Résumé
BACKGROUND: Atrial fibrillation (AF) is the most common cause of embolic cerebral infarction. This study was performed to determine new risk factors and the mechanism underlying thromboembolism (TE) in patients with AF. METHODS: 192 patients (M:F=137:55, 61+/-11 years) with AF were randomly selected and divided into a TE (n=95) and non-TE group (n=97). Another 71 patients with AF (M:F=38:33, 55+/-14) were studied for endothelial function by measuring the level of von Willebrand factor (vWF; factor 8 related antigen), inflammation by WBC, ESR, and high sensitive CRP and coagulation system by fibrinogen, fibrinogen degradation product and fibrin d-dimer; the results were compared with 25 patients with normal sinus rhythm. RESULTS: The TE group was older than non-TE group. Hypertension (HTN), diabetes mellitus (DM), hypercholesterolemia, smoking and fine AF (AF wave amplitude <1 mm) were more frequent in the TE group. Mitral valvular disease, an ejection fraction <40% and dilated cardiomyopathy were more frequent in the TE group and the left atrial (LA) dimension was greater in the TE group. The use of anticoagulants, an angiotensin-II receptor blocker and statins were less frequently observed in the TE group. The vWF-factor 8 related antigen was higher in patients with advanced age, LV dysfunction, HTN, DM, mitral stenosis and positively correlated with age, LA dimension, LV end-diastolic and end-systolic dimension, ejection fraction, NYHA class and AF duration. The fibrinogen level was positively correlated with age, NYHA class, LA dimension and d-dimer with NYHA class. Markers for inflammation or coagulation were not significantly different in the atrial fibrillation and the sinus rhythm group. CONCLUSIONS: No use of an angiotensin-II receptor blocker or statin and fine AF may be new risk factors for TE in patients with AF. The TE risk factors are thought to increase TE by impairing endothelial function.