Hyperdense Middle Cerebral and/or Internal Carotid Arteries in Acute Ischemic Stroke: Rate, Predictive Factors and Influence on Clinical Outcome

<i>Background:</i> In patients with acute stroke, the hyperdense middle cerebral artery (MCA) and internal carotid artery (ICA) signs on CT scans are markers of early ischemia, but their prognostic implications remain unclear.The aims of this prospective study were to assess: (1) the occurrence rate of hyperdense MCA and/or ICA in patients admitted for acute ischemic stroke; (2) the risk factors for hyperdense MCA and/or ICA; (3) the correlation between hyperdense MCA and/or ICA and functional outcome at 3 months. <i>Methods:</i> Consecutive patients admitted with ischemic stroke between 1 January 2006 and 30 June 2010 were included in this prospective single-centre cohort study. <i>Results:</i> 1,010 patients (mean age 71.9 years; 56.7% males) were included in the study. Among these patients, 148 (14.7%; mean age 71.2 years; 52% males) had hyperdense MCA and/or ICA. Overall, 163 patients (16.1%) had a final infarct covering more than one third of the MCA territory. Seventy-eight of 148 patients (52.7%) with hyperdense MCA and/or ICA had an infarct involving more than one third of the MCA territory compared to 85 of the 862 patients without artery hyperdensity (9.9%). At 3 months, 18 patients were lost to follow-up, 325 patients (32.8%) were disabled and 165 died (16.5%). Age (OR 1.06 for 1 added year; 95% CI 1.04–1.08), National Institute of Health Stroke Scale score for 1 added point on admission (OR 1.2; 95% CI 1.2–1.3), stroke due to atherosclerosis (OR 2.3; 95% CI 1.0–5.4), hemorrhagic transformation of the ischemic lesion (OR 2.2; 95% CI 1.0–4.9), and hyperdense MCA and/or ICA (OR 2.0; 95% CI 1.0–4.0) were associated with adverse outcome. <i>Conclusions:</i> In this prospective cohort of patients with acute ischemic stroke, we observed an incidence of hyperdense MCA and/or ICA arteries of about 15%; hyperdense MCA and/or ICA were associated with a final infarct involving more than one third of the MCA territory and poor functional outcome at 3 months.