Association between circulating monocytes and coronary plaque progression in patients with acute myocardial infarction

Monocyte to high-density lipoprotein ratio is associated with mortality in patients with coronary artery diseases

BACKGROUND

Whether the monocyte to high-density lipoprotein ratio (MHR) is associated with the prognosis of coronary artery disease (CAD) is inconclusive.

METHODS

Patients with CAD were enrolled and their data were collected. Blood was sampled within 24 h after admission. Multivariate Cox regression analysis was performed to determine the relationship between the MHR and all-cause mortality as well as complications during hospitalization.

RESULTS

We included 5371 patients in our cohort study. Among them, 114 (2.12%) patients died in hospital. MHR was independently associated with all-cause mortality (hazard ratio [HR], 1.81; 95% confidence interval [CI] 1.35, 2.42), cardiovascular mortality (1.69; 1.17, 2.45) and non-cardiovascular mortality (2.04; 1.27, 3.28). This association was only observed in patients with hypertension (P for interaction = 0.003). Patients with higher MHR levels also have a higher risk of complications, including infection, pneumonia, electrolyte disturbance, gastrointestinal bleeding, multiple organ dysfunction syndrome, and disturbance of consciousness. The receiver operating characteristic (ROC) analysis showed that the MHR had higher prognostic values than monocytes and high-density lipoprotein.

CONCLUSION

MHR was an independent predictor of all-cause mortality and in-hospital complications in patients with CAD, especially in patients with hypertension.

Association between monocyte to high-density lipoprotein cholesterol ratio and multi-vessel coronary artery disease: a cross-sectional study

BACKGROUND

Patients with multi-vessel coronary artery disease (MV-CAD) have poorer clinical outcomes than those with single-vessel coronary artery disease (SV-CAD). Solid evidence underlines that high-density lipoprotein cholesterol (HDL-C) plays a protective role and monocyte plays a negative role in coronary artery disease (CAD). However, the monocyte to high-density lipoprotein ratio (MHR) has not been studied in relation to MV-CAD.

METHODS

In this study, 640 patients underwent coronary angiography, of whom 225 had severe coronary artery disease. Then divide the above two groups of patients into three groups based on the MHR tertiles, respectively. Logistic regression and subgroup analysis were carried out to estimate the association between MHR and MV-CAD. The receiver operating characteristic (ROC) curve analysis was constructed by combining classic CAD risk factors with MHR in response to MV-CAD. In addition, the mediating effect of MHR between smoking and MV-CAD in suspected CAD Patients was analyzed.

RESULTS

Among the three MHR groups, a statistically discrepant was observed in the number of patients with CAD, Severe-CAD and MV-CAD (PCAD < 0.001; PSevere-CAD < 0.001; PMV-CAD = 0.001) in suspected CAD patients. Furthermore, the number of patients with MV-CAD (P < 0.001) was different in Severe-CAD patients among three MHR groups. Non-CAD and CAD patients showed statistically discrepant in MHR levels (P < 0.001), and this difference also was observed between SV-CAD and MV-CAD patients (P < 0.001). In the analysis of suspected CAD patients, a significantly positive relationship was found between MHR and CAD, Severe-CAD, and MV-CAD (P for trend < 0.001). The effect of MHR on MV-CAD was consistent across all subgroups, with no significant randomized factor-by-subgroup interaction (P-interaction = 0.17-0.89). ROC analysis showed that the model constructed with MHR and classic influencing factors of CAD was superior to the model constructed solely based on classic influencing factors of CAD (0.742 vs.0.682, P = 0.002). In the analysis of Severe-CAD patients, patients with higher MHR levels had a higher risk of MV-CAD [OR (95%CI): 2.90 (1.49, 5.62), P for trend = 0.002] compared to patients with lower MHR. The trends persisted after adjusting for demographic (P for trend = 0.004) and classic influencing factors of CAD (P for trend = 0.009). All subgroup factors for patients with MV-CAD had no interaction with MHR (P-interaction = 0.15-0.86). ROC analysis showed that the model combining MHR and classic influencing factors of CAD was superior to the one including only the classic influencing factors of CAD (0.716 vs.0.650, P = 0.046). Assuming that MHR played a mediating effect between smoking and MV-CAD in suspected CAD patients. The results indicated that MHR played a partial mediating effect of 0.48 (P < 0.001).

CONCLUSION

A higher MHR was mainly associated with multi-vessel coronary artery disease and MHR partially mediated the association between smoking and MV-CAD.

Immunophenotyping of Monocyte Migration Markers and Therapeutic Effects of Selenium on IL-6 and IL-1β Cytokine Axes of Blood Mononuclear Cells in Preoperative and Postoperative Coronary Artery Disease Patients

Multivessel coronary artery disease (CAD) is characterized by underlying chronic vascular inflammation and occlusion in the coronary arteries, where these patients undergo coronary artery bypass grafting (CABG). Since post-cardiotomy inflammation is a well known phenomenon after CABG, attenuation of this inflammation is required to reduce perioperative morbidity and mortality. In this study, we aimed to phenotype circulating frequencies and intensities of monocyte subsets and monocyte migration markers, respectively, and to investigate the plasma level of inflammatory cytokines and chemokines between preoperative and postoperative CAD patients and later, to intervene the inflammation with sodium selenite. We found a higher amplitude of inflammation, postoperatively, in terms of CCR1high monocytes and significantly increased pro-inflammatory cytokines, IL-6, IL-8, and IL-1RA. Further, in vitro intervention with selenium displayed mitigating effects on the IL-6/STAT-3 axis of mononuclear cells derived from postoperative CAD patients. In addition, in vitro selenium intervention significantly reduced IL-1β production as well as decreased cleaved caspase-1 (p20) activity by preoperative (when stimulated) as well as postoperative CAD mononuclear cells. Though TNF-α exhibited a positive correlation with blood troponin levels in postoperative CAD patients, there was no obvious effect of selenium on the TNF-α/NF-κB axis. In conclusion, anti-inflammatory selenium might be utilized to impede systemic inflammatory cytokine axes to circumvent aggravating atherosclerosis and further damage to the autologous bypass grafts during the post-surgical period.

