Noninvasive Assessment Of Diastolic Heart Failure In Patients With Essential Hypertension: Comparison Of E/E' Ratio, E/A Ratio, And Brain Natriuretic Peptide

Objective: To evaluate whether the ratio of early diastolic transmitral inflow velocity(E) to early diastolic mitral annulus velocity(E′) (E/E′) can be applied to identify diastolic heart failure (DHF) noninvasively rather than using brain natriuretic peptide(BNP) and the ratio of early diastolic transmitral inflow velocity (E) to late diastolic transmitral inflow velocity (A) (E/A) in patients with essential hypertension by comparing the severity of HF symptoms.Methods: We examined 80 patients with essential hypertension and preserved left ventricular ejection fraction( >50%), ie, patients with diastolic HF accompanied with New York Heart Association(NYHA) functional classⅠtoⅣ(n=35,DHF group) and those without HF(n=45, non-HF group). No patients showed severity caused by secondary hypertension, coronary heart disease, cardiomyopathies, valvular heart disease, congenital heart disease, left ventricular systolic dysfunction(LVEF<50%), dysthyreosis, respiratory disease, renal failure, decompensated hepatic cirrhosis, or other disease states except essential hypertension. 30 healthy participants were selected randomly as the control group. Conventional ultrasonography (including two-dimensional ultrasound, M-mode ultrasonography and Doppler flow imaging) and tissue Doppler examination were performed for all patients. End-diastolic diameters of left ventricle(LVEDd), interventricular septum thickness(IVST), left ventricular posterior wall thickness(LVPWT), and end-systolic diameters of left ventricle(LVEDs) were measured by M-mode ultrasonography. In the apical four-chamber view, early diastolic transmitral inflow velocity (E) and late diastolic transmitral inflow velocity (A)were measured by pulsed-wave Doppler Imaging. And early diastolic mitral annulus velocity (E′) was recorded by Doppler Tissue Imaging. Left ventricular ejection fraction(LVEF) were calculated according to the formula. The above data were three consecutive cardiac cycles on average, and were observed by two ultrasound doctors fixed after operation the average double-blind. BNP levels were also examined. The measurement data were presented as mean±standard deviation. The Comparison between the two groups was X~2 statistics for categorical variables while t test for measurement data. Parameters among groups were compared using one-way analysis of variance. The diagnostic value of E/ A,E/E′and BNP was determined by the receiver operating characteristic (ROC) curve, and the correlation between parameters was tested by linear correlation analysis. P<0.05 indicated statistical significance. All data were analyzed using SPSS 13.0 software package.Results: 1)Comparison of routine parameters: There was no significant difference in the LVEDd, LVEDs and LVEF among the DHF group, NHF group and control group. IVST and LVPWT were significantly increased in the DHF group and the NHF group compared with control group(P=0.000).2) E/A<1 or E/A>2, left ventricular diastolic heart failure. 1< E / A <2, can be present in healthy individuals in those with left ventricular diastolic dysfunction. There was no significant correlation between BNP and E / A.E′was significantly lower in the DHF group than in the NHF group (7.1±1.8 vs 9.3±1.6cm, P<0.001). In the DHF group compared with the NHF group, there was an increase in the levels of E (104.3±11.3 vs 82.7±6.4cm/s, P<0.001), E/E′(15.7±4.9vs9.0±1.4,P <0.001), BNP (320.9±199.6vs140.4±75.8pg/ml,P<0.001). In all patients, E/E′showed an increase as the severity of HF, which was graded according to the NYHA classification.3) Using the ROC curve for identification of symptomatic DHF with HYHA functional classⅠ-Ⅳ, the areas under the curves were: E/E′,0.883(95% confidence interval 0.797-0.969);BNP,0.848(95% confidence interval 0.761-0.934);E/A,0.787(95% confidence interval 0.671-0.903. The optimal cutoff point is shown: E/E′>12.45 (sensitivity 77.1%, specificity 98.0%, Youden index 0.75), accuracy 88.7%; BNP>209.56pg/mL (sensitivity 65.7%, specificity 98%, Youden index 0.64), accuracy 83.75%.Conclusions: 1) BNP has a significant correlation in patients with DHF, and is increased with progression of NYHA functional class in patients with HF.2) E/A may be used for the diagnosis of DHF, but the sensitivity is not high for the existence of the pseudo-normalization.3) E/E′has a significant correlation with BNP in patients with DHF. 4) There is no significant correlation between E/A and BNP values, therefore E/E′is better than E/A.