An Exploratory stuDy of effectIveneSs and Safety of rivarOxaban in Patients With Left VEntricular Thrombus (R-DISSOLVE): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for An Exploratory stuDy of effectIveneSs and Safety of rivarOxaban in Patients With Left VEntricular Thrombus (R-DISSOLVE) (NCT04970381), a na na study. The primary outcome is Number of Participants With Left Ventricular Thrombus Resolution at 12 Weeks/Number of Participants at 12 Weeks.

2. Clinical Question

The study’s broader stated purpose was to examine the effect of rivaroxaban therapy using contrast echocardiography before and after treatment, and to provide data relevant to treatment outcomes, treatment duration and factors that may influence outcomes. These aims are exploratory: without a concurrent control group, a change between assessments cannot by itself separate a treatment effect from other explanations, such as the course of the condition or differences in who was assessed at each time.

The registry also lists secondary outcomes concerning thrombus resolution at 6 weeks and resolution or reduction at 6 and 12 weeks. These outcomes address different aspects of the imaging finding and different assessment times. The record does not give their results. Thus, the central clinical question is clear from the registered endpoint, but the posted registry information does not establish how often resolution occurred or how that frequency compares with an alternative.

3. Trial Design

R-DISSOLVE is registered as an exploratory study of rivaroxaban in patients with left ventricular thrombus. The record lists the study as completed, with enrollment of 75, a start date of 2020-09-27 and a primary completion date of 2022-10-30. China National Center for Cardiovascular Diseases is listed as the sponsor. The phase and allocation fields are recorded as NA.

The design is single-group and unmasked. Participants with ventricular mural thrombus received rivaroxaban anticoagulant therapy for 12 weeks. The recorded typical dosage was 20mg once daily, with 15mg once daily specified for patients on dual antiplateletagents or with creatinine clearance of 30-50mL/min. The registry’s description of the dosage does not, by itself, establish how many participants received each regimen.

Because there is no concurrent control group, the study can describe outcomes among participants treated in this study, but it cannot directly estimate a treatment contrast against another intervention. A before-and-after assessment can document findings at different times, yet the design alone cannot determine whether any observed change was caused by rivaroxaban. The absence of masking may also matter when outcomes involve assessment or decisions that could be influenced by knowledge of treatment; the registry record does not report further assessment procedures.

The registry lists a primary endpoint of thrombus resolution at 12 weeks, along with secondary outcomes on resolution at 6 weeks and resolution or reduction at 6 and 12 weeks. The record does not report the primary outcome result, results for the secondary outcomes, or analysis methods. It also does not report a detailed protocol, eligibility criteria, participant flow, or the statistical plan. Those omissions limit how fully the registered study can be evaluated from the registry record alone.

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

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.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Left Ventricular Thrombus Resolution at 12 Weeks/Number of Participants at 12 Weeks, measured over 12 weeks.

The primary endpoint counts participants with left ventricular thrombus resolution at 12 weeks and relates that count to the number of participants at 12 weeks. In plain terms, it is a binary outcome for each assessed participant: resolution was either recorded or not recorded. The registry describes the endpoint as a rate, but no observed count, denominator or rate is reported in the registry record.

Imaging-based resolution is a clinically interpretable way to describe whether the thrombus finding is present at the specified follow-up. It focuses on a defined finding at a defined time, rather than combining different outcomes such as reduction in size, symptoms or adverse events. The secondary outcomes make this distinction explicit by separately including resolution and resolution or reduction.

As a binary endpoint, the main summary would ordinarily be the proportion of assessed participants with resolution, accompanied by a measure of uncertainty. A confidence interval, in general, describes a range of values compatible with the data under a specified statistical method; it helps show precision, not whether a treatment caused the outcome. Neither the endpoint result nor its uncertainty is reported in the registry record. The endpoint therefore identifies what the study intended to measure, but the available record does not support a numerical conclusion about the frequency of resolution.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a binary endpoint summarize?

In general, a binary endpoint assigns each assessed participant to an outcome category, such as resolution or no recorded resolution. The natural summary is the number in the category of interest together with the number assessed. Dividing those quantities gives a proportion, often expressed as a rate in registry wording. The denominator is essential: a count without the number assessed does not show how common the outcome was in the group being summarized. For R-DISSOLVE, the primary endpoint is defined in this way, but its count and denominator are not reported in the registry record.

A proportion is a descriptive estimate for the participants included in that assessment. It is not automatically an estimate of what would occur in another population, and it is not by itself evidence that treatment caused the outcome. Interpretation depends on study design, how outcome assessments were made, which participants were included, and whether outcomes were missing.

What would a confidence interval add?

