Chest CTA derived score predicts catheterization difficulty from right radial approach.
Background
While radial access for coronary angiography (CA) is common, certain anatomical variants make catheterization difficult. Thoracic anatomy is often available for review via chest CT angiography (CTA) during CA planning. Review of CTA can identify procedure modifying findings (PMF) that are associated with decreased efficiency of CA from the right radial artery.
Methods
A single center retrospective cohort study was performed. We examined the records of 74 patients with aortic stenosis who underwent both diagnostic CA and CTA over a 6 month period. In 43 of these patients CTA was performed prior to CA (Group 1), and in 31 after (Group 2). Patients with prior CABG or CA within 5 years were excluded. Collected variables were: baseline characteristics, access site, time from skin anesthesia to 1stand 2nd coronary artery engagement, contrast volume, fluoroscopy time, and number of catheters. CTAs of group 1 patients with radial access were reviewed to identify PMF. A scoring system was created based on the following PMF: tortuosity of the subclavian/innominate artery, calcification of the innominate artery, type I aortic arch, and a tall ascending aorta (>70mm). The differences between the groups were analyzed using descriptive statistics, p<0.05 was considered significant.
Results
Right radial artery access was used in 88% of patients, 4% required switching to alternative access. Group 1 patients were older (80.6 vs 67.8 years; p: <0.001), had more heart failure (83.7% vs 45.2%; p:<0.001). There was no significant difference between the groups in time to 1st or 2nd artery engagement, fluoroscopy time, contrast use, or the number of catheters. 71% of reviewed CTAs had PMF. CTAs with 2 or greater PMF were associated with a significant increase in time, in seconds, to 1st artery engagement (0 PMF: 506 vs 1 PMF: 342 vs 2 PMF: 823; p: 0.0082) and 2nd artery engagement (0 PMF: 792 vs 1 PMF: 548 vs 2 PMF: 1220; p: 0.002).
Conclusions
We developed a simple anatomic score that predicts reduced procedural efficiency of CA from the right radial approach. The presence of 2 or greater PMF on chest CTA is associated with significant increase in time to left and right coronary engagement. Further study is warranted to determine if CTA can be beneficial for planning of CA.