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 Feasibility of an Integrated Patient Care (IPC) System Using Daily Filling Pressures (NCT01370564), a na phase 2 study. The primary outcome is Characterize the Technical Feasibility of the Network Based IPC System.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01370564 |
| Phase | Phase 2 |
| Condition | Heart Failure |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 21 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Medtronic Cardiac Rhythm and Heart Failure |
| Results posted | Yes |
2. Clinical Question
Population
People with heart failure who already had a Medtronic Chronicle Implantable Hemodynamic Monitor or Chronicle Implantable Cardioverter Defibrillator implanted and were enrolled in the COMPASS-HF Extension Phase Study. The registry record reports an enrollment of 21 participants.
Intervention
Daily diuretic adjustments, with associated supplements, based on cardiac filling pressures measured by the Chronicle device. The system used those pressure readings to generate patient instruction sets.
Comparator
There was no separate comparison group. The study is described as non-randomized, with a single-group model and allocation listed as NA. The intervention group therefore should not be read as a like-for-like comparison against a control arm.
Primary question
Could the network-based Integrated Patient Care system deliver a patient instruction set based on the participant’s daily pressure state on study days? The primary measure was the mean proportion of study days on which this occurred, from baseline through completion or exit, over a timeframe described as an average of 3 months. This is a question about technical feasibility, not a randomized test of clinical benefit.
The study focused on a system linking daily pressure measurements to medication instructions. Its primary question concerns whether that process operated as intended across participants’ study days. The registry record also lists secondary aims concerning system changes, daily patient-instruction compliance, clinical markers of heart failure and kidney function, and adverse events. It does not report an observed primary endpoint value, so the degree of technical feasibility cannot be quantified from the registry record.
3. Trial Design
This was a chronic, prospective, non-randomized feasibility study of the Integrated Patient Care concept. The registry classifies it as phase 2, single group, with allocation listed as NA and masking listed as none. The sponsor was Medtronic Cardiac Rhythm and Heart Failure. The record reports an enrollment of 21 and describes the study status as completed. The start is listed as 2011-06 and primary completion as 2011-12.
Participants already had a Chronicle Implantable Hemodynamic Monitor or Chronicle Implantable Cardioverter Defibrillator implanted and were enrolled in the COMPASS-HF Extension Phase Study. The intervention was daily adjustment of diuretics and associated supplements based on cardiac filling pressures. There was no separate randomized control group, so the design does not support a like-for-like between-group treatment comparison.
The primary outcome timeframe runs from baseline through completion or exit and is described as an average of 3 months. The registry defines the analysis population as the total number of study participants and describes a participant-level count of days when the system delivered an instruction set based on measured pressure state. It identifies the primary summary as a mean and the dispersion as a 95% confidence interval. However, the observed mean and interval are not reported in the registry record.
The record lists 7 outcome measures and 1 analysis. It does not report a sample-size justification, a detailed statistical analysis plan, or an interim-analysis plan. The study’s single-group feasibility design and absent comparator are central to interpreting its findings: it can describe operation of the system in the enrolled group, but it cannot isolate the effect of the intervention from other influences through a randomized comparison.
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 | Daily Diuretic Adjustment |
|---|---|
| STARTED | 21 |
| COMPLETED | 21 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: The analysis population is the total number of study participants. For each study subject, the number of days in which the IPC system delivered a patient instruction set based on the subject's pressure state as measured by the Chronicle ICD/IHM pressure sensor.
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 | Daily Diuretic Adjustment |
|---|---|---|
| Participants analysed | 21 | |
| Age, Continuous | years | 59.2 (SD 12.7) |
| Sex: Female, Male: Female | Participants | 6 |
| Sex: Female, Male: Male | Participants | 15 |
| Region of Enrollment: United States | participants | 21 |
| New York Heart Association Classification: Class I | Participants | 4 |
| New York Heart Association Classification: Class II | Participants | 12 |
| New York Heart Association Classification: Class III | Participants | 5 |
| New York Heart Association Classification: Class IV | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Characterize the Technical Feasibility of the Network Based IPC System, measured over Baseline through Completion/Exit (an average of 3 months).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | percentage of days |
| Endpoint classification | Continuous Endpoint |
The primary endpoint concerns the proportion of study days on which the system delivered a patient instruction set based on the participant’s daily pressure state, as measured by the Chronicle sensor. The registry specifies a mean as the summary measure and a 95% confidence interval as the dispersion measure. The timeframe is baseline through completion or exit, described as an average of 3 months.
This endpoint is useful for assessing the operational feasibility of a pressure-guided workflow. It focuses on whether measurements could be translated into instructions during study days. It does not directly measure whether the instructions changed medication use, improved symptoms, or altered clinical outcomes. Those are distinct questions; the registry lists some clinical markers among the secondary outcomes but does not report their results in this record.
