Comparison of Diagnostic Accuracy of Digital Plethysmography Versus Duplex Ultrasound in Detecting Radial Artery Occlusion After Transradial Access.

Background: Duplex Doppler ultrasonography (USG) remains the gold standard for evaluation of radial artery occlusion (RAO) after transradial access (TRA). The diagnostic accuracy of digital plethysmography, which is cheaper and widely available, for evaluation of RAO after TRA is not known.

Methods: Patients undergoing TRA were prospectively studied. After undergoing TRA for diagnostic or interventional coronary procedure and obtaining radial artery hemostasis, the radial artery was evaluated for presence or absence of RAO using digital plethysmography of the ipsilateral index finger and the thumb using modified reverse Barbeau's test (MRBT) and USG. Sensitivity, specificity, predictive values, likelihood ratios and other metrics of evaluation of diagnostic performance of MRBT in reference to USG, the current gold standard, were evaluated.

Results: 503 patients who underwent TRA for coronary procedures were studied. MRBT demonstrated a sensitivity = 96.2%, specificity = 99.8%, positive predictive value = 96.1, negative predictive value = 99.8, likelihood ratio (+) = 481, likelihood ratio (-) = 0.38, diagnostic accuracy = 99.6, diagnostic odds ratio = 11,904, Youden's index = 0.96, receiver operator characteristic derived c-statistic = 0.98 and Cohen's k = 0.98 when compared to USG. MRBT performed using the ipsilateral index finger and the thumb was no different. Agreement between absence of ipsilateral radial artery pulsation and RAO was weak (Cohen's k = 0.69).

Conclusions: MRBT using ipsilateral digital plethysmography performs comparably to USG for assessment of presence of RAO after TRA. There is no significant difference between MRBT performed using the ipsilateral thumb or the index finger.