Significance of Whole Blood Viscosity in Acute Ischemic Stroke

The paper provides a comprehensive review of the relationship between whole blood viscosity (WBV) and acute ischemic stroke (AIS) concerning AIS risk and type, and its treatment and prognosis. A significant increase in diastolic blood viscosity (DBV) at the onset of AIS was established in the small-artery occlusion stroke subtype. In patients with atherothrombotic causes of AIS, systolic (SBV) and DBV values were higher than in those with an embolic cause. The higher WBV at low shear rates on hospital admission is associated with an increased risk of early neurological deterioration and disease progression in the patients with AIS. Most studies reveal the association of increased WBV at the stroke onset with poor functional outcome after applying intravenous thrombolysis or endovascular thrombectomy. However, significant reduction in WBV after the combined use of these therapeutic methods in AIS patients was observed. Whole blood viscosity has an obvious effect on the risk of AIS, its clinical severity and outcome. Further research is needed due to the multiple devices and techniques used, like cone–plate viscometers, scanning capillary viscometers, EMS viscometers, parallel-plate rheometers and the different associations of WBV with some of the applied treatment strategies.