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 Controlling Rapid Atrial Fibrillation With Dexmedetomidine (NCT04042727), a randomized phase 2, phase 3 study. The primary outcome is Mean Systolic Blood Pressure.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04042727 |
| Phase | Phase 2, Phase 3 |
| Condition | Rapid Atrial Fibrillation, Heart Rate Control |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 13 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Stony Brook University |
| Results posted | Yes |
2. Clinical Question
Population
The intended population was patients in intensive care with rapid atrial fibrillation. The registry describes standard care as being determined as necessary by the patient's ICU team. The record does not report further eligibility details, such as specific heart-rate criteria or exclusions.
Intervention
The intervention was dexmedetomidine hydrochloride added to standard of care. The arm description specifies an intravenous infusion at 1mcg/kg/hr for 8 hrs. Standard care could be given as deemed necessary by the patient's ICU team.
Comparator
The comparator was normal saline placebo plus standard of care. The saline infusion is described at 1mcg/kg/hr for 8 hrs, alongside usual care as deemed necessary by the ICU team. The registry describes the study as randomized and double blinded in its summary.
Primary question
The listed primary endpoint was mean systolic blood pressure during the study-drug infusion period, assessed between the arms. The study summary describes an aim of assessing dexmedetomidine's effects on heart-rate control, but the posted primary endpoint is blood pressure. The endpoint data were not collected because of protocol termination, so the registry record does not answer whether the arms differed on this measure.
3. Trial Design
C-RAD was a randomized, parallel-group trial sponsored by Stony Brook University. Its registry phase designation is phase 2 and phase 3. The record classifies masking as quadruple; the brief summary describes the study as double blinded. It does not identify which people or roles were masked, so the exact masking arrangement cannot be inferred.
The intended comparison was dexmedetomidine plus standard care against normal saline plus standard care in patients with rapid atrial fibrillation. Both infusions were described as intravenous, at 1mcg/kg/hr for 8 hrs. The ICU team could provide standard care as deemed necessary. Thus, the comparison concerned adding the assigned infusion to usual care rather than replacing usual care.
The registry lists enrollment of 13 and gives the trial status as terminated. The listed primary completion date is 2021-12-31. The primary endpoint entry explicitly says that data were not collected because of protocol termination. Although the registry describes the study as randomized, the record does not report the randomization sequence, allocation concealment, or any analysis of baseline comparability.
The available record therefore describes the planned comparison and design, but not a completed efficacy comparison. It does not report results for heart rate, and the listed primary blood-pressure outcome has no collected data. Details of recruitment, reasons for termination, and any changes to the planned design 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 | Dexmedetomidine Plus Standard of Care | Placebo Plus Standard of Care |
|---|---|---|
| STARTED | 6 | 7 |
| COMPLETED | 6 | 7 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Data not collected because of protocol termination
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 | Dexmedetomidine Plus Standard of Care | Placebo Plus Standard of Care | Total |
|---|---|---|---|---|
| Participants analysed | 6 | 7 | 13 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 2 | 1 | 3 |
| Age, Categorical: >=65 years | Participants | 4 | 6 | 10 |
| Age, Continuous | years | 69.3 (SD 19.3) | 72.3 (SD 5.15) | 70.9 (SD 13.1) |
| Sex: Female, Male: Female | Participants | 2 | 3 | 5 |
| Sex: Female, Male: Male | Participants | 4 | 4 | 8 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 2 | 0 | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): White | Participants | 4 | 6 | 10 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 6 | 7 | 13 |
6. Primary Endpoint
The registry lists the primary outcome as Mean Systolic Blood Pressure, measured over During Study Drug Infusion Period.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is mean systolic blood pressure during the study-drug infusion period. The registry describes it as a comparison of measurements between the dexmedetomidine-plus-standard-care and placebo-plus-standard-care arms. No unit, summary parameter beyond the mean, or dispersion measure is reported.
As a general statistical consideration, systolic blood pressure describes one aspect of hemodynamic status. A mean over a defined observation period can provide a concise way to compare the average recorded level between groups. It can also obscure variation over time or differences among individuals, so the mean alone does not describe the full distribution of measurements. Those are general properties of mean-based endpoints, not additional details of this trial's analysis.
