Evidence from a Randomized Trial That Simvastatin,but Not Ezetimibe,Upregulates Circulating PCSK9 Levels

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a secreted inhibitor of the low-density lipoprotein (LDL) receptor and an important regulator of LDL metabolism. Elevated PCSK9 levels have been associated with cardiovascular risk. The purpose of this study was to investigate how ezetimibe and simvastatin, alone and in combination, affect PCSK9 circulating concentrations.

Methods

A single center, randomized, open-label parallel 3-group study in healthy men (mean age 32±9 years, body mass index 25.7±3.2 kg/m²) was performed. Each group of 24 subjects was treated for 14 days with either simvastatin 40 mg/d, ezetimibe 10 mg/d, or with both drugs. Multivariate analysis was used to investigate parameters influencing the change in PCSK9 concentrations under treatment.

Results

The baseline plasma PCSK9 concentrations in the total cohort were 52±20 ng/mL with no statistically significant differences between the groups. They were increased by 68±85% by simvastatin (P = 0.0014), by 10±38% by ezetimibe (P = 0.51) and by 67±91% by simvastatin plus ezetimibe (P = 0.0013). The increase in PCSK9 was inversely correlated with baseline PCSK9 concentrations (Spearman’s R = –0.47, P<0.0001) and with the percent change in LDL cholesterol concentrations (Spearman’s R = –0.30, P<0.01). In multivariate analyses, only baseline PCSK9 concentrations (β = –1.68, t = –4.04, P<0.0001), percent change in LDL cholesterol from baseline (β = 1.94, t = 2.52, P = 0.014), and treatment with simvastatin (P = 0.016), but not ezetimibe (P = 0.42), significantly influenced changes in PCSK9 levels. Parameters without effect on PCSK9 concentration changes were age, body mass index, body composition, thyroid function, kidney function, glucose metabolism parameters, adipokines, markers of cholesterol synthesis and absorption, and molecular markers of cholesterol metabolism.

Conclusions

Ezetimibe does not increase circulating PCSK9 concentrations while simvastatin does. When added to simvastatin, ezetimibe does not cause an incremental increase in PCSK9 concentrations. Changes in PCSK9 concentrations are tightly regulated and mainly influenced by baseline PCSK9 levels and changes in LDL cholesterol.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00317993","term_id":"NCT00317993"}}NCT00317993     

Effects of Renal Sympathetic Denervation on Post-Myocardial Infarction Cardiac Remodeling in Rats

Objective

To investigate the therapeutic effects of renal denervation (RD) on post- myocardial infarction (MI) cardiac remodeling in rats, the most optimal time for intervention and the sustainability of these effects.

Methods

One hundred SPF male Wistar rats were randomly assigned to N group (Normal, n = 10), MI group(MI, n = 20),RD group (RD, n = 10), RD3+MI (MI three days after RD, n = 20), MI1+RD (RD one day after MI, n = 20), MI7+RD (RD seven days after MI, n = 20). MI was produced through thoracotomic ligation of the anterior descending artery. RD was performed through laparotomic stripping of the renal arteriovenous adventitial sympathetic nerve. Left ventricular function, hemodynamics, plasma BNP, urine volume, urine sodium excretion and other indicators were measured four weeks after MI.

Results

(1) The left ventricular function of the MI group significantly declined (EF<40%), plasma BNP was elevated, urine output was significantly reduced, and 24-hour urine sodium excretion was significantly reduced. (2) Denervation can be achieved by surgically stripping the arteriovenous adventitia, approximately 3 mm from the abdominal aorta. (3) In rats with RD3+MI, MI1+RD and MI7+RD, compared with MI rats respectively, the LVEF was significantly improved (75±8.4%,69±3.8%,73±5.5%), hemodynamic indicators were significantly improved, plasma BNP was significantly decreased, and the urine output was significantly increased (21.3±5 ml,23.8±5.4 ml,25.2±8.7 ml). However, the urinary sodium excretion also increased but without significant difference.

Conclusions

RD has preventive and therapeutic effects on post-MI cardiac remodeling.These effects can be sustained for at least four weeks, but there were no significant differences between denervation procedures performed at different times in the course of illness. Cardiac function, hemodynamics, urine volume and urine sodium excretion in normal rats were not affected by RD.     

