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 FAST PV and mGFR™ Technology in Congestive Heart Failure (NCT03808948), a na na study. The primary outcome is Number of Participants With Treatment Related AEs and Serious Adverse Events (SAEs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03808948 |
| Phase | NA |
| Condition | CHF |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 50 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Charite University, Berlin, Germany |
| Results posted | Yes |
2. Clinical Question
Population
Hospitalized patients with acute decompensated congestive heart failure were the intended population. The registry record lists an enrollment of 50. It does not report further eligibility details or a fuller description of the analysis population.
Intervention
The study evaluated VFI, an injectable fluorescent tracer, for measuring plasma volume and glomerular filtration rate. The arm description specifies an intravenous dose of 47 mg / 3 mL and 2 doses for all patients.
Comparator
There was no separate comparator group: the study model is single group, with allocation listed as NA and masking listed as none. The planned comparisons concern measured values and established estimates, not randomized treatment groups.
Primary question
The primary outcome counts participants with treatment-related adverse events and serious adverse events during 30 days. The description states that the percentage of treatment-emergent serious adverse events considered surely related to VFI should be zero. The registry record does not report a result for that specific attribution question.
The broader study question was whether measurements obtained with the FAST methodology could characterize plasma volume and kidney function in acute decompensated congestive heart failure. Secondary outcomes planned comparisons of estimated and measured plasma volume, total blood volume, and glomerular filtration rate on Days 1 and 3. Other planned questions concerned acute kidney injury, response to diuretic therapy, and whether the measurements might influence clinical decision making.
These are measurement and feasibility questions rather than evidence from a randomized comparison of treatments. The record contains no comparison arm and does not report findings for the planned measurement-accuracy or clinical-decision outcomes. Consequently, the record describes what the study set out to assess, but does not establish whether the measurements agreed closely or changed decisions.
3. Trial Design
The registry identifies NCT03808948 as a completed, investigator-initiated study of fluorescent-tracer methods in hospitalized patients with acute decompensated congestive heart failure. Its model is single group, its allocation is listed as NA, and masking is listed as none. The record lists an enrollment of 50. The brief summary calls the study a phase 2 trial, while the registry phase field is NA.
The intervention is identified as VFI, classified as a device. The arm description specifies 47 mg / 3 mL, delivered intravenously, with 2 doses for all patients. The study was scheduled to start on 2019-01-10, had a primary completion date of 2019-08-17, and is marked completed. These dates and status describe the registry record; they do not establish that every planned outcome was reported.
Because there is a single group and no randomized allocation, the design does not support a like-for-like comparison between intervention and control arms. The secondary outcomes instead set measured values against estimates based on established measures, or assess clinical outcomes and survey responses. Those comparisons can address agreement or descriptive patterns, but they do not have the same interpretation as a randomized treatment contrast.
The registry record does not report the protocol’s sample-size justification, detailed eligibility criteria, a statistical analysis plan, planned interim analyses, or procedures for handling missing observations. The record’s planning illustrations are based on an observed effect and specified assumptions; they are not a report of the trial’s own design justification or observed power. The results available in the record are limited to the adverse-event counts and terms described in the safety account.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: No patients were excluded after enrollment but before assignment to the treatment group.
Overall Study
| Stage | All Patients |
|---|---|
| STARTED | 50 |
| COMPLETED | 50 |
| 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 | All Patients |
|---|---|---|
| Participants analysed | 50 | |
| Age, Continuous | years | 72.5 (SD 13.72) |
| Sex: Female, Male: Female | Participants | 10 |
| Sex: Female, Male: Male | Participants | 40 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 48 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: Germany | participants | 50 |
| Weight day 1 (kg) | kilograms | 89.21 (SD 22.24) |
| Height day 1 (cm) | Centimeters | 172.84 (SD 10.62) |
| BMI day 1 (kg/m2) | Kilograms / meter squared | 29.7 (SD 6) |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Treatment Related AEs and Serious Adverse Events (SAEs), measured over 30 days.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with treatment-related adverse events and serious adverse events, with a timeframe of 30 days. It is a count of participants, rather than a measure of plasma-volume agreement, kidney-function agreement, or change in clinical status. The accompanying description states that the percentage of treatment-emergent serious adverse events considered surely related to VFI should be zero.
