Background. Alien's test is widely used to assess the ulnar collateral bloo
d supply of the hand before radial artery harvest for coronary bypass surge
ry. This study was performed to determine the optimum cut-off point for a p
ositive Alien's test and the clinical reliability of Alien's test in this r
ole.
Methods. Patients undergoing coronary artery bypass surgery were examined b
y independent observers using both Alien's test and a Doppler ultrasound te
st of the ulnar collateral circulation.
Results. We examined 93 hands in 47 patients; mean age was 63.6 years. Rece
iver operating characteristic analysis found that at a conventional cut-off
of 6 seconds on Alien's test had a sensitivity of 54.5%, specificity of 91
.7%, and diagnostic accuracy of 78.5%. At a cut-off of 5 seconds diagnostic
accuracy was maximal (79.6%), with sensitivity of 75.8% and specificity of
81.7%; 100% sensitivity occurred at a cut-off of 3 seconds, with specifici
ty of 27% and diagnostic accuracy of 52%.
Conclusions. At no cut-off point does Alien's test perform satisfactorily a
s a discriminatory test. It should be replaced by more objective tests, suc
h as Doppler ultrasound. (C) 2000 by The Society of Thoracic Surgeons.