PLASMA CONCENTRATION OF THE N-TERMINAL PROHORMONE OF BRAIN NATRIURETIC PEPTIDE IS CORRELATED WITH THE RESTING HAEMODYNAMIC VARIABILITY IN HEART FAILURE PATIENTS WITH SYSTOLIC DYSFUNCTION
Authors: Tomasz Krauze, Jolanta Kaczmarek, Krysztof Klimas, Mateusz Dziarmaga, Mateusz Biczysko, Dariusz Karbowy, Jacek Tarchalski, Aneta Nowak, Marta Jastrzebska, Anna Palasz, Dagmara Prymuszala-Staszak, Mateusz Bryl, Katarzyna Barecka, Andrzej Wykretowicz, Henryk Wysocki, Jaroslaw Piskorski, Premyslaw Guzik
Objective: An increased amount of the N-terminal prohormone of brain natriuretic peptide (NT-pro-BNP) is secreted by both ventricles of the heart in response to an excessive load/stretching of the myocardium in heart failure (HF) patients. Impaired myocardial function is accompanied by a reduction in blood perfusion to tissues and organs in HF patients. Nevertheless, this perfusion should be as stable as possible which means that its large variability is rather unexpected. This study aimed at the evaluation of the relationship between the variability of the perfusion-related haemodynamic parameters and the NT-pro-BNP level in HF patients with systolic dysfunction
Methods: Consecutive 190 patients (35-85 years old; 28 female) with HF and left ventricular ejection fraction up to 40% were enrolled. Stroke volume (SV), cardiac output (CO) and systemic vascular resistance (SVR) were measured continuously during a 30-minute supine rest by cardiac impedance (Niccomo, Medis, Germany). The 30-minute variability of these parameters was reflected as the coefficient of variation (cv) (SVcv, COcv and SVRcv, respectively). The NT-pro-BNP concentration was measured in the peripheral venous blood. Nonparametric Spearman correlation was used in statistical analysis.
Results: Median values of the analysed parameters were as follows: NT-pro-BNP concentration 1046 ng/L (interquartile rate (IQR): 561-2774 ng/L), SVcv 12.9% (IQR: 10.2 – 16.5%), COcv 13.3% (IQR: 10.5-16.6%) and SVRcv 7.5% (IQR: 5.8-9.7%). Nonparametric Spearman correlation revealed that NT-pro-BNP was significantly and positively correlated with all analysed parameters and the rho coefficients were as follows: for SVcv 0.18 (p=0.013), for COcv 0.20 (p=0.006) and for SVRcv 0.34 (p<0.0001).
Conclusion: NT-pro-BNP is significantly correlated with the haemodynamic variability in patients with systolic HF. More variable (and less stable) organ/tissue perfusion translates to higher concentration of NT-pro-BNP. This study suggests that haemodynamic variability may also contribute to the NT-pro-BNP secretion in HF patients.