Safety endpoints are used to describe the adverse events observed during a study and to record whether investigators consider them related to the intervention. Seriousness and causal attribution are different judgments: an event can meet serious-event criteria without being judged related to the study intervention. The registry record reports counts of participants affected by serious and other adverse events, but does not give a result for the number of treatment-related events or the specific “surely related” assessment.
That distinction matters when interpreting the posted counts. The counts describe events recorded among participants; they do not by themselves establish causation. Nor do they answer the study’s planned measurement-accuracy questions. The primary endpoint is therefore a safety-focused outcome, while the plasma-volume and kidney-function comparisons are described as secondary outcomes.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a completed single-group study with an enrollment of 50. It reports that 21 participants were affected by serious adverse events and 37 by other adverse events; 1 death is recorded. These are descriptive safety counts. The record does not establish that the study intervention caused those events, and it does not report the specific count of events judged surely related to VFI.
The serious-event terms listed most often include Pneumonia, cardiac failure, and Acute kidney Injury, each reported as 6.0%. Endocarditis is listed as 4.0%, while Infectious pleural effusion and Urosepsis are each listed as 2.0%. These percentages are registry entries for event terms, not evidence that the event terms were caused by the tracer. The record does not explain whether a participant could contribute more than one term, so the terms should not be interpreted as mutually exclusive categories.
Although the study’s secondary outcomes concern agreement between estimated and measured plasma volume, total blood volume, and glomerular filtration rate, those outcome results are not reported in the registry record. The same applies to the planned outcomes concerning acute kidney injury prediction, diuretic refractoriness, and survey-based assessment of whether FAST measurements would influence clinical decisions. Without those results, no conclusion about measurement agreement or predictive performance can be drawn from the registry entry.
Precision also cannot be judged from the adverse-event counts alone. The available record does not report confidence intervals for those counts or percentages, nor does it give details about the statistical method used to summarize them. A confidence interval, as a general statistical concept, describes a range of values compatible with the data under a stated method; its width helps communicate uncertainty. Without an interval or an analysis plan, the displayed counts remain descriptive rather than a precise estimate of event risk.
The study has no randomized comparator group. Therefore, there is no concurrent control group in this record against which to separate events associated with hospitalization and acute illness from events potentially associated with the intervention. The single-group results can describe what was recorded among the enrolled participants, but cannot by themselves establish comparative safety or causal effects.
The record marks the study completed, but completion does not mean that every planned endpoint has a posted result. The registry entry is informative about the design, the intended questions, and the reported safety counts. It is incomplete as a report of the measurement objectives because their outcome findings are not reported in the registry record.
9. Statistical Methods Explained
Several statistical ideas are relevant to interpreting a single-group study that compares measurements with estimates. The following explanations are general; they do not describe methods confirmed for this study unless the registry record explicitly says so.
Agreement is not the same as association
When a measured value is compared with an estimated value, the central question is often whether the values are close enough for the intended purpose. A strong association between two measures would not, by itself, show that they agree: values could move together while differing systematically. Agreement analyses therefore examine the size and direction of discrepancies, or the share of observations falling within a prespecified tolerance. The registry lists planned thresholds of <15% and <30% for several comparisons. It does not report the corresponding outcome results or explain the detailed analysis method.
The planned comparisons included estimated plasma volume and measured plasma volume on Days 1 and 3; estimated total blood volume and measured total blood volume; and estimated glomerular filtration rate and measured glomerular filtration rate. The record also describes total blood volume as calculated from measured plasma volume and measured hematocrit. These are distinct measurement questions. A result for one comparison would not automatically establish agreement for another.
