Vascular Communications of the Hand in Patients Being Considered for Transradial Coronary Angiography: Is the Allen’s Test Accurate?

OBJECTIVES The purpose of this study was to assess the accuracy of the Allen’s test (AT) in predictinghand ischemia in patients undergoing transradial coronary angiography.BACKGROUND Patients with poor vascular communications between the radial artery (RA) and ulnar artery(UA), as indicated by an abnormal AT, are usually excluded from transradial coronaryangiography to avoid ischemic hand complications.METHODS Over a four-month period, patients undergoing coronary angiography were screened for ATtime. Circulation in the RA, UA, principal artery of the thumb (PAT), and thumb capillarylactate were measured before and after 30 min of RA occlusion.RESULTS Fifty-five patients were studied (20 normal, 15 intermediate, 20 abnormal). Three patientswith an abnormal AT were excluded, owing to absence of detectible flow in the distal UA.Patients with an abnormal AT were all men, had a larger RA (3.4 vs. 2.8 mm; p 0.001), andsmaller UA (1.9 vs. 2.5 mm; p 0.001), compared with patients with a normal AT. After 30min of RA occlusion in patients with abnormal AT, blood flow to the PAT improved (3.2to 7.7 cm/s; p 0.001) yet remained reduced relative to patients with normal AT (7.7 vs. 21.4cm/s; p 0.001. Thumb capillary lactate was elevated in patients with an abnormal AT (2.0vs. 1.5 mmol/l; p 0.019).CONCLUSIONS After 30 min of RA occlusion, patients with an abnormal AT showed significantly reducedblood flow to the thumb and increased thumb capillary lactate (compared with patients witha normal AT) suggestive of ischemia. Transradial cardiac catheterization should not beperformed in patients with an abnormal AT. (J Am Coll Cardiol 2005;46:2013–7) © 2005by the American College of Cardiology Foundation