Hypersensitive C-reactive Protein to HDL-C Ratio Predicts the Severity of Coronary Artery Disease

Background: Lipid and inammatory molecules play a key role in the development of coronary atherosclerosis. Hypersensitive C-reactive proteins are used as markers of inammation duration, and HDL-C is used as an anti-atherosclerosis component. However, few studies have combined the two indicators to explore coronary stenosis. We suggested that Hypersensitive C-reactive proteins as a marker of inammation persistence and HDL-C as an anti-atherosclerosis component should be integrated into a single biomarker , so as to explore the correlation of Hypersensitive C-reactive protein HDL-C ratio with the severity of coronary stenosis and to predict the severity of coronary stenosis in CAD patients. Methods: We examined 360 eligible patients who underwent coronary angiography. Based on the results of coronary angiography, patients with any major coronary arteries (the left anterior descending artery, the left circumex artery, the left main coronary artery, the right coronary artery) whose lumen diameter reduced by more than 50% were dened as CAD + group (n = 139) .Patients with luminal stenosis but no more than 50% were dened as CAD - group (n = 41), and patients without luminal stenosis (n = 180) were regarded as control group. The relationship between various serum markers and the severity of coronary stenosis was examined by Spearman correlation analysis. Logistic regression analysis was performed to identify the inuencing factors of the severity of coronary artery disease. Results: The modied Gensini score was positively correlated with Hypersensitive C-reactive protein HDL-C ratio . Multiple regression analysis showed that Hypersensitive C-reactive protein HDL-C ratio were signicantly associated with CAD. Hypersensitive C-reactive protein HDL-C ratio is an independent predictor of CAD. The ROC analysis provided a cut-off value of 1.17 for Hypersensitive C-reactive protein HDL-C ratio to predict CAD with 83.9% specicity and 0.242 Yoden index, and area under the ROC curve of 0.632 (95%CI 0.571-0.694, P <0.001).At and the Spearman correlation coecient was calculated. Binary logistic regression analysis was applied to the independent predictors of the severity of coronary artery disease. Univariate logistic regression models were rst performed to assess the crude association between the severity of coronary


Background
Coronary artery disease (CAD) caused by atherosclerosis is a major cause of death and morbidity worldwide. Its underlying pathogenesis includes maladaptive immune response and unbalanced lipid metabolism, including chronic in ammation of the arterial wall. Lipid accumulation and immune response are formed by homeostasis controlled by leukocyte transport and chemokines and their receptors 1 . Current studies have shown that plasma Hypersensitive C-reactive protein(hs-CRP) is a sensitive and nonspeci c biomarker of in ammatory response, re ecting plaque stability and vascular endothelial injury, and a predictor of cardiovascular risk 2 . In addition, High density lipoprotein cholesterol(HDL-C) is considered the so-called 'good cholesterol', largely based on epidemiological studies showing a negative correlation between lower HDL-C levels and an increased risk of CAD and myocardial infarction 3 . Hs-CRP and HDL-C are both important in the process of atherosclerosis. Recent studies had suggested that the in uence of coronary heart disease by 8.27% with dyslipidemia was mediated by the hs -CRP levels 4 .
However, no study has directly combined HDL-C and hs-CRP, two biological indicators, to explore the degree of coronary artery stenosis. Therefore, this study suggested that hs-CRP as a marker of in ammation persistence and HDL-C as an anti-atherosclerosis component should be integrated into a single biomarker CHR,so as to explore the correlation of CHR with CAD degree and to predict the severity of coronary stenosis among CAD patients.

Study design and participants
A retrospective evaluation of 360 subjects (152 males, 42.2%) who underwent coronary angiography at Sichuan Provincial People's Hospital from June 2018 to June 2020 for suspected or known coronary atherosclerosis was performed.The current work was in accordance with the principles of the Declaration of Helsinki. All patients with coronary stent implantation, acute coronary Syndrome (ACS), coronary artery bypass surgery, liver and kidney disease, in ammatory disease, congenital heart disease, severe heart failure, valvular heart disease, blood diseases, rheumatic diseases, malignant tumors, alcohol use and and infectious diseases were excluded. Based on the results of coronary angiography, patients with any major coronary arteries (left anterior descending artery, left circum ex artery, left main coronary artery, right coronary artery) whose lumen diameter reduced by more than 50% were classi ed as CAD + group.Patients with luminal stenosis but no more than 50% were classi ed as CAD − group, and patients without luminal stenosis were regarded as control group. Patients with diffuse coronary artery involvement but no stenosis were excluded.

