The Changes Of Plasma Levels Of Natriuretic Peptides In Patients With Chronic Heart Failure And Intervention Of Beta-blockers On Chronic Heart Failure

OBJECTIVES:This study was performed to explore the correlation among plasma levels of natriuretic peptides and the left ventricular function and structure in patients with chronic heart failure (CHF),and to investigate the effects on plasma levels of natriuretic peptides,the left ventricular function and remodeling when treated with metoprolol or carvedilol despite standard therapy.METHODS:We enrolled 48 patients with CHF (10 with coronary artery disease,22 with dilated cardiomyopathy,16 with hypertensive heart disease),according to the New York Heart Association (NYHA) class,15 classified NYHA II,24 NYHA III,9 NYHA IV. Plasma levels of atrial and brain and C-type natriuretic peptides (ANP,BNP,CNP) were measured by radioimmunoassay and immunoradiometric assay in these patients and 10 age and gender-matched healthy controls. Doppler echocardiography was performed to measure parameters of left ventricular function and structure. Among them,33 patients with stable NYHA class II -III and with left ventricular ejection fraction(LVEF)< 45% were randomly assigned to receive metoprolol or carvedilol orcontrol in addition to standard therapy for a total of 3 months. Effects was assessed by changes of plasma levels of natriuretic peptides and echocardiographic parameters of left ventricular function and structure.RESULTS:Plasma levels of ANP and BNP were significantly elevated in CHF patients (P all <0.01),and levels increased in proportion to the severity of left ventricular dysfunction. In patients with LVEF<45%,plasma level of BNP had a negative correlation with LVEF (P<0.05),both ANP and BNP levels had positive correlations with pulmonary artery systolic pressure (P<0.05 or 0.01),and BNP plasma level had a positive correlation with left ventricular end-diastolic diameter and left ventricular mass index (P all < 0.05). After 3 months optimized treatment,ANP and BNP plasma levels both decreased in all three groups,with no between-group difference of ANP changes,whereas there was significant difference of BNP changes between patients received beta-blockers and not. (3)In patients received beta-blockers,there was an improvement of NYHA class,a reduction of pulmonary artery systolic pressure,and an increase of LVEF in 8 patients with LVEF < 3 5% before treatment,but there was no significant difference between metoprolol and carvedilol groups. In the control group,there were no significant changes in NYHA class,LVEF and pulmonary artery systolic pressure. (4) No obvious changes of leftventricular structure had been observed over 3 months treatment.CONCLUSIONS:ANP and BNP plasma levels were good markers used to reflect left ventricular function,whereas BNP level was more sensitive and specific and had close relationship with left ventricular structure. Measurement of BNP plasma level was useful to reflect the immediate change of left ventricular function. Patients treated with beta-blockers in addition to the standard therapy for CHF show beneficial effect on left ventricular function,but according to echocardiographic parameters,no significant effect on ventricular remodeling within 3 months. There were no apparent differences in clinical results between metoprolol and carvedilol during 3 months therapy.