis actually used. The posted registry record contains no analyses, so no model-specific conclusion can be attributed to it.
What role do statistical tests and uncertainty play?
In general, a statistical test evaluates how compatible the observed data are with a specified null hypothesis under its assumptions. A p-value does not measure the size or clinical importance of an effect, and it does not describe predictive accuracy. An effect estimate paired with an uncertainty interval is usually more informative for judging magnitude and precision. No p-value, effect estimate, or confidence interval for the proposed peptide-outcome association is reported in the registry record.
Binary-event analyses can also be affected by over-dispersion in settings where observed variation exceeds what a chosen model expects. In general, accounting for over-dispersion can prevent uncertainty from being understated when the model’s assumptions do not match the data. Whether over-dispersion was relevant or considered in this study is not reported in the registry record. There is not enough posted analysis detail to assess model assumptions, diagnostics, or robustness.
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.
| Arm | Participants | Events | Observed % | Clopper-Pearson 95% CI | Wilson 95% CI | Bayesian 95% credible interval |
|---|---|---|---|---|---|---|
| No Treatment | 297 | 91 | 30.6% | 25.4% to 36.2% | 25.7% to 36.1% | 25.7% to 36.1% |
R code and output
arm <- c("No Treatment")
n <- c(297)
events <- c(91)
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 No Treatment 297 91 30.6 25.4 36.2 25.7 36.1 25.7 36.111. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures, but the primary result described in the record is the composite adverse cardiac event endpoint. The other outcome measures and their results are not reported in the registry record. With multiple outcomes or multiple statistical tests, general statistical practice considers multiplicity because repeated testing can increase the chance of a seemingly notable result arising by chance. Whether any multiplicity adjustment or hierarchy of outcomes was specified is not reported in the registry record.
The record reports zero posted analyses. This describes the registry record’s analysis entries; it does not establish whether analyses were conducted elsewhere. The statistical analysis plan, including any prespecified model, hypothesis tests, covariate adjustments, or handling of multiple comparisons, is not reported in the registry record. It is therefore not possible to determine whether the posted endpoint was analyzed as planned or whether selective reporting is a concern.
Missing-data methods and analysis populations are also not reported in the registry record. The record does not state whether all enrolled participants contributed to the primary endpoint analysis, whether any outcome status was unavailable, or how incomplete follow-up was handled. In general, missing outcomes can affect estimates if the participants without recorded outcomes differ systematically from those with complete information. No claim about the extent or consequences of missing data can be made from the posted information.
The registry enrollment is 297, and the reported adverse-event group lists 297 at risk. The record does not provide a participant flow, exclusions, or a definition of the population used for analysis. The event count should therefore be understood as the result recorded for the listed group, without assuming an unreported analysis population or missing-data procedure.
12. 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 |
|---|---|---|---|
| One Arm | 91 | 297 | 30.6% |
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 |
|---|---|
| One Arm | 0 of 297 |
Most frequent serious adverse event terms
| Event term | Organ system | One Arm |
|---|---|---|
| Serious Adverse cardiac events | Cardiac disorders | 91 of 297 |
Serious events with the highest arm-level rate: serious adverse cardiac events (30.6%).
The adverse-event entry lists one group with 297 participants at risk and 91 participants affected for serious adverse events. The registry’s serious-event term is “Serious Adverse cardiac events,” with 30.6% listed. This is a registry safety entry, separate from the primary endpoint description, although the event wording is similar. It should not be treated as a treatment-versus-control comparison because only one group is listed and allocation is not stated.
The entry also reports 297 at risk and 0 affected for the separate other-event field. The registry does not provide enough detail in the reported details to explain how that field relates to the serious-event entry, so the zero should be read only as the recorded count in that field. Deaths as a separate adverse-event count are not reported in the registry record. The primary composite includes death, but no component-specific event counts are given.
These entries describe recorded counts and do not establish that an intervention caused or prevented events. Because the listed arm is a single group of emergency surgery patients, there is no reported comparator from which to estimate a relative safety difference. Definitions, ascertainment methods, and timing for the adverse-event listing are not reported in the registry record.
13. What the Result Does, and Does Not, Mean
The record establishes that the study was registered as a prospective investigation of perioperative natriuretic peptides and adverse cardiac outcomes after emergency surgery. It reports enrollment of 297 participants, a primary composite endpoint, follow-up to a median of 34 months, and 91 participants with events in the reported group. It also documents the investigators’ hypothesis that perioperative peptide levels are associated with events.