In general, a confidence interval communicates the statistical precision of an estimate. A narrower interval indicates less sampling uncertainty under the chosen method, while a wider interval indicates more uncertainty. An interval does not account automatically for every source of bias, and it cannot repair weaknesses in a study design. For a single-group proportion, an interval would describe uncertainty around the observed proportion in that group; it would not create a comparison with an untreated or alternative-treatment group.

The registry record does not report an interval for the primary endpoint, or the result needed to assess its precision. It also does not specify the method used to calculate uncertainty. Therefore, no particular interval method or precision claim can be attributed to the registry analysis.

Why does the study structure affect inference?

In general, a randomized controlled comparison can help distinguish treatment-related differences from background changes by assigning participants to comparison groups under a prespecified allocation process. R-DISSOLVE is listed as single-group, with allocation recorded as NA. Its design supports a description of outcomes among treated participants, but not a randomized comparison. An observed change from an earlier assessment to a later assessment would still have alternative explanations, including natural change over time and differences in follow-up.

The study is also listed as unmasked. In general, masking can reduce the possibility that knowledge of treatment influences outcome assessment or other study procedures. Its relevance depends on how outcomes are measured and how much judgment is involved. The registry record does not provide enough information about assessment procedures to determine the extent of any such influence.

What do the planning assumptions mean?

In general, sample-size calculations are planning exercises based on assumptions about the effect to detect, the significance level, allocation, and statistical method. They are not evidence that a study had a particular chance of detecting an effect after the results are observed. The registry record includes planning-illustration assumptions: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The illustrations are explicitly not the trial’s own design. They should not be interpreted as the actual design of this single-group study or as observed power.

The record does not report a sample-size justification for the trial itself. It also does not report a hypothesized primary-outcome value or a detailed statistical plan. Without those details, the planning assumptions cannot be used to infer how the study was designed or how its primary result was analyzed.

What can be learned from the reported counts?

Counts of participants with events are descriptive summaries. Their interpretation depends on what the registry means by each category, the period during which events were collected, and whether a participant could appear in more than one category. The safety entries give at-risk and affected counts for serious and other adverse events, plus a death count and a percentage for rehospitalization among the top serious terms. They do not provide a comparative risk estimate or establish cause. No inferential analysis is listed in the registry record, and the outcome analyses are not reported there.

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("Rivaroxaban")
n      <- c(64)
events <- c(50)
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  Rivaroxaban  64  50  78.1  66.0  87.5  66.6  86.5  66.5  86.5

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome of left ventricular thrombus resolution at 12 weeks and secondary outcomes covering resolution at 6 weeks and resolution or reduction at 6 and 12 weeks. It reports 4 outcome measures and 0 analyses. The listed outcomes differ by assessment time and by whether they count resolution alone or resolution together with reduction. Looking at several outcomes can raise a multiplicity question: when many statistical tests are performed, the chance of at least one apparently notable result can increase. In general, a prespecified primary outcome helps focus interpretation, while a prespecified approach to secondary analyses clarifies whether they are confirmatory or exploratory.

The registry record does not report a multiplicity adjustment, a hierarchy among secondary outcomes, or inferential results. It is therefore not possible to determine how any multiplicity concerns were handled in the study’s analysis. The exploratory framing is relevant, but it does not substitute for a reported analysis plan.

Missing data are also important for the primary endpoint because the denominator is the number assessed at 12 weeks. The registry record does not give that denominator or explain whether any enrolled participants lacked follow-up imaging. It does not report how missing outcomes were handled, whether all enrolled participants were included in an analysis population, or whether results were analyzed according to a prespecified population definition. Without participant flow and missing-data methods, the effect of incomplete assessments cannot be evaluated.

The record also does not describe interim analyses or the statistical plan. These items are not reported in the registry record and should not be inferred from the completed status or from planning illustrations.

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: rehospitalization (9.3%).

The registry lists 75 participants at risk for serious adverse events and 7 affected. For other adverse events, it lists 75 at risk and 1 affected. It separately records 2 deaths. Rehospitalization is listed among the top serious terms at 9.3%. These entries are descriptive safety information; they do not provide a comparison with another group.

The counts should not be combined or treated as mutually exclusive categories. The registry record does not say whether a participant could experience more than one event, whether deaths overlap with adverse-event categories, or whether the event counts represent people or event occurrences in every field. The serious-term percentage should be read as the registry’s reported percentage, not recalculated from other entries.

The listed counts do not establish that rivaroxaban caused an event, and they do not by themselves quantify comparative safety. Interpretation would require details such as event definitions, collection and follow-up procedures, and the relationship of events to treatment. Those details are not reported in the registry record. The listed deaths are not characterized further, so their cause or relationship to treatment cannot be inferred.