Acute coronary syndrome screening in patients presenting with arteriosclerosis in health check-ups: a case-control study

OBJECTIVES

This research aimed to develop a simple and effective acute coronary syndrome (ACS) screening model in order to intervene early and focus on prevention in patients presenting with arteriosclerosis.

DESIGN

A case-control study.

SETTING

The study used a cross-sectional survey to collect data from 2243 patients who completed anonymous electronic medical record (EMR) data and coronary angiography was gathered at a hospital in Shandong Province between December 2013 and April 2016.

PARTICIPANTS

Adults 18 years old and above diagnosed as ACS or non-ACS according to the records in hospital EMR database, and with completed basic information (age and sex).

PREDICTORS

54 laboratory biomarkers and demographic factors (age and sex).

STATISTICAL ANALYSIS

A dataset without missing data of all patients' laboratory indicators and demographic factors was divided into training set and validation set after being balanced. After the training set balanced, area under the curve of random forest (AUCRF) and least absolute shrinkage and selection operator (LASSO) regression were used for feature extraction. Then two set random forest models were established with the different feature sets, and the process of comparison and analysis was made to evaluate models for the optimal model including sensitivity, accuracy and AUC receiver operating characteristic curves with the internal validation set.

MAIN OUTCOME MEASURES

To establish an ACS screening model.

RESULTS

An RF model with 31 features selected by LASSO with an AUC of 0.616 (95% CI 0.650 to 0.772), a sensitivity of 0.832 and an accuracy of 0.714 in the validation set. The other RF model with 27 features selected by AUCRF with an AUC of 0.621 (95% CI 0.664 to 0.785), a sensitivity of 0.849 and an accuracy of 0.728 in the validation set.

CONCLUSIONS

The established ACS screening model with 27 clinical features provides a better performance for practical solution in predicting ACS.

Elevated monocyte-to-HDL cholesterol ratio predicts post-stroke depression

OBJECTIVES

Inflammation plays an important role in the development of depression after stroke. Monocyte-to-HDL Cholesterol Ratio (MHR) recently emerged as a novel comprehensive inflammatory indicator in recent years. This study aimed to investigate whether there is a relationship between MHR levels and post-stroke depression (PSD).

METHODS

From February 2019 to September 2021, patients with acute ischemic stroke (AIS) were recruited within 7 days post-stroke from the two centers and blood samples were collected after admission. The 17-item Hamilton Depression Scale (HAMD-17) was used to measure depressive symptoms at 3 months after stroke. Patients were given the DSM-V criteria for diagnosis of PSD.

RESULTS

Of the 411 enrolled patients, 92 (22.38%) patients were diagnosed with PSD at 3-months follow-up. The results also showed significantly higher level of MHR in patients with depression [0.81 (IQR 0.67-0.87) vs. 0.61 (IQR 0.44-0.82), P < 0.001] at admission than patients without depression. Multivariate logistic regression revealed that MHR (OR 6.568, 95% CI: 2.123-14.565, P = 0.015) was an independent risk factor for the depression at 3 months after stroke. After adjustment for potential confounding factors, the odds ratio of PSD was 5.018 (95% CI: 1.694-14.867, P = 0.004) for the highest tertile of MHR compared with the lowest tertile. Based on the ROC curve, the optimal cut-off value of MHR as an indicator for prediction of PSD was projected to be 0.55, which yielded a sensitivity of 87% and a specificity of 68.3%, with the area under the curve at 0.660 (95% CI: 0.683-0.781; P = 0.003).

CONCLUSION

Elevated level of MHR was associated with PSD at 3 months, suggesting that MHR might be a useful Inflammatory markers to predict depression after stroke.

Investigating the relationship between the severity of coronary artery disease and inflammatory factors of MHR, PHR, NHR, and IL-25

Background: Coronary artery disease (CAD), as a most common cause of death, is mainly caused by atherosclerosis. Due to the role of inflammation in the process of atherosclerosis, in the present study, the relationship between the severity of coronary artery disease and inflammatory factors of monocyte to HDL-C ratio (MHR), platelet-to-HDL-C ratio (PHR), neutrophil to HDL-C ratio (NHR), and IL-25 was investigated.

Methods: In this cross-sectional study, 64 patients with diagnosis of coronary artery disease who were undergoing angiography in Farshchian heart center in Hamadan were studied. For each patient, the count of monocytes, neutrophils, platelet, and HDL-C, and IL-25 were measured from their blood and serum samples. Also, demographic information, such as age, gender, diabetes, smoking, and history of hypertension, was collected using a checklist. Data were described using frequency, percent, mean, and standard deviation. Statistical analysis was performed using independent t test, Mann-Whitney, Wilcoxon, and Spearman rank correlation tests, and multiple linear regression by SPSS version 25.0 SPSS Inc). P <.05 was considered as significant.

Results: The results of this study showed that IL-25 and MHR index has a significant correlation with coronary artery disease and Gensini score (P ˂.001). The PHR index was associated with coronary artery disease. Also, qualitative variables, such as history of hypertension, history of smoking, and gender, have a significant association with the severity of coronary artery disease (P <.05).

Conclusion: Among the inflammatory markers examined, IL-25 and MHR are stronger markers for assessing the severity of coronary artery disease. Simple and available IL-25 and MHR measurements may be able to, along with common risk factors and lipid profiles, predict the amount of vascular occlusion in treatment centers as an alternative of angiography as well as screening high risk patients prone to cardiovascular disease.

