Outcome of carotid artery occlusion is predicted by cerebrovascular reactivity

Background and Purpose-The purpose of this study was to investigate the pos sibility of obtaining prognostic indications in patients with internal caro tid occlusion on the basis of intracranial hemodynamic status, presence of previous symptoms of cerebrovascular failure, and baseline characteristics. Methods-Cerebral hemodynamics were studied with transcranial Doppler ultras onography. Cerebrovascular reactivity to apnea was calculated by means of t he breath-holding index (BHI) in the middle cerebral arteries. Sixty-five p atients with internal carotid artery occlusion were followed-up prospective ly (median, 24 months), 23 patients were asymptomatic and 42 symptomatic (2 0 with transient ischemic attack and 22 with stroke). Results-During the follow-up period, ii symptomatic patients and 1 asymptom atic patient had another ischemic event ipsilateral to carotid occlusion. A mong factors considered, only lower BHI values in the middle cerebral arter ies ipsilateral to carotid occlusion and older age were significantly assoc iated with the risk of developing symptoms (P=0.002 and P=0.003, respective ly; Cox regression multivariate analysis). Based on our data, a cut point o f the BHI value for distinguishing between pathological and normal cerebrov ascular reactivity was determined to be 0.69. All patients except one, who developed TIA or stroke during the follow-up period, had BHI values ipsilat eral to carotid occlusion of <0.69, Conclusions-These data suggest that impaired cerebrovascular reactivity is predictive for cerebral ischemic events in patients with carotid occlusion.