This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record.
1. Trial at a Glance
NOBLE was a randomized, parallel-design clinical trial comparing two procedural approaches for patients with coronary artery disease involving unprotected left main stenosis.
| Feature | NOBLE |
|---|---|
| NCT ID | NCT01496651 |
| Acronym | NOBLE |
| Condition | Coronary Artery Disease |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None |
| Primary purpose | Treatment |
| Enrollment | 1201 |
2. Clinical Question
Population
Patients with coronary artery disease involving unprotected left main stenosis.
Intervention
Percutaneous coronary intervention procedure.
Comparator
Coronary artery bypass graft operation procedure.
Primary question
The trial evaluated the comparative outcomes of PCI versus CABG.
3. Trial Design
The registry describes NOBLE as a randomized, parallel study with no masking. The trial started on 2008-11-06 and had a primary completion date of 2015-01-22.
| Design element | Description |
|---|---|
| Sponsor | Evald Hoej Christiansen |
| Sponsor type | OTHER |
| Allocation | Randomized |
| Number of arms | 2 |
4. Endpoints
The registered primary endpoint was a combined endpoint of death, stroke, non-index treatment related MI and new revascularization (PCI or CABG).
| Endpoint | Time frame |
|---|---|
| Combined endpoint of death, stroke, non-index treatment related MI and new revascularization (PCI or CABG) | From date of first randomisation until a total number of 275 events is reached (or max 5 years). |
5. Planned Analysis
The registry identifies the primary endpoint as a composite time-to-event outcome consisting of death, stroke, non-index treatment related myocardial infarction and new revascularization. For composite endpoints of this type, statistical analyses commonly examine the time until the first qualifying event and compare event occurrence between randomized groups using survival-analysis methods.
ClinicalTrials.gov does not report posted statistical analyses or numerical outcome results for the primary endpoint.
6. Statistical Methodology
The primary endpoint combines multiple clinically distinct events into one composite measure. Composite endpoints can increase the number of observed events, which may improve statistical efficiency, but interpretation depends on the contribution of each component.
A patient contributes an event when the first qualifying component occurs. The combined endpoint does not indicate that every component occurred equally often or that all components have identical clinical importance.
7. Statistical Methods Explained
Why use a composite endpoint?
Combining death, stroke, non-index treatment related MI and new revascularization creates a broader outcome measure that captures multiple possible clinical events after treatment.
Why does time frame matter?
The endpoint was defined from the date of first randomisation until either 275 total events were reached or a maximum of 5 years. This defines the observation period for the primary outcome.
Why is randomization important?
Random assignment helps balance measured and unmeasured factors between PCI and CABG groups, allowing comparisons of outcomes between treatment strategies.
Why are composite endpoints sometimes difficult to interpret?
A composite result may be influenced more strongly by frequent components than by less frequent but more severe outcomes.
What information is missing from the registry record?
The registry does not report posted statistical analyses, estimates, confidence intervals, p-values, subgroup analyses, or safety results.
8. Limitations
- The ClinicalTrials.gov record does not provide numerical primary endpoint results.
- No posted statistical analyses are available in the registry record.
- The composite endpoint combines multiple clinical outcomes that may differ in frequency and clinical importance.
- Without reported estimates and uncertainty measures, the magnitude and precision of treatment differences cannot be evaluated from the registry record alone.
9. Why This Trial Matters Statistically
| Concept | How it appears in NOBLE |
|---|---|
| Randomization | Randomized comparison of two procedural strategies |
| Parallel design | Two-arm treatment comparison |
| Composite endpoint | Death, stroke, non-index treatment related MI and new revascularization |
| Event-driven analysis | Primary endpoint defined by reaching 275 events or maximum 5 years |
| Time-to-event methods | Appropriate framework for outcomes occurring over follow-up |