A Correlation Between Monocyte to Lymphocyte Ratio and Long-Term Prognosis in Patients With Coronary Artery Disease After PCI

Monocyte to lymphocyte ratio (MLR) has been confirmed as a novel marker of poor prognosis in patients with coronary heart disease (CAD). However, the prognosis value of MLR for patients with CAD after percutaneous coronary intervention (PCI) needs further studies. In present study, we aimed to investigate the correlation between MLR and long-term prognosis in patients with CAD after PCI. A total of 3,461 patients with CAD after PCI at the First Affiliated Hospital of Zhengzhou University were included in the analysis. According to the cutoff value of MLR, all of the patients were divided into 2 groups: the low-MLR group (<0.34, n = 2338) and the high-MLR group (≥0.34, n = 1123). Kaplan–Meier curve was performed to compare the long-term outcome. Multivariate COX regression analysis was used to assess the independent predictors for all-cause mortality, cardiac mortality and MACCEs. Multivariate COX regression analysis showed that the high MLR group had significantly increased all-cause mortality (ACM) [hazard ratio (HR) = 1.366, 95% confidence interval (CI): 1.366-3.650, p = 0.001] and cardiac mortality (CM) (HR = 2.379, 95%CI: 1.611-3,511, p < 0.001) compared to the low MLR group. And high MLR was also found to be highly associated with major adverse cardiovascular and cerebrovascular events (MACCEs) (HR = 1.227, 95%CI: 1.003-1.500, p = 0.047) in patients with CAD undergoing PCI. MLR was an independent predictor of ACM, CM and MACCEs in CAD patients who underwent PCI.

Long-Term Clinical Outcomes After Filter Protection During Percutaneous Coronary Intervention in Patients With Attenuated Plaque - 1-Year Follow up of the VAMPIRE 3 (Vacuum Aspiration Thrombus Reemoval 3) Trial

BACKGROUND

Selective use of distal filter protection during percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) decreased the incidence of no-reflow phenomena and in-hospital serious adverse cardiac events compared with conventional PCI in patients with attenuated plaque ≥5 mm; however, its long-term clinical outcome remains unknown.Methods and Results:Patients who had ACS with attenuated plaque ≥5 mm were assigned to receive distal protection (DP) (n=98) or conventional treatment (CT) (n=96). The rate of major adverse cardiovascular events (MACE), a composite of death from any cause, non-fatal myocardial infarction, or target vessel revascularization (TVR) at 1 year, was the pre-specified secondary endpoint of the trial. MACE at 1 year occurred in 12 patients (12.2%) in the DP group and 3 patients (3.1%) in the CT group (P=0.029), which was driven by a higher risk of TVR (11 [11.2%] vs. 2 [2.1%], P=0.018). In patients treated with bare-metal stents (n=42), MACE occurred in 25.0% of the patients in the DP group and in none of the patients in the CT group (P=0.029), whereas in patients treated with drug-eluting stents (n=151), rates of MACE were similar in the groups (8.1% vs. 3.9%, P=0.32).

CONCLUSIONS

In ACS patients with attenuated plaque ≥5 mm, the 1-year rates of MACE were higher in the DP group than in the CT group. This effect might be mitigated by the use of drug-eluting stents.

Variables associated with subclinical atherosclerosis among rheumatoid arthritis patients of Gulf Cooperative Council countries

OBJECTIVES

To evaluate the cardiovascular disease (CVD) as demonstrated by carotid intima-media thickness (cIMT) and the cluster risk factors of CVD including traditional and non-traditional, urinary functions, iron buildup, and hemorheology in rheumatoid arthritis (RA) patients of Gulf Cooperative Council (GCC) countries.

METHODS

Carotid intima-media thickness was obtained from 216 RA patients, free of atherosclerotic diseases. The correlation between cIMT and the possible CVD risk factors was carried out using regression analysis. Results: The mean cIMT was observed as 0.58±0.11 mm. Mean age was 48±13 years. Univariate analysis revealed a positive association (p less than 0.05) between cIMT and age, body mass index, systolic blood pressure (SBp), and diastolic blood pressure, c-reactive protein (CRP), triglycerides (TG), low-density lipoprotein (LDL), erythrocyte sedimentation rate (ESR), hemoglobin (Hb), hematocrit (Hct), mean cell volume, platelet, monocytes, eosinophils, ferritin, creatinine, and uric acid. Negative relationship was observed between cIMT and glomerular filtration rate (GFR), transferrin, and high-density lipoprotein. Multiple linear regression analysis exhibited a positive association between cIMT and the age, LDL, eosinophil, SBp, and the ESR, whereas, negative connection with the GFR and transferrin. Conclusion: In this study, we found that the eosinophils, and low transferrin, are the potential candidates for the CVD risk factors in RA patients. Fasting blood glucose level was also observed to be a significant risk factor in diabetic as well as non-diabetic RA. The remaining CVD risk factors in RA patients of GCC countries including older age, high SBp, ESR, LDL, and low GFR were similar to the international population.

Inflammation and Coronary Heart Disease Risk in Patients with Depression in China Mainland: A Cross-Sectional Study

OBJECTIVE

The risk of coronary heart disease (CHD) in patients with major depressive disorder (MDD) is higher than that in the general population. However, the mechanisms underlying the increased CHD risk in patients with MDD remain unclear. Inflammation plays an important role in the pathogenesis of MDD and CHD. Therefore, we explored the relationship between inflammatory biomarkers and CHD risk in patients with MDD.

METHODS

We included 454 patients with acute MDD and 458 controls that matched the sample in age and gender. A readily available complete blood count was used to reflect inflammation, and the risk of CHD was assessed using the Framingham risk score.

