Transradial coronary catheterization and intervention across the whole spectrum of Allen test results.

OBJECTIVES: The aim of this study was to investigate the safety and feasibility of transradial coronary catheterization across the whole spectrum of Allen test (AT) results.

BACKGROUND: Whether the AT can predict ischemic complications after transradial access (TRA) is controversial. No prospective assessment exists on the safety and feasibility of TRA across the whole spectrum of AT results.

METHODS: From October 2007 to June 2009, a total of 942 patients undergoing TRA were screened, and 203 were recruited, of whom 83, 60, and 60 had normal, intermediate, and abnormal AT results, respectively. Patients underwent serial assessments of thumb capillary lactate (the primary endpoint), thumb plethysmography, and ulnar frame count to investigate the patency of the ulnopalmar arches, as well as handgrip strength tests to examine the isometric strength of the hand and forearm muscles and discomfort ratings.

RESULTS: Lactate did not differ among the 3 study groups after the procedure (1.85 ± 0.93 mmol/l in patients with normal AT results, 1.85 ± 0.66 mmol/l in those with intermediate results, and 1.97 ± 0.71 mmol/l in those with abnormal results; p = 0.59) or at other time points during the study. Plethysmographic readings showed improvements of ulnopalmar collateralization in patients with non-normal AT results, whereas the ulnar frame count was decreased, suggesting enhanced ulnar flow, in patients with abnormal AT results after TRA. Handgrip strength test results and discomfort ratings did not differ across AT groups. No hand ischemic complications occurred.

CONCLUSIONS: This study provides proof of concept for a paradigm shift in cardiovascular intervention, suggesting the safety and feasibility of TRA across the whole spectrum of AT results. Given the multiple implications of our findings, a broader clinical validation is needed. (Predictive Value of Allen's Test Result in Elective Patients Undergoing Coronary Catheterization Through Radial Approach [RADAR]; NCT00597324).