Carotid artery occlusion: natural history

During a 5-year period, 212 patients (170 men and 42 women, median age 65 and 64 years, respectively) were diagnosed as having internal carotid artery occlusion. Mean follow-up was 24.9 months. Five-year cumulative survival and stroke-free rates by life-table analysis were 62% and 75%, respectively. Deaths were due to stroke in 7 of 40 patients (17%) and were of cardiac origin in 22 of 40 patients (55%). The strokes were ipsilateral in 20 of 31 patients (65%). No statistically significant difference between the sexes could be demonstrated for either death or stroke, nor was age correlated with stroke during follow-up. Diabetes and hypertension increased the risk of stroke, whereas gender and aspirin consumption had no discernible effect. Endarterectomy of the opposite carotid artery did not significantly affect the natural history but did reduce the stroke rate in the territory of the operated artery. Presenting symptoms were useful for estimating prognosis. Twenty-two of 111 patients referred for stroke (20%) suffered a further stroke and 21 of 111 patients (19%) died (three were stroke-related), whereas of those patients referred for transient ischemic attack (TIA), only 2 of 42 patients (5%) suffered a stroke and none died. TIAs occurred in 23 patients (11%) during follow-up, and these were premonitory for stroke in three cases (13%). The limited value of TIA in predicting stroke and the high mortality rate unrelated to stroke in this group are important considerations when therapy is considered for these patients.