The registry does not state why this endpoint was selected or how individual measurements were to be combined into the endpoint. Most importantly, it says the data were not collected because of protocol termination. There is therefore no reported endpoint mean, between-arm estimate, or measure of its precision.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record supports a description of the study's design and planned endpoint, but it does not support an estimate of the treatment contrast. The primary outcome entry states that data were not collected because of protocol termination. No analysis results are listed. Consequently, there is no reported difference in mean systolic blood pressure, confidence interval, or test result to interpret.
The study summary describes heart-rate control as the broader aim, while the named primary endpoint is mean systolic blood pressure during infusion. The registry record does not report a heart-rate outcome result. The distinction matters: an aim stated in a summary is not itself evidence that the intended comparison was measured or that a result was obtained.
Enrollment is listed as 13, and the adverse-event groups list 6 and 7 participants at risk. These counts provide context for the registry record, but they do not replace outcome data. The presence of enrollment does not establish that the primary endpoint was recorded, and the endpoint entry explicitly says it was not. The record does not report why the protocol was terminated or whether any observations were available for other outcomes.
Without an estimated between-arm effect and its uncertainty, the findings cannot establish the direction or size of a blood-pressure difference. Nor can the record show whether a possible difference would be precise or compatible with a range of effects. A confidence interval, in general, expresses uncertainty around an estimate; none is reported for this endpoint. A significance test also cannot be interpreted without a reported analysis result.
The appropriate reading is therefore that the intended randomized comparison is documented, but the registry record does not provide an efficacy result for its primary endpoint. The absence of a result is not evidence that the arms were equivalent, and it does not establish that one approach was better. It means the primary comparison cannot be evaluated from the posted outcome information.
9. Statistical Methods Explained
What does randomization contribute?
In general, random assignment is intended to make treatment allocation independent of participants' measured and unmeasured characteristics, apart from chance. This can support a fair comparison between groups when outcomes are collected and analyzed according to a suitable plan. Randomization does not guarantee that groups will be identical, especially in a small trial, and it does not resolve missing outcome data. The registry classifies C-RAD as randomized, but the sequence-generation and allocation-concealment procedures are not reported in the registry record.
What does a parallel-group design mean?
In a parallel design, participants are assigned to one of the study arms, and the arms are compared over the study period. Here the planned arms were dexmedetomidine plus standard care and saline placebo plus standard care. In general, a between-group analysis would compare an outcome summary across the assigned arms. The registry does not report the specific analysis method planned for the blood-pressure endpoint, and no analysis is listed.
Why does masking matter?
In general, masking can reduce the risk that knowledge of an assigned treatment influences care, outcome assessment, or reporting. The record classifies masking as quadruple, while its brief summary calls the trial double blinded. It does not say which roles were masked or how masking was maintained. Those operational details, and any assessment of whether masking was successful, are not reported in the registry record.
How should a mean endpoint be understood?
A mean is a summary of recorded values. For a continuous measurement such as systolic blood pressure, a group mean can be compared with another group's mean, or an adjusted model can estimate a contrast while accounting for selected covariates. These are general options, not methods confirmed for this trial. The registry gives no unit, standard deviation, standard error, or other dispersion measure, and no blood-pressure observations were collected according to the endpoint entry. It is therefore impossible to reconstruct an unadjusted estimate from the posted outcome information.
Repeated measurements can require a method that accounts for correlation among observations from the same participant. If a protocol defines one mean per participant over an observation period, the analysis might instead compare those participant-level summaries. The registry describes mean systolic blood pressure during the infusion period but does not specify the measurement schedule, aggregation rule, or statistical model. These details are not reported in the registry record and should not be assumed.
What would uncertainty measures say?
In general, a confidence interval communicates the range of effect estimates compatible with the observed data under the chosen model and its assumptions. Its width reflects precision: less precise estimates generally have wider intervals. A hypothesis test addresses compatibility with a specified null model, but a p-value does not measure the size or clinical importance of an effect. Neither an interval nor a test result is reported for the primary endpoint. Because the endpoint was not collected, there is no posted effect estimate whose precision or statistical compatibility can be evaluated.
