Optimizing quality care for the oral vitamin K antagonists (VKAs)

Abstract

Vitamin K antagonists (VKAs) have been the only oral anticoagulants for decades. The management of anticoagulant therapy with VKA is challenging because of the intricate pharmacological properties of these agents. The success of VKA therapy depends on the quality of treatment that is ensured through continuing comprehensive communication and education. The educational program should address important issues of the VKA therapy such as beginning of treatment, pharmacological, dietary, and drug-drug interactions, as well as treatment temporary suspension during surgical interventions or invasive maneuvers. In addition, the initial and continuing patient education is of imperative importance. A major role in the educational process may be addressed by patient associations. The quality of treatment is better reached if patients are followed in anticoagulation clinics. Moreover, a federation of anticoagulation clinics may improve patient care through regular meetings to update knowledge on VKA treatment. Learning objectives of this paper is to allow readers to correctly approach patients starting VKA treatment, recognize possible pitfalls of treatment, and provide adequate solutions.

Figure 1.

Effect of administering (A) 2 or (B) 3 mg of vitamin K to reverse overanticoagulation in asymptomatic patients or those presenting with minimal bleeding. Reprinted by permission from (A) Springer Customer Service Center GmbH: Springer Nature (Denas G, et al, J Thromb Thrombolysis, 2009) and (B) Schattauer GmbH, Thieme Group (Denas G, et al, Thrombosis Haemostasis, 2009).

Figure 2.

Declining of INR values during the 5 days of warfarin suspension before surgery/intervention. Different colors denote different warfarin indications. The orange line show the mean INR values for all indications. Warfarin was resumed at a 50% increased maintenance dose for 2 days starting the first or second day after surgery/intervention. Therapeutic INR values were usually reached after 1 week. AF, atrial fibrillation; VTE, venous thrombosis.

Figure 3.

Boxplot of center TTR by study year (reproduced from Tosetto et al. doi: 10.1371/journal.pone.0145318 under Creative Commons Attribution [CC BY] license).

Figure 4.

Efficacy and safety of warfarin for stroke prevention in patients with nonvalvular atrial fibrillation. Results from the Survey on Anticoagulated Patients Register compared with those using direct oral anticoagulants in registration studies.