HF Patients With LVADs Being Treated With SGLT2i: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for HF Patients With LVADs Being Treated With SGLT2i (NCT05278962), a randomized phase 4 study. The primary outcome is Change in Left Ventricular End-diastolic Dimension (LVEDD).

2. Clinical Question

The registry describes the main purpose as observing outcomes of SGLT2i in people with heart failure and LVADs. The primary endpoint focuses on LVEDD change, a measurement of left ventricular dimension. The posted results give a median and inter-quartile range for each arm and report a Wilcoxon (Mann-Whitney) comparison.

The study was randomized and used parallel arms, but masking was listed as none. This is a comparison of the assigned SGLT2i and No SGLT2i groups, not a comparison of otherwise specified treatments. Routine heart failure care was permitted in both arms. The registry record does not report additional details about how routine care was delivered or whether its components differed between participants.

The question is specific to people with heart failure with reduced ejection fraction who have LVADs. The results therefore describe the registry's study population and do not, on their own, establish what would be observed in other populations or settings. The registry record does not report participant characteristics beyond the stated condition and LVAD context.

3. Trial Design

This was a Phase 4, randomized, parallel-arm study sponsored by the University of Chicago. Masking was listed as none. The registry lists an enrollment of 32 and a completed status. The study start date was 2022-09-08, and primary completion was recorded as 2025-08-31.

Participants were assigned to SGLT2i or No SGLT2i. Those in the SGLT2i arm were asked to take an SGLT2i for 6 months; those in the comparator arm were not asked to take one. In both arms, heart failure care was managed according to routine care, and data were collected from participants' medical records. The registry record does not report further details about allocation procedures, treatment adherence, or the specific medicines and doses used.

The posted primary outcome has an analysis population of 18 in the SGLT2i arm and 13 in the No SGLT2i arm. The primary outcome description notes that one patient in the SGLT2i arm was lost to follow up. These arm-specific analysis counts should not be treated as a complete account of participant flow: details of enrollment, assignment, exclusions, and outcome availability are not reported in the registry record.

Secondary outcomes include weight change, diuretic dose, LVEF, right ventricular size, and laboratory measures. The record lists 9 secondary outcomes and 10 outcome measures overall. It reports one analysis. The registry record does not report the planned sample-size justification, detailed statistical analysis plan, or whether additional outcomes or analyses were specified in advance.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: One patient in SGLT2i arm was lost to follow up.

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 Change in Left Ventricular End-diastolic Dimension (LVEDD), measured over 6 months after pre-LVAD.

The primary endpoint is change in left ventricular end-diastolic dimension (LVEDD), measured in centimeters. The registry gives the timeframe as 6 months after pre-LVAD. LVEDD describes the dimension of the left ventricle at end-diastole; change in this measure is used to characterize how that dimension differs over the stated timeframe.

The results are summarized using the median and inter-quartile range (IQR). The median is the middle of the ordered observations, while the IQR describes the span of the central half of those observations. These summaries describe the observed distributions without requiring the values to follow a normal distribution. They do not show every participant's measurement or explain the shape of the full distribution.

The SGLT2i arm has a reported median change of -1.1 cm, with IQR endpoints of -2.4 and -0.4 cm. The No SGLT2i arm has a reported median change of -0.9 cm, with IQR endpoints of -1.3 and -0.5 cm. The registry reports a Wilcoxon (Mann-Whitney) test for the comparison. It does not provide a confidence interval or an estimated between-arm effect for the primary endpoint.

The endpoint's clinical interpretation depends on context that is not reported in the registry record, including details of measurement procedures and the timing of the baseline measurement. The timeframe is stated as 6 months after pre-LVAD; the record does not clarify that wording further.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the Wilcoxon test compare?

The sponsor-reported method is the Wilcoxon (Mann-Whitney) test. In general, this rank-based test compares observations from two independent groups by ordering their values and assessing whether values in one group tend to rank higher or lower than values in the other. It does not require the same distributional assumptions as a test that compares means under a normal model.

