Correlation of N-terminal pro-B-type natriuretic peptide with clinical parameters in patients with hypertension

Identification of patients with arterial hypertension and a possible onset of heart failure by determining the concentration of N-terminal pro-B-type natriuretic peptide (NT-proBNP) enables timely intensification of treatment and allows clinicians to prescribe and implement optimal and appropriate care. The aim of this study was to evaluate NT-proBNP in patients with longstanding hypertension and in patients with signs of hypertensive cardiomyopathy.

The study involved 3 groups, with 50 subjects each: "healthy" persons (control group), patients with hypertension and normal left ventricular systolic function (group 1) and patients with longstanding hypertension and signs of hypertensive cardiomyopathy with impaired left ventricular systolic function (group 2). We measured levels of NT-proBNP, C-reactive protein and creatinine according to the manufacturer's instructions. All the patients were clinically examined including physical examination of the heart with blood pressure, pulse rate, electrocardiogram (ECG) and echocardiogram.

Our results showed that the determined parameters generally differed significantly (Student's t-test) among the groups. The mean (+/- SD) values of NT-proBNP in the control group, group 1 and group 2 were: 2.794 (+/- 1.515) pmol/L, 9.575 (+/- 5.449) pmol/L and 204.60 (84,93) pmol/L, respectively. NT-proBNP correlated significantly with the determined parameters both in the group 1 and the group 2. In the group 1, the highest correlation was obtained with C-reactive protein (r = 0.8424). In the group 2, the highest correlation was obtained with ejection fraction (r = -0.9111). NT-proBNP showed progressive increase in proportion to the New York Heart Association (NYHA) classification. The patients in the- group 2 who belonged to the II and III NYHA class had significantly higher levels of NT-proBNP than those in the NYHA class I (ANOVA test, p = 0.001).

The obtained results suggest that NT-proBNP is a useful biomarker in the treatment of patients with longstanding hypertension who are at risk for heart failure.