What about distributional assumptions?
Methods for continuous outcomes often rely on assumptions about the outcome distribution, residuals, or the sampling distribution of an estimate. General alternatives may be considered when those assumptions are unsuitable, depending on the data and design. Over-dispersion is a concern in some count-data models when variability exceeds what a chosen model expects; it is not a basis for interpreting this unobserved continuous endpoint. The registry does not report a statistical model, diagnostics, transformation, or alternative analysis. Since no endpoint data were collected, assumptions cannot be checked against trial observations.
Can planning calculations be read as trial results?
No. A planning illustration is conditional on its assumptions and is not an observed treatment effect or observed power. The registry record does not report a sample-size justification or a statistical plan. With no collected primary endpoint data and no reported analysis, a planning calculation cannot supply the missing treatment estimate. Any effect size or precision implied by an illustration should be kept separate from evidence actually observed in the trial.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure, but it does not report an analysis for that outcome. The primary endpoint entry states that data were not collected because of protocol termination. No analysis results are listed, and the statistical analysis plan is not reported in the registry record.
Multiplicity arises when a study makes several statistical comparisons, for example across outcomes, time points, treatment groups, or analysis populations. In general, conducting multiple tests can increase the chance of obtaining at least one apparently notable result by chance. A prespecified strategy may define which comparisons are primary and whether or how error rates are controlled. The registry record does not report a multiplicity strategy, adjustment, hierarchy of outcomes, or planned contrast details. In the absence of an analysis result, there is no multiplicity-adjusted or unadjusted finding to interpret.
Missing-data handling is also not reported in the registry record. The endpoint note attributes the absence of data to protocol termination; it does not describe partial measurements, reasons for missingness at the participant level, imputation, or sensitivity analyses. The record likewise does not define the analysis population, such as whether an intention-to-treat or per-protocol approach was planned. These omissions limit what can be concluded about analysis procedures, but they do not justify assuming that any particular method was used.
In general, missing-data methods cannot recover information without assumptions about why data are missing and how the unobserved values relate to observed information. Here, the primary endpoint itself is reported as not collected, so no endpoint-based comparison can be evaluated from the registry record.
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 |
|---|---|---|---|
| Dexmedetomidine Plus Standard of Care | 0 | 6 | 0.0% |
| Placebo Plus Standard of Care | 0 | 7 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Dexmedetomidine Plus Standard of Care | 0 of 6 |
| Placebo Plus Standard of Care | 0 of 7 |
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 |
|---|---|
| Dexmedetomidine Plus Standard of Care | 0 of 6 |
| Placebo Plus Standard of Care | 0 of 7 |
The registry lists the dexmedetomidine-plus-standard-care group with 6 at risk for serious adverse events and 0 affected. It lists 6 at risk for other adverse events and 0 affected. The placebo-plus-standard-care group has 7 at risk for serious adverse events and 0 affected, and 7 at risk for other adverse events and 0 affected. Deaths are listed as 0 in each group.
These are the posted event counts, not a complete characterization of safety. The registry record does not provide event terms, timing, severity grading beyond the serious/other categories, or detail about how events were collected. No serious adverse-event terms are listed. The counts should be read as what the record reports, not as proof that no events occurred outside the recorded information or that the treatments have equivalent safety. The small amount of recorded enrollment and the absence of detailed event information limit interpretation.
12. What the Result Does, and Does Not, Mean
The record shows that a randomized parallel-group study was planned to compare dexmedetomidine plus standard care with saline placebo plus standard care in patients with rapid atrial fibrillation. It specifies an infusion period and identifies mean systolic blood pressure during that period as the primary endpoint. These details describe the intended question and design.
The record does not show the answer to that primary question. It explicitly states that endpoint data were not collected because the protocol was terminated, and it lists no analyses. Therefore, there is no observed blood-pressure contrast to characterize as favorable, unfavorable, or neutral. No conclusion about an effect on heart rate is supported by a reported heart-rate result either.