Thresholds and continuous differences
Reporting the percentage of a population within a chosen discrepancy threshold can make agreement easier to interpret against a stated criterion. However, a threshold summary does not show the full distribution of discrepancies. It may conceal whether values just outside the threshold differ only slightly or substantially, and whether errors tend to be in one direction. General practice may include examining the distribution of paired differences and checking for systematic bias, but the registry record does not say whether such analyses were planned or performed.
Thresholds should also be interpreted as analysis definitions, not as universal standards. Their relevance depends on the measurement’s intended use and the consequences of error. The registry record gives the planned thresholds but does not explain their justification.
Precision and uncertainty
An estimate from a study is subject to sampling uncertainty. A confidence interval communicates that uncertainty by giving a range associated with a specified statistical procedure. Narrower intervals usually indicate greater precision, while wider intervals indicate less precision. A point estimate alone does not convey how much uncertainty surrounds it. The registry record does not report confidence intervals for the outcomes, so precision of the posted safety counts and planned measurement comparisons cannot be assessed from the entry.
For a binary outcome, such as whether a participant experienced an event, the observed count describes the study participants. Estimating how often the event might occur in a broader population requires uncertainty measures and careful consideration of how the study participants were selected. A small or narrowly defined study population may not represent all patients with the condition. Generalizing beyond the enrolled group therefore requires more than observing an event count.
Single-group interpretation
In a single-group study, outcomes are observed among participants exposed to the study intervention, without a randomized control group. Such a design can describe measurements and events in the enrolled group. It cannot, on its own, estimate what would have happened to the same participants under a different intervention or no intervention. This matters particularly for safety: serious illness can itself be associated with adverse events, and the registry record contains no concurrent control group to help distinguish those possibilities.
Measurement comparisons within participants can still be useful for assessing agreement between methods, but they answer a different question from a treatment comparison. The record lists estimated-versus-measured comparisons; it does not report their results. The results therefore cannot be used to infer how well the estimates performed or whether FAST measurements improved patient outcomes.
Planning calculations and power
Sample-size planning uses assumptions about a target effect, variability, significance level, and design to estimate how many participants may be needed for a planned analysis. The registry’s planning illustrations are described as using a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects set as stated fractions of an observed effect. The record also specifies that time-to-event illustrations use total events, while other illustrations use participants per arm.
Those assumptions describe planning illustrations, not the single-group trial’s design. They should not be read as the study’s own sample-size justification, a protocol decision, or observed power. Observed power is not a substitute for interpreting an estimate and its uncertainty; after a study, the actual result and its precision are the relevant evidence. The registry record does not report the trial’s own sample-size justification.
Outcome definitions and analysis details
Interpretation depends on an outcome being defined clearly, including its measurement timing, population, and handling of incomplete data. The registry describes several time-specific measurement outcomes and a 30-day primary safety timeframe. It does not report detailed rules for missing measurements, repeated observations, exclusions from analyses, or adjustment for potential confounding. Those choices can affect both the analysis and its interpretation.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 8 outcome measures and 1 analysis. Several secondary outcomes include related accuracy questions for plasma volume, total blood volume, and kidney function, with assessments on Days 1 and 3. Other outcomes concern acute kidney injury, diuretic refractoriness, and clinical decision making. When a study examines multiple outcomes or time points, the chance of at least one apparently notable finding can increase if each is assessed separately. General approaches include identifying a primary analysis in advance and controlling or explicitly describing multiplicity. The registry record does not report a multiplicity-adjustment method or a detailed statistical analysis plan.
The primary outcome is a safety count over 30 days, while the planned secondary outcomes address measurement agreement and clinical questions. These outcomes are not interchangeable, and a finding for one would not automatically answer another. No results for the listed secondary outcomes are reported in the registry record, so their statistical significance, effect estimates, and precision cannot be assessed.
The registry record does not report how missing observations were handled, whether all enrolled participants contributed to each endpoint, or the definitions of analysis populations. These details matter because incomplete measurements can change which participants contribute to a comparison. If missingness is related to a participant’s condition or measured values, a complete-case summary may not represent the enrolled group. This is a general concern, not a claim that data were missing in this study.
