[Comparison of the safety of rivaroxaban versus dabigatran therapy in patients with persistent atrial fibrillation].

UNLABELLED: For 60 years, vitamin K antagonists have been used in prevention of thromboembolic complications in the course of atrial fibrillation (AF), however such therapy is associated with many inconveniences. New oral anticoagulants (NOAC), rivaroxaban and dabigatran, represent an attractive alternative to VKA.

THE AIM OF THE STUDY: Yo evaluate the safety of a 6-month therapy with rivaroxaban and dabigatran in patients (pts) with persistent AF.

MATERIALS AND METHODS: The analysis included 24 pts (14 females, 10 males) with nonvalvular AF and indications for oral anticoagulant therapy (CHA2DS2-VASc > or = 2, HAS-BLED < 3), hospitalized in the Clinic of Internal Diseases and Clinical Pharmacology of the Medical University of Lodz between July 2012 and September 2013. In the group of patients treated chronically with VKA, laboratory tests (GFR, creatinine, ALT AST, coagulation) were performed during their stay in the clinic. The patients were randomly assigned to the treatment with one of the new NOACs, rivaroxaban or dabigatran. After a 6-month period, the patients completed a questionnaire on their general health condition and follow-up laboratory tests were performed.

RESULTS: In the group of pts. receiving dabigatran INR increased by 23% (p = 0.0002) and APTT prolongation by 91% was noted (p = 0.0004) whereas in the group of pts receiving rivaroxaban an INR increase by 17% (p = 0.04) and APTT prolongation by 32% (p = 0.0043) were observed. After a 6-month therapy, dabigatran prolongs APTT significantly more, as compared to rivaroxaban (p=0.0002). Among patients using dabigatran, 16.7% experienced the following symptoms: abdominal pain, gastritis, nausea. 8.3% patients experienced bleeding from haemorrhoids, easier bruising. In the group of patients receiving rivaroxaban, 16.7% experienced the following symptoms: nosebleeds and easier bruising; 8.3%: bleeding from gums, haematuria. 25%: pruritus, rash: 8.3%. The hazard ratio (HR) for occurrence of dyspeptic symptoms was 1.13 for dabigatran. Minor bleeding is 3.6 times more common when using rivaroxaban.

CONCLUSIONS: Significant increase of INR and prolongation of APTT are observed after a 6-month therapy with rivaroxaban or dabigatran. Additionally, dabigatran significantly prolongs the prothrombin time. Despite the fact that dabigatran caused larger prolongation of APTT minor bleeding episodes occurred more frequently in patients treated with rivaroxaban. No worsening of kidney or liver function was observed during the 6-month therapy with rivaroxaban or dabigatran. Rywaroxaban more frequently causes minor bleeding, whereas treatment with dabigatran is associated with more frequent gastrointestinal adverse symptoms.