Evaluation of a new classification of cerebrovascular disease: CHAT.

A new scheme that classifies cerebrovascular disease on the basis of current and prior clinical symptoms, arteriographic findings, and target organ abnormalities has been evaluated. The scheme proved to be easy to learn and to use. Its utility was demonstrated by the previously unreported distinctions that became apparent when various patient subsets were analyzed according to the CHAT classification. These included an improved probability of stroke-free survival in patients operated on for brief strokes (transient ischemic attack) as opposed to temporary strokes (reversible ischemic neurologic deficit), and similarly improved survival probability in patients operated on for amaurosis fugax in comparison to those with carotid territory hemispheric transient ischemic attacks. The impact of multiple arterial lesions and positive computerized tomography scan findings appeared to be minimal with respect to both late stroke and survival in our preliminary observations. The simplicity and utility of the CHAT scheme make it a useful method to evaluate and report clinical experience with cerebrovascular disease.