br Material and methods br Results br Discussion The present
Material and methods
Discussion The present study found that the plasma BNP level was higher in patients with LAA thrombus than in those without LAA thrombus. Additionally, the BNP level was negatively associated with peak LAA velocity evaluated using TEE and positively associated with the D-dimer level. Moreover, the optimal plasma cut-off level of BNP for detecting LAA was 251.2pg/mL, and a plasma BNP level >251.2pg/mL was an independent predictor of LAA thrombus in patients with unanticoagulated NVAF. Therefore, a plasma BNP level >251.2pg/mL could be used to differentiate between patients with and those without LAA thrombus. Patients with NVAF are treated with anticoagulation therapy on the basis of the CHADS2 scoring system because this system is convenient and easy to apply for predicting thromboembolism in these patients. However, for the management of AF, the definition of CHF is unclear in the current guidelines [14,15]. The BNP level is widely used for assessing patients with CHF. An elevated BNP level is correlated with left ventricular systolic and diastolic dysfunction [12,16,17]. Previous studies have demonstrated that the BNP level is associated with left ventricular filling pressure [18,19] and is well correlated with the severity of hcv protease inhibitors failure [20,21]. Recent clinical reports have shown that blood coagulability is enhanced in patients with AF [22,23]. Jafri et al.  reported that patients with severe heart failure with a high norepinephrine level or low EF are more likely to have an activated platelet and coagulation system. In addition to hemostatic abnormalities, endothelial dysfunction may contribute to the hypercoagulability observed in patients with CHF . Concordant with these findings, a BNP level >251.2pg/mL, CHF (NYHA classification ≥II), and systolic dysfunction (EF <40.2%) were significantly associated with the presence of LAA thrombus in the present study. Watanabe et al.  reported that elderly patients with an elevated plasma BNP level have a greater incidence of systemic thromboembolism. LAA thrombus is reported to be associated with the D-dimer level and thromboembolism in patients with NVAF [7–10]. In the present study, a positive association was found between plasma BNP and D-Dimer levels, suggesting that plasma hypercoagulability is closely associated with cardiac dysfunction. Additionally, a negative association was found between the BNP level and peak LAA velocity evaluated by using TEE. Peak LAA velocity measured by using TEE has been proposed for assessing the degree of blood stasis and risk of thromboembolism. These findings indicate that the severity of CHF is associated with a hypercoagulable state possibly from blood stagnation in the LAA. The results of the present study demonstrate that the BNP level may be a useful surrogate marker for the presence of LAA thrombus. In addition, BNP may be a quantitative and objective marker of risk stratification. In this study, a plasma BNP level >251.2pg/mL was an independent predictor of LAA thrombus in patients with unanticoagulated NVAF. Therefore, a plasma BNP level >251.2pg/mL may be useful to differentiate between patients with and those without LAA thrombus, and may provide better identification of high-risk patients with unanticoagulated NVAF. From these perspectives, measuring the BNP level may help in the diagnosis of CHF and the detection of high-risk patients by not only cardiologists but also general physicians. Nevertheless, further prospective clinical studies are required to clarify the impact of the cut-off levels of BNP determined in the present study on the prognosis of patients with NVAF. The present findings will contribute to the prompt detection of unanticoagulated NVAF patients with high risk of thromboembolism.
Conclusions In patients with unanticoagulated NVAF, the BNP level may help predict the incidence of LAA thrombus and may be used as a surrogate marker of CHF in the CHADS2 scoring system. The BNP level is clinically useful for the risk stratification of systemic thromboembolism in patients with unanticoagulated NVAF.