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

Abstract

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.