Decreased Plasma IL-35 Levels Are Related to the Left Ventricular Ejection Fraction in Coronary Artery Diseases

Background

Accumulating evidence shows that the novel anti-inflammatory cytokine IL-35 can efficiently suppress effector T cell activity and alter the progression of inflammatory and autoimmune diseases. The two subunits of IL-35, EBI3 and p35, are strongly expressed in human advanced plaque, suggesting a potential role of IL-35 in atherosclerosis and coronary artery disease (CAD). However, the plasma levels of IL-35 in patients with CAD have yet to be investigated.

Methods

Plasma IL-35, IL-10, TGF-β1, IL-12 and IL-27 levels were measured using an ELISA in 43 stable angina pectoris (SAP) patients, 62 unstable angina pectoris (UAP) patients, 56 acute myocardial infarction (AMI) patients and 47 chest pain syndrome patients as a control group.

Results

The results showed that plasma IL-35 levels were significantly decreased in the SAP group (90.74±34.22 pg/ml), the UAP group (72.20±26.63 pg/ml), and the AMI group (50.21±24.69 pg/ml) compared with chest pain syndrome group (115.06±32.27 pg/ml). Similar results were also demonstrated with IL-10 and TGF-β1. Plasma IL-12 and IL-27 levels were significantly increased in the UAP group (349.72±85.22 pg/ml, 101.75±51.42 pg/ml, respectively) and the AMI group (318.05±86.82 pg/ml, 148.88±68.45 pg/ml, respectively) compared with chest pain syndrome group (138.68±34.37 pg/ml, 63.60±22.75 pg/ml, respectively) and the SAP group (153.84±53.86 pg/ml, 70.84±38.77 pg/ml, respectively). Furthermore, lower IL-35 levels were moderately positively correlated with left ventricular ejection fraction (LVEF) in CAD patients (R = 0.416, P<0.01), whereas higher IL-27 levels were weakly negatively correlated with LVEF in CAD patients(R = −0.205, P<0.01).

Conclusions

The results of the present study show that circulating IL-35 is a potentially novel biomarker for coronary artery disease. Regulating the expression of IL-35 also provides a new possible target for the treatment of atherosclerosis and CAD.     

Raised Plasma Robo4 and Cardiac Surgery-Associated Acute Kidney Injury

Objective

Endothelial dysfunction associated with systemic inflammation can contribute to organ injury/failure following cardiac surgery requiring cardiopulmonary bypass (CPB). Roundabout protein 4 (Robo4), an endothelial-expressed transmembrane receptor and regulator of cell activation, is an important inhibitor of endothelial hyper-permeability. We investigated the hypothesis that plasma levels of Robo4 are indicative of organ injury, in particular acute kidney injury (AKI), after cardiac surgery.

Methods

Patients (n = 32) undergoing elective cardiac surgery with CPB were enrolled, prospectively. Plasma Robo4 concentrations were measured pre-, 2 and 24 h post-operatively, using a commercially available ELISA. Plasma and endothelial markers of inflammation [interleukin (IL) -6, -8, -10: von Willibrand factor (vWF) and angiopoeitin-2 (Ang-2)] and the AKI marker, neutrophil gelatinase-associated lipocalin (NGAL), were also measured by ELISA.

Results

Plasma Robo4 increased significantly (p<0.001) from pre-operative levels of 2515±904 pg/ml to 4473±1915 pg/ml, 2 h after surgery; and returned to basal levels (2682±979 pg/ml) by 24 h. Plasma cytokines, vWF and NGAL also increased 2 h post-operatively and remained elevated at 24 h. Ang-2 increased 24 h post-operatively, only. There was a positive, significant correlation (r = 0.385, p = 0.0298) between Robo-4 and IL-10, but not other cytokines, 2 h post-operatively. Whilst raised Robo4 did not correlate with indices of lung dysfunction or other biomarkers of endothelial activation; there was a positive, significant correlation between raised (2 h) plasma NGAL and Robo4 (r = 0.4322, p = 0.0135). When patients were classed as AKI or non-AKI either using NGAL cut-off of 150 ng/ml, or the AKI Network (AKIN) clinical classification; plasma Robo4 was significantly higher (p = 0.0073 and 0.003, respectively) in AKI vs. non-AKI patients (NGAL cut-off: 5350±2191 ng/ml, n = 16 vs. 3595±1068 pg/ml, n = 16; AKIN: 6546 pg/ml, IQR 5025–8079, n = 6; vs. 3727 pg/ml, IQR 1962–3727, n = 26) subjects.