RESULTS

The results showed that patients with MDD showed low-grade inflammation with an elevated platelet (p<0.001) and monocyte count (p<0.001), high platelet/lymphocyte (p=0.003) and monocyte/lymphocyte ratios (p<0.001), and a raised systemic immune-inflammation index (p=0.002). In addition, monocyte count was the only factor significantly associated with CHD risk in patients with MDD (B=7.521, 95% CI: 3.409-11.633, t=3.594, p<0.001).

CONCLUSION

Collectively, the results of this study support the hypothesis that MDD is systemic inflammation, and suggest that monocyte count predicts the risk of CHD in patients with MDD.

Differences in Monocyte Subsets and Monocyte-Platelet Aggregates in Acute Myocardial Infarction-PreliminaryResults

BACKGROUND

Monocyte-platelet interaction may favor the development of a proatherogenic monocyte phenotype. It is still uncertain which of the 3 monocyte subpopulations interact with platelets to form monocyte-platelet aggregates (MPAs) in acute myocardial infarctions. The aim of our study was to evaluate the monocyte subsets, the percentage of MPAs and the involvement of monocyte subsets in MPA formation among patients with ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI), and compared to patients with stable angina (SA).

METHODS

Monocyte subsets and MPAs formation were measured in blood collected in 3.2% sodium citrate tubes by means of flow cytometry.

RESULTS

Classical, intermediate and nonclassical monocyte percentages were statistically different when comparing patients with STEMI and NSTEMI. Moreover, classical and intermediate monocytes were statistically different when comparing the STEMI and SA group; however, only the classical monocyte subset was found to be higher in the acute myocardial infarction group compared to the SA group. The percentage of MPAs was significantly higher in STEMI (50.1%) compared to NSTEMI (22.9%). We found no differences in the involvement of monocyte subsets in MPA formation between patients with STEMI and NSTEMI and in comparison with the SA group.

CONCLUSIONS

These findings suggest that the increase in circulating levels of classical monocytes in patients with STEMI as compared to NSTEMI reflects the severity of the acute event. The increased percentage of MPAs may favor the development of STEMI compared to NSTEMI.

Circulating CD14+CD16- classical monocytes do not associate with a vulnerable plaque phenotype, and do not predict secondary events in severe atherosclerotic patients

AIMS

Mouse studies have established distinct monocyte subtypes that participate in the process of atherosclerotic lesion formation. The pro-inflammatory Ly6C^high monocyte subtype actively contributes to murine plaque progression and destabilization. Also in humans, different peripheral monocyte subtypes have been identified, of which the CD14⁺CD16^- classical monocyte is suggested to display similar pro-atherosclerotic properties as the murine Ly6C^high subtype. We aimed to investigate if circulating CD14⁺CD16^- classical monocytes associate with characteristics of a vulnerable carotid atherosclerotic plaque and if they associate with the risk of secondary adverse manifestations of atherosclerotic disease.

METHODS AND RESULTS

We enrolled 175 carotid endarterectomy patients of the Athero-Express biobank in our study. Just prior to surgical procedure, blood was collected and peripheral blood mononuclear cells were isolated. Characterization of monocyte subsets was performed by flow cytometry. Plaque characteristics were semi-quantitatively scored for the presence of fat, collagen, intraplaque hemorrhage and calcification. Vessel density, smooth muscle cells and macrophages were assessed quantitatively on a continuous scale. All features of a vulnerable plaque phenotype, including low amounts of collagen and smooth muscle cells, and increased fat content, vessel density, intraplaque hemorrhage and plaque macrophages were not significantly associated with differential levels of peripheral classical CD14⁺CD16^- monocytes or other monocyte subsets. Using Cox regression models to evaluate the prognostic value of circulating monocyte subtypes, we found that total counts of peripheral monocytes, as well as CD14⁺CD16^- classical and other monocyte subtypes were not associated with the risk of secondary cardiovascular events during 3 years follow-up.

CONCLUSION

Circulating classical CD14⁺CD16^- monocytes do not associate with specific vulnerable plaque characteristics. In addition, they do not predict secondary adverse manifestations. This suggests that in patients with established carotid artery disease, the circulating monocytes do not reflect plaque characteristics and have no value in identifying patients at risk for future cardiovascular events.

Prolonged Fever After ST-Segment Elevation Myocardial Infarction and Long-Term Cardiac Outcomes

Background

The biphasic inflammation after ST‐segment elevation myocardial infarction (STEMI) plays an important role in myocardial healing and progression of systemic atherosclerosis. The purpose of this study is to investigate the impact of fever during the first and second phases of post‐STEMI inflammation on long‐term cardiac outcomes.

Methods and Results

A total of 550 patients with STEMI were enrolled in this study. Axillary body temperature (BT) was measured and maximum BTs were determined for the first (within 3 days: max‐BT_1–3d) and second (from 4 to 10 days after admission: max‐BT_4–10d) phases, respectively. Patients were followed for cardiac events (cardiovascular death, acute coronary syndrome, and rehospitalization for heart failure) for a median 5.3 years. During the follow‐up period, 80 patients experienced cardiac events. A high max‐BT_4–10d was strongly associated with long‐term cardiac events (hazard ratio, 95% CI) for a 1°C increase in the max‐BT_4–10d: 2.834 (2.017–3.828), P<0.0001, whereas the max‐BT_1–3d was not associated with cardiac events (1.136 [0.731–1.742], P=0.57). Even after adjustment for coronary risk factors, estimated glomerular filtration rate, infarct size, pericardial effusion, and medications on discharge, fever during the second phase (max‐BT_4–10d ≥37.1°C) was significantly associated with future cardiac events (hazard ratio [95% CI] 2.900 [1.710–5.143], P<0.0001).

Conclusions

Fever during the second phase but not the first phase of post‐STEMI inflammation was a strong associated factor with worse long‐term cardiac outcomes in patients after STEMI, suggesting the need to consider the optimal timing for anti‐inflammatory strategies after STEMI.

