Cardiology Letters 2012, 21(2):113-123

Quality of oral anticoagulation therapy with warfarin in the outpatient clinical practice in Slovakia in patients with nonvalvular atrial fibrillation

Hatala R¹, Urban L¹, Hlivák P¹, Smolková K², Spitzerová H²

¹ Oddelenie arytmií a kardiostimulácie, Kardiologická klinika, Národný ústav srdcových a cievnych chorôb, a. s. a Lekárska fakulta Slovenskej zdravotníckej univerzita v Bratislave, Slovenská republika

² Boehringer-Ingelheim s.r.o., Slovenská republika

Background: Correct management of oral anticoagulation therapy with warfarin is crucial for effective prevention of stroke and systemic thromboembolism in higher risk patients with nonvalvular atrial fibrillation. Warfarin therapy is effective and safe only under the condition that the achieved anticoagulation level is within the optimal therapeutic range with INR values 2-3. Warfarin is widely used drug for the prevention of thromboembolism of atrial fibrillation in clinical practice in Slovakia, however, there are no systematic data on the quality of anticoagulation management in these patients.

Objective: The aim of this retrospective multicentre epidemiological survey was to evaluate the quality of anticoagulation in real life outpatient clinical practice among cardiologists and internists working in the Slovak Republic.

Patients and methods: This survey has recruited patient with nonvalvular atrial fibrillation using warfarin continuously without interruption for at least two years. The quality of anticoagulation therapy management was assessed as the proportion of time when the patients was within optimal therapeutic range of INR 2-3 during the last 12 months of anticoagulation therapy (time in therapeutic range - TTR). The data were acquired retrospectively from charts of 540 patients (55% men). Mean age of men was 65.4 years (SD 9.1); the mean age of women was 70.5 years (SD 8.6). All patients were systematically followed in outpatient clinics of 108 internists and cardiologists. The regional distribution of patients corresponds to the demographic distribution of the Slovak population.

Results: In the analyzed cohort of patients with nonvalvular atrial fibrillation the observed TTR has achieved 56%. The mean time interval between INR controls was 40.3 days (SD 0,7 days). We have identified significant differences in the quality of anticoagulation therapy among internists and cardiologists as well as among individual regions within Slovakia.

Conclusions: The presented analysis of the quality of anticoagulation therapy with warfarin in real life outpatient clinical practice in the Slovak Republic in patients with nonvalvular atrial fibrillation demonstrated a suboptimal level of anticoagulation with INR outside the therapeutic range in 44% of time. These results are comparable with the data from several national registries from other countries and point out to a need for principal improvement of the prevention of thromboembolic complications in patients with nonvalvular atrial fibrillation.

Keywords: atrial fibrillation; stroke prevention; anticoagulation therapy; warfarin

Published: February 1, 2012  Show citation