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 Quantification of Intramyocardial Lipid by Proton Magnetic Resonance Spectroscopy (NCT00469911), a randomized na study. The primary outcome is Correlation Co-efficient Between MRS Spectroscopy and Endomyocardial Biopsy in Heart Transplant Participants.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00469911 |
| Phase | NA |
| Condition | Heart Transplantation |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 18 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Washington University School of Medicine |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns heart transplant participants. The registry record also lists control subjects as an arm. The primary outcome’s population field is blank, so further eligibility details and the exact population included in the correlation analysis are not reported in the registry record.
Intervention
Magnetic resonance spectroscopy (MRS) was used to measure triglyceride accumulation in myocardial tissue in vivo. The record describes MRS as a procedure and says participants first had MRS spectroscopy.
Comparator
The stated comparison is MRS spectroscopy against endomyocardial biopsy. The record describes the biopsy as a routine clinical biopsy of myocardial tissue. The precise way participants were assigned to the listed arms, and whether every participant underwent both procedures, are not reported in the registry record.
Primary question
The primary question is whether MRS measurements correlate with endomyocardial biopsy findings in heart transplant participants. The registry specifies a correlation coefficient as the outcome, with a timeframe of 2 to 10 days. It does not report the coefficient or its uncertainty.
3. Trial Design
The registry record describes a randomized, parallel study with no masking. It lists an enrollment of 18 and identifies heart transplantation as the condition. The study status is completed. The listed start is 2005-08 and the primary completion is 2009-06. The sponsor is Washington University School of Medicine. The phase is recorded as NA.
The listed procedures are magnetic resonance spectroscopy and ex vivo heart biopsy. The MRS arm description says the procedure measures in vivo accumulation of triglycerides in myocardial tissue. The biopsy arm description refers to a normal routine clinical biopsy of myocardial heart tissue. A separate arm label identifies control subjects. These descriptions establish what the registry lists, but do not fully describe the allocation process or the relationship among the named groups and the primary outcome.
The primary outcome description says participants first had MRS spectroscopy and that the images were compared with endomyocardial biopsy. The stated timeframe is 2 to 10 days. The record does not give more detail about the timing for individual participants, image processing, biopsy assessment, or how paired observations were selected for the analysis.
Randomized allocation and a parallel model are recorded, but the allocation ratio, randomization method, concealment procedures, and any stratification are not reported in the registry record. Masking is listed as none; the record does not clarify which people involved in measurement or assessment were unmasked. Details of eligibility criteria, participant flow, withdrawals, and protocol deviations are also not reported in the registry record. The reported enrollment describes the study record, but no further breakdown of enrollment by analysis population is included.
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 | Heart Transplant | Controls |
|---|---|---|
| STARTED | 8 | 10 |
| COMPLETED | 8 | 10 |
| NOT COMPLETED | 0 | 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 | Heart Transplant | Control Subjects | Total |
|---|---|---|---|---|
| Participants analysed | 8 | 10 | 18 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 8 | 10 | 18 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 5 | 5 | 10 |
| Sex: Female, Male: Male | Participants | 3 | 5 | 8 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 8 | 10 | 18 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 8 | 10 | 18 |
| Region of Enrollment: United States | Participants | 8 | 10 | 18 |
6. Primary Endpoint
The registry lists the primary outcome as Correlation Co-efficient Between MRS Spectroscopy and Endomyocardial Biopsy in Heart Transplant Participants, measured over 2 to 10 days.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | correlation co-efficient |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is a correlation coefficient between MRS spectroscopy and endomyocardial biopsy in heart transplant participants. The record describes MRS images being compared with biopsy after participants first underwent MRS. The specified timeframe is 2 to 10 days. The endpoint is intended to address whether measurements from the non-invasive imaging method are associated with biopsy findings.
In general, correlation describes the strength and direction of association between paired measurements. It does not, by itself, establish that the measurements agree closely in their actual values. For example, measurements can track together while differing systematically in scale or level. Assessing agreement would require an analysis suited to that question, and such an analysis is not described in the registry record.
The record gives the outcome’s name, unit, timeframe, and a brief description, but no numerical correlation coefficient, confidence interval, p-value, or other estimate of precision. Those results are not reported in the registry record. Without the estimate, the direction and strength of the observed association cannot be characterized from this record. The record also does not explain how biopsy findings or MRS images were quantified, or how missing or unusable measurements were handled.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies correlation between MRS spectroscopy and endomyocardial biopsy as the primary outcome. However, it does not report a correlation coefficient or an uncertainty measure. As a result, the posted registry information does not establish the observed strength or direction of the relationship. It also does not allow a reader to judge how precisely that relationship was estimated.
