Blood rheology in patients with transient ischemic attacks

E Ernst, A Matrai, M Marshall
1988 Stroke  
A complete ischemic stroke is associated with a significant hemorheologic disturbance leading to a rise of the viscous component of the peripheral resistance. This abnormality represents a consequence of the acute event. Nonetheless, it could be causally related to ischemia. In an attempt to clarify this question, 26 patients suffering from transient ischemic attacks were compared with controls in terms of blood and plasma viscosity, hematocrit, blood cell filterability, and erythrocyte
more » ... ion. In patients there was a significant impairment of blood fluidity comprising plasma viscosity, blood cell filterability, and erythrocyte aggregation, suggesting that the flow properties of blood are jeopardized even before an acute stroke. Most likely this is due to the underlying arteriosclerotic process. Our results open the way to speculating that hemorheologic mechanisms might predispose to the development of a stroke by decreasing cerebral blood flow. If this hypothesis were true, it would have important therapeutic implications. (Stroke 1988;19:634-636) T here is ample information on the flow properties of blood after an acute ischemic stroke. 1 " 6 These studies unanimously agree that both cellular and plasmatic abnormalities lead to a marked limitation of blood fluidity. Such changes may be looked upon as a consequence of a stroke; however, they could also contribute to the development of ischemia by virtue of their detrimental influence on cerebral blood flow. 7 -8 A transient ischemic attack (TLA) with hemodynamicalry relevant stenosis of the internal carotid artery represents a precursor of stroke.*" 11 Little is known about the flow properties of blood in this condition. Our study was aimed at investigating the blood rheology of TLA patients and testing the hypothesis that blood fluidity is impaired not only after, but also before, an ischemic stroke. Subjects and Methods Twenty-six consecutive outpatients (12 women, 14 men; aged 50 ± 15 years) with a history of TIAs (a minimum of one attack within the last 4 weeks) and ultrasonic evidence of a stenosis of the internal carotid artery of at least 75% were investigated. A control group (n -26) was selected to match the age (47 ± 14 years) and sex distributions (12 women, 14 men) of the patients. The frequency and distribution of cardiovascular risk factors (hypertension, smoking, hyperlipidemias, diabetes, obesity) were comparable in both groups (Table 1 ). The control group
doi:10.1161/01.str.19.5.634 pmid:3363598 fatcat:nfvd6dad7zhodlbggki2chemoq