The record also does not report whether analyses were adjusted for baseline characteristics, how repeated measurements were handled, or whether any interim analyses were planned. Such details should not be inferred from the outcome descriptions or the completed status. Without the analysis plan and endpoint-specific results, the record supports a description of intended questions but not a full assessment of their statistical execution.
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 |
|---|---|---|---|
| All Patients | 21 | 50 | 42.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| All Patients | 1 of 50 |
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 |
|---|---|
| All Patients | 37 of 50 |
Most frequent serious adverse event terms
| Event term | Organ system | All Patients |
|---|---|---|
| Pneumonia | Infections and infestations | 3 of 50 |
| cardiac failure | Cardiac disorders | 3 of 50 |
| Acute kidney Injury | Renal and urinary disorders | 3 of 50 |
| Endocarditis | Infections and infestations | 2 of 50 |
| Infectious pleural effusion | Infections and infestations | 1 of 50 |
| Urosepsis | Infections and infestations | 1 of 50 |
| Anaemia postoperative | Injury, poisoning and procedural complications | 1 of 50 |
| Lumbar vertebral fracture | Injury, poisoning and procedural complications | 1 of 50 |
| Post procedural fistula | Injury, poisoning and procedural complications | 1 of 50 |
| Post procedural haemorrhage | Injury, poisoning and procedural complications | 1 of 50 |
Most frequent non-serious adverse event terms
| Event term | Organ system | All Patients |
|---|---|---|
| Diarrhoea | Gastrointestinal disorders | 6 of 50 |
| Pneumonia | Infections and infestations | 6 of 50 |
| Sleep disorder | Psychiatric disorders | 5 of 50 |
| Acute kidney injury | Renal and urinary disorders | 5 of 50 |
| Hypokalaemia | Metabolism and nutrition disorders | 4 of 50 |
| Aspartate aminotransferase increased | Investigations | 3 of 50 |
| Pyrexia | General disorders | 3 of 50 |
| Fall | Injury, poisoning and procedural complications | 3 of 50 |
| Cardiac failure | Cardiac disorders | 3 of 50 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 3 of 50 |
Serious events with the highest arm-level rate: pneumonia (6.0%), cardiac failure (6.0%), acute kidney injury (6.0%), endocarditis (4.0%), infectious pleural effusion (2.0%).
The safety record lists 21 participants affected by serious adverse events and 37 affected by other adverse events, with 50 participants at risk in each category. It also records 1 death. The serious adverse-event terms listed include Pneumonia (6.0%), cardiac failure (6.0%), Acute kidney Injury (6.0%), Endocarditis (4.0%), Infectious pleural effusion (2.0%), and Urosepsis (2.0%).
These counts and percentages describe events recorded in the study group. They do not establish that VFI caused an event. Seriousness is a classification of an event, whereas relatedness is an assessment of whether it is considered connected to the intervention. The primary-outcome description specifies that the percentage of treatment-emergent serious adverse events considered surely related to VFI should be zero, but the registry record does not report the result of that specific attribution assessment.
The categories of serious and other adverse events should not be added together to infer a total number of participants with any event; the record does not say whether participants could appear in both categories. Likewise, event-term percentages should not be treated as mutually exclusive or as causal estimates. The record does not report confidence intervals or a comparative safety analysis.
12. What the Result Does, and Does Not, Mean
The registry entry establishes that a single-group study of VFI and FAST measurement methods was completed, with an enrollment of 50. It documents a primary safety question and planned secondary comparisons involving plasma volume, total blood volume, glomerular filtration rate, acute kidney injury, diuretic response, and clinical decisions. The posted adverse-event counts describe what was recorded among participants; they do not identify the cause of those events.
The entry does not report the results needed to judge whether estimated and measured values agreed within the planned discrepancy thresholds. It also does not report results for the planned acute kidney injury, diuretic refractoriness, or clinical-decision outcomes. The absence of those findings in the registry record is not evidence that the outcomes were positive, negative, or unchanged. It means that those results cannot be interpreted from this record.
