Better stability of acenocoumarol compared to warfarin treatment in one-year observational, clinical study in patients with nonvalvular atrial fibrillation

Aim To evaluate differences in the treatment quality between often used oral anticoagulants, warfarin and acenocoumarol in patients with nonvalvular atrial fibrillation (NVAF). Methods This was an observational, comparative, one-year clinical study, conducted in the Blood Transfusion Institute of Sarajevo, Bosnia & Herzegovina. All patients who were using warfarin/acenocoumarol and monitored were eligible. Patients who met inclusion criteria (the age of 40-80, diagnosed NVAF, CHADS2 index score ?2, the planned long-term treatment) were included in two parallel groups of 60 patients, composed according to the warfarin/acenocoumarol treatment as well as the gender and age. Routinely measured International normalised ratio (INR) values were the basic parameter for individual quality and stability assessment. Results All average, monthly INR values were in therapeutic range(2.0-3.0) in both therapeutic groups. There were no significant differences either in the number of therapeutic INR values per patient (50.53±23.72% vs. 51.74±26.68%, P = 0.795) or in individual quality of treatment: >50% therapeutic INR values (60.0% vs. 64.9%, P = 0.721) and >75% therapeutic INR values (18.3%vs. 22.8%, P = 0.714) in the warfarin and acenocoumarol group,respectively. Significantly better stability was determined for acenocoumarol as compared with warfarin treatment in terms of alonger period of the total observed time during which therapeuticINR values were stable (37.6% vs. 35.7%, P = 0.0002). Conclusion Both drugs have shown similar quality of individual anticoagulation control, but acenocoumarol have shown signifi-cantly better anticoagulation stability with therapeutic INR values covering significantly longer time of treatment