The test is sometimes described as a comparison of medians, but that interpretation requires additional assumptions about the shapes of the group distributions. More generally, it assesses a difference in the distributions or relative ordering of observations. The registry reports medians and IQRs, but does not provide the individual observations or distribution plots needed to examine distribution shape. It also does not report the test statistic or the exact computational details.

How should the p-value be read?

The reported p-value is 0.38. In general, a p-value is calculated under a null model and describes how unusual data at least as incompatible with that model would be if the model and test assumptions held. It is not a measure of the magnitude of the observed difference, and it does not quantify the probability that chance alone produced the result.

A p-value is most informative when considered alongside an effect estimate and its uncertainty. The registry record does not report a confidence interval or an estimated between-arm effect for this endpoint. As a result, the p-value cannot show which effect sizes remain compatible with the data, and it cannot establish equivalence. The record also does not report whether the analysis used a prespecified significance threshold or whether any alternative analysis was planned.

Why report medians and IQRs?

The median gives the middle observation in an ordered set of values. The IQR spans the central half of those values and is a measure of spread that is less influenced by extreme observations than the range. These summaries can be useful when data are skewed or when a rank-based comparison is used. They do not describe the full distribution, and the medians and IQRs alone do not provide a standard error or confidence interval for the difference between arms.

The primary summaries are -1.1 cm with IQR endpoints -2.4 and -0.4 cm for SGLT2i, and -0.9 cm with IQR endpoints -1.3 and -0.5 cm for No SGLT2i. The registry does not state whether any values were transformed, how ties were handled in the test, or how missing observations were handled.

What does randomization contribute?

In general, random assignment is intended to make treatment groups comparable on average with respect to both measured and unmeasured characteristics at the time of assignment. It can support a causal interpretation when the trial is conducted and analyzed appropriately. Randomization does not guarantee that the realized groups are alike, especially when group sizes are limited, and it does not remove bias from missing outcomes, departures from assigned treatment, or measurement processes.

This study is listed as randomized, parallel, and unmasked. The registry record does not report the randomization sequence method, allocation concealment, adherence, or whether analyses followed assigned groups regardless of treatment received. The record therefore does not allow a full assessment of how randomization was implemented or how the analysis population was defined.

What can planning calculations tell readers?

Planning sample sizes are conditional illustrations, not observed evidence about the trial's power after completion. The registry describes a planning approach based on the observed effect, a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is expressed as a fraction of the observed effect. The record does not report a sample-size justification from the trial's own design.

Such illustrations depend on their assumptions and should not be interpreted as observed power. Observed power, calculated after results are known from the estimated effect, does not provide a useful substitute for an effect estimate and its confidence interval. The registry record does not report the numerical planning outputs in the outcome details.

The record lists 9 secondary outcomes and 10 outcome measures overall, alongside one reported analysis. A count of outcomes does not establish how many statistical tests were planned or conducted. The registry record does not report whether multiplicity adjustments, a hierarchy among outcomes, or a prespecified analysis plan were used.

10. Analyses Reported by the Sponsor

The registry reports the sponsor's primary comparison as a Wilcoxon (Mann-Whitney) test with p = 0.38. It does not report a sponsor-estimated between-arm effect, a confidence interval for that effect, or the test statistic. The posted medians and IQR endpoints describe each arm, but they are not a replacement for an estimated contrast with an uncertainty interval.

No recalculated comparison is reported for this primary endpoint in the registry record. The record indicates that values were missing or not estimable for a two-arm comparison for another endpoint. That note does not supply a second estimate of the primary comparison. Because there is no recalculated primary estimate to compare with the sponsor's result, there is no discrepancy to interpret for this outcome.

When a recalculation differs from a sponsor analysis, the sponsor's own analysis takes precedence when the registry record identifies a discrepancy. That condition is not indicated for this primary result. The most direct account is therefore the sponsor-reported test and p-value, read together with the posted arm summaries and the limitations of the reported information.

