title: Usefulness of brain natriuretic peptide for predicting left atrial appendage thrombus in patients with unanticoagulated nonvalvular persistent atrial fibrillation.
abstract: BACKGROUND
  The CHADS2 scoring system is simple and widely accepted for predicting thromboembolism in patients with nonvalvular atrial fibrillation (NVAF). Although congestive heart failure (CHF) is a component of the CHADS2 score, the definition of CHF remains unclear. We previously reported that the presence of CHF was a strong predictor of left atrial appendage (LAA) thrombus. Therefore, the present study aimed to elucidate the relationship between LAA thrombus and the brain natriuretic peptide (BNP) level in patients with unanticoagulated NVAF.
  
  
  METHODS
  The study included 524 consecutive patients with NVAF who had undergone transesophageal echocardiography to detect intracardiac thrombus before cardioversion between January 2006 and December 2008, at Hiroshima City Asa Hospital. The exclusion criteria were as follows: paroxysmal atrial fibrillation, unknown BNP levels, prothrombin time international normalized ratio ≥2.0, and hospitalization for systemic thromboembolism.
  
  
  RESULTS
  Receiver operating characteristic analysis yielded optimal plasma BNP cut-off levels of 157.1 pg/mL (area under the curve, 0.91; p<0.01) and 251.2 pg/mL (area under the curve, 0.70; p<0.01) for identifying CHF and detecting LAA thrombus, respectively. Multivariate analyses demonstrated that a BNP level >251.2 pg/mL was an independent predictor of LAA thrombus (odds ratio, 3.51; 95% confidence interval, 1.08-10.7; p=0.046).
  
  
  CONCLUSIONS
  In patients with unanticoagulated NVAF, a BNP level >251.2 pg/mL may be helpful for predicting the incidence of LAA thrombus and may be used as a surrogate marker of CHF. The BNP level is clinically useful for the risk stratification of systemic thromboembolism in patients with unanticoagulated NVAF.
authors.affiliation: Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ochiumi
authors.affiliation: Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Kagawa
authors.affiliation: Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Kato
authors.affiliation: Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Sasaki
authors.affiliation: Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nakano
authors.affiliation: Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan.
authors.forename: Kiho
authors.initials: K
authors.lastname: Itakura
authors.affiliation: Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Takiguchi
authors.affiliation: Department of Cardiology, City Uwajima Hospital, Ehime, Japan.
authors.forename: Shuntaro
authors.initials: S
authors.lastname: Ikeda
authors.affiliation: Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Dote
keywords: AUC, area under the curve; Atrial fibrillation; BNP, brain natriuretic peptide; Brain natriuretic peptide; CHF, congestive heart failure; EF, ejection fraction; Heart failure; LAA, left atrial appendage; Left atrial appendage thrombus; NVAF, nonvalvular atrial fibrillation; NYHA, New York Heart Association; PT-INR, prothrombin time international normalized ratio; ROC, receiver operating characteristic; TEE, transesophageal echocardiography