The registry record does not report the observed endpoint mean or its confidence interval. As a result, the direction, size, and precision of the primary feasibility estimate cannot be described. The enrollment of 21 participants does not itself indicate how often the system generated instructions, because the endpoint is based on study days rather than enrollment alone. Details such as the observed number of eligible days and how missing daily measurements were handled are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record identifies a clear operational target: the proportion of study days on which the pressure-based system delivered an instruction set. It also specifies a mean and a 95% confidence interval. But it does not report the observed mean or interval. Without those results, there is no basis in this record for saying how often the system delivered instructions or how precisely that rate was estimated.
The enrolled group comprised 21 participants, but that count is not the primary endpoint result. The measure concerns study days, and a participant may contribute multiple days. The registry description says the analysis population is the total number of participants and describes days for each participant; it does not report how participant-level contributions were combined, how many study days were included, or whether all participants contributed data through completion or exit.
The study is prospective and non-randomized, with a single-group model and no masking. It therefore describes experience with the IPC system in this enrolled group rather than a controlled contrast. Changes in clinical markers, if reported, would not by themselves establish that the system caused those changes. The registry record does not report the results for those secondary outcomes, either.
The safety listing reports 2 serious adverse-event affected in the Daily Diuretic Adjustment group, with 21 at risk, and 4 other adverse-event affected, also with 21 at risk. Deaths are listed as 0. The serious-event terms shown include Cardiac Failure, Myocardial Infarction, and Mental status change, each listed as 4.8%. These figures describe the registry’s safety entries; they do not establish whether events were caused by the intervention. The record does not provide further detail about event timing, duration, severity beyond the serious classification, or attribution.
Overall, the registry record outlines a feasibility objective and some safety counts, but does not include the primary endpoint estimate or detailed outcome results. Interpretation should therefore remain limited to the study’s design and the information actually reported. It is not possible from this record to quantify technical performance or to draw a comparative conclusion about clinical effects.
9. Statistical Methods Explained
The primary endpoint is a continuous measure summarized by a mean. Although it is expressed as a proportion of study days, the registry’s stated parameter is the mean across the analysis population. The record describes a participant-level count of days on which an instruction set was delivered based on pressure state. It does not specify the precise aggregation procedure used to turn those participant-level records into the reported mean.
What does a mean describe?
In general, a mean describes the average value across the observations included in an analysis. For this endpoint, the underlying quantity is a proportion of study days. A mean can provide a concise description of typical observed performance, but its interpretation depends on what counts as an observation and how observations are weighted. For example, a mean of participant-level proportions and a proportion pooled across all days answer related but not necessarily identical questions. The registry record does not report which detailed aggregation method was used.
The unit of analysis also matters. Daily records from the same participant are not necessarily independent: they come from the same person and may share circumstances or device-related patterns. In general, treating clustered daily observations as if each day were independent can make uncertainty appear smaller than it is. An analysis can account for such within-participant structure in different ways, but the statistical model and variance calculation are not reported in the registry record. This is a limitation on interpreting the stated confidence interval, even apart from the fact that its value is not reported.
How should the confidence interval be read?
In general, a confidence interval is an estimate of uncertainty around a statistical summary under the assumptions of the method used. A 95% confidence interval gives a range of values compatible with the data and method; it is not a statement that there is a 95% probability that a fixed true value lies in that particular calculated interval. The interval’s width is informative about precision, while its location relates to the estimated level of the outcome.
Here, the registry specifies a 95% confidence interval for the mean but does not report the interval’s endpoints or the method used to calculate it. Its precision therefore cannot be assessed. The record also does not report the observed mean, so neither the estimated level nor its uncertainty can be described. A confidence interval cannot be reconstructed from enrollment alone; it would require the relevant observed outcome data and an analysis method.
Why do repeated days need care?
In general, repeated observations within a participant can be correlated. A participant with more recorded days may contribute more information if the analysis weights days directly, whereas an analysis that first calculates a proportion for each participant may give participants more equal influence. Those approaches can differ in estimand and precision. The endpoint description indicates that participant-level day counts were relevant, but the exact weighting, handling of unequal observation periods, and treatment of repeated measurements are not reported in the registry record.
Missing daily readings or unavailable instruction records can also affect a proportion. The denominator might depend on which days were considered eligible or observed, and different missing-data rules can change the interpretation. The record does not state how incomplete daily records were handled, whether participants with partial follow-up were included, or whether any imputation was performed. These details are important for understanding what the endpoint represents in practice.
What can be inferred from the design?
