Hemorheologic changes in patients with a history of stroke or cerebral remittent ischemic attacks.

Hemorheologic parameters were measured in cerebrovascular patients with a history of stroke or recurrent ischemic attacks in a quiescent phase of the disease. All patients were submitted to aortic arch angiography and then classified according to the presence or absence of detectable arterial lesions. In comparison with a group of control subjects, cerebrovascular patients had significantly elevated levels of blood and plasma viscosity, fibrinogen, factors VIII:C and VIIIR:Ag and lowered values of erythrocyte filtration. Blood viscosity was increased and erythrocyte filtration reduced only in male patients. Elderly patients had higher blood viscosity and fibrinogen levels, and those with a history of stroke also showed the highest hematocrit and plasma viscosity values. Patients with a stroke history compared with those affected by remittent ischemic attacks, and patients with positive in comparison with those with negative angiograms were characterized only by higher fibrinogen (and sometimes factor VIII) levels, but not by other differences in hemorheologic values. It is concluded that changes in hemorheologic values consistent with hyperviscosity are a feature of cerebrovascular patients also in the quiescent phase of the disease and not only as a result of acute ischemic attacks. These changes are however most frequent in males and in elderly subjects, while they seem to be almost evenly distributed in patients with or without evidence of arterial disease.