Prognostic Value of Circulating Inflammatory Cells in Patients with Stable and Acute Coronary Artery Disease

Atherosclerosis is a lipid driven chronic inflammatory disease underlying the majority of ischemic events such as myocardial infarction or stroke. Clinical management of ischemic events has improved considerably in the past decades. Accordingly, survival rates have increased. Nevertheless, 12% of patients die within 6 months after the initial event. To improve secondary prevention, appropriate risk prediction is key. However, up to date, there is no clinically available routine marker to identify patients at high risk for recurrent cardiovascular events. Due to the central role of inflammation in atherosclerotic lesion progression and destabilization, many studies have focused on the role of circulating inflammatory cells in these processes. This review summarizes the current evidence on the potential of circulating inflammatory cells as biomarkers for recurrent adverse manifestations in acute coronary syndrome and stable coronary artery disease patients.

Monocyte subsets in myocardial infarction: A review

BACKGROUND

Monocytes form an important part of the human innate immune system by taking part in inflammatory reactions. With time, monocytes have gained interest in the role they may play during the event of myocardial infarction (MI). The current paradigm suggests that monocytes consist of three subdivisions which differ in phenotypic and dynamic patterns after an MI. In the inflammation that ensues, the different subsets have been shown to have an impact on reparative processes and patient recovery.

METHODS & RESULTS

We searched Medline and Embase until April 5, 2016, for observational studies or clinical trials regarding monocyte functions and dynamics in MI. Apart from studies in humans, extensive work has been done in mice in an effort to understand the complex nature of monocyte dynamics. Animal models might add useful information on mapping these processes.

CONCLUSION

The question still remains whether animal data can, to a certain degree, be extrapolated to monocyte functions during human MI. This review aims to summarize current available evidence on both mice and men with particular focus on the understanding of monocyte subsets dynamics and effects in human MI.

Prognostic significance of circulating leukocyte subtype counts in patients with coronary artery disease

BACKGROUND AND AIMS

This study investigated the association of leukocyte subtype counts with vascular endothelial dysfunction and future cardiovascular events in patients with coronary artery disease (CAD).

METHODS

The study included 389 consecutive CAD patients (259 male, 130 female; mean age, 70.1 ± 9.9 years). The patients underwent coronary angiography, and measurement of blood parameters, including leukocyte subtype counts.

RESULTS

There were 84 cardiovascular events during a mean follow-up of 586 ± 378 days. Kaplan-Meier analysis showed a higher probability of cardiovascular events in the high-monocyte group (≥360/mm³) compared with the low-monocyte group (<360/mm³) (log-rank test, p = 0.047). Multivariate Cox hazard analysis identified a high monocyte count as an independent predictor of cardiovascular events (hazard ratio: 1.63, 95% confidence interval:1.05-2.51, p = 0.028). Peripheral endothelial function in 355 of the CAD patients was assessed by reactive hyperemia peripheral arterial tonometry index (RHI) to examine the association of ln-RHI with leukocyte subtype counts. Total leukocyte, monocyte and neutrophil counts were significantly higher in CAD patients with low ln-RHI (<0.57: the mean ln-RHI value) compared with those with high ln-RHI (≥0.57). Univariate analyses revealed that ln-RHI in CAD patients was positively correlated with ln-total leukocyte (r = -0.187, p < 0.001), ln-monocyte (r = 0.316, p < 0.001), and neutrophil (r = -0.175, p = 0.001) counts. Multiple regression analysis showed that the monocyte count was a significant and independent factor associated with ln-RHI (adjusted R² = 0.126, p < 0.001).

CONCLUSIONS

A high monocyte count was an independent and incremental predictor of cardiovascular events in CAD patients. The monocyte count was also significantly correlated with peripheral endothelial dysfunction in CAD patients.

Association of the Monocyte to HDL Cholesterol Ratio With Thrombus Burden in Patients With ST-Segment Elevation Myocardial Infarction

Intracoronary thrombus burden is associated with some adverse events and poor prognosis in patients with ST-segment elevation myocardial infarction (STEMI). Identifying predictors of the intracoronary thrombus burden may contribute to the management of STEMI. In this study, we evaluated whether monocyte count to high-density lipoprotein cholesterol ratio (MHR) is a predictor of intracoronary thrombus burden in patients with STEMI. The study population consisted of 414 patients with STEMI who underwent primary percutaneous coronary intervention (PCI). Angiographic thrombus burden was classified based on thrombolysis in myocardial infarction (TIMI) thrombus grades. The patients were grouped into 2 categories of low thrombus burden and high thrombus burden. The MHR was significantly higher in the high thrombus burden group compared with the low thrombus group (16.0 [9.2-22.1] vs 25.4 [13.5-44.6]; P < .001). In multivariate logistic regression analysis, MHR was an independent predictor of high thrombus burden (odds ratio: 1.067, 95% CI: 1.031-1.105; P < .001). The area under the receiver–operating characteristic curve of the MHR was 0.688 (0.641-0.733; P < .001) to predict high thrombus burden. In conclusion, MHR was independent predictor of high thrombus burden in patients with STEMI who underwent primary PCI.

The Monocyte-to-Lymphocyte Ratio Correlates with Psycho-Neuro-Inflammatory Factors in Patients with Stable Coronary Artery Disease

BACKGROUND

Psychosocial stress and depression have been recognized as major risk factors of coronary artery disease (CAD). Although monocytes are known to be key players in atherosclerosis, monocyte-based associations with psychoneuroendocrino-immuno-inflammatory (PNI) markers have not been widely investigated in stable CAD.

OBJECTIVE

We examined associations between the monocyte-to-lymphocyte ratio (MLR) and key PNI markers in stable CAD.

