Validation of 4 French catheters for quantitative coronary analysis: in vivo variability assessment using 6 French guiding catheters as reference scaling devices

Although numerous studies have established the utility of 4 F catheters for routine coronary angiography, its adequacy for automatic quantitative coronary analysis has not been previously assessed. METHODS: In 32 consecutive patients, coronary angiography was performed sequentially with 4 F diagnostic catheters and 6 F guiding catheters after intracoronary nitroglycerin. A total of 43 lesions were evaluated for quantitative analysis using both types of catheter as scaling devices. Possible differences in the reference diameter, minimal luminal diameter and percent diameter stenosis were evaluated. All measurements were performed offline by the same operator and intraobserver variability estimation was performed by repeating the evaluation in 12 lesions randomly selected after 1 month. RESULTS: The mean reference diameter was 2.98+/-0.48 mm, mean minimal luminal diameter was 1.00+/-0.52 mm and percent diameter stenosis was 67.1+/-15.3%. Accuracy (mean difference of values) was 0.009 mm for reference diameter, 0.005 mm for minimal luminal diameter and 0.25% for percent diameter stenosis. Precision (mean standard deviation of the differences) was 0.17 mm for reference diameter, 0.19 mm for minimal luminal diameter and 5.93% for percent stenosis. Linear correlation for these three variables was 0.94, 0.93 and 0.93, respectively. Intraobserver variability analysis showed similar values for accuracy, precision and linear correlation. CONCLUSIONS: Angiography with 4 F catheters allows adequate quantification of luminal diameters as compared to most accepted clinical standards. These results may have implications for the selection of diagnostic catheters for routine follow-up assessment of percutaneous coronary interventions.