PROGNOSTIC IMPLICATIONS OF LEFT ATRIAL SPONTANEOUS ECHO CONTRAST IN NONVALVULAR ATRIAL-FIBRILLATION

Objectives. This study examined the influence of left atrial spontaneo us echo contrast on the subsequent stroke or embolic event rate and on survival in patients with nonvalvular atrial fibrillation. Background . Left atrial spontaneous echo contrast is associated with atrial fibr illation and a history of previous stroke or other embolic events. How ever, the prognostic implications of spontaneous contrast in patients with nonvalvular atrial fibrillation are unknown. Method. The study gr oup comprised 272 consecutive patients with nonvalvular atrial fibrill ation undergoing transesophageal echocardiography. Clinical and echoca rdiographic data were collected at baseline, and patients were prospec tively followed up, and all strokes, other embolic events and deaths w ere documented. The relation between spontaneous contrast at baseline and subsequent stroke, other embolic events acid survival was analyzed . Results. Left atrial spontaneous echo contrast was detected at basel ine in 161 patients (59%). The mean follow-up was 17.5 months. The str oke or other embolic event rate was 12%/year (15 strokes, 3 transient ischemic attacks, 2 peripheral embolisms) in patients with, compared w ith 3%/year (5 strokes) in patients without, baseline spontaneous cont rast (p = 0.002). In 149 patients without previous thromboembolism, th e event rate was 9.5%/year in patients with and 2.2%/year in patients without spontaneous contrast (p = 0.003). There were 25 deaths in pati ents with acid 11 deaths in patients without spontaneous contrast. Pat ients with spontaneous contrast had significantly reduced survival (p = 0.025). On multivariate analysis, spontaneous contrast was the only positive predictor (odds ratio 3.5, p 0.03) and warfarin therapy on fo llow-up the only negative predictor (odds ratio 0.23, p = 0.02) of sub sequent stroke or other embolic events. Conclusions. Transesophageal e chocardiography can risk-stratify patients with nonvalvular atrial fib rillation by identifying left atrial spontaneous echo contrast. These patients have both a significantly higher risk of developing stroke or other embolic events and a reduced survival, and they may represent a subgroup in whom the risk/benefit ratio of anticoagulation may be mos t favorable.