The registry describes a prospective, non-randomized, single-group feasibility study. In general, prospective collection can define an intended sequence of observation, but it does not substitute for random allocation or a concurrent control group. With no comparator, observations can describe system operation in the enrolled group; they cannot separate the intervention’s contribution from other changes over time or other influences. No causal treatment effect should be inferred from this design alone.
The record identifies a mean and confidence interval but does not give a fuller analysis plan, including distributional assumptions, transformations, outlier handling, or any adjustment for clustering. Those methods are not reported in the registry record and should not be presumed. The registry also does not report an interim-analysis plan or a sample-size justification. Enrollment of 21 is a design fact, not evidence by itself of adequate precision or of a particular power.
In general, a planning calculation asks what sample size might be needed under stated assumptions; it is not an observed result and does not replace an analysis of collected data. No trial-specific sample-size justification is reported in the registry record. Any planning illustration should therefore be kept distinct from what this study observed, and it should not be described as observed power.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 7 outcome measures and 1 analysis. It identifies secondary aims involving IPC setup system changes, compliance with daily patient instruction sets, clinical markers of heart failure and kidney function, and adverse events. The clinical-marker aim appears more than once in the outcome list. The record does not explain whether those entries represent distinct measures, time points, or repetitions in the listing.
When several outcomes are examined, the chance of at least one apparently notable result can increase. In general, multiplicity procedures can address that issue, but the registry record does not report whether any adjustment was planned or used. It also does not provide a detailed analysis plan explaining which outcomes were primary for inference or how secondary findings were to be interpreted. Because the primary estimate itself is not reported, there is no basis for comparing its result with secondary findings.
The stated primary analysis population is the total number of study participants. The endpoint description refers to each participant’s study days, but the record does not report how many participants contributed usable primary outcome data or how many days were observed. Rules for missing daily pressure measurements, missing instruction records, early exit, or incomplete follow-up are not reported in the registry record. The record also does not state whether missing values were excluded, imputed, or handled through another method.
These omissions matter because the proportion of days depends on both its numerator and denominator. If the set of observed or eligible days differs among participants, the resulting summary may depend on how those differences are handled. Without the missing-data rules and analysis details, readers cannot determine the extent to which incomplete records may have influenced the estimate. The registry record does not report an analysis population distinct from its stated total-participant population.
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 |
|---|---|---|---|
| Daily Diuretic Adjustment | 2 | 21 | 9.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Daily Diuretic Adjustment | 0 of 21 |
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 |
|---|---|
| Daily Diuretic Adjustment | 4 of 21 |
Most frequent serious adverse event terms
| Event term | Organ system | Daily Diuretic Adjustment |
|---|---|---|
| Cardiac Failure | Cardiac disorders | 1 of 21 |
| Myocardial Infarction | Cardiac disorders | 1 of 21 |
| Mental status change | Psychiatric disorders | 1 of 21 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Daily Diuretic Adjustment |
|---|---|---|
| Hyperglycaemia | Metabolism and nutrition disorders | 2 of 21 |
| Asthma | Respiratory, thoracic and mediastinal disorders | 1 of 21 |
| Cardiac failure | Cardiac disorders | 1 of 21 |
| Gastrointestinal haemorrhage | Gastrointestinal disorders | 1 of 21 |
| Hyponatraemia | Metabolism and nutrition disorders | 1 of 21 |
| Urinary tract infection | Infections and infestations | 1 of 21 |
Serious events with the highest arm-level rate: cardiac failure (4.8%), myocardial infarction (4.8%), mental status change (4.8%).
For the Daily Diuretic Adjustment group, the registry lists 21 participants at risk for serious adverse events and 2 serious adverse-event affected. It also lists 21 at risk for other adverse events and 4 other adverse-event affected. The deaths entry is 0. These are the counts recorded for the group; the record does not provide event-level narratives or further details about how events were classified.
The serious-event terms listed are Cardiac Failure, Myocardial Infarction, and Mental status change, each reported as 4.8%. The record does not clarify in this listing whether participants could contribute to more than one term, so the term percentages should not be added or treated as mutually exclusive categories. No new percentage or rate is inferred from the counts.
These figures are descriptive. They do not establish whether an event was caused by diuretic adjustment or by the IPC system, and the registry record does not report causal attribution. The record also does not provide the timing of events, duration of exposure, or further information needed to compare risk against an untreated or randomized control group. With a single group and no comparator, the entries should be read as recorded safety counts rather than as a comparative safety estimate.
12. What the Result Does, and Does Not, Mean
The study asks whether a system could use daily Chronicle pressure readings to generate patient instruction sets for diuretic adjustments. Its primary endpoint is designed to describe that operational process through a mean proportion of study days. The registry record reports the endpoint definition and its planned summary, but not the observed mean or 95% confidence interval. The central feasibility result is therefore not quantifiable from this record.
