Appropriate Selection of the Initial Diagnostic Catheter for Left Coronary Angiography Using Computed Tomography

In patients with a dilated ascending aorta, a diagnostic catheter with a larger curve than the Judkins left 4.0 (JL4) is occasionally required to engage the left coronary artery. However, the specific size of the ascending aorta and other parameters have not been sufficiently investigated. We examined the relationship between aortic morphological parameters and the need for a larger catheter size during left coronary angiography (CAG).

At our hospital, consecutive patients who underwent both CAG and contrast-enhanced computed tomography (CT) for aorta and coronary imaging were divided into two groups based on the catheter used for left CAG: the JL4 group and the Judkins left 5.0 (JL5) group. Nine selected aortic morphological parameters from the CT images were measured and compared between the two groups.

The JL5 and JL4 groups included 19 and 230 patients, respectively. The JL5 group had higher numbers of coronary diagnostic catheters used, longer procedure times, and greater contrast volumes compared to the JL4 group. Among the nine aortic morphological parameters, significant differences were found in the maximum area and length of the ascending aorta, the total length of the aorta, and the width and depth of the aorta. Multivariate analysis revealed that the maximum area of the ascending aorta was most strongly associated with the need for JL5 in left CAG (odds ratio (95% CI) per 100 mm², 1.71 (1.33-2.21), p < 0.0001). The cutoff value for the maximum area of the ascending aorta was 1111.2 mm² (corresponding to an ascending aortic diameter of approximately 38 mm).

Selecting a large-curve diagnostic catheter, such as the JL5, as the initial diagnostic catheter for engaging the left coronary artery in patients with an ascending aorta diameter greater than 38 mm on CT may optimize left CAG.