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 Reversing Ticagrelor's Effects With Fresh Platelets (NCT02201394), a non-randomized phase 4 study. The primary outcome is P2Y12 Reaction Unit (PRU).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02201394 |
| Phase | Phase 4 |
| Condition | Coronary Artery Disease |
| Allocation | Non-Randomized |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Icahn School of Medicine at Mount Sinai |
| Results posted | Yes |
2. Clinical Question
Population
Patients with stable cardiovascular disease (CVD) were the study population. The registry record reports enrollment of 20 participants. The study rationale refers to acute coronary syndrome patients taking antiplatelet drugs who may need coronary artery bypass grafting (CABG), but the enrolled population is described as patients with stable CVD.
Intervention
Participants received ticagrelor and aspirin, either as loading doses or as maintenance doses. Fresh donor platelets were added at different concentrations to blood samples from treated patients; the record describes supplementation levels of 0%, 25%, 50%, and 75%.
Comparator
This was a non-randomized, single-group study, not a randomized comparison of treatment groups. The supplementation concentrations permit assessment of platelet reactivity in the samples under different conditions, but the record does not describe a separate clinical control group.
Primary question
How does platelet reactivity, measured as P2Y12 Reaction Unit (PRU), vary after ticagrelor dosing and with different fresh-platelet concentrations in the treated blood samples? Measurements were planned at baseline and at stated post-dose timepoints through 48 hours.
The clinical motivation was the waiting period described for patients taking antiplatelet drugs before CABG: the brief summary states that they may have to wait 5-7 days for drug effects to wear off, leaving them vulnerable during that interval. This study addresses a laboratory question related to shortening that period. It investigates platelet reactivity in blood samples, not whether giving fresh platelets to patients changes clinical outcomes or makes surgery safer. The registry record does not report a clinical normalization threshold or numerical results answering the primary question.
3. Trial Design
This is a completed Phase 4 study with non-randomized allocation, no masking, and a single-group model. The registry record lists enrollment of 20 and identifies patients with stable CVD as the population. The study began in 2014-07, had primary completion in 2016-06, and is listed as completed. The sponsor is Icahn School of Medicine at Mount Sinai.
The record describes two dosing schedules. The loading-dose group received a single ticagrelor loading dose and aspirin loading dose. The maintenance-dose group received ticagrelor and aspirin maintenance doses for one week. The study then assessed platelet function in blood samples, adding fresh platelets at stated concentrations. This is distinct from administering fresh platelets to participants as a clinical treatment.
The primary measure was PRU, assessed with VerifyNow at baseline (pre-treatment) and at 4, 6, 24, and 48 hours after the loading dose or last maintenance dose. The endpoint description refers to platelet function normalization using 0%, 25%, 50%, and 75% fresh-platelet supplementation. The record does not specify a separate randomized control group, a masking procedure, or a like-for-like treatment comparison. The non-randomized allocation and single-group structure therefore limit interpretation of differences between dosing schedules as causal treatment effects.
The registry lists 2 outcome measures, but detailed information for another outcome is not reported in the registry record. The record contains no listed statistical analyses. It does not report a protocol-based sample-size justification, an interim-analysis plan, or the statistical analysis plan.
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.
Loading Dose
| Stage | Patients With Stable CVD |
|---|---|
| STARTED | 20 |
| COMPLETED | 20 |
| NOT COMPLETED | 0 |
Maintenance Dose
| Stage | Patients With Stable CVD |
|---|---|
| STARTED | 20 |
| COMPLETED | 20 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Patients with stable CVD
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 | Patients With Stable CVD |
|---|---|---|
| Participants analysed | 20 | |
| Age, Continuous | years | 56.9 (SD 7.9) |
| Sex: Female, Male: Female | Participants | 7 |
| Sex: Female, Male: Male | Participants | 13 |
| Diabetic | Participants | 15 |
| BMI | kg/m^2 | 30.7 (SD 4.5) |
| Hypertension | Participants | 16 |
| Systolic blood pressure | mm Hg | 127.2 (SD 17.5) |
| Diastolic blood pressure | mm Hg | 70.6 (SD 9.0) |
| Hypercholesterolemia | Participants | 19 |
| Cholesterol level | mg/dL | 158.7 (SD 62.0) |
| Triglycerides level | mg/dL | 165.4 (SD 91.4) |
| LDL level | mg/dL | 85.6 (SD 51.7) |
| HDL | mg/dL | 42.5 (SD 12.6) |
| Smoking History: Current | Participants | 2 |
| Smoking History: Past | Participants | 8 |
| Smoking History: Never | Participants | 10 |
| Alcohol Use: Current | Participants | 9 |
| Alcohol Use: Past | Participants | 3 |
| Alcohol Use: Never | Participants | 8 |
6. Primary Endpoint
The registry lists the primary outcome as P2Y12 Reaction Unit (PRU), measured over Baseline (pre-treatment), 4, 6, 24 and 48 hours post Loading dose/last Maintenance dose.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | PRU |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is P2Y12 Reaction Unit (PRU), a continuous measure of platelet reactivity. The record describes PRU as an arbitrary unit representing the amount of platelet aggregation specific to the P2Y12 receptor. It was assessed using VerifyNow. The endpoint is expressed as a mean with standard deviation, and the specified assessment times are baseline (pre-treatment), 4, 6, 24, and 48 hours after the loading dose or last maintenance dose.
