title: Fate of left atrial thrombi in patients with atrial fibrillation determined by transesophageal echocardiography and cerebral magnetic resonance imaging.
abstract: Patients with atrial fibrillation (AF) and atrial thrombi have an increased risk for cerebral embolism. However, there is little knowledge about the long-term fate of atrial thrombi and the incidence of cerebral embolism in patients receiving continued oral anticoagulation. Forty-three consecutive patients with AF and atrial thrombi were enrolled in the study. Serial and prospective transesophageal echocardiographic studies, cranial magnetic resonance imaging (MRI), and clinical examinations were performed during a period of 12 months. Oral anticoagulation was continued or initiated in all patients. An international normalized ratio of 2.0 to 3.0 was regarded as effective. During follow-up, 56% of the thrombi disappeared (7 [16%] at 1 month, 18 [42%] at 3 months, 21 [49%] at 6 months, and 24 [56%] at 12 months). Patients with the disappearance of thrombi had significantly smaller thrombi compared with patients with persistent thrombi (1.5 +/- 0.8 cm in length and 0.8 +/- 0.5 cm in width vs 1.9 +/- 0.6 cm in length and 1.3 +/- 0.4 cm in width, p = 0.04), reduced echogenicity of thrombi (46% vs 89%, p <0.01), and smaller left atrial (LA) volume (83 +/- 27 vs 116 +/- 55 cm(3)). Seven patients (16%) had embolic lesions during follow-up MRI. Six of these patients (86%) had clinically apparent embolisms, and 1 died from stroke. The only independent predictors of cerebral embolism were an elevated peak emptying velocity of the LA appendage (p <0.01) and previous thromboembolic events (p = 0.02). Patients with AF and atrial thrombi have a large likelihood of cerebral embolism (16%) and/or death despite oral anticoagulation therapy. Thrombus size may predict thrombus resolution under continued anticoagulation.
authors.affiliation: Department of Medicine-Cardiology, University of Bonn, Bonn, Germany. bernhardt@cardiomrt.de
authors.forename: Peter
authors.initials: P
authors.lastname: Bernhardt
authors.forename: Harald
authors.initials: H
authors.lastname: Schmidt
authors.forename: Christoph
authors.initials: C
authors.lastname: Hammerstingl
authors.forename: Matthias
authors.initials: M
authors.lastname: Hackenbroch
authors.forename: Torsten
authors.initials: T
authors.lastname: Sommer
authors.forename: Berndt
authors.initials: B
authors.lastname: Lüderitz
authors.forename: Heyder
authors.initials: H
authors.lastname: Omran
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging; D003328:Coronary Thrombosis / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging; D017548:Echocardiography, Transesophageal; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006801:Humans; D015994:Incidence; D002542:Intracranial Embolism and Thrombosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric