MICROEMBOLIC SIGNALS AND RISK OF EARLY RECURRENCE IN PATIENTS WITH STROKE OR TRANSIENT ISCHEMIC ATTACK

Background and Purpose-Asymptomatic microembolic signals (MES) can be demonstrated in patients with cerebral ischemia using transcranial Dop pler (TCD) ultrasonographic monitoring of the middle cerebral artery. However, the clinical relevance of MES remains uncertain. The purpose of this study was to estimate the independent contribution of microemb olism to the risk of early ischemic recurrence (EIR) in patients with stroke or transient ischemic attack (TIA) of presumed arterial origin. Methods-We studied the incidence of EIR in 73 consecutive patients wi th carotid stroke or TIA in whom TCD scanning of the symptomatic middl e cerebral artery was performed within 7 days from the onset of sympto ms. Patients with a potential cardiac source of embolism were excluded from the study. Results-Eight patients had EIR during a mean+/-SD fol low-up of 10+/-8 days. The incidence of EIR was 4.3 per 100 patient-da ys in patients with MES and only 0.5 per 100 patient-days in patients without MES, The presence of MES was a significant predictor of EIR af ter adjustment for the presence of carotid stenosis or aortic arch ath eroma, antiplatelet therapy during follow-up, and other potential conf ounding variables (relative risk, 8.7; 95% confidence interval, 2 to 3 8.2; P=0.0015). Conclusions-Microembolism is a significant independent predictor of EIR in patients with stroke or TIA of presumed arterial origin.