Outcome of Carotid Artery Occlusion Is Predicted by Cerebrovascular Reactivity

TLDR

Internal carotid artery occlusion is a major risk factor for cerebral ischemia, but prognostic indicators based on intracranial hemodynamics remain unclear. This study aimed to determine whether intracranial hemodynamic status, prior cerebrovascular symptoms, and baseline characteristics could predict future ischemic events in patients with internal carotid occlusion. Cerebral hemodynamics were assessed by transcranial Doppler ultrasonography and breath‑holding index measurements in the middle cerebral arteries of 65 patients followed for a median of 24 months. Lower ipsilateral BHI values (<0.69) and older age were significantly associated with subsequent ischemic events, with 11 symptomatic and 1 asymptomatic patient experiencing ipsilateral events during follow‑up.

Abstract

Background and Purpose —The purpose of this study was to investigate the possibility of obtaining prognostic indications in patients with internal carotid 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 ultrasonography. Cerebrovascular reactivity to apnea was calculated by means of the breath-holding index (BHI) in the middle cerebral arteries. Sixty-five patients with internal carotid artery occlusion were followed-up prospectively (median, 24 months), 23 patients were asymptomatic and 42 symptomatic (20 with transient ischemic attack and 22 with stroke). Results —During the follow-up period, 11 symptomatic patients and 1 asymptomatic patient had another ischemic event ipsilateral to carotid occlusion. Among factors considered, only lower BHI values in the middle cerebral arteries ipsilateral to carotid occlusion and older age were significantly associated with the risk of developing symptoms ( P =0.002 and P =0.003, respectively; Cox regression multivariate analysis). Based on our data, a cut point of the BHI value for distinguishing between pathological and normal cerebrovascular reactivity was determined to be 0.69. All patients except one, who developed TIA or stroke during the follow-up period, had BHI values ipsilateral to carotid occlusion of &lt;0.69. Conclusions —These data suggest that impaired cerebrovascular reactivity is predictive for cerebral ischemic events in patients with carotid occlusion.