Death from ischemic stroke in the anterior circulation: The contralateral carotid matters

Death from acute hemispheric infarction is commonly associated with stroke size, but the potential role of the internal carotid artery (ICA) in this p henomenon is poorly understood. The aim of the present study was to analyse the relation between the degree of ipsilateral and contralateral ICA steno sis, infarct type and death. We studied 2,148 first-ever stroke patients wi th anterior circulation infarction from the Lausanne Stroke Registry. Doppl er ultrasonography with frequency spectral analysis and Duplex-scanning wer e performed systematically during the acute phase of stroke. The patients w ere divided into groups according to the degree of ipsilateral and contrala teral ICA stenosis. The case fatality ratios (CFR) at hospital discharge we re obtained for each group. Several clinical features including age, stroke topography, level of consciousness, limb weakness on admission, type of on set, hyperglycemia, previous transient ischemic attack, cardiac ischemia, c ardiac arrhythmia and left ventricular hypertrophy were also studied. Morta lity increased significantly with ipsilateral ICA stenosis: less than or eq ual to 50% stenosis, 2.8%, (44/1,549); >50% and less than or equal to 90% s tenosis, 3.5%, (6/170); >90% stenosis, 5.6%, (24/429); p = 0.026, but not s ignificantly with contralateral ICA stenosis. However, patients without ips ilateral ICA stenosis had significantly higher mortality when contralateral stenosis was present: 16.7% (3/18) versus 2.7% (41/1,531), p = 0.013. This corresponded to an increased frequency of strokes involving the whole midd le cerebral artery territory, with impaired consciousness at onset of strok e. Patients with ipsilateral stenosis had similar CFR independently of the presence or absence of contralateral stenosis. In conclusion, patency of th e contralateral ICA may be an important contributory factor of larger infar ction and indirectly of stroke mortality in patients with no ipsilateral st enosis.