The study’s stated purpose was to examine platelet-function normalization in samples treated with different concentrations of fresh platelets. PRU is relevant to that purpose because it quantifies platelet aggregation associated with the receptor targeted by ticagrelor. The repeated timepoints describe how measurements were intended to be followed after dosing; the supplementation levels describe the sample conditions used to assess potential changes in reactivity.
Mean PRU describes the average measured response for a group or condition. Standard deviation describes the spread of individual measurements around that mean; it is not a confidence interval and does not by itself show how precisely the mean has been estimated. No PRU means, standard deviations, or numerical comparisons are reported in the registry record. A threshold defining “normalization,” and the rule for determining that it had been reached, are also not reported in the registry record. Therefore, the endpoint description establishes what was to be measured, but does not establish whether or when platelet reactivity was normalized.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record states the intended endpoint and measurement schedule, but it does not report numerical PRU results. It also lists no analyses. Consequently, the record does not permit a numerical assessment of how PRU changed over time, whether measurements differed across supplementation conditions, or whether the pattern differed between the loading-dose and maintenance-dose schedules. No estimate of effect or measure of its precision can be interpreted from the information recorded.
The study design is important to that reading. Allocation was non-randomized, masking was absent, and the model was single-group. The record does not describe a randomized clinical control group. Any contrast among sample supplementation conditions would concern the samples and assay conditions described, rather than a randomized comparison of patient outcomes. The record does not report a prespecified comparison or statistical model for such contrasts, so their analysis cannot be reconstructed from the registry information.
The endpoint is a continuous laboratory measure reported in principle as a mean and standard deviation. In general, a difference in means describes the average separation between conditions, while a confidence interval describes the range of effect sizes compatible with the data under the analysis assumptions. A confidence interval’s width reflects precision; the registry record does not report one for this endpoint. A standard deviation describes variability among measurements and should not be read as uncertainty in the estimated mean.
The study’s motivating clinical situation concerns patients awaiting CABG after antiplatelet treatment, but the primary endpoint is PRU measured in blood samples. The registry record does not report surgical outcomes, bleeding outcomes, or evidence that sample-level changes translate into changes in patient care. It also does not report a threshold for normal platelet reactivity. Thus, the stated aim should be read as a laboratory investigation of platelet reactivity, not as a demonstrated change in clinical waiting time or outcome.
The adverse-event record lists 0 serious adverse events, 0 other adverse events, and 0 deaths for the group, with 20 at risk for each adverse-event category. These are recorded counts; they do not establish that no unrecorded or unobserved events occurred. The record does not provide further details on adverse-event collection or follow-up.
The registry’s sample-size description characterizes its calculations as planning illustrations based on an observed effect, rather than as the trial’s own design justification. Numerical sample-size illustrations and the underlying observed effect are not reported in the registry record. They cannot be used to infer the trial’s actual power or the precision of its endpoint estimates.
9. Statistical Methods Explained
What does a mean PRU represent?
PRU is a continuous measure of platelet reactivity specific to the P2Y12 receptor. A group mean gives the average value of the measurements in that group or condition. It is a compact description, not a complete account of the data: measurements can vary around the mean, and different distributions can share the same mean. The registry specifies standard deviation as the measure of dispersion. In general, standard deviation describes how spread out observations are around their mean. It does not describe the precision of the mean estimate; that requires an estimate of uncertainty, such as a confidence interval.
The registry record does not report numerical PRU means, standard deviations, or confidence intervals. It also does not provide a rule or cut-off for classifying PRU as normalized. The word “normalization” is part of the stated study objective, but the record does not define a numerical endpoint for deciding that normalization occurred. Without observed values and an operational definition, the degree of reactivity or the timing of any normalization cannot be assessed.
Why are timepoints and supplementation conditions relevant?
Repeated assessments can describe how a measure changes over time after dosing. Here, the specified assessments were at baseline (pre-treatment), 4, 6, 24, and 48 hours after the loading dose or last maintenance dose. The endpoint description also names fresh-platelet supplementation conditions of 0%, 25%, 50%, and 75%. In general, repeated measurements on the same participant or sample are related, so analyses should account for that dependence rather than treating every measurement as independent. The registry record does not report how repeated observations were modeled, or whether the statistical unit was the participant, sample, or another unit.
