title: Echocardiographic predictors of left atrial appendage thrombus formation.
abstract: BACKGROUND
  Although transesophageal echocardiography is the definitive test for the detection of left atrial (LA) appendage thrombus, transthoracic echocardiography has yet to prove useful for the determination of increased risk for LA appendage thrombus formation. The authors hypothesized that higher LA volume and/or lower left ventricular ejection fraction (LVEF) might prove valuable as markers of increased risk for LA appendage thrombus formation and tested this hypothesis in a consecutive retrospective series of patients with atrial fibrillation undergoing both transthoracic and transesophageal echocardiography.
  
  
  METHODS
  Three hundred thirty-four consecutive patients with atrial fibrillation undergoing transesophageal echocardiography for the detection of LA appendage thrombus were studied. Anticoagulation status, CHADS(2) scores, and echocardiographic parameters were catalogued. The relationship between the presence of LA appendage thrombus and covariates was analyzed using binary logistic regression.
  
  
  RESULTS
  LA appendage thrombus was detected in 52 patients (15.6%). A higher CHADS(2) score (odds ratio, 1.45; P < .004), increased LA volume index (odds ratio, 1.02; P = .018), and lower LVEF (odds ratio, 1.02; P = .05) were significant predictors of LA appendage thrombus formation. LA appendage thrombus was not seen in patients with CHADS(2) scores ≤ 1, LVEFs > 55%, and a LA volume indexes < 28 mL/m(2). A ratio of LVEF to LA volume index ≤ 1.5 produced 100% sensitivity for the presence of LA appendage thrombus.
  
  
  CONCLUSIONS
  The presence of LA appendage thrombus is related to both clinical and echocardiographic variables. Although no single echocardiographic variable discriminated between the presence and absence of LA thrombus, a normal LVEF and normal LA volume index were associated with the absence of LA appendage thrombus formation. For patients with atrial fibrillation with CHADS(2) scores ≤ 1, normal left ventricular systolic function and normal LA volume in combination may be a useful measure for the identification of patients at low risk for LA appendage thrombus formation.
authors: Cardiology Division, Hartford Hospital, Hartford, Connecticut, 06102, USA. disilverman@harthosp.org
authors: Srilatha
authors: S
authors: Ayirala
authors: Simi
authors: S
authors: Kumar
authors: David M
authors: DM
authors: O'Sullivan
authors: David I
authors: DI
authors: Silverman
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging* / Q000473:pathology; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000473:pathology; D016001:Confidence Intervals; D017548:Echocardiography, Transesophageal; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000473:pathology; D016017:Odds Ratio; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D013927:Thrombosis / Q000000981:diagnostic imaging* / Q000473:pathology; D016277:Ventricular Function, Left