Relationship Between The Level Of NT-proBNP And Left Ventricular Diastolic Function In Chronic Heart Failure Patients With Preserved Ejection Fraction

Objective:To investigate the NT-proBNP level and echocardiographic parameter in patients with chronic heart failure with preserved ejection fraction (HFPEF) and evaluate the correlation, specificity and sensitivity on these indices.Methods:Thirty-six symptomatic patients with isolated diastolic dysfunction and preserved left ventricular ejection fraction (LVEF) (≥50%) and twenty-three patients with normal left ventricular (LV) function were examined by conventional echocardiography, tissue Doppler imaging (TDI). Plasma NT-proBNP levels were determined simultaneo-usly. The following parameters were assessed respectively:left atrial dimension(LAD),interventricular septum thick(IVST),left ventricular posterior wall(LVPW),left ventricular end-diastolic dimension(LVEDD),left ventricular end-systolic dimension(LVESD),E-wave,A-wave,E-wave deceleration time, (DT),left ventricular ejection fraction (LVEF),the early annular velocity of lateral mitral leaflets origin(Em), left ventricular mass index(LVMI).Results:1.Compared with control group, NT-proBNP,E/Em,LVMI were higher significantly in HFPEF(P<0.01);LVEF,Em were lower significantly. Median of NT-proBNP plasma levels were elevated (1362(70.57-4625) pg/mL vs.100(33.62-301.69) pg/mL);Mean of E/Em were also higher in HFPEF(13.6±5.4 VS.7.97±1.81).2.NT-proBNP correlated significantly with E/Em(correlation coefficient r=0.574).And NT-proBNP had a weak correlation with LVMI, did not correlate with DT. DT correlated significantly with E/Em,LVMI(with r-values of 0.401,0.348, respectively). There was no correlation between E/Em and LVMI.3.According to the recevier operating characteristic analysis, the AUC (area under curve) of E/Em, LVMI, NT-proBNP were 0.913,0.832, 0.817, respectively. AS the cut-off value of E/Em was 9.5, the sensitivity and specificity were 0.861,0.800, respectively. The sensitivity and specificity were 0.711,0.678, respectively, by LVMI at a cut-off value of 125 g/m2. The sensitivity and specificity were 0.919,0.720, respectively, by NT-proBNP at a cut-off value of 130pg/ml. NT-proBNP had a good negative predictive value(92.8%) by a cut-off value of 90pg/ml. Conclusion:1. NT-proBNP,E/Em, LVMI were significantly markers for reflecting left ventricular diastolic function and good tools for diagnosing HFPEF.2. Plasma NT-proBNP had a significantly negative predictive value(92.8%) when NT-proBNP< 90pg/ml.