Author + information
- Kuljit Singh, MBBS, PhD,
- Aun-Yeong Chong, MBBS, BSc (Med), MD and
- Derek Y. So, MD∗ ()
- ↵∗University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa ON K1Y 4W7, Canada
We would like to thank Dr. Santucci and colleagues for their interest in our case report (1) and for raising an important issue regarding the use of Allen’s test before cardiac catheterization using the transradial approach (TRA). The importance of the TRA for patient comfort and same-day discharge post–coronary intervention cannot be overemphasized.
Increasingly, the TRA is the default approach, and Allen’s test is performed variably to assess the patency of the ulnar artery before the TRA. Importantly, this practice varies among centers and is not commonly performed everywhere. One reason for this variability is that the sensitivity and specificity of Allen’s test to assess artery patency are minuscule (2). A variety of noninvasive options, including plethysmography, pulse oximetry, and duplex ultrasonography, are available to supplement Allen’s test. Still, there is no consensus on the best test for assessing collateral circulation of the hand, and the choice of test depends on the preference of cardiologist or the availability of equipment. Given the high false positive rate of Allen’s test, many patients are wrongly excluded from the TRA for coronary angiography (3). Furthermore, hand ischemia is usually caused by either digital embolization of radial artery thrombus or in situ thrombosis of collateral vessels because of severe vasospasm, which usually occurs in the setting of normal radial, ulnar, and superficial palmar arteries.
There are many strategies for reducing radial artery occlusion, such as patent hemostasis (4), the use of a 5-F system for diagnostic angiography, proper administration of antispasm medications, and the use of at least 50 U/kg unfractionated heparin, all of which are backed by scientific evidence. We agree with Santucci et al. that the presence of a normal result on Allen’s test may not reduce ischemic complications, as illustrated by our case presentation. We believe that the TRA should be the default in the majority of patients, especially post-thrombolysis; nonetheless, occasional devastating complications occur, and we as interventional cardiologists need to be cognizant of their existence.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
- Singh K.,
- Abunassar J.,
- So D.Y.
- Jarvis M.A.,
- Jarvis C.L.,
- Jones P.R.,
- Spyt T.J.
- Pancholy S.,
- Coppola J.,
- Patel T.,
- Roke-Thomas M.