Evaluation of the significance of cystatin C levels in patients suffering from coronary artery disease

Pre-Operative Plasma Extracellular Vesicle Proteins are Associated with a High Risk of Long Term Secondary Major Cardiovascular Events in Patients Undergoing Carotid Endarterectomy

OBJECTIVE

Patients undergoing carotid endarterectomy (CEA) maintain a substantial residual risk of major cardiovascular events (MACE). Improved risk stratification is warranted to select high risk patients qualifying for secondary add on therapy. Plasma extracellular vesicles (EVs) are involved in atherothrombotic processes and their content has been related to the presence and recurrence of cardiovascular events. The association between pre-operative levels of five cardiovascular disease related proteins in plasma EVs and the post-operative risk of MACE was assessed.

METHODS

In 864 patients undergoing CEA from 2002 to 2016 included in the Athero-Express biobank, three plasma EV subfractions (low density lipoprotein [LDL], high density lipoprotein [HDL], and tiny extracellular vesicles [TEX]) were isolated from pre-operative blood samples. Using an electrochemiluminescence immunoassay, five proteins were quantified in each EV subfraction: cystatin C, serpin C1, serpin G1, serpin F2, and CD14. The association between EV protein levels and the three year post-operative risk of MACE (any stroke, myocardial infarction, or cardiovascular death) was evaluated using multivariable Cox proportional hazard regression analyses.

RESULTS

During a median follow up of three years (interquartile range 2.2 - 3.0), 137 (16%) patients developed MACE. In the HDL-EV subfraction, increased levels of CD14, cystatin C, serpin F2, and serpin C1 were associated with an increased risk of MACE (adjusted hazard ratios per one standard deviation increase of 1.30, 95% confidence interval [CI] 1.15-1.48; 1.22, 95% CI 1.06-1.42; 1.36, 95% CI 1.16-1.61; and 1.29, 95% CI 1.10-1.51; respectively), independently of cardiovascular risk factors. No significant associations were found for serpin G1. CD14 improved the predictive value of the clinical model encompassing cardiovascular risk factors (net re-classification index = 0.16, 95% CI 0.08-0.21).

CONCLUSION

EV derived pre-operative plasma levels of cystatin C, serpin C1, CD14, and serpin F2 were independently associated with an increased long term risk of MACE after CEA and are thus markers for residual cardiovascular risk. EV derived CD14 levels could improve the identification of high risk patients who may benefit from secondary preventive add on therapy in order to reduce future risk of MACE.

Higher serum level of Cystatin C: An additional risk factor of CAD

Cystatin C has been proposed as a useful biomarker of early impaired kidney function and a predictor of mortality risk. The present study is to investigate the association between serum Cystatin C and the severity of coronary artery lesions, Gensini score (GS), and the risk of coronary artery disease (CAD).A total of 682 CAD patients (230 females, 452 males; mean age 62.6 ± 10.7 years, range from 31 to 86 years) and 135 controls (41 females, 94 males; mean age 58.0 ± 10.3 years, range from 38 to 84 years) were recruited in the present study. Enzyme-linked immunosorbent assay was applied to measure serum cystatin C levels and other serum indexes. The estimated glomerular filtration rate and GS were calculated.Serum low-density lipoprotein cholesterol (LDL-C), uric acid, Cystatin C, and homocysteine (HCY) were significantly elevated in CAD patients compared to controls. There were significant differences regarding total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, cystatin C, eGFR and GS among stable angina pectoris (SAP), unstable angina group (UAP), and acute myocardial infarction (AMI) patients. AMI group had an elevated serum Cystatin C, LDL-C, HCY, and GS than SAP and UAP patients. When stratified patient groups by the quartiles of Cystatin C, we found age, the proportion of male and patients with diabetes, HCY, and GS were increased in Q4 than in other quartile groups. Spearman correlation test revealed a positive relationship between Cystatin C, HCY, and GS. Multivariate logistic regression analysis revealed that serum Cystatin C level, presence of hypertension and diabetes, HCY, age, and male were the risk factors for coronary artery lesions.In summary, our results suggested that cystatin C is a promising clinical biomarker that provides complementary information to the established risk determinants. The serum Cystatin C level is strongly associated with GS and could be used to evaluate the severity of coronary artery lesions.

