Two hundred forty-seven patients with early Alzheimer's disease were studied for the association of demographic, functional, and cognitive status and vascular comorbidities and risk factors present at index visit to rate of clinical disease progression over 3 years and to survival time. Patients who progressed to the moderate stage were designated fast progressors; those who remained in the early stage were designated slow progressors. At index visit, Mini-Mental State Exam score was significantly lower for the fast than the slow group; global impairment was significantly higher for the fast group. Cognitive scores showed greater annual decline in the fast group, and the fast group also had a greater annualized global change. The fast group had a shorter median survival time from onset, but age at onset, age at initial visit, history of heart problems, myocardial infarct, stroke, hypertension, diabetes, or past or current smoking did not differ between groups.