METHODS

We studied 23 patients with stable CAD who completed the Beck Depression Inventory (BDI) and Rahe's Brief Stress and Coping Inventory. A white blood cell differential was performed, and levels of cortisol, chromogranin A (CgA), LL-37, interleukin-6 (IL-6) and C-reactive protein (CRP) were assayed in plasma.

RESULTS

Monocyte fraction, MLR and plasma CgA levels exceeded reference values, the social support score was low, and 7 patients had elevated BDI scores. In the multivariate-adjusted analysis, a higher MLR was associated with greater depressive symptom severity (r = 0.624, p < 0.01) as well as with higher concentrations of CgA (r = 0.660, p < 0.01), LL-37 (r = 0.643, p < 0.01), IL-6 (r = 0.532, p < 0.05) and CRP (r = 0.470, p < 0.05). BDI scores associated with CgA concentration (r = 0.618, p < 0.01) and CgA level correlated negatively with the social support score (r = -0.511, p < 0.05).

CONCLUSIONS

Our findings suggest that, in patients with stable CAD, elevated MLR may be associated with depressive symptoms, with increased neuroendocrine-sympathetic activity (marked by CgA) and inflammatory markers that are pertinent to atherosclerosis initiation and progression. The increased neuroendocrine-sympathetic activity correlated with low social support and depressive symptom severity. The MLR might serve as an easy-to-obtain and inexpensive proxy measure of an activated PNI network in stable CAD.

The Role of Different Monocyte Subsets in the Pathogenesis of Atherosclerosis and Acute Coronary Syndromes

The inflammation underlying both atherosclerosis and acute coronary syndromes is strongly related to monocyte-related actions. However, different monocyte subsets can play differential roles in the formation and destabilization of atherosclerotic plaque as well as healing of damaged myocardial tissue. Monocytes are currently being divided into three functionally distinct subsets with different levels of CD14 (cluster of differentiation 14) and CD16 expression. Thus, there are classical CD14++CD16-, intermediate CD14++CD16+ and non-classical CD14+CD16++ monocytes. Here, we summarize the current knowledge on complex activities of different monocyte subsets in atherosclerosis and acute coronary syndromes. Moreover, we discuss which monocyte subsets can serve either as predictive biomarkers of cardiovascular risk or as potential targets used in atherosclerosis and its complications.

Inflammation, plaque progression and vulnerability: evidence from intravascular ultrasound imaging

Increasing evidence points to a critical role of inflammation in the development and propagation of atherosclerotic cardiovascular disease. Pathological studies in human and animal models have elucidated specific inflammatory mediators contributing to the progression and rupture of atherosclerotic plaque in the artery wall. These observations not only outline the importance of inflammation in atheroma progression but also the potential of anti-inflammatory therapeutic approaches to prevent and stabilize atherosclerotic disease. Intravascular ultrasonography enables direct atheroma visualization in vivo. Additionally, refinements in ultrasound technology permitting radiofrequency backscatter analysis enhance plaque characterization associated with disease instability. These imaging modalities will continue to provide opportunities for evaluating novel inflammatory mechanisms and anti-inflammatory therapies.

Leukocyte subtype counts and its association with vascular structure and function in adults with intermediate cardiovascular risk. MARK study

OBJECTIVES

We investigated the relationship between leukocyte subtype counts and vascular structure and function based on carotid intima-media thickness, pulse wave velocity, central augmentation index and cardio-ankle vascular index by gender in intermediate cardiovascular risk patients.

METHODS

This study analyzed 500 subjects who were included in the MARK study, aged 35 to 74 years (mean: 60.3±8.4), 45.6% women.

MEASUREMENT

Brachial ankle Pulse Wave Velocity (ba-PWV) estimate by equation, Cardio-AnkleVascular Index (CAVI) using the VaSera device and Carotid ultrasound was used to measure carotid Intima Media Thickness (IMT). The Mobil-O-Graph was used to measure the Central Augmentation Index (CAIx).

RESULTS

Total leukocyte, neutrophil and monocyte counts were positively correlated with IMT (p < 0.01) in men. Monocyte count was positively correlated with CAIx in women (p < 0.01). In a multiple linear regression analysis, the IMT mean maintained a positive association with the neutrophil count (β = 1.500, p = 0.007) in men. CAIx maintained a positive association with the monocyte count (β = 2.445, p = 0.022) in women.

CONCLUSION

The results of this study suggest that the relationship between subtype circulating leukocyte counts and vascular structure and function, although small, may be different by gender. In men, the neutrophil count was positively correlated with IMT and in women, the monocyte count with CAIx, in a large sample of intermediate-risk patients. These association were maintained after adjusting for age and other confounders.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01428934.

Bifurcation and dynamics in a mathematical model of early atherosclerosis: How acute inflammation drives lesion development

We present here a mathematical model describing the primary mechanisms that drive the early stages of atherosclerosis. This involves the interactions between modified low density lipoprotein (LDL), monocytes/macrophages, cytokines and foam cells. This model suggests that there is an initial inflammatory phase associated with atherosclerotic lesion development and a longer, quasi-static process of plaque development inside the arterial wall that follows the initial transient. We will show results that show how different LDL concentrations in the blood stream and different immune responses can affect the development of a plaque. Through numerical bifurcation analysis, we show the existence of a fold bifurcation when the flux of LDL from the blood is sufficiently high. By analysing the model presented in this paper, we gain a greater insight into this inflammatory response qualitatively and quantitatively.

Monocyte fate in atherosclerosis

Monocytes and their descendant macrophages are essential to the development and exacerbation of atherosclerosis, a lipid-driven inflammatory disease. Lipid-laden macrophages, known as foam cells, reside in early lesions and advanced atheromata. Our understanding of how monocytes accumulate in the growing lesion, differentiate, ingest lipids, and contribute to disease has advanced substantially over the last several years. These cells' remarkable phenotypic and functional complexity is a therapeutic opportunity: in the future, treatment and prevention of cardiovascular disease and its complications may involve specific targeting of atherogenic monocytes/macrophages and their products.

