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Relationship between Quantitative Parameters of Echocardiography and Vascular Endothelial Function in Patients with Chronic Heart Failure and Its Predictive Value for Short-Term MACE Risk

Objective To investigate the relationship between quantitative parameters of echocardiography and vascular endothelial function in patients with chronic heart failure (CHF) and the predictive value of short-term major adverse cardiovascular events (MACE). Methods From February 2018 to February 2020, 86 CHF patients in our hospital were selected as the observation group, and 46 healthy subjects were selected as the control group during the same period. Quantitative parameters of echocardiography (left ventricular ejection fraction (LVEF), left ventricular short-axis shortening rate (FS), and ratio of peak flow velocity between early and late mitral valve diastole (E/A)) and endothelial function indexes (endothelin-1 (ET-1)/nitric oxide (NO)) were compared between the two groups. The correlation between quantitative parameters of echocardiography and vascular endothelial function in patients with CHF was analyzed. A logistic regression equation was used to analyze the risk factors of MACE in patients with CHF. The receiver operating characteristic curve (ROC) was used to analyze the predictive value of quantitative parameters of echocardiography and NO/ET-1 for the risk of MACE in patients with CHF. Result LVEF, FS, and NO/ET-1 in the observation group were lower than those in the control group, while E/A was higher than that in the control group (P < 0.05). In CHF patients, LVEF and FS were positively correlated with NO/ET-1, while E/A was negatively correlated with NO/ET-1 (P < 0.05). Logistic regression analysis showed that the decrease of LVEF, FS, NO/ET-1, and E/A were risk factors for MACE (P < 0.05) after adjusting for age, body mass index, and cardiac function grading. The AUC value of short-term MACE predicted by quantitative parameters of echocardiography and NO/ET-1 combined was 0.883, with a corresponding sensitivity of 86.21% and specificity of 73.13%. Conclusion Quantitative parameters of echocardiography in CHF patients are related to vascular endothelial function, and their combination can effectively predict the risk of MACE in the near future, providing reference for clinical treatment.


Introduction
Chronic heart failure (CHF) is the final stage of the development of various cardiovascular diseases, characterized by high morbidity and mortality, and its prevention and treatment is an important public health issue [1,2]. erefore, early diagnosis, effective treatment, and accurate prognosis assessment of CHF patients are particularly important. Echocardiography is a simple, safe, and low-cost noninvasive diagnostic technology that provides not only abundant information on structure and etiology but also prognostic information, which has been widely used in the diagnosis and evaluation of CHF condition and prognosis [3,4]. Guidelines issued by the American College of Cardiology indicate that echocardiography is the most useful method for evaluating cardiac function in patients with heart failure [5]. A large number of studies have confirmed vascular endothelial function impairment in CHF patients, manifested by excessive upregulation of endothelin-1 (ET-1), relative augment of nitric oxide (NO), and decrease of ET/NO [6,7]. At present, there are few clinical studies on the relationship between quantitative parameters of echocardiography and vascular endothelial function in patients with CHF. To determine whether vascular endothelial function impairment is the mechanism of continuous deterioration of cardiac function in patients with CHF is expected to provide support for cardiac prognosis of patients with vascular endothelial cell function-targeted therapy. Based on this, this study investigated the relationship between quantitative parameters of echocardiography and vascular endothelial function in patients with CHF and the predictive value of the risk of major adverse cardiovascular events (MACE) in the near future reported as follows.

General Data.
From February 2018 to February 2020, 86 CHF patients in our hospital were selected as the observation group, and 46 healthy subjects were selected as the control group during the same period. Inclusion criteria: (1) the observation group all met the diagnostic criteria of CHF in the guidelines for the diagnosis and treatment of acute and chronic myocardial failure issued by the European Society of Cardiology [8] and the guidelines for the diagnosis and treatment of acute and chronic heart failure issued by the European Heart Association in 2016 [9] and had typical symptoms of heart failure and objective evidence of abnormal cardiac function at the static site; (2) all subjects gave informed consent and signed a consent form. Exclusion criteria: (1) acute coronary syndrome occurred before admission; (2) congenital heart disease; (3) pulmonary heart disease; (4) severe valvular diseases; (5) severe liver and kidney failure; (6) malignant tumor; (7) infection or acute or chronic inflammation; and (8) have a history of glucocorticoid treatment or are taking glucocorticoid treatment within 3 months.

