A Preliminary Investigation of Computed Tomographic Angiography in the Assessment of Coronary Artery Distensibility

OBJECTIVE: To test 2 hypotheses: first, that coronary distensibility can be measured noninvasively using 64-slice computed tomographic angiography (CTA); and second, that the extent of coronary artery disease (CAD) in any individual patient is related to the degree of distensibility detected by CTA. MATERIALS AND METHODS: Computed tomographic angiography was performed in 30 healthy adults and in 30 patients. All subjects were younger than 55 years. The main lesion located in the left anterior descending branch in patients with CAD. The cross-sectional coronary area of the left main and the left anterior descending arteries were measured in each phase (5%-95%, 10% each), and any change in the ratio was quantified. A distensibility value (D value) was determined for each artery. RESULTS: Compared with healthy subjects, the coronary area of the patients with CAD was significantly decreased in 65% to 85% (P < 0.05). There was a significant difference in the D value between healthy subjects and patients with both single-vessel and 2-vessel disease (P < 0.05). CONCLUSIONS: Coronary artery distensibility can be measured noninvasively using data obtained from CTA. The distensibility of the coronary artery decreased with the increasing number of involved pathological coronary vessels. The distensibility of the coronary artery correlated with the extent of CAD.