Carotid hemodynamics is associated with monocyte count determined by serum homocysteine level in patients with essential hypertension

To examine the association between pulsatility index (PI) in the common carotid artery (CCA) as a marker of vascular resistance and cardiovascular risk factors, including serum homocysteine and inflammation, 67 hypertensive patients were enrolled. PI correlated with homocysteine and interleukin-6, monocyte count, gender, age and BMI, with monocyte count and age being independent determinants for PI. In turn, monocyte count correlated with homocysteine, tumor necrosis factor-alpha, and HDL-cholesterol, BMI, and gender, with HDL-cholesterol and homocysteine being independent determinants for monocyte count. These results indicated monocyte count determined by homocysteine is associated with arterial stiffness in hypertensive patients.

Longitudinal associations between lymphocyte count and LDL cholesterol in a health screening population

BACKGROUND

Longitudinal associations between leukocyte subtype counts and LDL cholesterol have not been reported.

METHODS AND RESULTS

This is a retrospective observational study in a health screening population. Spearman's correlation coefficients were calculated between leukocyte subtype counts and LDL cholesterol levels at baseline and after four years. Using Cox regression models, hazard ratios (HRs) of hyper-LDL cholesterolemia for leukocyte subtype counts during four years of follow-up were calculated adjusted for age, sex, high-sensitivity C-reactive protein (hs-CRP) and other confounders. Spearman's correlation coefficients (p values) between changes in counts of neutrophil, lymphocyte, monocyte, basophil and eosinophil and changes in LDL cholesterol levels through 4 years were 0.02 (0.494), 0.12 (<0.001), 0.06 (0.016), 0.02 (0.524) and 0.03 (0.257), respectively among 1735 subjects who visited our medical check-up center, did not use anti-hyperlipidemic drugs and revisited after 4 years. Among 1992 followed subjects, 481 developed hyper-LDL cholesterolemia during four years (60.4 per 1000 person-years). The HRs (95% confidence intervals; p values) of hyper-LDL cholesterolemia for each one SD increase in counts of neutrophil, lymphocyte, monocyte, basophil and eosinophil were 1.08 (0.99-1.19; 0.085), 1.14 (1.04-1.25; 0.005), 1.05 (0.95-1.15; 0.339), 1.01 (0.92-1.11; 0.858) and 1.04 (0.95-1.14; 0.397), respectively.

CONCLUSIONS

Lymphocyte count and LDL cholesterol were longitudinally positively correlated and lymphocyte count was associated with incidence of hyper-LDL cholesterolemia independently of hs-CRP in a health screening population.

Association between circulating leukocyte subtype counts and carotid intima-media thickness in Japanese subjects with type 2 diabetes

Background

An increased leukocyte count is an independent risk factor for cardiovascular events, but the association between leukocyte subtype counts and carotid atherosclerosis in patients with diabetes has not been determined. We therefore investigated the correlation between leukocyte subtype counts and intima-media thickness of the common carotid artery (CCA-IMT) in subjects with type 2 diabetes.

Methods

This cross-sectional study involved 484 in-patients with type 2 diabetes (282 males and 202 females), who were hospitalized for glycemic control and underwent carotid ultrasonography at Kumamoto University Hospital between 2005 and 2011. Mean and maximum CCA-IMT was measured by high-resolution B-mode ultrasonography.

Results

Univariate analyses revealed that mean CCA-IMT was positively correlated with age, systolic blood pressure, brachial-ankle pulse wave velocity (PWV), urinary albumin excretion and duration of diabetes, but was negatively correlated with diastolic blood pressure and fasting plasma glucose. Maximum CCA-IMT was positively and negatively correlated with the same factors as mean CCA-IMT except for fasting plasma glucose. Mean CCA-IMT was positively correlated with total leukocyte (r = 0.124, p = 0.007), monocyte (r = 0.373, p < 0.001), neutrophil (r = 0.139, p = 0.002) and eosinophil (r = 0.107, p = 0.019) counts. Maximum CCA-IMT was positively correlated with total leukocyte (r = 0.154, p < 0.001), monocyte (r = 0.398, p < 0.001), neutrophil (r = 0.152, p < 0.001) and basophil counts (r = 0.102, p = 0.027). Multiple regression analyses showed that monocyte count, age and PWV were significant and independent factors associated with mean CCA-IMT (adjusted R² = 0.239, p < 0.001), and that monocyte count, age and urinary albumin excretion were significant and independent factors associated with maximum CCA-IMT (adjusted R² = 0.277, p < 0.001).

Conclusions

Monocyte counts were positively correlated with both mean CCA-IMT and maximum CCA-IMT in patients with type 2 diabetes. Monocyte count may be a useful predictor of macrovascular complications in patients with type 2 diabetes.

Trial registration

Trial registry no: UMIN000003526.

