Warfarin versus non-vitamin k antagonist oral anticoagulants: how the degree of coagulation differs during catheter ablation of atrial fibrillation

Abstract

Aim. To evaluate intraoperative doses of administered heparin to achieve the target value of activated clotting time (ACT) in patients receiving preoperative anticoagulant therapy with warfarin or one of the non-vitamin K antagonists oral anticoagulants (NOAC).Materials and methods. The study was of a retrospective. Inclusion criteria: patients with atrial fibrillation (AF) who have indications for catheter ablation in accordance with national clinical guidelines; age 18-75 years; absence of thrombus and the effect of echocontrasting 3-4 stage in the left atrium cavity according to transesophageal echocardiography or computed tomography with contrast enhancement; regular intake of anticoagulants prescribed at least 3 weeks before hospitalization. Exclusion criteria: additional intake of antiplatelet drugs; contraindications to the anticoagulant therapy, including intolerance to the components of drugs; weight more than 100 kg. According to the criteria for inclusion in the study 279 patients were included (211 of them received warfarin and 68 received one of the NOAC). The mean age of the patients was 59.2±8.9 years, the body mass index was 59.2±8.9 kg/m2. Among them, men accounted for 155 (55,6%), diabetes mellitus was diagnosed in 28 (10%), arterial hypertension - in 224 (80.3%), coronary heart disease - in 103 (36.9%). Paroxysmal AF was observed in 185 (66.3%) of patients, persistent AF - in 77 (27.6%), and long-standing persistent AF - in 17 (6.1%). To ensure maximum comparability of the groups pseudorandomization was performed with the formation of 67 pairs of patients.Results. A group of patients taking warfarin for preoperative preparation required lower doses of heparin to achieve the target AСT and amounted to 14.8±5.1 thousand ME compared to 17.9±4.4 thousand ME in the NOAC group (p=0.0001). Despite the lower dose of heparin the ACT level in the warfarin group was significantly higher than in patients taking NOAC (441.5±203.4 sec. and 345.4±148.8 sec. accordingly, p=0.0001).Conclusions. A significantly lower dose of heparin was required in the warfarin group to achieve the target ACT (>300) than in the group of NOAC, while the maximum ACT value was higher. Thus, with the standard starting dose of heparin, the target anticoagulation was achieved faster in patients receiving warfarin.