The registry record does not explain the statistical analysis plan or give the details needed to reproduce the sponsor's test. The reported p-value should consequently be treated as the posted analysis result, not as a fully independently verified estimate of the treatment contrast.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 9 secondary outcomes and 10 outcome measures overall. The named secondary outcomes include weight change, diuretic dose, LVEF, right ventricular size, and laboratory measures. The presence of multiple outcomes raises a general statistical issue: when many hypotheses are tested, the chance of at least one apparently unusual result can increase. Common approaches include adjusting for multiple comparisons or specifying a hierarchy of outcomes, but the registry record does not report whether either approach was used.

The record lists one analysis and reports a Wilcoxon (Mann-Whitney) comparison for the primary endpoint. It does not report the full set of analyses conducted, whether additional comparisons were planned, or a multiplicity strategy. The listed number of outcomes should not be mistaken for a count of statistical tests.

The primary outcome description notes that one patient in the SGLT2i arm was lost to follow up. The record does not report the reason, timing, or consequences of this loss, nor does it state how missing outcome measurements were handled. It does not describe imputation, sensitivity analyses, or a missing-data assumption. The analysis population is not defined beyond the arm-specific outcome counts and the note about follow up.

The registry record also does not report whether the primary analysis included participants according to randomized assignment, whether participants who did not follow their assigned approach were retained, or how exclusions were handled. These details affect the interpretation of a randomized comparison. Without them, the posted result cannot establish the robustness of the finding to missing data or analysis-population choices.

The enrollment entry is 32, while the primary outcome lists arm-specific counts of 18 and 13. The registry record does not provide a participant-flow account that explains these entries. They should be read as separate record details rather than as a complete description of recruitment, assignment, and outcome availability.

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 non-serious adverse event terms

The registry reports serious adverse events for the SGLT2i arm among 18 participants at risk and the No SGLT2i arm among 13 participants at risk. Serious adverse events affected 0 participants in each arm. Deaths were also reported as 0 in each arm. No serious adverse event terms are listed.

The record separately reports other adverse events affecting 8 participants in the SGLT2i arm and 6 in the No SGLT2i arm, among the same arm-specific counts at risk. These counts are distinct from the serious adverse event counts. The registry does not give the event types, severity breakdown, timing, or duration of safety follow up in the material reported.

Zero reported serious events does not show that the risk is absent. Safety counts from a study of this size can describe what was recorded in the study, but they do not precisely establish the frequency of uncommon events or rule out events that were not captured. The registry record does not provide a safety analysis plan, exposure-adjusted rates, or further information about event ascertainment. These figures should therefore be read as reported counts, not as a complete characterization of safety.

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

The primary result describes LVEDD change in the two study arms and reports a Wilcoxon (Mann-Whitney) p-value of 0.38. The arm summaries are medians with IQR endpoints. They characterize the observed measurements, while the p-value summarizes the sponsor's comparison under the test's assumptions. Neither result, by itself, establishes that the approaches are equivalent or that any observed change is clinically important.

The record does not give a confidence interval or an estimated between-arm effect. That limits assessment of precision: readers cannot use the posted primary result to identify the range of between-arm differences compatible with the data. The outcome description also notes one patient lost to follow up in the SGLT2i arm, without reporting how that missing outcome was handled.

The result applies to the population and care context described in the registry: people with heart failure with reduced ejection fraction and LVADs, with routine heart failure care in both arms. It does not establish effects in people without LVADs or in other clinical settings. The record does not report participant characteristics that would allow readers to judge how closely the study population resembles a particular group.

The study was randomized but unmasked. Randomization can support comparisons between assigned groups, while lack of masking may matter for behavior, care, and outcome assessment. The record does not report enough detail to determine how these issues were managed. In addition, the registry lists secondary outcomes but does not report a multiplicity plan.