Norepinephrine increases NADPH oxidase-derived superoxide in human peripheral blood mononuclear cells via α-adrenergic receptors

Many diseases associated with sympathoexcitation also exhibit elevated reactive oxygen species (ROS). A recent animal study indicated that exogenous administration of the sympathetic neurotransmitter norepinephrine (NE) increased systemic ROS via circulating leukocytes. The mechanisms contributing to this effect of NE and whether these findings can be translated to humans is unknown. Thus we tested the hypothesis that NE increases superoxide production in human peripheral blood mononuclear cells (PBMCs) via NADPH oxidase. Primary human PBMCs were freshly isolated from healthy young men and placed in culture. After NE (50 pg/ml, 50 ng/ml, and 50 μg/ml concentrations) or control treatments, NADPH oxidase mRNA expression (gp91(phox), p22(phox), and p67(phox)) was assessed using real-time RT-PCR, and intracellular superoxide production was measured using dihydroethidium fluorescence. PBMCs were also treated with selective adrenergic agonists-antagonists to determine the receptor population involved. In addition, CD14(+) monocyte-endothelial cell adhesion was determined using a fluorescent-based assay. NE significantly increased NADPH oxidase gene expression and intracellular superoxide production in a time-dependent manner (superoxide: 0.9 ± 0.2 fold, 6 h vs. 3.0 ± 0.3 fold, 36 h; NE, 50 μg/ml; P < 0.05). The sustained increase in NE-induced superoxide production was primarily mediated via α-adrenergic receptors, preferentially α2-receptors. The NADPH oxidase blocker diphenylene iodonium and protein kinase C inhibitor Staurosporine significantly attenuated NE-induced increases in superoxide production. Importantly, NE treatment increased CD14(+) monocyte-endothelial cell adhesion. These findings indicate for the first time that NE increases superoxide production in freshly isolated primary human PBMCs via NADPH oxidase through α-adrenergic receptors, an effect facilitating monocyte adhesion to the endothelium.

Genetic deletion of chemokine receptor Ccr6 decreases atherogenesis in ApoE-deficient mice

RATIONALE

The chemokine receptor Ccr6 is a G-protein-coupled receptor expressed on various types of leukocytes identified in mouse atherosclerotic lesions. Recent evidence suggests that both CCR6 and its ligand CCL20 are also present in human atheroma; however, their functional roles in atherogenesis remain undefined.

OBJECTIVE

Our objective was to delineate the role of Ccr6 in atherogenesis in the apolipoprotein E-deficient (ApoE(-/-)) mouse model of atherosclerosis.

METHODS AND RESULTS

Both Ccr6 and Ccl20 are expressed in atherosclerotic aorta from ApoE(-/-) mice. Aortic lesion area in Ccr6(-/-)ApoE(-/-) mice was ∼40% and ∼30% smaller than in Ccr6(+/+)ApoE(-/-) mice at 16 and 24 weeks of age, respectively. Transplantation of bone marrow from Ccr6(-/-) mice into ApoE(-/-) mice resulted in ∼40% less atherosclerotic lesion area than for bone marrow from Ccr6(+/+) mice; lesions in Ccr6(-/-)ApoE(-/-) mice had 44% less macrophage content than lesions in Ccr6(+/+)ApoE(-/-) mice. Ccr6 was expressed on a subset of primary mouse monocytes. Accordingly, Ccl20 induced chemotaxis of primary monocytes from wild-type but not Ccr6(-/-) mice; moreover, Ccl20 induced monocytosis in ApoE(-/-) mice in vivo. Consistent with this, we observed 30% fewer monocytes in circulating blood of Ccr6(-/-)ApoE(-/-) mice, mainly because of fewer CD11b(+)Ly6C(high) inflammatory monocytes.

CONCLUSIONS

Ccr6 promotes atherosclerosis in ApoE-deficient mice, which may be due in part to Ccr6 support of normal monocyte levels in blood, as well as direct Ccr6-dependent monocyte migration.

Lymphocyte count was significantly associated with hyper-LDL cholesterolemia independently of high-sensitivity C-reactive protein in apparently healthy Japanese

The aim of this study was to investigate the association between leukocyte subtype counts and hyper-LDL cholesterolemia, hypertriglyceridemia, and hypo-HDL cholesterolemia. Logistic regressions using hyper-LDL cholesterolemia, hypertriglyceridemia, and hypo-HDL cholesterolemia as a dependent variable and total leukocyte, basophil, eosinophil, neutrophil, lymphocyte, and monocyte counts as an independent variable were calculated adjusting for age, body mass index (BMI), high-sensitivity C-reactive protein (hs-CRP), smoking, drinking, and physical activity in apparently healthy Japanese men (1,803) and women (1,150). The odds ratio (OR) of hyper-LDL cholesterolemia for total leukocyte, eosinophil, and lymphocyte counts, the OR of hypertriglyceridemia for total leukocyte, eosinophil, neutrophil, and lymphocyte counts, and the OR of hypo-HDL cholesterolemia for total leukocyte, neutrophil, and lymphocyte counts were significant in men, and the OR of hyper-LDL cholesterolemia, for lymphocyte count, and the OR of hypo-HDL cholesterolemia for eosinophil count were significant in women. Lymphocyte count was significantly associated with hyper-LDL cholesterolemia independently of hs-CRP in apparently healthy Japanese.

[Atherosclerosis : on the trail of chemokines]

Atherosclerosis, which is more than a problem of lipid metabolism, is associated with chronic inflammation of large arteries. This is notably caused by the recruitment of circulating blood monocytes to the arterial wall. Extensive studies in humans and mice have shown that the chemokines and their receptors, responsible for leukocyte recirculation, are strongly implicated in the initial onset of atherosclerosis. Murine models have provided further proof of the role of the CCR2/CCL2, CX3CR1/CXCL16 and CCR5/CCL5 axes in the different stages of disease, as well as the preventative roles of CCR1/CCL5 and CXCR6/CXCL16. The integration at the cellular level of various signals in the chemokine network underlines the complex process of leukocyte recruitment to the lesional area. Furthermore the capacity of chemokines to modulate atherosclerosis lies not just with their chemoattractant properties but also with their influence on leukocyte homeostasis. These molecules have therefore quickly become therapeutic targets for atherosclerosis and have opened up new avenues for treating inflammatory diseases. This review principally addresses the implication of chemokines and their receptors in the initial recruitment steps of blood monocytes, and provides an overview of recent research on these molecular controllers of inflammation.