Antikoagulation mit oralen vitamin-K-antagonisten bei risikopatienten: Klinischer und wirtschaftlicher nutzen einer adäquaten prävention

Background: Long-term anticoagulation with oral vitamin-K-antagonists (OVKA) in patients with risk factors (atrial fibrillation [AF], mechanical heart valve replacement [MVR]) represents an effective method in the primary and secondary prevention of thromboembolic complications. However, due to the fact that these drugs have the potential to induce severe haemorrhagic events, the use of OVKA requires close monitoring of the anticoagulation level. The aim of this pharmacoeconomic analysis was to assess the efficacy of OVKA compared to acetylic salicylic acid (ASA) as well as the efficiency depending on the method of monitoring (self-measurement vs. ambulatory monitoring). Methods: A pharmaco-economic analysis was performed using two Markov models to assess the outcomes of using OVKA and ASA in patients with diagnosed AF and the method of monitoring in patients with MVR. The models included the clinical complications of bleeding, stroke and mortality as well as treatment, monitoring and complication related costs, which were derived from published sources. For both scenarios, the cumulated ten-year mortality, total costs and life years gained were calculated for different risk groups. Results: In patients with AF, the cumulated 10-year mortality varied between 25.4 % and 75.7 % according to patient risk category; the total costs ranged from EUR 2867 to EUR 22,071. For the low-risk patient group (CHADS₂ score between 0 and 2), OVKA treatment resulted in a moderate improvement in survival compared to ASA treatment, however, the higher cost of OVKA yielded a cost per life year gained between EUR 193,503 and EUR 104. In contrast, the OVKA-treated group with a CHADS₂ score ≥ 3 showed a reduced mortality and lower total costs. Patient self-monitoring was associated with lower mortality and lower total cost compared to ambulant monitoring in all age groups. Conclusion: The use of OVKA in AF patients is not only a valuable treatment for high-risk patients but also for moderate-risk patients and patient self-measurement is a valuable alternative to ambulant monitoring.