In our study, we used the index of EF ≤ 50% as left ventricular dysfunction. - Evaluating Systolic Pulmonary Artery Pressures (PAPs): + Normal PAPs: < 30 mmHg + High PAPs: ≥ 30 mmHg - Evaluating hemodynamics index: Using monitor to follow continuous cardiac output (CCO) through Flotrac system: + Cardiac index (CI): Normal CI: 2.5 - 4.0 L / min / m2 Decreased CI: ≤ 2.4 L / min / m2 + Cardiac output (CO): Normal CO: 4.0 - 8.0 L / min Decreased CO: < 4.0 L / min + Stroke volume index (SVI): Normal SVI: 33 - 47 ml / m2 Decreased SVI: ≤ 32 ml/m2 2.2.4.3. Criteria in the association between NT-proBNP and LCOS after surgery: - The association between NT-proBNP and the prognosis ability of LCOS.