Background: Arteriosclerotic extra cranial carotid arteries stenosis is an important risk factor for
ischemic stroke, and transient ischemic attack (TIA) accounting for 15-20% of all ischemic strokes. Symptomatic patients with significant carotid artery stenosis benefit from endarterectomy with medical management as opposed to medical management. There is a wide range of sensitivity of carotid duplex scan in detecting a significant stenosis compared to CT arteriography. The general objective of the study is to compare the agreement, sensitivity, specificity and predictive values of carotid duplex ultrasonography with the carotid tomographic arteriography to detect significant carotid artery stenosis.
Method: This is a retrospective validation study with chart review of all patients of the Philippine Heart Center from Jan 2005 to December 2014 who had both carotid duplex scan and CT angiography. The results were categorized according to the Philippine Society of Vascular Medicine Consensus for classification of stenosis for duplex study and NASCET criteria for conventional angiography with the inter-rater variability analyzed by kappa.
Results: Twelve (12) patients comprised the study with a total of 24 carotid arteries were available for evaluation. Sensitivity of duplex study in detecting significant (>70%) carotid artery stenosis was 76% with a specificity of 86%, positive predictive value of 93% and negative predictive value of 60%.
Conclusion: Carotid duplex ultrasonography at the Philippine Heart Center is 79% accurate in
detecting significant carotid artery stenosis. This present study indicates that despite the agreement of 79%, it is not great enough to eliminate the use of computed tomographic evaluation of the carotid arteries in situations where hemodynamically significant stenosis is