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Optimal detection of the progression of coronary artery disease: comparison of methods suitable for risk factor
Insights
Quantifying coronary artery disease progression is best achieved by measuring the change in mean diameter over time. This method offers the most reliable assessment for interventional study planning.
Area of Science:
- Cardiology
- Medical Imaging
- Quantitative Analysis
Background:
- Accurate quantification of coronary artery disease (CAD) progression is crucial for evaluating treatment efficacy.
- Existing methods for measuring CAD progression have varying degrees of reliability.
- Standardized and precise measurement techniques are needed for clinical trials.
Purpose of the Study:
- To compare four different quantitative methods for assessing coronary artery disease progression.
- To identify the most reliable measurement for detecting changes in coronary stenosis over time.
- To inform sample size calculations for future interventional studies on CAD.
Main Methods:
- Analysis of coronary angiograms from 35 medically treated patients over a 5-year period.
- Evaluation of 114 coronary segments with stenoses <70% using catheter calibration and an automated computer algorithm.
- Measurement of absolute dimensions (mean/minimum diameters) and derived metrics (percent stenosis, atheroma area).
Main Results:
- Mean and minimum diameters showed lower coefficients of variation than percent stenosis and atheroma area.
- Change in mean diameter over time was the most significant indicator of CAD progression (p < .001).
- Estimated sample sizes for intervention studies: 470 patients for 33% reduction, 207 for 50% reduction in progression.
Conclusions:
- Change in mean coronary artery diameter is the superior method for quantifying CAD progression.
- This finding has implications for the design and power calculations of clinical trials in cardiology.
- Reliable quantification is essential for demonstrating therapeutic effects on disease progression.
Abstract:
To assess the best method of quantitating progression of coronary disease, we studied four measurements in 114 coronary segments from 35 medically treated patients from whom angiograms were obtained 5 years apart. Only stenoses of less than 70% that were visualized in nearly identical projections on both angiograms were evaluated. Vessel edges were measured by use of catheter calibration and an automated computer algorithm yielding two "absolute dimensions" (mean and minimum diameters) and two measurements (percent stenosis and atheroma area) that required a "normal reference" diameter. The coefficient of variation for repeated segment measurements was less for mean and minimum diameter than for percent stenosis and area of atheroma. The best measure of progression of coronary disease as determined by t test comparison of different methods was the change in mean diameter over time (6.7 +/- 14.1% decrease), whether calculated on a per coronary segment or per patient basis (p less than .001). Based on this measurement and its standard deviation of progression of coronary disease in this patient subset with relatively benign disease, it is estimated that 470 patients per group would be required for an interventional study to demonstrate a 33% reduction in disease progression (207 patients for 50% reduction) at a 95% confidence level and 90% power.