Role of transesophageal echocardiography in the prediction of thromboembolism in patients with chronic nonvalvular atrial fibrillation

The purpose of this study was to determine whether parameters derived from transesophageal echocardiography (TEE) could predict thromboembolism in pat ients with chronic nonvalvular atrial fibrillation (AF). Eighty-nine patien ts, mean age 66 +/-9 years, who underwent TEE in 1996 to 1999 were studied. The clinical endpoint was a thromboembolic event, including transient isch emic attack (TIA). Sixty-seven patients (75%) were anticoagulated with warf arin after TEE. After a follow-up period of 29 +/- 10 months, 1 patient die d suddenly, 4 had a thromboembolism, and 3 had a TIA; the annual embolic ev ent rate was 3.3%. Left atrial appendage (LAA) thrombus (86% vs 17%, p <0.0 01), LAA dysfunction (LAA velocity < 20 cm/s; 71% vs 25%, p=0.009), and sev ere LA spontaneous echo contrast (29% vs 2%, p=0.002) were more prevalent i n patients with an embolic event than in those without. In patients with LA A thrombus, the annual event rate was 11% as compared with 1.2% in those wi thout (p=0.004). On the Cox proportional hazards model analysis, LAA thromb us (chi-square 7.0, p=0.008), severe LA spontaneous echo contrast (chi-squa re 7.0, p=0.008), and LAA dysfunction (chi-square 5.9, p=0.015) were signif icantly related to thromboembolism. Multivariate analysis revealed that LAA thrombus (chi-square 5.5, p=0.019) and LAA dysfunction (chi-square 4.0, p= 0.045) were the independent predictors. In conclusion, TEE parameters, part icularly the presence of LAA thrombus, can be used to assess thromboembolic potential in patients with chronic nonvalvular AF.