A correlation estimate would describe association between the paired measurements under the analysis used. In general, an estimate alone is not enough to assess precision: an interval estimate conveys how compatible a range of values is with the data and analysis assumptions. Neither a confidence interval nor another measure of uncertainty is reported in the registry record. The record also does not report a p-value for the primary outcome. No claim about statistical significance can therefore be made from the information recorded.
The outcome is described as a comparison of MRS images with endomyocardial biopsy, with MRS performed first and a timeframe of 2 to 10 days. That timing matters for interpretation because the target is a relationship between measurements taken in proximity, not a treatment effect on a clinical event. The record does not give individual measurement dates, the number of paired measurements analyzed, or details of image and biopsy scoring. The precise estimand—the population-level quantity the analysis sought to estimate—is therefore not fully specified.
Correlation and agreement answer related but different measurement questions. In general, strong correlation may indicate that values tend to vary together, while agreement concerns whether readings are sufficiently similar in their actual values. A correlation coefficient alone would not establish interchangeability or define the accuracy of either procedure. The registry does not report an agreement analysis or a criterion for acceptable measurement performance.
The record lists 18 enrolled participants and includes heart transplant and control-subject labels in its arm information. It does not provide a participant flow or show how many contributed to the primary outcome. Consequently, the enrollment figure should not be treated as the number analyzed for the correlation endpoint. The record also does not explain whether the primary analysis used all eligible paired observations or a subset.
The safety entries report no serious adverse events, other adverse events, or deaths in the listed groups, with the at-risk and affected counts described separately in the safety reading. These entries are descriptive registry data, not evidence that no events could occur. Taken together, the record provides a study question, design labels, and safety counts, but not the primary numerical result needed to assess the measurement association.
9. Statistical Methods Explained
The statistical method named by the primary outcome is a correlation coefficient. The registry record does not specify which correlation method was used, how measurements were prepared, or how uncertainty was estimated. The explanations below describe general statistical concepts, not additional analyses reported for this study.
What does correlation measure?
In general, correlation summarizes how two variables vary together. A positive association means that larger values of one variable tend to occur with larger values of the other; a negative association means that larger values of one tend to occur with smaller values of the other. The magnitude describes the degree of linear association when a conventional linear correlation is used. The registry does not identify the specific coefficient or provide its observed value, so these concepts cannot be used to characterize this study’s result.
Correlation is not the same as agreement. Two methods could rank or track measurements similarly while one method consistently gives higher readings. A correlation analysis does not by itself show whether the readings are close enough for one method to replace another. Agreement methods would require a defined approach and clinically or scientifically meaningful criteria; neither is described in the registry record.
Why do paired measurements matter?
A comparison of MRS and biopsy is meaningful as a paired measurement analysis only when both measurements correspond to the same participant or relevant sampling unit. The outcome description says images were compared with endomyocardial biopsy, and that MRS came first. The registry does not report how many complete pairs were available, whether there were repeated images or biopsies, or how multiple observations from a participant would be handled. These details affect the uncertainty calculation and the interpretation of the coefficient.
The timeframe is recorded as 2 to 10 days. In general, a time gap between measurements can matter if the underlying biological quantity changes over time. The record does not explain whether this interval was prespecified for each participant or whether timing was considered in the analysis. It also does not report whether the methods assessed the same tissue location or how image and biopsy measurements were aligned.
How should uncertainty be understood?
In general, a confidence interval gives a range of values compatible with the observed data under a specified statistical model and its assumptions. Its width reflects precision: wider intervals indicate less precision than narrower intervals. A p-value, when reported, addresses compatibility of data with a specified null model; it is not a measure of effect size or the probability that a hypothesis is true. The registry record reports neither an interval nor a p-value for the primary endpoint, so no inference about precision or statistical evidence can be drawn from those measures.
Correlation estimates can be sensitive to the distribution of measurements, outlying observations, and the range of values in the sample. In general, a restricted range can make an association appear weaker even when measurement behavior is similar in another population. Outlying points can have substantial influence on some correlation methods. The registry does not report distributional checks, outlier handling, transformations, or sensitivity analyses. It also does not identify whether a linear or rank-based association was intended.