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

The record documents an exploratory, completed, single-group study of rivaroxaban therapy for 12 weeks in patients with left ventricular thrombus. It identifies thrombus resolution at 12 weeks as the primary endpoint and lists additional imaging outcomes at 6 and 12 weeks. These details describe the study question and planned outcome measures; they are not the outcome findings.

The primary outcome count, number assessed and rate are not reported in the registry record. The secondary outcome results are not reported either. As a result, the posted information does not show how frequently thrombus resolution or reduction occurred. It also does not provide an estimate of uncertainty for those outcomes. The registry’s enrollment figure cannot substitute for the endpoint denominator, since the number assessed at follow-up is not stated.

The single-group design also limits what the study can establish. Even if a change had been reported, without a concurrent comparator it would not isolate the effect of rivaroxaban from other possible influences. The record therefore does not support a causal comparison with another treatment or with no treatment.

The safety entries describe serious adverse events, other adverse events, deaths and rehospitalization in the study group. They do not show how those counts compare with another group, establish event causation, or resolve whether categories overlap. In general, the value of a study record lies partly in making its questions and methods visible; conclusions about outcomes, precision and comparative effects require the relevant results and analysis details. Those are not reported in the registry record for the primary endpoint.

14. Why This Trial Matters Statistically

This study is statistically instructive because the registered endpoint and the study design answer different parts of a clinical question. The endpoint specifies a measurable finding—left ventricular thrombus resolution at 12 weeks—while the single-group design determines the kind of inference that can be drawn. A clearly defined endpoint does not, on its own, establish a treatment effect. Comparative causal inference generally requires a suitable comparison and methods that address differences between groups.

The record also illustrates why outcome denominators matter. A count of participants with resolution would need to be interpreted alongside the number assessed at 12 weeks. Enrollment of 75 describes the registered study size, not necessarily the follow-up denominator. Since the endpoint result and denominator are not reported, the primary outcome cannot be summarized quantitatively from the registry record.

Its exploratory objectives and multiple registered imaging outcomes also highlight the value of distinguishing a primary endpoint from secondary measures. Resolution is not identical to reduction, and outcomes measured at different times address different questions. Clear reporting of which outcomes were analyzed, how uncertainty was quantified, and how missing assessments were handled would make the results easier to interpret. Those analysis details are not reported in the registry record.

Finally, safety counts need their own context. Counts and a reported percentage can describe what was recorded in a study group, but without a comparator and additional event details they do not establish relative safety or causation. The registry record therefore serves as a useful example of why statistical interpretation depends not only on the endpoint definition, but also on study structure, follow-up, denominators and transparent reporting.

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 main limitation for interpreting efficacy is that the registry record does not report the primary endpoint result. It gives neither the number of participants with thrombus resolution at 12 weeks nor the number assessed at that time. Results for the listed secondary outcomes are also not reported. Accordingly, outcome frequency and statistical precision cannot be evaluated from this record.

The single-group design has no concurrent treatment comparator, and the allocation field is recorded as NA. The study is unmasked. These design features mean that the record cannot provide a randomized between-group estimate, and any before-and-after change would not by itself establish causation. The registry record does not provide further details about imaging assessment procedures that would allow their susceptibility to assessment influence to be judged.

The record does not report participant flow, baseline characteristics, eligibility criteria, analysis populations, missing-data methods, or a detailed statistical plan. It also does not report how multiplicity was handled, whether interim analyses were conducted, or how the sample size was justified for the trial. Those items are not reported in the registry record; their absence should not be filled in by assumption.

Safety interpretation is limited by the lack of a comparator and by missing detail on event definitions, timing, overlap and attribution. The death count is not characterized further. Finally, planning illustrations based on an observed effect are not the trial’s own design and cannot replace a reported analysis or outcome result.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: An Exploratory stuDy of effectIveneSs and Safety of rivarOxaban in Patients With Left VEntricular Thrombus (R-DISSOLVE) — NCT04970381.
• Registry record last updated 2024-08-02; status last verified 2024-02.
• Results first posted 2024-08-02.
• 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

R-DISSOLVE is a completed, unmasked, single-group exploratory study sponsored by China National Center for Cardiovascular Diseases. The registry lists enrollment of 75, a start date of 2020-09-27 and a primary completion date of 2022-10-30. Participants with ventricular mural thrombus received rivaroxaban for 12 weeks, with a typical recorded dosage of 20mg once daily or 15mg once daily for specified circumstances.

The primary endpoint is the number of participants with left ventricular thrombus resolution at 12 weeks relative to the number assessed then. Secondary outcomes concern resolution and reduction at 6 and 12 weeks. Outcome results and analyses are not reported in the registry record. Safety entries list 7 participants affected by serious adverse events among 75 at risk, 1 affected by other adverse events among 75 at risk, 2 deaths, and rehospitalization at 9.3% among the top serious terms. The record does not establish comparative effects or event causation.