Real-world effectiveness and safety of oral anticoagulation strategies in atrial fibrillation: a cohort study based on a German claims dataset

Sabrina Mueller,1 Antje Groth,1 Stefan G Spitzer,2,3 Anja Schramm,4 Andreas Pfaff,5 Ulf Maywald6 1Institute for Pharmacoeconomics and Medication Logistics, University of Wismar, Wismar, Germany; 2Praxisklinik Herz und Gefäße Dresden, Academic Educational Practice Clinic, TU Dresden, Dresden, Germany; 3Institute of Medical Technology, Brandenburg University of Technology Cottbus–Senftenberg, Senftenberg, Germany; 4AOK Bayern, Regensburg, Germany; 5AOK Baden-Württemberg, Stuttgart, Germany; 6AOK PLUS, Dresden, Germany Objective: To compare the real-world effectiveness and safety of non-vitamin-K-antagonist oral anticoagulant (NOAC) treatment in atrial fibrillation (AF) patients with a vitamin-K-antagonist (VKA)-based treatment. Methods: This was a retrospective analysis of an anonymized claims dataset from 3 German health insurance funds covering the period from January 01, 2010 to June 30, 2014, with a minimum observation time of 12 months. All continuously insured patients with at least 2 outpatient AF diagnoses and/or 1 inpatient respective diagnosis who received at least 1 outpatient prescription of a NOAC or VKA were included. Outcomes and measures: Death, ischemic strokes (IS), non-specified strokes, transient ischemic attacks (TIAs), myocardial infarctions (MIs), arterial embolism (AE), hemorrhagic strokes, severe bleedings, and composite outcomes. Main comparisons were done based on propensity score-matched (PSM) cohorts. Results were reported as incidence rate ratios and hazard ratios (HRs). Results: We assigned 37,439 AF patients to each PSM cohort (NOAC cohort: mean age 78.2 years, mean CHA2DS2VASc score 2.96, mean follow-up 348.5 days; VKA cohort: mean age 78.2 years, mean CHA2DS2VASc 2.95, mean follow-up 365.5 days). NOAC exposure was associated with significantly higher incidence rate ratios; 95% CI/HRs; 95% CI for the following outcomes: death (1.22; 1.17–1.28/1.22; 1.17–1.28), IS (1.90; 1.69–2.15/1.92; 1.69–2.19), non-specified strokes (2.04; 1.16–3.70/1.93; 1.13–3.32), TIAs (1.52; 1.29–1.79/1.44; 1.21–1.70), MIs (1.26; 1.10–1.15/1.31; 1.13–1.52), AE (1.75; 1.32–2.32/1.81; 1.36–2.34) and severe bleeding (1.92; 1.71–2.15/1.95; 1.74–2.20). Multivariable Cox regression analyses and additional sensitivity analysis, including analysis of PSM-matched NOAC/VKA treatment-naive patients, only confirmed the above results. The study was documented under clinicaltrials.gov (NCT02657616). Conclusion and relevance: A VKA therapy seems to be more effective and safer than a NOAC therapy in a real-world cohort of German AF patients. Keywords: atrial fibrillation, AF, anticoagulation, NOAC, VKA, cohort study