The contribution of microembolic signals (MES) detection in cardioembolic stroke

Cardioembolic stroke accounts for about one third of all strokes. Microembolic signals (MES) are frequently found in patients with acute stroke. The role of MES in cardioembolic stroke is less well investigated. Medline based literature review of clinical trials linking MES and stroke with cardiac sources of various risks. MES are a rare finding in patients with cardioembolic stroke as well as in sources of potential cardiac embolism (e.g. myocardial infarction, atrial fibrillation, left ventricular thrombus). The low number of patients with MES and the low number of MES during the investigation times leads to a limited statistical power of positive and negative findings. MES in patients with artificial heart valves and the DeBakey left ventricular assist device (LVAD) are predominantly gaseous and do not correlate with stroke risk. In patients with the Novacor LVAD, MES strongly correlate with stroke risk. Currently, the role of MES in cardioembolic stroke is only limited due to both, the low prevalence of MES and the number of MES per investigation. Larger studies would be needed to strengthen this role.