Platelet aggregability and in vivo platelet deposition in patients with ischemic cerebrovascular disease - evaluation by indium-111-platelet scintigraphy -

In ischemic cerebrovascular disease, it is not clear whether platelet function in vitro actually reflects the situation in vivo. Using indium-111 platelet scintigraphy as a method for detecting platelet activation in vivo, we tried to elucidate this problem. Twenty eight patients with chronic stage of ischemic cerebrovascular disease (CVD) and 17 control subjects were examined. Platelet scintigrams were positive in 9 of 28 patients in CVD, while all were negative in control. A comparison of the results obtained from qualitative platelet imaging and platelet aggregability was performed to evaluate whether threshold aggregation concentration (TAC) grade differed across the three groups(control, CVD patients without platelet deposition and CVD patients with platelet deposition). CVD patients with platelet deposition showed a higher TAC than those patients who did not show platelet deposition (P < 0.05) or control subjects without platelet deposition (P < 0.05). These results suggest that some patients in chronic stages of CVD may have active platelet deposition on carotid atheromatous lesions, and presence of platelet deposition in vivo could contribute to reduce platelet reactivity in peripheral blood.