Those details do not establish that peptide levels predicted outcomes. The peptide measurements and a statistical analysis relating them to the endpoint are not reported in the registry record. Without those results, readers cannot assess the direction or size of an association, its precision, or the performance of any prediction method. The recorded event count is not a substitute for a biomarker analysis.
The record also does not estimate a treatment effect. It lists a single “No treatment” arm, and does not report a comparison group or allocation method. The results therefore describe events in the listed group rather than showing that one treatment performed better or worse than another. No medical conclusion about treatment benefit or harm follows from this registry entry.
In general, a study can have an informative objective and a clearly defined outcome while still leaving its main inferential question unanswered in the registry record. Here, the endpoint definition and follow-up timeframe indicate what was intended to be measured, but the key association and uncertainty estimates are absent. The completed status does not resolve that limitation. Interpretation should remain bounded to the registry entries recorded: study objective, one-group design description, event count, and stated follow-up.
14. Why This Trial Matters Statistically
This study is statistically notable for the difference between its stated scientific aim and the results available in the registry record. The aim concerns prediction: whether perioperative natriuretic peptide levels can identify participants at risk of later cardiac events. The record gives an event count, but does not report the measurements or analysis needed to assess that prediction question. This distinction is important because a descriptive outcome count and evidence of predictive performance answer different questions.
The case also illustrates why design structure determines which inferences are possible. A single listed group can contribute information about observed outcomes in that group, but it cannot provide a randomized treatment contrast without a comparator. The “No treatment” label does not change that. Allocation is not stated, and the record does not present a like-for-like control comparison.
Composite endpoints require careful interpretation as well. Combining nonfatal myocardial infarction, acute heart failure, and death gives a single primary outcome, but the overall event count does not reveal which component contributed to it. Component results are not reported in the registry record, so the total cannot be decomposed.
Finally, the entry highlights the value of reporting analysis details alongside a completed study. Effect estimates, uncertainty, measurement definitions, missing-data handling, and analysis populations would help readers judge how precisely the research question was answered. Their absence does not prove that no analysis was performed; it means the registry record does not display the evidence needed to evaluate the stated predictive aim.
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.
The registry record does not report the perioperative natriuretic peptide values, measurement schedule, assay details, or how any measurements were incorporated into an analysis. Since the study’s stated objective concerns prediction from these measurements, this absence prevents assessment of the central research question. Model specification, effect estimates, uncertainty intervals, and predictive-performance results are also not reported in the registry record.
Only one group is listed, and no comparison group is described. Allocation is not stated. The record therefore does not support a randomized comparison or a causal estimate of treatment effect. The “No treatment” label should not be interpreted as evidence of a control arm.
The primary endpoint is a composite of nonfatal myocardial infarction, acute heart failure, or death. Counts for the separate components are not reported in the registry record, so it is not possible to determine which types of events contributed to the total. The timeframe extends to a median follow-up of 34 months, but individual follow-up durations, event timing, censoring, and outcome ascertainment details are not reported.
The registry lists three outcome measures but no posted analyses. The statistical plan, multiplicity handling, missing-data methods, participant flow, and analysis population are not reported in the registry record. These omissions limit evaluation of precision, robustness, and potential differences between enrolled and analyzed participants. The record’s completed status does not supply those missing details.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: Natriuretic Peptides - Predictors of In-hospital and Long-term Major Adverse Cardiac Events After Emergency Surgery? — NCT00942786.
- Registry record last updated 2015-06-29; status last verified 2015-06.
- Results first posted 2015-06-29.
- 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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19. Record Summary
This completed prospective study, sponsored by the Medical University of Graz, concerns perioperative natriuretic peptides and adverse cardiac outcomes after emergency surgery. Enrollment was 297; the registry records a start of 2008-02 and primary completion of 2014-01.
The listed group is consecutive patients undergoing emergency surgery, labeled “No treatment.” The primary endpoint is the number of participants with a composite of nonfatal myocardial infarction, acute heart failure, or death after the index surgery, through a median follow-up of 34 months. The reported group has 91 participants with events among 297 at risk.
The registry states the hypothesis that perioperative natriuretic peptide levels are associated with in-hospital and long-term events, but peptide results and analyses of that relationship are not reported in the registry record. The record lists three outcome measures and zero posted analyses. It does not describe a comparison group, a statistical analysis plan, or missing-data methods.