Extracellular Vesicle cystatin c is associated with unstable angina in troponin negative patients with acute chest pain

Background

Despite the use of high-sensitive cardiac troponin there remains a group of high-sensitive cardiac troponin negative patients with unstable angina with a non-neglectable risk for future adverse cardiovascular events, emphasising the need for additional risk stratification. Plasma extracellular vesicles are small bilayer membrane vesicles known for their potential role as biomarker source. Their role in unstable angina remains unexplored. We investigate if extracellular vesicle proteins are associated with unstable angina in patients with chest pain and low high-sensitive cardiac troponin.

Methods

The MINERVA study included patients presenting with acute chest pain but no acute coronary syndrome. We performed an exploratory retrospective case-control analysis among 269 patients. Cases were defined as patients with low high-sensitive cardiac troponin and proven ischemia. Patients without ischemia were selected as controls. Blood samples were fractionated to analyse the EV proteins in three plasma-subfractions: TEX, HDL and LDL. Protein levels were quantified using electrochemiluminescence immunoassay.

Results

Lower levels of (adjusted) EV cystatin c in the TEX subfraction were associated with having unstable angina (OR 0.93 95% CI 0.88–0.99).

Conclusion

In patients with acute chest pain but low high-sensitive cardiac troponin, lower levels of plasma extracellular vesicle cystatin c are associated with having unstable angina. This finding is hypothesis generating only considering the small sample size and needs to be confirmed in larger cohort studies, but still identifies extracellular vesicle proteins as source for additional risk stratification.

Plasma extracellular vesicle proteins are associated with stress-induced myocardial ischemia in women presenting with chest pain

Diagnosing stable ischemic heart disease (IHD) is challenging, especially in females. Currently, no blood test is available. Plasma extracellular vesicles (EV) are emerging as potential biomarker source. We therefore aimed to identify stress induced ischemia due to stable IHD with plasma extracellular vesicle protein levels in chest pain patients. We analyzed 450 patients suspected for stable IHD who were referred for ⁸²Rb PET/CT in the outpatient clinic. Blood samples were collected before PET/CT and plasma EVs were isolated in 3 plasma subfractions named: TEX, HDL, LDL. In total 6 proteins were quantified in each of these subfractions using immuno-bead assays. CD14 and CystatinC protein levels were independent significant predictors of stress-induced ischemia in the LDL and the HDL subfraction and SerpinC1 and SerpinG1 protein levels in the HDL fraction. Subgroup-analysis on sex revealed that these associations were completely attributed to the associations in women. None of the significant EV proteins remained significant in men. Plasma EV proteins levels are associated with the presence of stable IHD in females presenting with chest pain. This finding, if confirmed in larger cohort studies could be a crucial step in improving diagnostic assessment of women with suspected IHD.

Association of serum cystatin C levels with acute coronary syndrome in patients of advanced age

Objective

This study was performed to investigate the relationship between the serum cystatin C (Cys C) level and acute coronary syndrome (ACS) in patients of advanced age.

Methods

The study included 184 patients with ACS and 46 healthy control subjects. Statistical analysis was performed using SPSS version 14.0 (SPSS Inc., Chicago, IL, USA).

Results

The serum Cys C level was significantly higher in patients with than without ACS (1.24 ± 0.30 vs. 1.42 ± 0.46 mg/L, respectively). Patients with more stenotic coronary arteries were significantly more likely to have higher median serum Cys C and creatinine levels and a lower estimated glomerular filtration rate. The multivariate logistic regression analysis demonstrated that the serum Cys C level was independently associated with the presence of ACS and the quantity of stenotic coronary arteries after adjustment for confounding factors. Additionally, the serum Cys C level was positively correlated with age, the creatinine level, and the N-terminal pro-B-type natriuretic peptide level in all patients but was negatively correlated with the estimated glomerular filtration rate.

Conclusion

A high serum Cys C level was independently associated with ACS and the quantity of stenotic coronary arteries in patients of advanced age regardless of renal function.