Clinical data and De nitions
Serological indicators such as creatinine, uric acid, neutrophils,albumin, bilirubin, triglyceride, total cholesterol, high-density lipoprotein cholesterol (HDL-C), albumin, low-density lipoprotein cholesterol (LDL-C), the estimated glomerular ltration rate (eGFR), and Hypersensitive C-reactive protein(hsCRP) were collected.Height and weight were collected to calculate body mass index (BMI), which was counted as weight divided by height squared, weight in kilograms and height in meters. The ratio of hypersensitive C-reactive protein to HDL and the ratio of neutrophils to HDL were calculated. Hypertension was de ned as blood pressure ≥ 140 mmHg and/or a diastolic blood pressure ≥ 90 mmHg taken from at least threetimes, or they were being given antihypertensive drugs. Those who had been diagnosed with hypertension in the past were all de ned as having a history of hypertension. Patients were considered to have diabetes if their fasting glucose level ≥ 7.0 mmol/ L or fasting glucose level ≥ 11.1 mmol/ L or plasma glucose-lowering drugs use. Current smokers were de ned as those who smoked at least one cigarette a day for more than one year in a row; long-term smokers who still quit smoking for less than six months were still considered to have a history of smoking.

Assessment of the severity of CAD
When measuring the degree of obstuction on lumenogram, a comprehensive judgment was made by two experienced professional doctors blindly.The modi ed Gensini score (GS) system is a relatively mature evaluation system to measure CAD severity prospectively 5 . This was done by multiplying the sum of the positional scores of each lesion by the obstruction severity score, which re ected the severity of the disease. The detailed calculation of the modi ed Gensini scoring system is shown in Table 1. the Kruskal-Wallis test was performed to compare the differences of the non-conforming measurement data. The chi-square test was used when comparing categorical variables. The correlation between Gensini score and serum indexes was analyzed by Pearson or Spearman correlation coe cient, and the Spearman correlation coe cient was calculated. Binary logistic regression analysis was applied to evaluate the independent predictors of the severity of coronary artery disease. Univariate logistic regression models were rst performed to assess the crude association between the severity of coronary stenosis and each index, including the ratio of hsCRP to high-density lipoprotein(CHR),the ratio of neutrophils to high-density lipoprotein (NHR), age, sex, smoking, hypertension, albumin, creatinine, uric acid, HDL cholesterol, LDL cholesterol, neutrophils and hs-CRP individually. Factors that were signi cant in the univariate model at the p < 0.10 level were enrolled in the multivariate logistic regression model so as to detect factors independently related to the presence of coronary artery stenosis. The backward stepby-step approach was used to build the nal prediction model which included all the statistically signi cant factors(P < 0.05). A receiver operating characteristic (ROC) curve was given to compare the diagnostic accuracy of CHR and NHR. Regression coe cients and 95% con dence intervals (CIs) for risk factors signi cantly associated with CAD were obtained. All statistical analyses were performed on SPSS 25.0 for Mac and all statistical tests were double-sided. P value < 0.05 was de ned as statistically signi cant.

