RISK FOR SYSTEMIC EMBOLIZATION OF ATRIAL-FIBRILLATION WITHOUT MITRAL-STENOSIS

The risk for systemic embolization was studied in 272 patients without mitral stenosis or prosthetic valves who were referred to the echocardiography laboratory with atrial fibrillation (AF). During a mean follow-up period of 33 months (range < 1 to 83), 27 (10%) patients had a systemic embolic event, which was cerebral in 23 patients (85%) and peripheral in 4 (15%). In the analysis of individual variables, the risk of embolization was increased by female sex, underlying heart disease and left atrial size ≥4.0 cm, but not by age, hypertension or type of AF (paroxysmal vs chronic). In multivariable analysis, left atrial size ≥4.0 cm was the single strongest predictor of increased risk for embolization (p < 0.001), but female sex (p = 0.014) and underlying heart disease (p = 0.027) also contributed. When each of these 3 factors was assigned 1 point in a risk score, embolie events were found to occur in none (0%) of 24 patients with a risk score of 0, in 2 (3%) of 83 patients with a risk score of 1, in 13 (11%) of 118 patients with a risk score of 2 and in 12 (26%) of 47 patients with a risk score of 3. The score allows patients with AF and without mitral stenosis to be stratified into high-, medium-and low-risk groups for systemic embolization. Such information could be useful in decision making for anticoagulation in patients with AF. © 1990.