Decreased Activity of the Protein C Anticoagulant Pathway in the Early Hours of Paroxysmal Atrial Fibrillation

Abstract

Background: Increased coagulation activity has been established in paroxysmal atrial fibrillation (PAF), but data on the anticoagulant system are scarce. Purpose: To examine the protein C anticoagulant pathway in the early hours of the disease. Materials and Methods: Fifty-one patients (26 men and 25 women; mean age 59.84 ± 1.60 years) and 52 controls (26 men and 26 women; mean age 59.50 ± 1.46 years) were selected for the study. Protein C antigen and its activity, total protein S, free protein S and its activity, soluble forms of endothelial protein C receptor (sEPCR), and thrombomodulin (sTM) were examined in the plasma. Results: The indicators were studied in patients between the 2nd and the 24th hour after the onset of arrhythmia. Levels of protein C were significantly elevated in patients compared to controls (111.40% ± 6.66% vs 94.83% ± 4.47%; P =.039). Protein C activity showed significant reduction in PAF (73.13% ± 5.80% vs 103.3% ± 3.80%; P