Abstract T MP51: Relation of Spontaneous Microembolic Signals to Stratification of Risk, Recurrence and Morbi-mortality of Ischemic Stroke by Transcranial Doppler: A Prospective Trial

Abstract

Background: The role of spontaneous microemboli signals (MES) by Transcranial Doppler (TCD) in the acute phase of stroke has been studied little and has potential application for locating emboligenic source and for predicting risk. We assessed the hypothesis that investigating MES prevalence in the acute phase of stroke is related to risk stratification, stroke recurrence and morbi-mortality. Methods: This is an analytic observational study of a single non-concurrent cohort with 111 patients diagnosed with ischemic stroke of anterior circulation in the first 48 hours of ictus. All patients underwent monitoring of the middle cerebral arteries by TCD for at least 30 minutes. The examiner who conducted the monitoring was unaware of the risk stratification of the patient (single-blinded). Then, the examination record was independently analyzed by two neurologists to identify the MES. After monitoring, risk stratification was carried out for all patients by complementary examinations; the recurrence and morbi-mortality were evaluated by ambulatory monitoring for months. The relation between risk factors, stratified for risk with MES was obtained by Odds-Ratio taking into consideration confounding factors (thrombolysis and anticoagulation level) at the moment of monitoring, and the relation of MES to stroke recurrence and morbi-mortality by multiple regression logistics, considering values statistically significant if p<0.05. Results: Of the 111 patients studied, 70 were male (63.1%), 90 white (81.1%), with median age of 68 years. The MES frequency was 7% in the total sample. There was a relation between MES and symptomatic carotid disease (OR=22.7;CI95%=(4.1-125.7);p<0.001), shorter time between ictus and monitoring commencement (OR=12.4; CI95%=(1.4-105.4);p=0.02), and stroke recurrence (OR=16.83;CI95%=(2.01-141);p=0.009). MES was not significantly related to morbi-mortality (OR=1.7;CI95%=(0.28-10.90);p=0.547), or to such risk factors as cardioembolic source or atrial fibrillation. Conclusions: It was found that MES detection shows higher correlation with symptomatic carotid disease, and shorter time between ictus and monitoring commencement, in addition to the presence of MES as a predictor for stroke occurrence.