The supplementation conditions concern fresh platelets added to blood samples. They should not be interpreted as clinical treatment groups receiving fresh platelets. The registry describes the study as single-group and non-randomized, and does not specify a separate randomized comparison. It does not report the exact laboratory procedures for adding platelets or a statistical contrast among the concentrations.
How should uncertainty and comparisons be read?
In general, an effect estimate gives the direction and size of a contrast under a defined analysis, while a confidence interval describes the uncertainty around that estimate. A narrow interval indicates greater precision than a wide interval, though precision does not by itself establish clinical importance. A p-value, when reported, describes how compatible the data are with a specified null model under the analysis assumptions; it does not measure the probability that the null hypothesis is true. No effect estimates, confidence intervals, or p-values are reported in the registry record, and no statistical analyses are listed.
When a study examines multiple timepoints and supplementation conditions, it may make multiple comparisons. General statistical practice distinguishes a prespecified primary contrast from additional exploratory comparisons, and considers whether multiplicity adjustment is needed for the intended interpretation. The registry record does not report a hierarchy of comparisons, an adjustment method, or an analysis plan. It is therefore not possible to determine which contrast, if any, was intended to provide the main inferential result.
What can the sample-size information establish?
The registry’s sample-size description labels its calculations as planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. Those assumptions describe illustrative planning calculations, not observed trial results or observed power. The registry record does not report the numerical observed effect or the resulting sample-size values, so their implications cannot be evaluated. The record also does not report a trial-specific sample-size justification.
In general, power calculations depend on assumptions about the effect to detect, variability, significance level, allocation, and analysis. A planning calculation is not evidence that a study was adequately powered for every endpoint or comparison. Nor can a calculation based on an observed effect be treated as a prospective design rationale unless the timing and method of that calculation are documented. Those details are not reported in the registry record.
What statistical details remain unknown?
The record does not report how missing measurements were handled, which analysis population was used, whether analyses adjusted for baseline measurements, or what model accounted for repeated assessments. It does not report diagnostic checks, a distributional assumption for PRU, a missing-data strategy, or procedures for multiple comparisons. These are general issues that can affect analysis of a continuous repeated-measures endpoint. Their absence from the registry record means the results cannot be independently interpreted through those methodological details. It does not establish which approach was used outside the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The primary endpoint description includes multiple assessment times and fresh-platelet supplementation conditions, and the study has loading-dose and maintenance-dose schedules. Examining several conditions or timepoints can create multiple possible contrasts. In general, the more comparisons that are considered, the greater the chance that at least one appears unusual by chance if each is assessed independently. A statistical plan can address this by defining a primary comparison, distinguishing confirmatory from exploratory analyses, and specifying any multiplicity adjustment.
The registry record does not report a hierarchy of endpoint comparisons, a multiplicity adjustment, or an analysis plan. It lists 2 outcome measures, but details for the other outcome are not reported in the registry record. No listed analyses are available to clarify which comparisons were performed or how they were interpreted.
Missing-data handling and analysis populations are also not reported in the registry record. The record does not say how many endpoint observations were available at each timepoint, whether any measurements were missing, how missing values were treated, or whether all enrolled participants were included in each analysis. It does not describe an intention-to-treat, per-protocol, or other analysis population. These omissions matter because repeated measurements may not be available for every participant or condition, and the analysis population can affect the interpretation of estimates.
General statistical practice would describe the handling of missing observations and the assumptions used to analyze them. The registry record does not provide those details, so no claim about completeness or the potential influence of missingness can be made.
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 |
|---|---|---|---|
| Patients With Stable CVD | 0 | 20 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Patients With Stable CVD | 0 of 20 |
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 |
|---|---|
| Patients With Stable CVD | 0 of 20 |
The registry lists one group, titled Patients With Stable CVD. It records 20 participants at risk for serious adverse events and 0 affected, 20 at risk for other adverse events and 0 affected, and 0 deaths. These are the adverse-event counts recorded for the group in the registry.
A count of 0 means no events were recorded in that category in this entry; it should not be interpreted as proof that an event could not occur, or that every possible event was detected. The registry record does not provide additional detail about how adverse events were collected, how long participants were monitored for safety, or how events were attributed to study procedures or drug dosing. It also does not list serious adverse-event terms.
These safety figures do not answer the primary laboratory question about PRU. They should be read separately from the platelet-reactivity endpoint. The study description concerns adding fresh platelets to blood samples; the adverse-event record alone does not establish the safety of administering fresh platelets to patients.
