Warfarin for prevention of thromboembolism in atrial fibrillation: comparison of patient characteristics and outcomes of the "Real-World" Michigan Anticoagulation Quality Improvement Initiative (MAQI(2)) registry to the RE-LY, ROCKET-AF, and ARISTOTLE trials

Document Type


Publication Date


Publication Title

Journal of thrombosis and thrombolysis


Randomized controlled trials (RCTs) examining warfarin use for stroke prevention in atrial fibrillation (AF) may not accurately reflect real-world populations. We aimed to determine the representativeness of the RCT populations to real-world patients and to describe differences in the characteristics of trial populations from trial eligible patients in a real-world setting. We hypothesized that a significant fraction of real-world patients would not qualify for the RE-LY, ROCKET-AF, and ARISTOTLE trials and that real-world patients qualifying for the studies may have more strokes and bleeding events. We compared the inclusion and exclusion criteria, patient characteristics, and clinical outcomes from RE-LY, ROCKET-AF, and ARISTOTLE against data from the Michigan Anticoagulation Quality Improvement Initiative (MAQI2), a regional network of six community- and academic-based anticoagulation clinics. Of the 1446 non-valvular AF patients in the MAQI2 registry taking warfarin, approximately 40-60% would meet the selection criteria used in RE-LY (788, 54.5%), ROCKET-AF (566, 39.1%), and ARISTOTLE (866, 59.9%). The most common reasons for exclusion from one or more trial were anemia (15.1%), other concurrent medications (11.2%), and chronic kidney disease (9.4%). Trial-eligible MAQI2 patients were older, more frequently female, with a higher rate of paroxysmal AF, and lower rates of congestive heart failure, previous stroke, and previous myocardial infarction than the trial populations. MAQI2 patients eligible for each trial had a lower rate of stroke and similar rate of major bleeding than was observed in the trials. A sizable proportion of real-world AF patients managed in anticoagulation clinics would not have been eligible for the RE-LY, ROCKET-AF, and ARISOTLE trials. The expected stroke risk reduction and bleeding risk among real-world AF patients on warfarin may not be congruent with published clinical trial data.

Medical Subject Headings

Anticoagulants; Atrial Fibrillation; Female; Humans; Male; Michigan; Patient Selection; Quality Improvement; Randomized Controlled Trials as Topic; Registries; Thromboembolism; Treatment Outcome; Warfarin

PubMed ID






First Page


Last Page