DECREASED LEFT VENTRICULAR CONTRACTILITY AND VENTRICULAR-ARTERIAL MATCHING INDEX CORRELATION WITH N-TERMINAL PRO B-TYPE NATRIURETIC PEPTIDE IN HEART FAILURE

Abstract

This study is aimed to assess (1) Left ventricle (LV) contractile function and ventricular-arterial matching from echocardiography; (2) whether ventricular-arterial matching (VAM) is associated with N-terminal pro B-type natriuretic peptide (NT-proBNP), and stroke output in patients with heart failure. Normal subjects (n = 81) and heart failure patients (n = 80) underwent echocardiography, Doppler echocardiography and tissue Doppler imaging. Only heart failure patients underwent blood test for NT-proBNP. The LV contractility was calculated as dσ ⁎ /dt max = 3 × (dV/dt) max /2V m = 3 × V peak × (π × D2/4)/(2V m ), and the arterial elastance was calculated as Ea = SBP × 0.9/ SV , wherein V peak and D are peak velocity and diameter of LV outflow tract, Vm is myocardial volume, SBP is the systolic blood pressure and SV is stroke volume measured from LVOT. The VAM index was expressed as the ratio of LV contractility to arterial elastance (dσ ⁎ /dt max /Ea). We found that HF patients had (i) decreased dσ ⁎ /dt max (1.46 ± 0.73 versus 4.06 ± 1.06 s-1), (ii) increased Ea (2.90 ± 0.87 versus 1.81 ± 0.38 mmHg/mL), and (iii) attenuated ventricular-arterial matching index (0.66 ± 0.57 versus 2.38 ± 0.91 mL/mmHg⋅s) (all p < 0.001) compared with normal subjects. The VAM index was correlated inversely with NT-proBNP (r = -0.32, p < 0.05), but positively with the stroke volume (r = 0.85, p < 0.001). The VAM index of < 1.51 was able to clearly differentiate the failing heart from normal hearts (AUC = 0.959, Sensitivity = 0.911, Specificity = 0.905). Heart failure patients demonstrated impaired ventricular contractility, enhanced arterial stiffening, and attenuated ventricular-arterial matching index. The attenuated ventricular-arterial matching index value was associated with elevated NT-proBNP levels and lower cardiac output.