Conclusion

Plasma Robo4 levels are increased, transiently, following cardiac surgery requiring CPB; and higher levels in patients with AKI suggest a link between endothelial dysregulation and onset of AKI.     

Soluble CD93 Levels in Patients with Acute Myocardial Infarction and Its Implication on Clinical Outcome

Background

Inflammation plays a key role in the pathogenesis of acute myocardial infarction (MI). However, it is unclear whether marker of immune activation will provide prognostic information in these patients. We hypothesized that circulating levels of soluble CD93 (sCD93), a soluble form of transmembrane glycoprotein CD93, is increased in acute MI patients and its level would be associated with clinical outcomes in patients with acute MI.

Methods

We measured circulating levels of sCD93 in 120 patients with acute MI (63±13 yrs, M∶F = 85∶35) and in 120 age, sex-matched control subjects. In patients with acute MI, clinical characteristics, echocardiographic and laboratory findings were assessed at the time of initial enrollment. The primary outcome was defined as all-cause and cardiovascular death.

Results

Circulating sCD93 levels were significantly higher in patients with acute MI than in control subjects (552.1±293.7 vs. 429.8±114.2 ng/mL, p<0.0001). Upon in vitro inflammatory stimulation, increased CD93 shedding was demonstrated in acute MI patients but not in control subjects. During follow up period (median 208 days, 3-1058 days), the primary outcome occurred in 18 (15%) patients (9 cardiovascular deaths). Circulating levels of sCD93 were associated with all cause (p<0.0001) and cardiovascular (p<0.0001) mortality in patients with acute MI. Multivariate Cox regression analysis revealed that initial sCD93 level was found to be an independent predictor of all cause (p = 0.002) and cardiovascular mortality (p = 0.033) when controlled for age and left ventricular ejection fraction.

Conclusions

Circulating levels of sCD93 are elevated in patients with acute MI and their levels were associated with adverse clinical outcomes.     

Increased Plasma YKL-40/Chitinase-3-Like-Protein-1 Is Associated with Endothelial Dysfunction in Obstructive Sleep Apnea

Purpose

Obstructive sleep apnea (OSA) is a common disorder affecting 15–24% of the adults and is associated with increased risk of hypertension and atherosclerosis. The exact mechanisms underlying hypertension in OSA are not entirely clear. YKL-40/Chitinase-3-like protein-1 is a circulating moiety with roles in injury, repair and angiogenesis that is dysregulated in atherosclerosis and a number of other diseases. We sought to determine the role of YKL-40 in endothelial dysfunction and hypertension in OSA.

Methods

We studies 23 normotensive OSA (N-OSA) and 14 hypertensive OSA (H-OSA) without diabetes and apparent cardiovascular disease. Endothelial-dependent nitric oxide-mediated vasodilatory capacity was assessed by flow-mediated vasodilation (FMD). YKL-40, vascular endothelial growth factor (VEGF) and the soluble form of VEGF receptor-1or sFlt-1 were measured in plasma using ELISA methodology.

Results

N-OSA subjects aged 49.1±2.3 years and H-OSA aged 51.3±1.9 years with BMI 36.1±1.6 and 37.6±1.9 kg/m², respectively. The apnea-hypopnea index (AHI) was 41±5 events/hr in N-OSA and 46±6 in H-OSA with comparable degree of oxygen desaturations during sleep. FMD was markedly impaired in H-OSA (8.3%±0.8) compared to N-OSA (13.2%±0.6, P<0.0001). Plasma YKL-40 was significantly elevated in H-OSA (55.2±7.9 ng/ml vs. 35.6±4.2 ng/ml in N-OSA, P = 0.02) and had an inverse relationship with FMD (r = −0.52, P = 0.013). There was a significant positive correlation between sFlt-1/VEGF, a measure of decreased VEGF availability, and YKL-40 (r = 0.42, P = 0.04).

Conclusion

The levels of plasma YKL-40 were elevated in H-OSA group and inversely correlated with the endothelial-dependent vasodilatory capacity whereas there was a positive correlation between sFlt-1/VEGF and YKL-40. These findings suggest that YKL-40 is dysregulated, in part, due to perturbation of VEGF signaling, and may contribute to endothelial dysfunction and hypertension in OSA.     

