Platelet and coagulation hemostasis status in patients with atrial fibrillation depending on warfarin dosing method

The aim. To evaluate indicators of induced platelet aggregation and D-dimer level in patients with atrial fibrillation (AF) depending on the method of warfarin (WF) dosing. Materials and methods. The study involved 110 patients with AF (mean age 68.72 ± 0.79; men – 57, women – 53). Patients with AF were divided into two groups: the main group – 50 patients with AF and genotype-guided dosing method, the control group – 60 patients with AF and traditional dosing method. CYP2C9, CYP4F2, VKORC1 genetic polymorphisms were determined using multiplex real time polymerase chain reaction, D-dimer concentration – by the method of solid-phase enzyme immunoassay; ADP- and epinephrine-induced aggregation indicators – by the method of G. Born. Results. The percentage (by 24 %), time (by 3 min 6 s) and rate in 30 s (by 19.5 %/min) of ADP-induced platelet aggregation were significantly lower in patients with AF and genotype-guided WF dosing method. D-dimer concentration in patients of the main and control groups did not differ significantly. However, significantly fewer patients with elevated D-dimer values were registered in the group with genotype-guided WF dosing method compared to the group with traditional dosing method: 0 (0.00 %) vs. 7 (11.67 %) at 500 ng FEU/ml cut-off (χ2 = 4.43, P < 0.05), 1 (2.00 %) vs. 9 (15.00 %) at 390 ng FEU/ml cut-off (χ2 = 4.16, P < 0.05), 0 (0.00 %) vs. 7 (11.67 %) at age-adjusted cut-off (χ2 = 4.43, P < 0.05). Conclusions. The obtained results may indicate a potentially lower risk of thrombotic events in patients with AF and genotype-guided WF dosing method compared to the group with traditional dosing method, which confirms the benefit of the widespread use of the pharmacogenetic testing in clinical practice.