Progression and clinical recurrence of symptomatic middle cerebral artery stenosis: a long-term follow-up transcranial Doppler ultrasound study.

BACKGROUND AND PURPOSE Patients with symptomatic intracranial atherosclerotic stenosis have a high rate of recurrence. We conducted a prospective study to determine which factors are associated with the progression of symptomatic middle cerebral artery (MCA) stenosis and to evaluate the relationship between progression and clinical recurrence. METHODS Between January 1996 and February 2000, of a total of 2564 consecutive first-ever transient ischemic attack (TIA) or stroke patients admitted to our cerebrovascular unit, 145 showed an MCA stenosis signal on transcranial Doppler (TCD) on admission, and 40 fulfilled all criteria to enter this study, including angiographic confirmation. Patients were prescribed antiplatelet or anticoagulant agents following the criteria of the neurologist in charge. TCD recordings and clinical interviews were performed regularly during follow-up. Progression of MCA stenosis was defined as an increase >30 cm/s in TCD-recorded maximum mean flow velocity. Logistic regression analyses were used to identify predictors of progression and clinical recurrence. RESULTS With a median follow-up of 26.55 months, 13 (32.5%) MCA stenoses progressed, 3 (7.5%) regressed, and 24 (60%) remained stable. Absence of significant extracranial internal carotid artery (ICA) stenosis (P=0.049) and the use of oral anticoagulants (P=0.045) were significantly associated with a lower progression rate in univariate analysis, and anticoagulation remained an independent predictor when a logistic regression model was applied (OR 7.25, CI 1.1 to 48.1, P=0.019). A new ischemic event during follow-up in the territory supplied by the stenosed MCA occurred in 8 cases (20%), and 13 patients had a major vascular event. Progression of the MCA stenosis detected by TCD was independently associated with a new ipsilateral ischemic event (OR 2.89, CI 1.09 to 7.71, P=0.031) and with the occurrence of any major vascular event (OR 7.03, CI 1.6 to 30.9, P=0.0071). CONCLUSIONS Progression of symptomatic MCA stenosis detected by means of TCD predicts clinical recurrence. Anticoagulation is independently associated with a lower progression rate of symptomatic MCA stenosis.