Correlation of Circulating MMP-9 with White Blood Cell Count in Humans: Effect of Smoking

Background

Matrix metalloproteinase-9 (MMP-9) is an emerging biomarker for several disease conditions, where white blood cell (WBC) count is also elevated. In this study, we examined the relationship between MMP-9 and WBC levels in apparently healthy smoking and non-smoking human subjects.

Methods

We conducted a cross-sectional study to assess the relationship of serum MMP-9 with WBC in 383 men and 356 women. Next, we divided the male population (women do not smoke in this population) into three groups: never (n = 243), current (n = 76) and former (n = 64) smokers and compared the group differences in MMP-9 and WBC levels and their correlations within each group.

Results

Circulating MMP-9 and WBC count are significantly correlated in men (R² = 0.13, p<0.001) and women (R² = 0.19, p<0.001). After stratification by smoking status, MMP-9 level was significantly higher in current smokers (mean ± SE; 663.3±43.4 ng/ml), compared to never (529.7±20.6) and former smokers (568±39.3). WBC count was changed in a similar pattern. Meanwhile, the relationship became stronger in current smokers with increased correlation coefficient of r = 0.45 or R² = 0.21 (p<0.001) and steeper slope of ß = 1.16±0.30 (p<0.001) in current smokers, compared to r = 0.26 or R² = 0.07 (p<0.001) and ß = 0.34±0.10 (p<0.001) in never smokers.

Conclusions

WBC count accounts for 13% and 19% of MMP-9 variance in men and women, respectively. In non-smoking men, WBC count accounts for 7% of MMP-9 variance, but in smoking subjects, it accounts for up to 21% of MMP-9 variance. Thus, we have discovered a previously unrecognized correlation between the circulating MMP-9 and WBC levels in humans.     

Is Bladder Tumor Location Associated with Prostate Cancer Detection after Intravesical Bacillus Calmette-Guérin Instillation?

Objectives

The aim of this study was to evaluate the effect of bladder tumor (BT) location on prostate cancer (PCa) detection in patients with elevated PSA levels after intravesical BCG instillation.

Methods

Between February 2004 and January 2013 prostate biopsies were performed in 59 non-muscle invasive bladder cancer (NMIBC) patients whose PSA level were elevated (≥3 ng/ml) after a 6 week course of intravesical BCG (Oncotice, 12.5 mg in 50 ml normal saline). Differences in PCa detection according to the BT location [bladder neck and/or trigone (Group 1, n = 22) vs. other locations (Group 2, n = 37)] were evaluated. The Fisher''s exact test and the Mann-Whitney U test were used to evaluate the association between categorical and continuous variables, respectively.

Results

A total of 14 patients (23.7%) were diagnosed with PCa. The mean ± standard deviation (SD) PSA before intravesical BCG instillation and prostate biopsy were 1.36±1.04 ng/ml in Group 1 and 1.09±1.12 ng/ml in Group 2 (P = 0.633), and 6.05±3.57 ng/ml in Group 1 and 5.13±3.88 ng/ml in Group 2 (P = 0.378), respectively. Interestingly, whereas PCa was detected upon biopsy in only one patient in Group 1 (4.5%), 13 cases were detected in Group 2 (35.1%) (P = 0.009).

Conclusions

PCa detection after intravesical BCG was highly associated with BT location. Prostate biopsy should therefore be considered when PSA level is elevated after BCG instillation and his BT is located far from the bladder neck.     

Genetic Variants in PCSK1 Gene Are Associated with the Risk of Coronary Artery Disease in Type 2 Diabetes in a Chinese Han Population: A Case Control Study

Background

Insulin and glucagon-like peptide 1 (GLP-1), converted by proprotein convertase 1 (PC1/3) from proinsulin and proglucagon, are associated with type 2 diabetes (T2DM) and coronary artery disease (CAD). The aim of this study is to investigate the association of PCSK1 gene, which encodes PC1/3, with the risk of CAD in Chinese patients with T2DM.

Methods

We selected and genotyped 5 haplotype-tagging single nucleotide polymorphisms (SNPs) at PCSK1 gene (across 39873bp locus) in a case-control study of Chinese Han population involving 425 diabetic patients (62.1% male, mean age 63.2 years) with CAD as positive cases and 258 diabetic patients (44.2% male, mean age 62.0 years) without CAD as controls.