Lack of association between cystatin C and different coronary atherosclerotic manifestations

Cystatin C (CysC) is known to be related to cardiovascular disease (CVD), including the presence and severity of coronary artery disease (CAD) and future clinical events. In this study, the association between CysC levels and (1) coronary artery calcification (CAC) in asymptomatic individuals from the general population as well as (2) different subgroups of patients with suspected or definite acute myocardial infarction (MI) was investigated. CysC levels were measured in serum from asymptomatic individuals as part of a screening study for CAC using non-contrast cardiac CT scan (N = 1039) as well as in subgroups of hospitalized patients with a suspected MI (N = 769). CysC was not associated with CAC in asymptomatic individuals after adjusting for relevant risk factors. No difference in CysC levels was observed between patients with type 1 MI (1.07 mg/L) and patients with normal troponin (with or without prior CAD: 1.14 and 1.01 mg/L, respectively). However, patients with type 2 MI and patient subgroups with elevated troponin but without MI had significantly higher CysC levels (1.24, 1.23 and 1.31 mg/L), even after adjusting for other risk factors. CysC was not associated with CAC in middle-aged asymptomatic individuals from the general population. Furthermore, CysC levels were found to be significantly lower in patients with type 1 MI compared to patients with type 2 MI and patients with elevated troponins but without MI. Thus, in two independent and clinically different populations, no association between CysC and coronary atherosclerotic manifestations could be demonstrated.

Saliva and plasma levels of cardiac-related biomarkers in post-myocardial infarction patients

AIM

To relate cardiac biomarkers, such as cystatin C and growth differentiation factor-15 (GDF-15) in saliva to myocardial infarction (MI) and to periodontal status, and to investigate the relation between salivary and plasma cardiac biomarkers.

MATERIALS AND METHODS

Two hundred patients with MI admitted to coronary care units and 200 matched controls without MI were included. Dental examination and collection of blood and saliva samples was performed 6-10 weeks after the MI for patients and in close proximity thereafter for controls. Analysing methods: ARCHITECT i4000SR, Immulite 2000 XPi or ELISA.

RESULTS

The mean age was 62 ± 8 years and 84% were male. Total probing pocket depth, fibrinogen, white blood cell counts and HbA1c were higher in patients than controls. GDF-15 levels correlated with most of the included clinical variables in both study groups. No correlation was found between plasma and saliva levels of cystatin C or GDF-15.

CONCLUSION

Salivary cystatin C and GDF-15 could not differentiate between MI patients and controls.

Correlations of serum cystatin C and glomerular filtration rate with vascular lesions and severity in acute coronary syndrome

Background

The aim of this study was to evaluate the predictive value of cystatin C (CysC) and estimated glomerular filtration rate (eGFR) regarding vascular lesions and their severity in patients with acute coronary syndrome (ACS).

Methods

According to the results of coronary angiography, 195 ACS patients were divided into a single-vascular-lesion group (91 cases), a dual-vascular-lesion group (67 cases), and a multiple-vascular-lesion group (37 cases) to assess the severity of coronary artery disease according to Gensini scores and to analyze the correlations of CysC and eGFR level with vascular lesions and severity in ACS patients.

Results

Intergroup comparisons of univariate and multivariate regression analyses showed that CysC was positively correlated with vascular lesions (P < 0.05), but eGFR showed no correlation. Regarding the severity of vascular lesions, CysC was positively correlated with Gensini score (Pearson’s correlation coefficient r = 0.1811, P < 0.05), but eGFR was not correlated (P > 0.05).

Conclusions

Serum CysC levels could reflect the severity of vascular lesions in ACS patients, and a high CysC level had predictive value regarding the severity of vascular lesions in ACS.

Association between serum cystatin C levels and the severity or potential risk factors of acute ischemic stroke

OBJECTIVE

We sought to investigate whether serum cystatin C levels are correlated with either stroke severity or with potential risk factors of acute ischemic stroke.

METHODS

171 patients with acute ischemic stroke and 99 control subjects with minor, unrelated diseases with stroke were included in this retrospective study. Serum cystatin C levels were determined in all subjects. Serum concentrations of several vascular risk factors in stoke patients were determined by biochemical assays. The severity of strokes was scored via the National Institutes of Health Stroke Scale (NIHSS).