Results
A total of 360 patients were included in our research. Baseline demographic and biochemical characteristics of all patients were presented in Table 2. The study included 139 patients with CAD (CAD + group, 54.7% males), 41 patients with atherosclerosis (CAD − group,34.1% males), and 180 patients with normal arterial status (control group, 34.4% males). The smoking incidence, diabetes incidence, hypertension incidence, creatinine, neutrophil levels and hsCRP levels in CAD + group were clearly higher than that in CAD − group and control group (P < 0.05, respectively). Compared with the CAD − group, the Gensini score in the CAD + group was signi cantly higher (P < 0.05). However, the levels of HDL-C and albumin in the CAD + group were lower than those in the CAD − group (P < 0.05). The age and gender differences among the three groups were statistically signi cant, and the average age of patients in the CAD + group was higher than that in control group (P < 0.001). The proportion of males in the CAD + group was apparently higher than that in the CAD − group and control group (P < 0.05, respectively). There were no signi cant differences in BMI, uric acid, bilirubin, total cholesterol, triglyceride and LDL-C among the three groups (P > 0.05, respectively). Spearman rank correlation analysis was applied to elucidate the relationship between various risk factors and the modi ed Gensini score in patients with coronary atherosclerotic heart disease. The correlation coe cient was shown in Table 3. The results indicated that the Gensini score was positively correlated with CHR,NHR, neutrophils, hsCRP,LDL-C, sex, smoking, and hypertension, while Gensini score was negatively correlated with albumin, eGFR, HDL-C. Gensini score was not correlated with creatinine, uric acid, bilirubin, total cholesterol, triglycerides, or diabetes. The scatter diagram is shown in Fig. 1. To further explore the possible risk factors for coronary artery stenosis, univariate and multivariate logistic regression analyses were applied (Table 4). Univariate Logistic regression analyses showed that risk factors associated with CAD included CHR,NHR, hsCRP, smoking, hypertension, diabetes mellitus, gender, age, creatinine, albumin, HDL-C, neutrophils, and eGFR (p < 0.05). Additionally, after adjusting for all covariates, multiple regression analyses showed that CHR,NHR, age, sex, and diabetes were signi cantly correlated with CAD. Consequently, CHR is an independent predictor of CAD,as well as NHR.The ROC analysis displayed that the critical value of NHR was 1.17, 83.9% of speci city and 0.242 of Yoden index could predict CAD, and the area under the ROC curve was 0.632 (95%CI 0.571-0.694, P < 0.001). At the same time, the area under the ROC curve of NHR was 0.620, indicating that CHR as a predictor of CAD has better diagnostic performance than NHR, as shown in Fig. 2.