Results

The allele frequencies at rs3811951 were significantly different between cases and controls (30.7% vs. 37.2%), with the allele G associated with decreased risk for CAD (OR = 0.75, 95% CI = 0.59–0.94, p = 0.013). In recessive inheritance mode, the carriers of GG had a lower risk (OR = 0.50, 95%CI = 0.31–0.82, p = 0.005), even after adjusted for gender, age, BMI and smoking (OR = 0.43, 95%CI = 0.24–0.77, p = 0.004). The carriers of the minor allele A at rs156019 had a higher risk (OR = 1.66, 95%CI = 1.10–2.50, p = 0.016 after adjustment) in dominant inheritance mode. The SNP rs6234 was also significantly associated with CAD risk in women, with the carriers of the minor allele G at rs6234 associated with a reduced CAD risk in recessive inheritance mode (OR = 0.42, 95% CI = 0.18–0.95, p = 0.036 after adjustment).

Conclusions

Our results found that common genetic variants in PCSK1 were associated with CAD in Chinese patients with T2DM.     

Progression of Kidney Disease in Non-Diabetic Patients with Coronary Artery Disease: Predictive Role of Circulating Matrix Metalloproteinase-2, -3, and -9

Background

Circulating matrix metalloproteinase (MMP)-2, -3 and -9 are well recognized in predicting cardiovascular outcome in coronary artery disease (CAD), but their risks for chronic kidney disease (CKD) are lacking. Therefore, the present study aimed to investigate whether circulating MMP levels could independently predict future kidney disease progression in non-diabetic CAD patients.

Methods

The prospective study enrolled 251 non-diabetic subjects referred for coronary angiography, containing normal coronary artery (n = 30) and CAD with insignificant (n = 95) and significant (n = 126) stenosis. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI formula. eGFR decline rate was calculated and the primary endpoint was a decline in eGFR over 25% from baseline.

Results

The eGFR decline rate (ml/min/1.73 m² per year) in patients with CAD (1.22 [−1.27, 1.05]) was greater than that in those with normal coronary artery (0.21 [−2.63, 0.47], P<0.01). The circulating MMP-2, -3 and -9 were independently associated with faster eGFR decline among CAD patients. The mean follow-up period was 8.5±2.4 years, and 39 patients reached the primary endpoint. In multivariate Cox regression model, the adjusted hazard ratios of MMP-2 ≥861 ng/mL, MMP-3 ≥227 ng/mL and MMP-9 ≥49 ng/mL for predicting CKD progression were 2.47 (95% CI, 1.21 to 5.07), 2.15 (1.12 to 4.18), and 4.71 (2.14 to 10.4), respectively. While added to a model of conventional risk factors and baseline eGFR, MMP-2, -3 and -9 further significantly improved the model predictability for CKD progression (c statistic, 0.817). In the sensitivity analyses, the results were similar no matter if we changed the endpoints of a decline of >20% in eGFR from baseline or final eGFR < 60 mL/min/1.73 m².

Conclusion

Circulating MMP-2, -3 and -9 are independently associated with kidney disease progression in non-diabetic CAD patients and add incremental predictive power to conventional risk factors.     

Renal Hyperfiltration and Systemic Blood Pressure in Patients with Uncomplicated Type 1 Diabetes Mellitus

Background

Patients with type 1 diabetes mellitus (DM) and renal hyperfiltration also exhibit systemic microvascular abnormalities, including endothelial dysfunction. The effect of renal hyperfiltration on systemic blood pressure (BP) is less clear. We therefore measured BP, renal hemodynamic function and circulating renin angiotensin aldosterone system (RAAS) mediators in type 1 DM patients with hyperfiltration (n = 36, DM-H, GFR≥135 ml/min/1.73 m²) or normofiltration (n = 40, DM-N), and 56 healthy controls (HC). Since renal hyperfiltration represents a state of intrarenal RAAS activation, we hypothesized that hyperfiltration would be associated with higher BP and elevated levels of circulating RAAS mediators.

Methods

BP, glomerular filtration rate (GFR - inulin), effective renal plasma flow (paraaminohippurate) and circulating RAAS components were measured in DM-H, DM-N and HC during clamped euglycemia (4–6 mmol/L). Studies were repeated in DM-H and DM-N during clamped hyperglycemia (9–11 mmol/L).

