Abstract P596: How Common Are Microembolic Signals After Cerebrovascular Events and Are They Related to Recurrent Admissions?

Abstract

Introduction: Microembolic signals (MES) identified by transcranial Doppler (TCD) reflect an ongoing embolic phenomenon with implications for the recurrence of cerebrovascular events and complications. In this study, we investigated the prevalence of MES detected after stroke or transient ischemic attack (TIA) and studied their relationship with future re-admissions. Method: This clinical cohort study is comprised of 961 consecutive patients (mean age 65 years, 59% male) admitted to Northwestern Memorial Hospital with the diagnosis of acute stroke (n: 872) or TIA (n: 89) and underwent TCD evaluation. TCD is performed within the first 48 hours of admission as a routine component of stroke etiology evaluation at our institution. After discharge, patients were followed for an average of 18 months for any hospital readmissions. Cox regression models were used to estimate risk of re-admissions in relation to MES. Results: MES were detected in 99 (10%, 95% CI; 8-12%) patients. During the follow up period, 356 patients had emergency room re-admissions. Compared to patients without MES, those with MES were younger ( p =0.007) and had longer index hospital stay ( p =0.008). Patients with MES, as compared to patients without MES, had 1.56-fold (hazard ratio 95% CI=1.15, 2.13; p =0.005) higher risk of readmission. This association was independent of age, sex, race, smoking, history of hyperlipidemia, diabetes, atrial fibrillation, history of pulmonary emboli, deep vein thrombosis, hypertension, coronary artery disease and heart failure. Conclusion: We show that MES are present in one tenth of patients admitted with stroke or TIA, and they are associated with higher risk of re-admission. These data highlight the importance of embolic signals in stroke complication risk stratification and suggest the need for prospective clinical trials targeting MES in secondary stroke risk and complication prevention.