title: Incidence of left atrial abnormalities under treatment with dabigatran, rivaroxaban, and vitamin K antagonists.
abstract: BACKGROUND
  Non-vitamin K antagonist oral anticoagulants (NOACs) such as dabigatran or rivaroxaban are alternatives to vitamin K antagonists (VKAs) for prevention of stroke and systemic embolism in patients with atrial fibrillation (AF) and atrial flutter (AFL). Incidences of risk factors for left atrium (LA) and left atrial appendage (LAA) thrombus formation, such as dense spontaneous echo contrast (SEC), low LAA velocity (LAAV) <20 cm/s under treatment with dabigatran and rivaroxaban in comparison with VKAs are unknown.
  
  
  METHODS
  We studied 306 patients with AF (94 %) and AFL (6 %) undergoing transesophageal echocardiography. Patients received VKAs (n = 138), dabigatran (n = 68), or rivaroxaban (n = 100) for at least 3 weeks prior to investigation. Time in therapeutic range was 67 % for VKA. Mean CHADS2score and CHA2DS2-VASc score were 1.3 and 2.5, respectively. Left atrial abnormality was defined as either dense SEC, low LAAV <20 cm/s, or thrombus.
  
  
  RESULTS
  Any LA abnormality occurred in 9, 3, and 5 % of patients receiving VKA, dabigatran, and rivaroxaban, respectively. The most frequent abnormality was LAA thrombus (VKA: 4 %, dabigatran: 0 %, rivaroxaban: 2 %) and low LAAV of less than 20 cm/s (VKA: 4 %, dabigatran: 1 %, rivaroxaban: 1 %), followed by dense SEC (VKA: 2 %, dabigatran: 1 %, rivaroxaban: 2 %). Results of uni- and multivariate analyses revealed a numerically lower but not significantly different frequency of any LA abnormality under dabigatran (OR 0.4, 95 % Cl 0.08 - 1.88, p = 0.25) and rivaroxaban (OR 0.65, 95 % Cl 0.22 - 1.98, p = 0.45) compared to VKA.
  
  
  CONCLUSIONS
  With respect to the incidence of LA abnormalities, dabigatran and rivaroxaban are not inferior to VKA.
authors: Department of Cardiovascular Medicine, University Hospital Muenster, 48149, Muenster, Germany. stefan.reers@ukmuenster.de.
authors: Stefan
authors: S
authors: Reers
authors: Department of Cardiology/Angiology/Intensive Care Medicine, University Heart Center Luebeck, Luebeck, Germany.
authors: Tolga
authors: T
authors: Agdirlioglu
authors: Department of Cardiology/Angiology/Intensive Care Medicine, University Heart Center Luebeck, Luebeck, Germany.
authors: Michael
authors: M
authors: Kellner
authors: Institute of Biostatistics and Clinical Research, University of Muenster, Muenster, Germany.
authors: Matthias
authors: M
authors: Borowski
authors: Department of Cardiology/Angiology/Intensive Care Medicine, University Heart Center Luebeck, Luebeck, Germany.
authors: Holger
authors: H
authors: Thiele
authors: Department of Cardiovascular Medicine, University Hospital Muenster, 48149, Muenster, Germany.
authors: Johannes
authors: J
authors: Waltenberger
authors: Department of Cardiology/Angiology/Intensive Care Medicine, University Heart Center Luebeck, Luebeck, Germany.
authors: Michael
authors: M
authors: Reppel
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000188:drug therapy*; D001282:Atrial Flutter / Q000188:drug therapy*; D016279:Atrial Function, Left / Q000187:drug effects / Q000502:physiology; D000069604:Dabigatran / Q000009:adverse effects* / Q000627:therapeutic use; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006325:Heart Atria / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D000069552:Rivaroxaban / Q000009:adverse effects* / Q000627:therapeutic use; D013927:Thrombosis / Q000139:chemically induced; D014812:Vitamin K / Q000037:antagonists & inhibitors
chemical_list: D014812:Vitamin K; D000069552:Rivaroxaban; D000069604:Dabigatran
keywords: Atrial fibrillation; Dabigatran; Left atrial appendage; Rivaroxaban; Thrombus; Vitamin K antagonist