RESULTS

Serum cystatin C levels were significantly increased in patients with acute ischemic stroke compared with control subjects (1.26 ± 0.34 mg/L vs. 0.78 ± 0.24 mg/L, p < 0.001).When analyzed in quartiles of serum cystatin C levels, concentrations were low (<0.75 mM) for 5 stroke patients (2.92%), intermediate (0.75-1 mM) for 42 patients (24.56%), high (1-1.25 mM) for 45 patients (26.32%), and very high (>1.25 mM) for 79 patients (46.20%). However, serum cystatin C levels were not correlated with NIHSS scores, serum total cholesterol, high-density lipoprotein, low-density lipoprotein, apolipoprotein a, or apolipoprotein b levels. Further, serum cystatin C concentrations in stroke patients were not correlated with the presence of intracranial arterial stenosis, hypertension, or diabetes.

CONCLUSION

Our study suggests that there is a close relationship between cystatin C and acute ischemic stroke, independently of conventional risk factors. But the levels of cystatin C are not correlated with the stroke severity.

Biomarkers and degree of atherosclerosis are independently associated with incident atherosclerotic cardiovascular disease in a primary prevention cohort: The ARIC study

BACKGROUND AND AIMS

Biomarkers and atherosclerosis imaging have been studied individually for association with incident cardiovascular disease (CVD); however, limited data exist on whether the biomarkers are associated with events with a similar magnitude in the presence of atherosclerosis. In this study, we assessed whether the presence of atherosclerosis as measured by carotid intima media thickness (cIMT) affects the association between biomarkers known to be associated with coronary heart disease (CHD) and incident cardiovascular disease (CVD) in a primary prevention cohort.

METHODS

8127 participants from the ARIC study (4th visit, 1996-1998) were stratified as having minimal, mild, or substantial atherosclerosis by cIMT. Levels of C-reactive protein, lipoprotein-associated phospholipase A2, cardiac troponin T, N-terminal pro-brain natriuretic peptide, lipoprotein(a), cystatin C, and urine albumin to creatinine ratio were measured in each participant. Hazard ratios were used to determine the relationship between the biomarkers and incident CHD, stroke, and CVD in each category of atherosclerosis.

RESULTS

While each of the biomarkers was significantly associated with risk of events overall, we found no significant differences noted in the strength of association of biomarkers with CHD, stroke, and CVD when analyzed by degree of atherosclerosis.

CONCLUSIONS

These findings suggest that the level of atherosclerosis does not significantly influence the association between biomarkers and CVD.

Assessment of Serum Cystatin C Levels in Newly Diagnosed Acute Myocardial Infarction at the Onset and at the Time of Hospital Discharge

BACKGROUND

Cystatin C (Cys-C) is a marker of renal damage. Higher serum levels of Cys-C were observed in cardiovascular disease. This study aimed to test the null hypothesis that Cys-C levels in newly diagnosed acute myocardial infarction (AMI) may remain high in the survival and the impact of the cardiometabolic risk factors is small.

METHODS

Forty patients with AMI are enrolled in this study. The cardiometabolic factors including the anthropometric measurements, blood pressure and lipid profile were determined. The diagnosis of AMI is based on the electrocardiograph, cardiac enzymes and positive troponin-c (cTn) test. Quantitative determination of serum high sensitive C-reactive protein (hs-CRP) and Cys-C was carried out, at the time of admission and at the time of the discharge, using the enzyme-linked immunosorbent assay (ELISA) technique.

RESULTS

Serum Cys-C levels significantly increased at the time of the admission (1,296 ± 431.8 ng/mL) and at the time of the discharge (1,244.6 ± 482 ng/mL) compared with the reference levels (0.7 ± 0.2 ng/mL) of the healthy subjects. Non-significant differences were found between Cys-C levels in respect to the presence or absence of the cardiometabolic risk factors at the times of admission and discharge. Significant decrease of Cys-C levels was found in patients who have negative cTn at the time of discharge compared with corresponding levels at the time of admission.

CONCLUSIONS

We conclude that AMI patients have significant high serum levels of Cys-C at the time of admission and the levels significantly decreased in patients with negative cTn test within few days indicating an association between infarct size and the levels of Cys-C.