Measurement of NT- ProBNP in patients with heart failure

ABSTRACT

Heart failure is the final complication of many diseases and an important cause of morbidity and mortality. N-Terminal B-Type Natriuretic Peptide [NT-ProBNP] is a new diagnostic tool for evaluation of the severity of heart failure and for differentiation between systolic function of left and right heart. In addition, plasma level of NT-ProBNP serves as a good guide in the management and follow-up of patients under treatment for heart failure. Patients with left side heart failure who referred to Taleghani hospital were consecutively recruited for this study. Diagnosis of heart failure was done through clinical evaluation and echocardiographic procedure. The severity of heart failure was determined according to New York heart association [NYHA] classification and clinical stage for each patient. Three ml citrated venous blood was obtained from the subjects and all samples were sent to the Endocrine and Metabolism research center laboratory of Shahid Beheshti Medical University for evaluation of plasma NT-ProBNP level by enzyme multiplied immunoassay technique [ELISA]. Patients with acute coronary syndrome, severe valvular stenosis, severe lung disease, liver cirrhosis, primary hyperaldesteronism, hyperthyroidism, acute respiratory distress syndrome [ARDS], and candidates for heart transplantation were excluded. Plasma level of NT-ProBNP for each classification of NYHA and clinical stages and left ventricular ejection fraction [LVEF] were evaluated. Seventy nine patients, with a mean age of 63.1+ 14 years were included in the study. Fifty-five [69.6%] subjects were male. Forty-eight patients [60.8%] were hypertensive, twenty- two patients [27.8%] were diabetic and sixty- four patients [81.0%] suffered from ischemic heart disease [IHD]. The mean plasma level of NT-ProBNP in subjects aged 60 years or more was higher than younger subjects, [485.8 +/- 418.6 versus 308.7 +/- 300.5], [P= 0.033]. The evaluation of NT- Pro BNP plasma levels showed correlation with decreased ejection fraction [P= 0.013], clinical stages [P< 0.001], and function class according to NYHA classification [P< 0.001]. In this study plasma levels of NT-ProBNP were elevated proportional to decrease in ejection fraction and systolic function of left ventricle in patients with heart failure. Measurement of NT-ProBNP is a good laboratory indicator for detection of left ventricular failure and its severity