Discussion
In our study, the results showed that increased CHR levels were closely related to the degree of coronary artery stenosis. And we also found that CHR was an independent predictor of CAD.As far as we know, our study is the rst research to investigate whether CHR is associated with CAD severity of coronary artery disease. A total of 360 patients were included in our work, and the results showed that CHR (OR: 0.904, 95%CI: 0.819-0.998), NHR, age, male, and history of diabetes were independent risk factors for CAD. we also demonstrate that elevated CHR levels are a predictor of severity of coronary artery disease and perform better than NHR in terms of diagnostic e cacy.
In recent years, with the rapid economic development, the change of lifestyle and the adoption of unhealthy diet cardiovascular disease has been the " rst killer" of human health 6 , seriously threatening the life expectancy and quality of life of people all over the world 7 . In Europe, more than 4 million people die each year from cardiovascular disease (CVD) 8 . The incidence of cardiovascular disease (CVD) in China is also on the rise. At present, there are about 290 million people with cardiovascular diseases in China, including 11 million patients with coronary heart disease 9 . Therefore, for patients with chest pain, assessing the severity of coronary artery stenosis is a necessary prerequisite for preventing and controlling cardiovascular disease progression, and helps clinicians develop individualized, comprehensive treatment strategies to improve patients' quality of life 10 .
In fact, the pathophysiological process of CAD is mainly atherosclerosis, in which dyslipidemia and chronic in ammation of the arteries as well as various in ammatory factors play a central role 11 . Studies have shown that hs-CRP levels and dyslipidemia have a synergistic effect in the pathogenesis of CAD, and the association between dyslipidemia and CAD seems to be strengthened by the increased hs-CRP levels. Mediation analysis showed that the effect of dyslipidemia on CHD is 8.27% mediated by hs-CRP levels, and the direct effect is 0.621 4 . To our knowledge, however, no study has directly combined HDL-C and hs-CRP, two biological indicators, to explore the degree of coronary artery stenosis. In ou work, we assumed that CHR is a biomarker composed of in ammation marker and lipid cholesterol marker. through univariate and multivariate analysis, we explored many factors related to CAD. the results show that CHR is positively correlated with Gensini score. after adjusting for confounding factors, we nd that CHR is an independent predictor of CAD disease.In addition, our study also found that THE speci city of CHR cut-1.17 for predicting CAD was 83.9%.
Based on our analysis, we attempted to interpret the results associated with increased CHR and severity of coronary artery stenosis.hs-CRP is a blood biomarker produced by the liver, representing acute systemic in ammation, and is considered a perfect marker for assessing systemic in ammation because its serum level does not change with circadian rhythm within 24 hours and does not change with food intake 12 . hs-CRP is widely used in clinical practice, especially in cerebrovascular and cardiovascular diseases 13 . hs-CRP is considered as a risk factor of cardiovascular diseases and can increase the mortality of cardiovascular diseases 14,15 . CRP is involved in the pathogenesis and development of vascular in ammation and coronary atherosclerosis 16 .It directly affects complement activation, apoptosis, vascular cell activation, monocyte recruitment, lipid accumulation, and thrombosis and other atherosclerotic processes 17,18 . Epidemiological meta-analysis showed that hs-CRP > 3.0 mg/dL compared to < 1.0 mg/dL increased the risk of CAD by 1.6 times, and the hs-CRP levels were positively associated with the severity of coronary heart disease, which increase with the increase of lesion count 19 . Therefore, plasma hs-CRP has become a sensitive biomarker of in ammation 2 ,which is of great signi cance to predict the stability of coronary plaque in coronary heart disease, the severity of vascular disease, restenosis of coronary arteries after coronary angioplasty, and the incidence of cardiovascular events 9 .
Our results showed that the levels of hs-CRP in the CAD + group were signi cantly higher than those of the CAD − group and control group, and Gensini score was positively related to hs-CRP, which was also consistent with previous studies 20 .
Dyslipidemia is viewed as a necessary condition for atherosclerosis, and studies have shown that dyslipidemia may account for 50% of the attributable risk in patients with CAD. Therefore, recent studies on the correlation between lipid biomarkers and coronary heart disease have become the focus 21 . HDL-C, as a typical lipid related biomarker, plays an important protective role in the process of atherosclerosis and in ammation due to its anti-oxidant, anti-in ammatory, anti-apoptotic and anti-thrombotic properties [22][23][24] . HDL-C has been shown to regulate cholesterol e ux, protect vascular endothelium, stabilize plaque, and prevent rupture [25][26][27] . In addition, HDL reduces in ammation by inhibiting the expression of adhesion molecules in endothelial cells and reduces coronary atherosclerosis by inhibiting the oxidation of low-density lipoprotein 28,29 . Therefore, HDL-C, on the one hand, inhibits the progression of atherosclerosis and on the other hand promotes plaque regression 30 . It had been estimated that for each increment of 1 mg/dL in HDL-C, the CAD risk was reduced by 2% in males and by 3% in females 31,32 . Current evidence suggested an inverse correlation between HDL-C levels and CAD, myocardial infarction, carotid atherosclerosis, and stroke.Increased HDL levels can prevent coronary heart disease 24,33 .
In conclusion, due to the interaction between decreased HDL-C and increased CRP in CAD, increased CHR may be associated with in ammatory activity and dyslipidemia. In addition, a comprehensive CHR indicator may be more effective and reliable than a single indicator in explaining the complex interactions between CRP and HDL-C. As far as we know, there was no study to discuss the relationship between CHR and the degree of coronary artery disease. In our work, we directly explored the correlation between the severity of coronary artery disease and conducted regression analysis on the predictors of multiple indicators, which was our advantage. Studies have shown that NHR was correlated with the degree of coronary artery disease 34 . In our work, CHR, as a new predictor for patients with coronary heart disease, has more diagnostic advantages than NHR in evaluating the severity of coronary artery stenosis. This may be because hs-CRP is more sensitive than neutrophils in detecting low-grade in ammation.
The modi ed Gensini score is an reliable marker for assessing the severity of coronary artery disease. Some experts found that patients with severe CAD were grouped according to the modi ed Gensini score, and the results indicated that there were signi cant differences between the highly rated groups and other groups 35,36 . In our work, CHR was positively correlated with the modi ed Gensini score, suggesting that patients with relatively high CHR may have more severe coronary stenosis, and that CHR may be useful in predicting the severity of the lesion.
In conclusion, we believe that CHR may preliminarily re ect the severity of coronary artery, so as to better guide clincal practice. However, our work had some limitations. First, this was a single-center retrospective design, and the type of study had determined its limitations; In addition, we did not apply a China-PAR(prediction for ASCVD risk in China) model to explore the correlation between CHR and MACE events. In future work, we will expand the sample size for multi-center discussion.

Conclusion
We found that CHR was not only closely related to the degree of coronary artery stenosis, but also an independent predictor of severe coronary artery stenosis. Different from many other biological indicators, CHR can be calculated from the complete blood count at admission, which is fast and convenient. It can be used as a simple and effective auxiliary indicator for the prediction and assessment of coronary artery stenosis, and may have certain clinical application value.