Method
(1) Quantitative parameters of echocardiography: the Vivid E95 color Doppler ultrasound diagnostic instrument of GE company was applied. M5Sc probe parameters mainly included left ventricular ejection fraction (LVEF), fraction shortening rate of left ventricle (FS), and E peak of early diastole/A peak of late diastole (E/A). (2) NO/ET-1 detection: 3 ml of fasting peripheral venous blood was collected and centrifuged (radius 8 cm, 3500 r/min, 10 min). Serum was taken, and enzyme-linked immunosorbent assay was used to detect ET-1 and NO using a Wuhan Huamei Bioengineering Co., LTD., kit. (3) Treatment methods: the observation group received conventional anti-heart failure drugs, including β-blocker, angiotensin-converting enzyme inhibitor or angiotensin ii receptor antagonist, aldosterone receptor antagonist, and digoxin and diuretics when necessary.

Observation Target
(1) General data, quantitative parameters of echocardiography, and vascular endothelial function indexes of the two groups (2) Correlation between quantitative parameters of echocardiography and vascular endothelial function in CHF patients ( . An independent-sample T-test was used for comparison between groups. Count data were expressed by n (%) and the χ 2 test. Correlation was analyzed by Pearson. e influencing factors were analyzed by logistic regression. e predictive value was analyzed by the receiver operating characteristic curve (ROC) to obtain AUC, confidence interval, sensitivity, specificity, and cutoff values. e combined prediction was performed by logistic binary regression fitting. e prediction probability logit (p) is returned as the independent test variable. A bilateral test was used for all cases, and P < 0.05 was considered statistically significant.

General Data, Quantitative Parameters of Echocardiography, and Vascular Endothelial Function Indexes of the Two Groups.
ere were 28 patients in grade II, 37 patients in grade III, and 21 patients in grade IV cardiac function in the observation group. LVEF, FS, and NO/ET-1 were lower than those in the control group, while E/A was higher than that in the control group, with statistically significant differences (P < 0.05), as shown in Table 1.

Correlation between Quantitative Parameters of Echocardiography and Vascular Endothelial Function in Patients with CHF.
In CHF patients, LVEF (r � 0.728, P < 0.001) and FS (r � 0.679, P < 0.001) were positively correlated with NO/ ET-1, while E/A was negatively correlated with NO/ET-1 (R � −0.822, P < 0.001), as shown in Figure 1.

Univariate Analysis of Recent MACE Risk in CHF Patients.
MACE occurred in 19 patients (22.09%, 19/86) 6 months after treatment. Gender, smoking history, and LDL-C and HDL-C levels were not associated with recent MACE risk in CHF patients (P > 0.05). Age, body mass index, cardiac function grading, quantitative parameters of echocardiography (LVEF, FS, and E/A), and NO/ET-1 were all influential factors for the recent risk of MACE in CHF patients (P < 0.05), as shown in Table 2.

Multivariate Analysis of Recent MACE Risk in CHF
Patients. Taking the occurrence of MACE as the dependent variable (NO � 0, yes � 1), the factors with statistically significant differences in Table 1 were included in the logistic regression model. After adjusting for age, body mass index, and cardiac function grading, the decrease of LVEF, FS, and NO/ET-1 and the increase of E/A were all risk factors for the occurrence of MACE (P < 0.05), see Table 3.

e Predictive Value of Quantitative Parameters of Echocardiography and NO/ET-1 for the Risk of MACE in the
Near Future. Using quantitative echocardiographic parameters (LVEF, FS, and E/A) and NO/ET-1 of patients with MACE as positive samples and quantitative echocardiographic parameters (LVEF, FS, and E/A) and NO/ET-1 of patients without MACE as negative samples, ROC curves for predicting the risk of MACE were drawn. e results showed that the AUC of LVEF-, FS-, E/A-, and NO/ET-1-predicted MACE was 0.740, 0.719, 0.797, and 0.691, respectively. e joint application ROC theoretical model of SPSS software was used to construct the joint prediction ROC model of each indicator. e results showed that the joint prediction AUC was the largest, which was 0.883, as shown in Figure 2 and Table 4.