These results are a statistical account of the posted registry data, not medical advice. They do not determine an individual treatment choice, prove a benefit or lack of benefit, or answer questions about outcomes that were not reported. The sponsor-reported test should be interpreted alongside the descriptive summaries, missing-data information, and the limits of the registry record.

14. Why This Trial Matters Statistically

This trial addresses a defined statistical challenge: comparing outcome distributions in a specialized population while reporting a median-based summary and a rank-based test. Medians and IQRs can be informative when distributions are not well represented by means and standard deviations. The Wilcoxon (Mann-Whitney) test provides a rank-based comparison, but its result is not automatically a test of medians alone.

The record also illustrates why a p-value is not enough to convey the size or precision of a result. The sponsor reports p = 0.38, but the registry does not report a confidence interval or an estimated between-arm contrast. Arm summaries help describe observed outcomes, yet they do not show the uncertainty around the contrast. Those pieces answer different statistical questions and are best considered together.

Missing outcome information is another important part of interpretation. The primary outcome description notes one patient lost to follow up in the SGLT2i arm, but the record does not state how missing data were handled. In a randomized study, the analysis population and handling of missing observations can affect how well the comparison retains the advantages of random assignment.

Finally, the registry includes multiple outcomes without reporting a multiplicity plan. Statistical interpretation depends not only on the test and endpoint, but also on whether the analysis choices were specified in advance and how a set of outcomes was handled. These details are not reported in the registry record, so the available result is best read as a limited account of the posted primary comparison rather than a complete analysis plan.

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 primary comparison has limited reporting detail. The registry gives arm medians, IQR endpoints, and a p-value, but not a confidence interval or an estimated between-arm effect. The test statistic and detailed test implementation are also not reported. This makes it difficult to assess the precision of the comparison or independently reproduce the analysis.

The outcome timeframe is stated as 6 months after pre-LVAD. The registry record does not clarify the wording, describe the timing of baseline measurements, or give details of how LVEDD was measured. These details are relevant when interpreting a change score, because the meaning of change depends on the measurements being compared and their timing.

The study was unmasked, and the registry does not report allocation concealment, treatment adherence, or whether the analysis followed randomized assignment. It also does not report how the loss to follow up in the SGLT2i arm was handled. The available record therefore does not establish whether missing outcomes or post-assignment events affected the result.

The registry lists secondary outcomes and outcome measures but does not report a multiplicity strategy, a complete analysis plan, or whether additional analyses were conducted. The sample-size assumptions describe a planning illustration based on the observed effect, not the trial's own design justification. The enrollment entry and primary outcome arm counts are not accompanied by a participant-flow account.

Finally, the posted safety counts do not include event descriptions or detailed ascertainment information. The record does not report enough participant characteristics to evaluate representativeness. These limitations constrain interpretation of this specific registry result; they do not establish that unreported procedures or analyses did not occur.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: HF Patients With LVADs Being Treated With SGLT2i — NCT05278962.
• Registry record last updated 2026-06-03; status last verified 2026-04.
• Results first posted 2026-05-08.
• 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

NCT05278962 is a completed Phase 4 randomized, parallel-arm study sponsored by the University of Chicago. It enrolled people with heart failure with reduced ejection fraction and LVADs to an SGLT2i or No SGLT2i approach. Masking was listed as none. The registry gives an enrollment of 32, a start date of 2022-09-08, and a primary completion date of 2025-08-31.

The primary endpoint was change in LVEDD, reported in centimeters as medians and IQR endpoints at 6 months after pre-LVAD. The sponsor-reported Wilcoxon (Mann-Whitney) comparison had p = 0.38. The record notes one patient lost to follow up in the SGLT2i arm and does not report a confidence interval for the between-arm effect or a detailed missing-data method.

The registry lists 9 secondary outcomes and 10 outcome measures overall. Serious adverse events and deaths were reported as 0 in each arm; other adverse events affected 8 participants in the SGLT2i arm and 6 in the No SGLT2i arm. Additional details about outcome analyses, multiplicity, and safety ascertainment are not reported in the registry record.