The study enrolled 21 participants with existing Chronicle devices who were in the COMPASS-HF Extension Phase Study. That enrollment describes the size of the study group; it does not show how often the system produced instructions, whether participants followed them, or how clinical markers changed. The record lists those as separate outcome topics, but their results are not reported in the registry record.
The design also sets limits on what any observed changes could mean. This was a prospective, non-randomized single-group study without masking or a separate control group. In general, such a design can describe experience in the enrolled group, but it cannot establish that the IPC system caused changes or determine how those changes compare with an alternative approach.
The safety entries report serious and other adverse-event counts and list several serious-event terms. They do not establish causation, and the absence of a comparator prevents a controlled assessment of relative safety. The death count is recorded as 0, but that does not fill the gaps in event attribution, timing, or exposure information.
Accordingly, the record supports a description of the feasibility question, study structure, and selected safety counts. It does not support a numerical conclusion about the primary technical endpoint, an estimate of a clinical treatment effect, or a comparative safety conclusion. Those distinctions are essential when interpreting a feasibility study with no reported primary result.
13. Why This Trial Matters Statistically
This trial is statistically interesting because its main outcome is an operational measure built from repeated daily information rather than a single clinical event. The proportion of days with an instruction set connects device measurements to a decision-support process. That makes the definition of eligible days, the participant-level denominator, and the treatment of repeated observations important to the interpretation.
The registry identifies a mean and 95% confidence interval, which signals that both the estimated level of system operation and its precision were intended to be considered. Yet neither the estimate nor the interval is reported. This illustrates why a stated endpoint and analysis summary are not substitutes for the observed result. Without the result and details of how daily records were aggregated, readers cannot assess either performance or uncertainty.
The design also highlights the difference between feasibility and comparative effectiveness. A single-group, non-randomized study can document whether a workflow was used in a particular enrolled population. It does not supply a concurrent comparison that would separate the system’s contribution from other influences. That distinction remains important even when a study also tracks clinical markers or adverse events.
Finally, the safety entries illustrate the limits of event counts without attribution and comparison. Recorded counts can inform a descriptive account, but they cannot by themselves show whether the intervention caused an event or whether event frequency differed from another strategy. The registry record’s missing primary result and limited analytic detail make restraint in interpretation especially important.
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 the observed primary endpoint mean or its 95% confidence interval. It also does not report results for the secondary outcomes listed. As a result, the stated feasibility objective cannot be evaluated quantitatively from this record.
The study had a single-group, non-randomized design, with allocation listed as NA and no masking. There was no separate control group for comparison. This limits conclusions to descriptions of the enrolled group and does not permit a controlled estimate of the system’s effect. The population was restricted to people who already had a Chronicle device and were enrolled in the COMPASS-HF Extension Phase Study; the record does not establish how findings would apply outside that group.
The endpoint involves repeated study days, but the registry record does not report the number of observed or eligible days, the aggregation or weighting method, or how within-participant correlation was handled. It does not report rules for missing daily data, incomplete follow-up, or early exit. These omissions make it difficult to assess what the planned mean represents and how precise it would be.
The record does not report a sample-size justification, detailed statistical analysis plan, multiplicity strategy, interim-analysis plan, or missing-data method. It also provides limited detail on adverse-event timing and attribution. These are omissions in the registry record; they should not be filled by assumptions about what the study may have planned or done.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Feasibility of an Integrated Patient Care (IPC) System Using Daily Filling Pressures — NCT01370564.
- Registry record last updated 2018-07-11; status last verified 2018-06.
- Results first posted 2018-07-11.
- 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
NCT01370564 is a completed phase 2, prospective, chronic, non-randomized, single-group feasibility study sponsored by Medtronic Cardiac Rhythm and Heart Failure. It enrolled 21 participants with heart failure who already had a Chronicle Implantable Hemodynamic Monitor or Chronicle Implantable Cardioverter Defibrillator and were enrolled in the COMPASS-HF Extension Phase Study.
The intervention involved daily diuretic adjustments and associated supplements based on cardiac filling pressures. The primary endpoint was the mean proportion of study days on which the system delivered a patient instruction set based on pressure state, from baseline through completion or exit; the timeframe was described as an average of 3 months. The registry record specifies a 95% confidence interval but does not report the endpoint estimate or interval.
The safety listing records 2 serious adverse-event affected, 4 other adverse-event affected, and 0 deaths in the group. The record does not report the primary outcome results, detailed analysis methods, missing-data handling, or event attribution.