The single-group design also limits causal conclusions. Without a randomized comparator, the study cannot show how event counts or clinical outcomes would have differed under another approach. The record’s design may describe performance and events in the enrolled group, but does not provide a controlled estimate of the effect of using the device or measurements.
General statistical interpretation depends on estimates, uncertainty, outcome definitions, and the analysis population. The registry entry does not provide confidence intervals or sufficient detail about missing data and analysis populations to assess those features. The sample-size planning illustrations are not observed power and do not replace reported outcome estimates. The most defensible reading is therefore narrow: the record documents the design and selected safety counts, while the planned measurement-performance findings and their precision are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically notable because it poses measurement questions in a clinically complex setting while using a single-group design. Estimated and measured values can be compared within a study, but agreement is a distinct statistical property from association and from treatment effect. A careful analysis needs to show not only whether measures track one another, but also how large their discrepancies are and how precisely agreement is estimated.
The planned comparisons specify discrepancy thresholds of <15% and <30%, which define ways of summarizing the proportion of observations meeting selected criteria. Such summaries can be useful, but interpretation depends on why those thresholds were chosen, how differences are calculated, and whether the full pattern of errors is also examined. The registry record does not provide those methodological details or the outcome results.
The design also highlights a key distinction in clinical research: a single-group measurement study can describe observed performance and safety, but cannot provide the same causal evidence as a randomized comparison. This is especially important for adverse events in a population hospitalized with acute decompensated congestive heart failure, where the record itself does not include a separate control group.
Finally, this registry entry illustrates why completion status and a list of planned outcomes are not substitutes for posted endpoint results. The safety counts are informative as descriptive observations, while the measurement-accuracy and clinical-decision findings remain unavailable in the registry record. Statistical interpretation should follow the outcome actually reported and avoid treating missing registry results as evidence of either success or failure.
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 most direct limitation is that the registry record does not report results for the planned secondary outcomes. Those outcomes cover measurement agreement for estimated and measured plasma volume, total blood volume, and glomerular filtration rate, as well as acute kidney injury, diuretic refractoriness, and potential influence on clinical decisions. Their findings and precision therefore cannot be evaluated.
The study is listed as single group, with allocation NA and masking none. There is no randomized control group for comparative interpretation. This limits causal assessment of safety and prevents a controlled estimate of how outcomes might differ under another measurement approach.
The record does not report detailed eligibility criteria, the analysis populations, missing-data procedures, or a full statistical analysis plan. It also does not report confidence intervals for the safety counts, the number of events judged surely related to VFI, or the results of the primary outcome as described. These omissions constrain assessment of both precision and endpoint-specific interpretation.
The safety categories and event terms require caution. The record does not explain whether participants can be represented in both serious and other adverse-event groups, or whether the listed event terms are mutually exclusive. The event counts therefore should not be combined, and the term percentages should not be interpreted as causal estimates.
Finally, the brief summary describes the study as phase 2 while the registry phase field is NA. The record does not clarify this difference. The study’s enrollment of 50 and completed status do not, by themselves, resolve the limitations in design, analysis reporting, or missing outcome results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: FAST PV and mGFR™ Technology in Congestive Heart Failure — NCT03808948.
- Registry record last updated 2021-11-17; status last verified 2021-10.
- Results first posted 2021-11-17.
- 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
NCT03808948 is a completed, investigator-initiated study of VFI and FAST methods for assessing plasma volume and kidney function in hospitalized patients with acute decompensated congestive heart failure. The registry lists a single-group model, allocation NA, masking none, and an enrollment of 50. The brief summary describes it as phase 2, while the phase field is NA.
The primary outcome counts participants with treatment-related adverse events and serious adverse events over 30 days. The record lists 21 participants affected by serious adverse events, 37 affected by other adverse events, and 1 death. It does not report the number of serious events considered surely related to VFI.
Planned secondary questions included measurement agreement and clinical outcomes, but their results are not reported in the registry record. Details of the statistical plan, missing-data handling, and analysis populations are also not reported in the registry record.