What can randomization establish?
The record labels allocation randomized and the model parallel. Randomization is generally used to reduce systematic differences between groups for comparisons of assigned interventions. Here, the named primary outcome is a correlation between two measurement methods, rather than a conventional comparison of treatment effects. The record does not explain the role of randomization in the correlation analysis, what participants were randomized to receive, or whether assignment affected which measurements were collected. The randomization label alone cannot resolve these design details.
Masking is recorded as none. In general, knowledge of a measurement or group assignment can influence subjective steps such as image reading or biopsy assessment. The record does not indicate whether either measurement involved judgment, whether readers knew the paired results, or whether any independent assessment was used. No conclusion about the impact of masking can be drawn without those details.
How should the planning calculations be read?
The planning illustration is described as based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It is explicitly a planning illustration, not the trial’s own design. Such calculations explore the sample size needed under stated assumptions; they do not show the probability that this completed study detected an effect. That probability is often called observed power, and it should not be inferred from a planning illustration.
The record does not report a protocol sample-size justification or explain how the study’s enrollment was chosen. It also does not provide the primary observed effect needed to independently interpret the planning assumptions. The sample-size illustration should therefore be understood only as a hypothetical planning exercise under its stated assumptions, not as evidence that the study was adequately or inadequately sized.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure and one analysis. Those entries describe what is recorded, but do not establish that no additional analyses were conducted. The registry record does not report a multiplicity strategy, such as adjustment for multiple outcomes, comparisons, or exploratory tests. It also does not report whether the primary outcome or analysis was changed during the study.
Multiplicity matters in general when several hypotheses are tested: repeated testing can increase the chance of obtaining an apparently notable result by chance. The appropriate approach depends on the prespecified questions and the role of each analysis. Because the record does not describe a statistical analysis plan or a multiplicity procedure, it is not possible to determine how such issues were addressed.
Missing-data handling is not reported in the registry record. There is no description of missing MRS measurements, unavailable or inadequate biopsy samples, exclusions, or the assumptions used if data were incomplete. The number of participants contributing paired measurements is not reported. This matters because a correlation analysis generally requires paired values, and excluding incomplete pairs can affect both the estimate and its precision.
The analysis population is also not reported in the registry record. It is unclear whether the analysis included all enrolled participants, only participants with both measurements, or another defined group. No account of withdrawals, protocol deviations, or reasons for exclusion is given. These omissions limit assessment of selection effects and reproducibility, independently of the absent correlation estimate.
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 |
|---|---|---|---|
| Heart Transplant - Endomyocardial Biopsy | 0 | 8 | 0.0% |
| Control Subjects | 0 | 10 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Heart Transplant - Endomyocardial Biopsy | 0 of 8 |
| Control Subjects | 0 of 10 |
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 |
|---|---|
| Heart Transplant - Endomyocardial Biopsy | 0 of 8 |
| Control Subjects | 0 of 10 |
The registry lists two safety groups. For Heart Transplant - Endomyocardial Biopsy, 8 were at risk for serious adverse events and 0 were affected; 8 were at risk for other adverse events and 0 were affected. For Control Subjects, 10 were at risk for serious adverse events and 0 were affected; 10 were at risk for other adverse events and 0 were affected. Deaths are recorded as 0 in each group.
These are reported counts for the groups and event categories in the registry. They should not be interpreted as proof that a procedure has no risk. The record does not provide further information about event definitions, collection methods, follow-up completeness, or whether events were assessed as related to a procedure. The counts also do not describe the primary correlation outcome or its precision.
When reading zero affected counts, distinguish the observed registry entries from a guarantee about the possibility of events. The at-risk counts indicate the groups for which the record reports safety monitoring; they do not supply additional information about the measurement association.
12. What the Result Does, and Does Not, Mean
The study addresses a measurement question: whether MRS spectroscopy measurements of myocardial triglyceride content are associated with endomyocardial biopsy findings in heart transplant participants. The registry identifies a correlation coefficient as the primary outcome and describes MRS followed by comparison with biopsy within a 2 to 10 days timeframe. This defines the intended question, but the numerical outcome is not reported in the registry record.
Without the correlation estimate, there is no basis in the registry information to describe the observed association as strong, weak, positive, or negative. Without an interval or other uncertainty measure, its precision cannot be assessed. The record also does not report an agreement analysis, so it cannot establish whether MRS and biopsy readings are close enough to be used interchangeably.
