[Evaluation, by flow cytometry, of activated platelet levels after coronarography and intraluminal angioplasty].

Coronarography and intraluminal angioplasty induce platelet activation. In this study, activated platelets were evaluated by measuring platelet-bound fibrinogen using a polyclonal fluorescent antibody in flow cytometry on whole blood. For normal subjects, the percentage of platelets binding fibrinogen was low (16.67%) and reached 81.0% in response to ADP. The percentages of platelets binding fibrinogen were evaluated 24 hours before and after coronarography. During intracoronary angioplasty, blood was collected from the catheter before and after the dilation and aspirin bolus (1 g). In both groups, the percentages of activated platelets were lower compared with those of the control group (respectively 3.96% and 5.59% versus 16.67%) following aggregation inhibitor, anticoagulant and calcium inhibitor therapies. Twenty-four hours after coronarography, platelet activation was noted (9.71% versus 3.96%). During angioplasty no significant activation was observed immediately after dilation (6.54% versus 5.59%). In both groups before the intervention, ADP stimulation was still responsible for platelet activation but to a lesser extent than in the control group (60.42% and 66.31% versus 81.0%). After coronarography, the platelet response to ADP was identical to that in the control group (81.01% versus 81.0%). Immediately after dilation, this activation was not observed in patients with an angioplasty. This study shows that platelet activation occurs 24 hours after coronarography, whereas after dilation and an aggregation inhibitor bolus this activation is not observed during angioplasty.