Abstract 348: Overutilization of Carotid Duplex Ultrasonography in Evaluation of Cerebrovascular Disease

Introduction: Carotid Duplex Ultrasonography (CDUS) is one of the non-invasive imaging modalities used to evaluate for carotid artery stenosis. However, it is often used in patients with coronary artery disease (CAD), peripheral artery disease (PAD), syncope, and before heart surgery although its value is unclear. Our study aimed to further investigate the yield of CDUS in these conditions. Methods: A retrospective analysis was conducted on 827 consecutive carotid ultrasounds ordered between March 2013 and August 2013 at Newark Beth Israel Medical Center. Clinical variables tabulated were age, sex, smoking status, systemic hypertension, diabetes mellitus, CAD, PAD, carotid bruit and physician indications for ordering CDUS. Significant cerebrovascular disease (sCBVD) was defined as > 60% diameter reduction in internal carotid arteries (ICA) or occlusion in vertebrobasilar system as per Intersocietal Commission for Accreditation of Vascular Laboratories (ICAVL) guidelines. Results: Only 88 out of 827 (10.6%) patients had sCBVD. In these 88 cases, most common plaque characteristics identified were irregular hetergeneous and irregular calcified. Risk factors such as age, sex, cigarette smoking, systemic hypertension, diabetes mellitus, CAD or PAD did not make a significant difference in rate of sCBVD (Chi Square=0.72, p=0.95). However, patients with history of carotid endarterectomy (CEA) or carotid artery stenting and presence of carotid bruit had significantly higher proportion of sCBVD (Chi Square=113, p<0.001). Finally, yield of carotid ultrasound was lowest in patients with syncope, pre-operative evaluation for heart surgeries, Orthotopic Heart Transplantation and non-specific neurologic symptoms such as gait imbalance, delirium, visual problems, and paresthesias. Conclusion: Carotid Duplex Ultrasonography used in a real world hospital setting has very low diagnostic yield in patients presenting with syncope and in pre-operative evaluation for cardiac surgeries. This highlights poor cost-effectiveness of carotid ultrasound in such situations. Furthermore, we propose that randomized trials need to be conducted to optimize its effective utilization.