Prognosis of Asymptomatic Carotid Artery Occlusion

Abstract

Background and Purpose— The aim of this systematic review was to quantify the risk of ipsilateral stroke in patients with asymptomatic carotid artery occlusion (ACAO). Methods— Studies reporting ipsilateral stroke risk in ACAO were identified by a search of MEDLINE, EMBASE, and study bibliographies. Study estimates were pooled using a random effects model, and heterogeneity was quantified using the I 2 statistic. The primary outcome was the annual rate of ipsilateral stroke. Results— Thirteen studies were identified, encompassing 718 patients with ACAO who were followed up for a median of 2.8 years. The annual rate of ipsilateral stroke was 1.3% (95% confidence interval, 0.4–2.1; I 2 =53%). The annual rate of ipsilateral transient ischemic attack was 1.0% (95% confidence interval, 0.3–1.8; I 2 =40%). The annual rate of death was substantially higher at 7.7% (95% confidence interval, 4.3–11.2; I 2 =83%). Correction for possible publication bias for the primary outcome suggested a lower risk of ipsilateral stroke (0.3% per year; 95% confidence interval, –0.4 to 1.1). Conclusions— Stroke in ACAO is relatively infrequent, but patients face high mortality rates. This suggests the need for intensified medical therapy in ACAO.