Antikoagulation bei Vorhofflimmern

Abstract

Atrial fibrillation (AF) is characterized by insufficient coordination of atrial activity leading to a loss of effective atrial contraction. AF can lead to different clinical conditions, including cerebrovascular and systemic thromboembolism, decompensated heart failure, and/or oligosymptomatic and symptomatic tachycardias. A global therapeutic approach should target these issues, and encompass conversion of maintenance of rhythm by means of electric cardioversion and drug and/or interventional therapies and effective anticoagulation to prevent thromboembolism in certain risk groups. The risk for stroke increases depending on patient age and comorbidities. Therapeutic goal consists of safeguarding of effective anticoagulation under tolerable bleeding risk. This poses a growing challenge in the light of complex cases and individual risk factors, as well as the development of new antithrombotics. Treatment with vitamin K antagonists demands a complicated patient management, is difficult to handle and susceptible for drug interactions, nutritional influences and genetic polymorphisms. The aim of the subsequent article is to give a current overview over treatment strategies for prophylaxis of thromboembolism in patients with AF considering present treatments and recent development focussing on novel thrombin inhibitors.

Kernaussagen

• Komplikationen des Vorhofflimmerns sind zerebrovaskuläre Embolien, dekompensierte Herzinsuffizienz, Ischämien oder oligosymptomatische und symptomatische Tachykardien. Das Schlaganfallrisiko bei Patienten mit Vorhofflimmern hängt von begleitenden Risikofaktoren ab und steigt mit dem Alter an.

• Zur Vorbeugung von Thromboembolien ist bei bestimmten Risikogruppen eine effektive antikoagulatorische Behandlung wichtig. Die Indikation zur oralen Antikoagulation sollte man dabei anhand des individuellen Risikoprofils stellen.

• Eine besondere Risikogruppe für thrombotische Komplikationen sind Patienten mit Vorhofflimmern und symptomatischer KHK. Bei ihnen sollte man eine Kombination von oralen Antikoagulanzien und antithrombozytären Substanzen nach sorgfältiger Abschätzung des Blutungsrisikos in Erwägung ziehen.

• Vitamin-K-Antagonisten senken das Schlaganfallrisiko erheblich, ihre variable Wirksamkeit ist jedoch ein ernstes Problem. Sie erfordern eine komplizierte Patientenführung, sind schwierig zu steuern und anfällig für medikamentöse Wechselwirkungen, nutritive Einflüsse und genetische Polymorphismen.

• Neue orale Antikoagulanzien (direkte Thrombininhibitoren und Faktor-Xa-Antagonisten) sind derzeit in Phase-III-Studien zur Thrombembolieprophylaxe bei Vorhofflimmern in Erprobung. Bislang sind die Ergebnisse bezüglich ihrer Effektivität und Sicherheit im Vergleich zu den Vitamin-K-Antagonisten vielversprechend.

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