Even a reported correlation would answer a limited statistical question. In general, association between two measurement methods does not establish that one accurately measures the underlying biological quantity, nor does it establish a clinical benefit. It would not, on its own, show that using MRS improves diagnosis or management. Those conclusions would require evidence and analyses addressing those specific questions.
The record describes a completed randomized parallel study with no masking and an enrollment of 18, but it does not give the number contributing to the primary analysis or detailed participant flow. The design labels therefore do not substitute for the missing endpoint result or clarify exactly how the analysis was conducted. The safety entries report zero affected participants for the listed event categories and groups, but they do not resolve the measurement question.
The registry record is useful for identifying the study’s purpose, named procedures, endpoint, and broad design. Its lack of a reported primary estimate and analysis details sharply limits what can be concluded from the posted information. The appropriate reading is not that MRS was shown to succeed or fail, but that the record states a measurement-validation question without reporting the result needed to evaluate it.
13. Why This Trial Matters Statistically
This study is statistically interesting because it focuses on measurement comparison rather than a conventional treatment-versus-control outcome. MRS is described as an in vivo method for measuring myocardial triglyceride content, while endomyocardial biopsy is the reference measurement named in the primary outcome. A careful statistical analysis must distinguish association from agreement and make clear which measurement property is being evaluated.
Paired measurement studies depend on how observations are matched, how each method produces a value, and how variation within and between participants is handled. A correlation coefficient can describe whether measurements vary together, but it does not automatically establish acceptable agreement or accuracy. Choosing the right estimand and analysis is therefore central to interpreting measurement research.
The registry record offers a stated primary endpoint and a timeframe, but does not report the estimate, uncertainty, measurement procedures, or analysis details needed to judge the evidence. This illustrates why registration information and posted outcome data should be read separately: a clear research question is not itself a reported result. A numerical estimate with precision and a transparent description of the analysis would be needed to assess the statistical evidence.
The study also highlights the importance of reporting the analysis population and handling of incomplete pairs. In measurement research, missing values for either method can determine which paired observations enter the correlation analysis. Without that information, readers cannot assess whether the analyzed participants represent those enrolled or understand the reliability of the estimate.
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 primary limitation of the registry record is that it names a correlation coefficient as the endpoint but does not report the coefficient. No confidence interval, p-value, or other precision measure is reported in the registry record. The central question therefore cannot be answered from the posted outcome information.
The endpoint description is brief. It does not specify the correlation method, the scale or processing of MRS and biopsy measurements, the biopsy scoring procedure, or how the comparison was performed. It also does not report the number of paired observations analyzed. These details are important for understanding what the coefficient would represent and whether the method is reproducible.
The record gives a timeframe of 2 to 10 days but does not explain how the measurement interval was handled or whether timing varied across participants. It does not describe whether measurements represented corresponding tissue locations or how multiple observations, if any, were treated. These are relevant to interpreting a method-comparison endpoint.
Participant selection and analysis details are also limited. The primary outcome’s population field is blank, and the record does not provide eligibility criteria, participant flow, exclusions, withdrawals, missing-data methods, or the analysis population. Although enrollment is listed as 18, the number included in the primary analysis is not reported in the registry record.
Finally, randomization, masking, and parallel model are listed without operational details. The record does not clarify the allocation procedure or the role of assignment in the measurement comparison. It also does not report a statistical analysis plan, multiplicity handling, or protocol sample-size justification. These gaps constrain assessment of bias, precision, and reproducibility.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Quantification of Intramyocardial Lipid by Proton Magnetic Resonance Spectroscopy — NCT00469911.
- Registry record last updated 2018-09-13; status last verified 2018-09.
- Results first posted 2018-09-13.
- 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
The registry record describes a completed randomized, parallel study with no masking and an enrollment of 18. It lists magnetic resonance spectroscopy and ex vivo heart biopsy and identifies heart transplantation as the condition. The primary outcome is the correlation coefficient between MRS spectroscopy and endomyocardial biopsy in heart transplant participants, with a timeframe of 2 to 10 days.
The record does not report the primary coefficient, its uncertainty, or key details of the analysis population and methods. Safety entries list no serious adverse events, other adverse events, or deaths in the two named groups. Those counts are descriptive and do not provide evidence about the primary measurement association. The central statistical result remains unreported in the registry record.