Risk of brain injury during diagnostic coronary angiography: comparison between right and left radial approach

To assess the incidence of silent cerebral embolization when using the transradial approach for diagnostic coronary angiography (DCA).

Compared to other vascular access sites, the right transradial approach (RTA) could reduce the amount of brain emboli by avoiding mechanical trauma to the aortic wall caused by catheters and wire, whereas it increases manipulation of catheters in the ascending aorta and has a higher risk of direct embolization into the right common carotid artery. A recent study showed an increased incidence of microembolic signals (MES) in RTA compared to femoral. However, left transradial approach (LTA) has never been assessed.

40 patients with suspected coronary artery disease were randomized to DCA via RTA (n=20) or LTA (n=20) with contemporaneous bilateral transcranial Doppler monitoring.

MES were detected in all patients, with a significantly higher rate in the RTA group (median 61, interquartile range (IQR) 47-105, vs 48, IQR 31-60, p=0.035). MES generated during procedures needing >2 catheters (n=8), are higher than those detected during procedures performed with 2 catheters (n=32, 102, IQR 70-108, vs 48, IQR 33-60, p=0.001). At multivariate analysis increasing number of catheters was the only independent predictor of high incidence of MES (OR 16.4, 95% CI 1.23-219.9, p=0.034, -2LL=26.7).

LTA has a lower risk of brain embolization because of the lower number of catheter exchange maneuvers. Since the degree of brain embolism depends on the magnitude of mechanical manipulation, catheter changes should be minimized to reduce the risk of cerebral embolization.