Cardiovascular death in patients with atrial fibrillation is better predicted by left atrial thrombus and spontaneous echocardiographic contrast as compared with clinical parameters.

We hypothesized that altered intra-atrial thrombogenicity, as reflected by the presence of left atrial (LA) thrombus or spontaneous echocardiographic contrast (SEC), would predict cardiovascular death in patients with atrial fibrillation (AF). In 175 patients with AF and no more than mild mitral regurgitation as detected by transesophageal echocardiography (TEE), 13 cardiovascular deaths occurred during a mean follow-up of 31 +/- 20 months. Multivariate logistic regression analysis using clinical variables identified the presence of congestive heart failure (relative risk [RR] = 4.22; P = .02) as the only positive predictor of cardiovascular death. However, when the TEE variables were added to the model, LA thrombus (RR = 5.52; P = .024) and LA SEC (RR = 7.96; P = .013) emerged as the only positive predictors of cardiovascular death. Kaplan-Meier analysis demonstrated a lower event-free survival from cardiovascular death in patients with LA thrombus and/or SEC ( P = .0013). These findings support AF as a contributing cause of cardiovascular death independent of clinically associated risk factors, such as hypertension, diabetes mellitus, smoking, congestive heart failure, and prior myocardial infarction.