title: Effect of low-intensity warfarin therapy on left atrial thrombus resolution in patients with nonvalvular atrial fibrillation: a transesophageal echocardiographic study.
abstract: The presence of left atrial thrombus (LAT) is associated with an increased risk of embolic stroke. However, it has yet to be established definitively whether low-intensity warfarin therapy (INR: 1.5-2.0) can prevent LAT formation in patients with nonvalvular atrial fibrillation (NVAF). The present study analyzed the clinical and transesophageal echocardiography (TEE) features of 123 such patients to identify risk factors for LAT formation and the efficacy of prophylactic low-intensity warfarin therapy. Left atrial thrombi were found in 35 patients (28%) in whom systemic hypertension (49% vs 23%; p<0.01) and ischemic heart disease (17% vs 3%; p<0.01) were more frequent. Left ventricular ejection fraction (54+/-14% vs 60+/-11%; p<0.05), left ventricular end-diastolic dimension (51+/-7 mm vs 48+/-5 mm; p<0.05), spontaneous echo contrast (2.2+/-0.7 vs 1.4+/-0.9; p<0.01), left atrial diameter (50+/-6 mm vs 43+/-7 mm; p<0.01), left atrial appendage blood velocity (22.3+/-8.7 cm/s vs 37.2+/-21.5 cm/s; p<0.01) and the incidence of left ventricular hypertrophy (37% vs 15%; p<0.01) were also significantly different between the groups. Fourteen patients received continuous warfarin therapy (target INR: 1.5-2.0) and on the follow-up TEE study the left atrial thrombus resolved in 10 (71%). There were no thromboembolic events or major hemorrhagic complications in these patients, so it was concluded that low-intensity warfarin therapy is efficacious in treating LAT formation in patients with NVAF.
authors.affiliation: Second Department of Internal Medicine, Yamaguchi University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kimura
authors.forename: Y
authors.initials: Y
authors.lastname: Wasaki
authors.forename: H
authors.initials: H
authors.lastname: Ogawa
authors.forename: M
authors.initials: M
authors.lastname: Nakatsuka
authors.forename: T
authors.initials: T
authors.lastname: Wakeyama
authors.forename: T
authors.initials: T
authors.lastname: Iwami
authors.forename: K
authors.initials: K
authors.lastname: Ono
authors.forename: F
authors.initials: F
authors.lastname: Nakao
authors.forename: M
authors.initials: M
authors.lastname: Matsuzaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage* / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications*; D048909:Diabetes Complications; D004341:Drug Evaluation; D017548:Echocardiography, Transesophageal; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006331:Heart Diseases / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000517:prevention & control; D006801:Humans; D006973:Hypertension / Q000150:complications; D006980:Hyperthyroidism / Q000150:complications; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications; D013927:Thrombosis / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000209:etiology / Q000517:prevention & control; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D014859:Warfarin / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin