BIOLOGICAL RISK-FACTORS FOR RESTENOSIS AFTER PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY

In an attempt to discern biological (such as thrombotic or fibrinolytic) risk factors in patients developing restenosis after percutaneous transluminal coronary angioplasty, the following factors were measured prior to angiography in a population of 23 patients (20 men, 3 women, mean age 57 +/- 5 yr) treated by a successful angioplasty (gain > 20% and residual stenosis < 50%) for stable angina pectoris and who had a routine angiographic restudy. The following factors were thus assessed: lipid factors: cholesterol, triglycerides, high density lipoprotein cholesterol, low density lipoprotein cholesterol, apolipoprotein AI, apolipoprotein B; coagulation factors: fibrinogen, antithrombin III, fibrinopeptide A, factor VIII coagulant, factor VIII antigen, protein C; factors of physiological fibrinolysis: plasminogen, alpha2-antiplasmin, tissue plasminogen activator and euglobulin clot lysis time before and after venous occlusion, plasminogen activator inhibitor before venous occlusion; and factors of platelet release: beta-thromboglobulin, platelet factor 4. Also studied were clinical characteristics: age, gender, diabetes, hypertension, smoking habits, previous myocardial infarction; angiographic data: global extent of coronary artery disease, location of the stenosis in a bend or branch point, complexity of the lesion, initial and residual stenosis and treatment during follow-up. The coronary angiograms were analyzed by a computer-assisted method with automatic edge detection. On angiographic criteria, 6 patients (restenosis group) were judged to have developed a restenosis (30% decrease in diameter and/or return to a 50% stenosis). The other 17 patients (those without restenosis) were considered to have a persistent success. Apart from age (group without restenosis: 55 +/- 6; restenosis group 61 +/- 5, p < 0.04), there were no differences in clinical, angiographic or treatment variables. There were no differences in lipid factors, but significant differences were observed in hemostatic variables: fibrinogen (without restenosis: 3.18 +/- 0.83; restenosis: 3.83 +/- 0.51 g/l, p = 0.05), tissue plasminogen activator before venous occlusion (without restenosis: 10.9 +/- 26.8; restenosis: 232.5 +/- 371.2 IU, p < 0.04), euglobulin clot lysis time after venous occlusion (without restenosis: 176.5 +/- 100.5; restenosis: 78.6 +/- 40.2 min, p < 0.05) and for marker of the platelet release: platelet factor 4 (without restenosis: 10.8 +/- 7.9; restenosis: 20.5 +/- 7.5 ng/l, p < 0.04). These findings indicate that patients developing restenosis after coronary angioplasty tend to have an imbalance in the prothrombotic-antithrombotic equilibrium prior to the procedure.