LEUKOCYTE ACTIVATION WITH PLATELET-ADHESION AFTER CORONARY ANGIOPLASTY - A MECHANISM FOR RECURRENT DISEASE

Objectives. The purpose of this pilot study was to determine whether l eukocyte activation occurs, whether leukocyte-platelet complexes devel op and whether there is any association between these findings and cli nical outcome after coronary angioplasty, Background, Increased expres sion of CD11b on monocytes and neutrophils promotes their adhesion to endothelial cells, extracellular matrix and smooth muscle cells, Throm bin activated plate lets adhere to monocytes and neutrophils through P -selectin, These cell complexes may affect the inflammatory process an d, thus, the outcome of coronary angioplasty, Methods. During elective single-vessel coronary angioplasty in 11 men, samples were obtained f or how cytometric detection of CD11b, as well as the percent of leukoc ytes with adherent platelets and the intensity of bound platelet fluor escence (number of platelets/leukocyte). Results. After angioplasty, t here was an increase in CD11b (monocytes: p = 0.001, neutrophils: p = 0.02) and leukocytes with adherent platelets (p = 0.02), During follow -up, five patients remained in stable condition and six had subsequent clinical events: restenosis and progression of disease requiring coro nary artery bypass grafting (n = 3), myocardial infarction involving t he dilated artery (n = 1) and unstable angina (n = 2), Values for leuk ocyte CD11b expression, the percent of leukocytes with adherent platel ets and the intensity of bound platelet fluorescence were higher both before and after angioplasty in the six patients experiencing clinical events, Conclusions, Despite standard aspirin and heparin therapy, le ukocyte activation with platelet adherence occurs after coronary angio plasty, The magnitude of leukocyte activation and platelet adherence a ppears to be higher in patients experiencing late clinical events.