Duplex screening for asymptomatic carotid artery disease in Hispanic diabetic patients undergoing lower extremity revascularization: is it a worthwhile endeavor?

Screening for carotid artery disease in patients with systemic manifestations of atherosclerosis (e.g., peripheral vascular disease or coronary artery disease) has been recommended. We have been anecdotally impressed by what appears to be a unique atherosclerotic disease pattern in the Hispanic patient population of South Texas. To determine the prevalence of significant carotid artery disease in Hispanic patients with diabetes presenting with limb-threatening ischemia and to identify factors predictive of occurrence, we conducted a year-long prospective study of 92 consecutive patients undergoing infrainguinal bypass for limb salvage at The University of Texas Health Science Center in San Antonio. Peak systolic and end diastolic velocities in both internal carotid arteries were recorded by perioperative color duplex scanning. We found that the presence of a carotid artery stenosis did not correlate with any variables other than advanced age and presence of a bruit. Only 2 patients had a greater than 80% stenosis. We concluded that screening for carotid artery disease in diabetic Hispanics with critical lower extremity ischemia cannot be justified in younger patients. Even in patients older than 60 years, the presence of high-grade stenosis and, therefore, the need for carotid endarterectomy, is unlikely. However, screening in older patients is recommended to identify persons with moderate stenosis (peak systolic velocity greater than 175 cm/sec) whose disease is more likely to progress.