ABSENCE OF A PROTHROMBOTIC STATE IN RESTENOTIC PATIENTS

Aims: To determine whether, in patients undergoing percutaneous transl uminal coronary angioplasty (PTCA), there are prothrombotic markers in dicating those with a predisposition to restenosis. Methods: Venous bl ood samples were obtained from patients undergoing PTCA for chronic st able angina. Patients with restenotic lesions, conduit stenoses or occ lusive lesions were not included in the study. Samples were assayed fo r coagulation factors (fibrinopeptide A, antithrombin III, protein C), fibrinolytic factors [tissue-type plasminogen activator (t-PA), alpha (2) antiplasmin, plasminogen activator inhibitor (PAI-1)] and markers of platelet activation (platelet factor 4, beta thromboglobulin). Resu lts: Of 46 patients who underwent successful PTCA, restenosis, defined as loss in absolute gain of more than 50%, occurred in 16 (35%). The minimal luminal diameter (mean+/-SD) at follow-up in those who had suf fered restenosis was 1.07+/-0.7mm compared with 1.73+/-0.5mm in the no n-restenotic patients. However, no significant differences in the leve ls of markers of platelet activation, coagulation factors, or fibrinol ytic factors were observed between the two groups. The only significan t difference between the groups was a higher platelet count in the res tenotic patients [median (interquartile range): 263 (247-278) versus 2 24 (175-263), P<0.05]. Conclusion: Our results suggest that patients w ho suffer restenosis following PTCA appear to have no clearly detectab le pre-existing imbalance in their prothrombotic/antithrombotic status . Although the platelet count was higher in restenotic patients, the l evels of markers of platelet activation were no different in the two g roups. Thus, it is at present unlikely that simple blood assays before PTCA assessing an individual's 'thrombotic state' can help to predict which of the 30-40% of patients undergoing PTCA will suffer restenosi s.