Comparison Of Bleeding Events, Strokes, And Myocardial Infarcts On Warfarin Or Dabigatran For Treatment Of Atrial Fibrillation: Results Of A Real-World Data Analysis

Abstract

Objectives: To compare‐in a real‐world setting‐the frequency of bleeding events, myocardial infarctions and strokes in patients receiving warfarin versus dabigatran for atrial fibrillation.‐To evaluate whether the main results of randomized clinical outcome trials and of a national surveillance system can be replicated by a federated EMR based network for a fraction of their costs and duration. Methods: TriNetX, a federated global health research network, was used to analyze electronic medical records (EMR) of > 1 Million patients with atrial fibrillation (ICD10 I48). Patients were included if they started either warfarin or dabigatran between November 2010 and May 2014. Non‐rheumatic cardiac valve diseases, kidney transplant status and end stage renal disease were excluded. Events were defined by ICD10 codes after start of therapy: Bleeding by having either one of 23 ICD10 codes describing various cerebral, gastrointestinal, or other hemorrhages, stroke by I63, and myocardial infarction by I21. Results: 42,130 patients with warfarin (W) and 7480 with dabigatran (D) fulfilled the eligibility criteria. 41% (W) and 34% (D) were female. Mean age was 76 (W) and 72 (D) years. Mean INR and aPTT were 1.85 and 39.9 (W) versus 1.37 and 40.4 (D), respectively. 12.5% (W) and 2.3% (D) had a bleeding event, 15.9% (W) and 12.2% (D) had a stroke or myocardial infarction. Both differences were statistically significant (p= 0.0001). Conclusions: Dabigatran patients were on average four years younger and had significantly fewer bleeding events and significantly fewer cardiovascular events than patients with warfarin. This real world study conducted on electronic medical records (EMR) of large unmatched populations could confirm the results of randomized clinical trials and of an FDA sponsored, mainly claims based national surveillance system. The access to laboratory values, by using EMR rather than claims data, added value for internal validation, i.e. coagulation parameters.