In general, a non-significant test would not prove equivalence, and a missing test result is not a non-significant result. Equivalence requires a suitable design, a prespecified margin, and an estimate sufficiently precise to rule out differences beyond that margin. The registry record does not report such a margin or an equivalence analysis. It also does not support a conclusion that there was no effect; the underlying primary outcome data were not collected.
The posted adverse-event counts record 0 serious events, 0 other events, and 0 deaths in each arm, with the arm-specific at-risk counts listed in the safety information. Those entries do not establish comparative safety or rule out unrecorded events. The registry record does not explain termination, so the reason for ending the trial should not be inferred from the outcome or safety entries.
Overall, the record is informative about the planned comparison and the fact that the primary endpoint was not obtained. It does not establish efficacy, lack of efficacy, equivalence, or a definitive safety comparison.
13. Why This Trial Matters Statistically
This trial illustrates why design information and outcome evidence need to be distinguished. Randomization, masking, a defined comparator, and a specified primary endpoint describe how a study intends to answer a question. They do not themselves provide an estimate of the difference between groups. For C-RAD, the registry documents those design features but also states that the primary endpoint data were not collected.
That distinction is important when interpreting a clinical-trial record. A listed enrollment value and a completed or expected study period do not mean that the planned outcome was measured or analyzed. Similarly, an aim described in the summary is not a substitute for a reported result. Readers need an endpoint estimate and information about its uncertainty to assess what the data can establish; neither is available for the primary endpoint.
The record also demonstrates the limits of sparse safety summaries. Zero event counts are descriptive entries, but without event details and fuller follow-up information they do not establish that the arms have the same safety profile. Clear reporting of outcome collection, analysis populations, missingness, and reasons for termination would help readers understand how far a record can support a conclusion. Those details are not reported in the registry record.
Statistically, the central lesson is not about which arm had the better outcome: there is no primary-outcome comparison to make. It is about recognizing when the planned inferential question cannot be answered from the posted results and avoiding treating missing findings as evidence of no difference.
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 says primary endpoint data were not collected because of protocol termination. Consequently, the record contains no estimate of mean systolic blood pressure by arm, no between-arm effect, and no measure of uncertainty. The reason for termination is not reported in the registry record, so it cannot be linked to any outcome or safety finding.
The trial is listed with enrollment of 13, and the registry gives arm-specific at-risk counts for adverse-event reporting. The limited enrollment context and lack of primary outcome data prevent meaningful assessment of the planned comparison. The record does not report recruitment details, baseline characteristics, adherence, treatment exposure beyond the stated infusion description, or the number of measurements intended per participant.
Methodological details relevant to interpretation are also absent: the randomization procedure, allocation concealment, the roles covered by masking, endpoint measurement and aggregation rules, the statistical model, missing-data methods, analysis populations, and multiplicity handling are not reported in the registry record. No outcome analysis is listed. The registry does not provide a sample-size justification or explain whether the planned design changed before termination.
These limitations mean that the intended study question cannot be answered using the posted primary endpoint information. They should not be replaced with assumptions about why the study stopped, what analyses might have been planned, or what uncollected results would have shown.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Controlling Rapid Atrial Fibrillation With Dexmedetomidine — NCT04042727.
- Registry record last updated 2024-06-04; status last verified 2024-06.
- Results first posted 2024-06-04.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT04042727, titled “Controlling Rapid Atrial Fibrillation With Dexmedetomidine,” is listed as a randomized, quadruple-masked, parallel phase 2 and phase 3 trial sponsored by Stony Brook University. The planned arms were dexmedetomidine plus standard care and normal saline placebo plus standard care. Each infusion was described at 1mcg/kg/hr for 8 hrs.
The registry lists enrollment of 13 and status as terminated. Mean systolic blood pressure during the study-drug infusion period was the primary endpoint, but its entry says data were not collected because of protocol termination. No analyses are listed. The posted adverse-event information reports 0 serious events, 0 other events, and 0 deaths in each arm. The registry record does not provide an efficacy comparison or explain the reason for termination.