Objective To detect the N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in patients with chronic heart failure, and to evaluate the difference of the levels in patients with chronic left and right heart failure.
Methods 1. 83 patients with chronic heart failure as the experimental group, and 25 patients without organic heart disease as the control group were included in the study. The patients in the experimental group were divided into left heart failure group (31 cases), right heart failure group (25 cases) and total cardiac failure group (27 cases), in which 25 patients of right heart failure group had chronic cor pulmonale, and the left heart failure and total cardiac failure group included 31 cases of coronary heart disease, 15 cases of hypertensive heart disease, 12 cases of heart valve disease. In the left heart failure and total cardiac failure group, the patients were further divided into three subgroups according to the classification of the New York Heart Academy (NYHA), including 17, 22 and 19 patients in Class II, III and IV, respectively; 2. Collected peripheral vein blood from each patient, and assayed the plasma NT-proBNP, creatinine (CRE), blood urea nitrogen (BUN), uric acid (UA), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) by ELISA; 3. Evaluated the left ventricular ejection fraction (LVEF), left ventricular end diastolic diameter (LVEDD), right ventricular end diastolic diameter (RVEDD) and ventricular septal thickness (IVST) of these patients by echocardiography; 4. SPSS11.5 was used for statistical analysis, statistical significance was established at p<0.05.
Results 1. The level of plasma NT-proBNP were 79.53±36.77 pg/ml, 2076.95±1024.32 pg/ml, 743.26±152.82 pg/ml and 4815.52±3165.98 pg/ml in the control group, the left heart failure group, the right heart failure group and the total cardiac failure group respectively (p<0.05); 2. The NT-proBNP was significantly increased with the heart function deteriorated, as observed of 1018.16±551.03 pg/ml, 2557.27±1582.38 pg/ml, 6359.77±2605.76 pg/ml, in the subgroups of NYHA ClassII, III and IV, respectively, which were all significant greater than that in Group Control. 3. The plasma NT-proBNP level of chronic cor pulmonale (743.26±152.82 pg/ml) was significantly lower than coronary heart disease (3670.48±1619.55 pg/ml), hypertension (3404.78±1056.10 pg/ml) and heart valve disease (2462.31±1130.25 pg/ml) (p<0.05); The plasma NT-proBNP level was no significant difference among coronary heart disease, hypertension and heart valve disease disease (p>0.05); 4. The plasma NT-proBNP level was negatively correlated with LVEF (r=−0.425, p<0.05), and positively correlated with BUN (r=0.231, p<0.05), CRE (r=0.405, p<0.05) and LVEDD (r=0.371, p<0.05), but had no correlation with age, UA, TC, TG, HDL-C, LDL-C, RVEDD and IVST (p>0.05). Multivariate stepwise regression analysis demonstrated that the CRE and LVEF were the independent factors influencing the plasma NT-proBNP level.
Conclusions 1. The plasma NT-proBNP level of the patients with chronic heart failure was higher than normal, and the plasma NT-proBNP levels were significantly increased with the severity of cardiac function classification, and it is good at reflecting the abnormal of cardiac function. The plasma NT-proBNP level of the left heart failure was significantly higher than the right heart failure. Furthermore detecting the plasma NT-proBNP levels can distinguish between cardiac dyspnoea and pulmonary dyspnoea; 2. The plasma NT-proBNP level of the total cardiac failure group was significantly higher than the other groups. The plasma NT-proBNP level is important to detect serious heart failure. The CRE of total cardiac failure group was higher than other groups. The highter CRE suggests that patients of serious heart failure are often accompanied with a decline of renal function; 3. The plasma NT-proBNP level was negatively correlated with the LVEF, and positively correlated with the BUN, CRE and LVEDD. The CRE and LVEF are independent impact factors effecting the plasma NT-proBNP level.