12. What the Result Does, and Does Not, Mean
The record establishes that this completed study was designed to investigate platelet reactivity after ticagrelor and aspirin dosing, with fresh donor platelets added to blood samples at different concentrations. It identifies PRU as the primary endpoint and specifies baseline and post-dose assessment times through 48 hours. It also describes loading-dose and maintenance-dose schedules in patients with stable CVD.
It does not report numerical PRU results, statistical analyses, or a defined threshold for normalization. As a result, the registry record does not show whether reactivity changed, whether one supplementation condition differed from another, or how precisely any such difference was estimated. It cannot establish when normalization occurred or whether the pattern differed between dosing schedules.
The clinical rationale refers to patients who may wait 5-7 days before CABG while antiplatelet effects wear off. However, the endpoint described is a laboratory measurement in blood samples. The record does not report clinical outcomes such as time to surgery, bleeding, or other consequences for patients. A sample-level PRU result, even if available, would not by itself establish a clinical benefit or harm.
The non-randomized, single-group design and absence of masking also limit the kinds of comparisons that can be supported. The registry does not describe a randomized control group or a statistical plan for comparing conditions. The appropriate conclusion is therefore limited: the record documents the research question, design, endpoint, and safety counts, but does not contain the outcome results needed to answer the primary question.
13. Why This Trial Matters Statistically
This study raises a focused measurement question: whether platelet reactivity in blood samples after ticagrelor dosing varies when fresh donor platelets are added at different concentrations. The question connects a receptor-specific laboratory measure, PRU, with a clinical motivation involving antiplatelet treatment before CABG. Statistically, it illustrates the importance of separating a biological measurement in a sample from a clinical outcome in a patient.
The design also highlights the role of comparison structure. Non-randomized allocation and a single-group model do not provide the same basis for causal inference as a randomized controlled comparison. The different dosing schedules and supplementation conditions may be informative descriptively, but interpretation depends on clearly stated contrasts and an analysis that accounts for the measurement structure. Those details are not reported in the registry record.
Repeated measurements over time and across sample conditions create practical analysis questions: how to handle dependence among observations, define the primary comparison, describe uncertainty, and address multiple comparisons and missing observations. The registry record does not report the statistical methods needed to assess those issues. Nor does it include numerical endpoint results. This makes the study a useful example of why registration details and posted outcome data serve different purposes: design and endpoint descriptions explain what was intended, while estimates and their uncertainty are needed to judge what the data show.
The recorded safety counts are also distinct from the laboratory endpoint and do not establish the safety of a clinical platelet intervention. Keeping the population, sample procedures, endpoint, and clinical motivation separate is essential to a statistically careful reading.
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 registry record does not report numerical results for the primary endpoint, despite describing its measurement and timing. It lists 2 outcome measures, but detailed information about the other outcome is not reported in the registry record. No statistical analyses are listed, so effect estimates, uncertainty intervals, and the approach used to compare conditions are unavailable.
The population is described as patients with stable CVD, while the rationale discusses acute coronary syndrome patients who may require CABG. The record does not explain how closely the enrolled population represents the clinical scenario in the rationale. The study assesses platelet function in samples after drug dosing; it does not report a clinical comparison of surgery timing or outcomes.
The study is non-randomized, unmasked, and single-group. The registry does not describe a separate randomized control group, a prespecified contrast, or how differences between the dosing schedules were to be interpreted. It does not report a numerical definition of platelet-function normalization, laboratory analysis details, handling of repeated observations, or a missing-data approach.
The record also does not report the statistical analysis plan, analysis populations, or protocol-based sample-size justification. Its sample-size description refers to planning illustrations based on an observed effect, but numerical calculations and the underlying effect are not reported in the registry record. Finally, adverse-event collection and follow-up details are not reported. These limitations restrict interpretation of both the intended endpoint and the recorded safety counts.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Reversing Ticagrelor's Effects With Fresh Platelets — NCT02201394.
- Registry record last updated 2017-12-05; status last verified 2017-10.
- Results first posted 2017-12-05.
- 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
NCT02201394, “Reversing Ticagrelor's Effects With Fresh Platelets,” is a completed Phase 4, non-randomized, unmasked, single-group study sponsored by Icahn School of Medicine at Mount Sinai. The registry lists enrollment of 20 patients with stable CVD. The study began in 2014-07 and had primary completion in 2016-06.
Participants received ticagrelor and aspirin as loading doses or maintenance doses. Fresh donor platelets were added to treated blood samples at concentrations described as 0%, 25%, 50%, and 75%. The primary endpoint was mean PRU, with standard deviation, assessed at baseline and at 4, 6, 24, and 48 hours after the loading dose or last maintenance dose.
The registry lists 2 outcome measures and no analyses. Numerical primary-endpoint results, detailed information for another outcome, and the statistical analysis plan are not reported in the registry record. The adverse-event entry records 0 serious adverse events, 0 other adverse events, and 0 deaths.