Discussion
CHF is a complex syndrome in which myocardial injury induces abnormal activation of the neuroendocrine regulatory system, resulting in sodium and water retention, circulating congestion, heart and vascular remodeling, etc [10,11]. erefore, the correct response to CHF should include hemodynamic measurement and evaluation of global cardiac function. From development to clinical application, echocardiography can provide effective information on the morphology, hemodynamics, and systolic and diastolic functions of the heart and great vessels and has the   Journal of Healthcare Engineering advantages of simplicity, repeatability, noninvasiveness, and low cost. erefore, echocardiography plays an increasingly important role in the diagnosis and treatment of CHF [12,13]. Among the quantitative parameters of echocardiography, expressions of LVEF and FS were used to evaluate left ventricular systolic function, and E/A was used to   is study showed that LVEF and FS in the observation group were lower than those in the control group, while E/A was higher than those in the control group, suggesting that CHF patients had cardiac systolic and diastolic dysfunction, which was consistent with previous studies [14,15].
CHF patients have poor quality of life, and the 5-year survival rate is similar to that of malignant tumors. About 40% of patients will be readmitted to hospital within 12 months due to deterioration of disease [16]. At present, there is still a lack of in-depth understanding of whether there are variable factors leading to cardiac function deterioration in CHF patients. NO and ET are two vasoactive substances with opposite effects that are synthesized and secreted by endothelial cells. Under physiological conditions, they are at a relatively constant level. However, in CHF patients, ET is excessively upregulated, but NO is upregulated at a slower rate than ET, which often shows that NO/ET balance shifts to ET [17]. CHF leads to vascular endothelial dysfunction, changes in vascular wall shear stress, activation of various endocrine and cytokine factors, and ischemia and hypoxia which can stimulate ET synthesis and release by regulating ET gene transcription and expression. Meanwhile, decreased renal perfusion and pulmonary circulation congestion reduce ET clearance metabolism, and elevated ET mediates myocardial fibrosis. Also, there is direct toxicity to cardiac myocytes [18]. NO is mainly synthesized and secreted by vascular endothelial cells, and studies have shown that the increase of NO may be a factor in the progression of CHF. Excessive NO can inhibit the β-adrenaline effect of cardiomyocytes, directly leading to the weakening of myocardial contractility [19]. is study was the first to explore the relationship between quantitative parameters of echocardiography and vascular endothelial function in CHF patients. It was found that LVEF and FS were positively correlated with NO/ET-1, while E/A was negatively correlated with NO/ET-1, suggesting that the reduction of NO/ET may be related to the continuous deterioration of cardiac function. Analysis of relevant mechanisms: (1) in the progression of heart failure, ET-1 binds to the ETA receptor on cardiomyocytes, causing fibrous connective tissue hyperplasia, cardiomyocyte hypertrophy, and accelerated ventricular remodeling [20]. (2) ET-1 can stimulate adrenergic β-receptor, promote NO synthesis in endothelial cells, activate the protein kinase G signal transduction pathway, reduce intracellular calcium ion concentration, increase matrix metalloproteinase synthesis, and accelerate ventricular remodeling by mediating negative myocardial muscle strength and vasodilation [21]. (3) Changes in hemodynamics in CHF patients lead to ischemia and hypoxia of tissues and organs in the whole body and induce massive production of vascular endothelial growth factor (VEGF) [22]. VEGF promotes NO production and maintains endothelial cell-dependent vascular tension and participates in the protection of vascular endothelial function in different ways, playing an important role in delaying the progression of CHF [23]. erefore, vascular endothelial cell function may be a variable factor for cardiac function deterioration in patients with CHF, but further studies are needed to determine whether treatment targeting vascular endothelial cell function can improve cardiac outcomes in patients with CHF.
CHF is a long-term progressive disease, and genetic and environmental factors can affect the prognosis of patients [24]. Evidence-based medicine has found that CHF patients with the same degree of myocardial injury and underlying etiology may have significant differences in the natural course of disease and prognosis [25,26]. erefore, it is of great importance to find simple and readily available prognostic markers, identify high-risk population early, carry out reasonable treatment and prognostic monitoring, and prevent adverse events. In this study, LVEF, FS, NO/ET-1 reduction, and E/A increase were all risk factors for the occurrence of short-term MACE in patients with CHF after treatment. e ROC curve showed that LVEF, FS, E/A, and NO/ET-1 could effectively predict the risk of short-term MACE, and the combined prediction AUC reached 0.883, higher than that predicted alone. It is suggested that the combined detection of LVEF, FS, E/A, and NO/ET-1 can provide a more effective quantitative reference for clinical prediction of MACE occurrence and theoretical basis for the optimization of treatment plan.
In conclusion, vascular endothelial function injury in CHF patients may be an important factor in the deterioration of cardiac function, and both of them can effectively predict the risk of MACE in the near future. erefore, vascular endothelial cell function is expected to become a target to improve the cardiac prognosis of patients. e shortcoming in this study is the research related to the MACE of the measured value of the variable is a single point in time, did not investigate the changes of these variables in a period of time influence on prognosis, is only a single-center study, prone to selection bias, and has yet to be further continued as a multicenter study with in-depth exploration and large sample size.

Data Availability
e labeled dataset used to support the findings of this study are available from the corresponding author upon request.