Risk Factor Profile of Previously Asymptomatic Patients Presenting With Carotid-Related Stroke

Abstract

Whereas carotid atherosclerosis-mediated stroke remains a major cause of morbidity and mortality, some have suggested that intervention in carotid stenosis should be limited to symptomatic patients, given advances in medical therapy. This study was conducted to assess atherosclerotic risk factor profiles of those previously asymptomatic patients admitted with stroke of carotid etiology. We reviewed 3382 patients admitted to a tertiary care center diagnosed with an ischemic stroke during 2005 to 2015. This study focused on patients admitted with a radiographically confirmed infarct ipsilateral to a documented carotid artery stenosis ≥50%, with the admitting neurology team adjudicating the stroke etiology as carotid related. Patients were excluded if they had previous transient ischemic attack, prior infarct ipsilateral to any carotid lesion, prior carotid revascularization, intracranial hemorrhage, or malignant disease. A total of 219 (7% of all strokes) carotid stroke patients were identified, of whom 61% were white and 66% were male, with a mean age of 68 ± 12 years. Hypertension (79%) and smoking (33% current; 29% former) were predominant risk factors. On admission, 47% were receiving antiplatelet therapy (aspirin, 42% [n = 92]; clopidogrel, 4% [n = 8]; dual therapy, 5% [n = 11]) and 55% were taking lipid-lowering agents (statin, 53% [n = 115]; other, 2% [n = 6]); 35% (n = 77) were receiving both antiplatelet and lipid-lowering therapy. Of these patients, 80% (n = 177) presented with a moderate or severe stroke (National Institutes of Health Stroke Scale ≥5 at admission), 25% (n = 54) received lytic therapy, 44% (n = 96) presented with an occluded ipsilateral internal carotid artery, and 53% (n = 117) ultimately underwent carotid revascularization at a median of 4 days. Individuals receiving both antiplatelet and lipid-lowering therapy were significantly less likely to experience a moderate or severe stroke event (44% vs 78%; P = .006). Previously asymptomatic patients receiving inadequate medical therapy presenting with carotid-related stroke are significantly more likely to experience a severe, debilitating stroke. However, those receiving appropriate medical therapy are still at risk for carotid-mediated stroke. These data refute the contention that medical therapy alone is sufficient stroke prevention therapy for patients with significant carotid bifurcation atherosclerotic stenosis.