Determination of the levels of brain natriuretic peptide and its N-terminal fragment for the evaluation of the efficiency of renal replacement therapy modalities in patients with decompensated chronic heart failure

Abstract

Aim: to compare the capabilities of identifying different types of brain natriuretic peptide (BNP) for the evaluation of renal replacement therapy modalities in patients with decompensated chronic heart failure (CHF). Subjects and methods. Patients (31 men and 9 women) aged 30 to 82 years with functional class II-IV CHF in its decompensation phase were examined. The patients were divided into 2 groups. A study group received medical therapy for CHF, such as angiotensin-converting enzyme inhibitors or angiotensin II receptor antagonists, verospirone, β-adrenoblockers, digoxin, loop diuretics (furosemide, diuver, in the doses not exceeding those taken before admission) in combination with renal replacement therapy: slow continuous ultrafiltration (SCUF) or continuous venovenous hemofiltration (CVVHF). A control group had only medical therapy for CHF (intravenous furosemide in the doses doubling those used before admission, i.e. l 80 mg/day required for an adequate response to the drug - daily urine volume > 1 liter). The patients from the study and control groups received furosemide m 40 mg/day or torsemide m 20 mg/day after a course of SCUF or CVVHF sessions or intravenous furosemide. There were 4 examination stages [control study points (CSP)]: 1) before study; 2) after CHF compensation achievement (a day before hospital discharge); 3) following 90 days; 4) following 180 days. The plasma concentration of active BNP was measured by enzyme immunoassay; that of the N-terminal fragment of BNP (NT-proBNP) was estimated on an analyzer. Results. There were direct correlations between the content of BNP and that of NT-proBNP) in all CSPs in the patients from both groups. The study group showed a significantly greater weight loss, which was accompanied by a more pronounced reduction in systolic pulmonary artery pressure, pulmonary venous hypertension, hydrothorax elimination, decreased liver size, lower plasma aldosterone concentration, decreased heart size, and higher left ventricular ejection fraction (LVEF). The study group displayed a steady-state reduction in the plasma concentrations of both BNP and NT-proBNP, significant inverse correlations between the lower BNP level and the higher LVEF throughout the follow-up. Conclusion. Extracorporeal dehydration techniques are more effective that intravenous diuretics. The direct correlations between the content of BNP and that of NT-proBNP and between the change in their concentrations during treatment assume the capacity and objectification of diagnosing CHF and its degree, by determining only one of the types of BNP.

Keywords

• brain natriuretic peptides
• renal replacement therapy
• heart failure