Platelet Deposition at Angioplasty Sites and Platelet Survival Time After PTA in lliac and Femoral Arteries: Investigations with Indium-111-Oxine Labelled Platelets in Patients with ASA (1.0 g/Day)-Therapy

Abstract

SummaryIn this study we have assessed the deposition of 111-In-oxine-labelled platelets - using a dual radiotracer method - at angioplasty sites of the lower extremities in 20 patients (14 male, 6 female; median age: 60 years) with ASA (1.0 g/day)-therapy. The platelet survival time (PST) - using the multiple hit model -was evaluated before and after percutaneous transluminal angio-plasry, and we also measured the plasma levels of β-thrombo-globulin (β TG) and platelet fuetui 4 (PF 4) before and after PTA.Before PTA, scintigraphy was positive in only one patient, while 24 hours after PTA a positive scintigraphic result was observed in 16/20 patients. The median target/non target-ratio was 1.0 (0.66-1.3) before PTA, and this ratio increased significantly (p <0.0005) to 1.53 (1.0-3.3) after PTA.The median PST decreased significantly (185.0 hours before PTA → 145.2 hours after PTA; p <0.001), while the median platelet turnover increased from 34,000/μl/day to 47,900/μl/day(p<0.01).The median plasma levels of the platelet specific proteins increased significantly immediately after PTA (p <0.001), but one day later they were not significantly different from the pretreatment values.The quantitative methods used in this study seem a valuable tool to evaluate the effects of different therapeutical - especially antiplatelet - interventions after PTA in humans, thus helping to find the best antithrombotic regimen for this widely used therapeutical procedure.