Results

Baseline GFR was elevated in DM-H vs. DM-N and HC (167±6 vs. 115±2 and 115±2 ml/min/1.73 m², p<0.0001). Baseline systolic BP (SBP, 117±2 vs. 111±2 vs. 109±1, p = 0.004) and heart rate (76±1 vs. 67±1 vs. 61±1, p<0.0001) were higher in DM-H vs. DM-N and HC. Despite higher SBP in DM-H, plasma aldosterone was lower in DM-H vs. DM-N and HC (42±5 vs. 86±14 vs. 276±41 ng/dl, p = 0.01). GFR (p<0.0001) and SBP (p<0.0001) increased during hyperglycemia in DM-N but not in DM-H.

Conclusions

DM-H was associated with higher heart rate and SBP values and an exaggerated suppression of systemic aldosterone. Future work should focus on the mechanisms that explain this paradox in diabetes of renal hyperfiltration coupled with systemic RAAS suppression.     

Non-Invasive Detection of Coronary Endothelial Response to Sequential Handgrip Exercise in Coronary Artery Disease Patients and Healthy Adults

Objectives

Our objective is to test the hypothesis that coronary endothelial function (CorEndoFx) does not change with repeated isometric handgrip (IHG) stress in CAD patients or healthy subjects.

Background

Coronary responses to endothelial-dependent stressors are important measures of vascular risk that can change in response to environmental stimuli or pharmacologic interventions. The evaluation of the effect of an acute intervention on endothelial response is only valid if the measurement does not change significantly in the short term under normal conditions. Using 3.0 Tesla (T) MRI, we non-invasively compared two coronary artery endothelial function measurements separated by a ten minute interval in healthy subjects and patients with coronary artery disease (CAD).

Methods

Twenty healthy adult subjects and 12 CAD patients were studied on a commercial 3.0 T whole-body MR imaging system. Coronary cross-sectional area (CSA), peak diastolic coronary flow velocity (PDFV) and blood-flow were quantified before and during continuous IHG stress, an endothelial-dependent stressor. The IHG exercise with imaging was repeated after a 10 minute recovery period.

Results

In healthy adults, coronary artery CSA changes and blood-flow increases did not differ between the first and second stresses (mean % change ±SEM, first vs. second stress CSA: 14.8%±3.3% vs. 17.8%±3.6%, p = 0.24; PDFV: 27.5%±4.9% vs. 24.2%±4.5%, p = 0.54; blood-flow: 44.3%±8.3 vs. 44.8%±8.1, p = 0.84). The coronary vasoreactive responses in the CAD patients also did not differ between the first and second stresses (mean % change ±SEM, first stress vs. second stress: CSA: −6.4%±2.0% vs. −5.0%±2.4%, p = 0.22; PDFV: −4.0%±4.6% vs. −4.2%±5.3%, p = 0.83; blood-flow: −9.7%±5.1% vs. −8.7%±6.3%, p = 0.38).

Conclusion

MRI measures of CorEndoFx are unchanged during repeated isometric handgrip exercise tests in CAD patients and healthy adults. These findings demonstrate the repeatability of noninvasive 3T MRI assessment of CorEndoFx and support its use in future studies designed to determine the effects of acute interventions on coronary vasoreactivity.     

Fibrin Clot Structure and Platelet Aggregation in Patients with Aspirin Treatment Failure

Background

Aspirin is a cornerstone in prevention of cardiovascular events and modulates both platelet aggregation and fibrin clot formation. Some patients experience cardiovascular events whilst on aspirin, often termed aspirin treatment failure (ATF). This study evaluated both platelet aggregation and fibrin clot structure in patients with ATF.

Methods

We included 177 stable coronary artery disease patients on aspirin monotherapy. Among these, 116 (66%) had ATF defined as myocardial infarction (MI) whilst on aspirin. Platelet aggregation was assessed by Multiplate® aggregometry and VerifyNow®, whereas turbidimetric assays and scanning electron microscopy were employed to study fibrin clot characteristics.

Results

Enhanced platelet aggregation was observed in patients with ATF compared with non-MI patients following stimulation with arachidonic acid 1.0 mM (median 161 (IQR 95; 222) vs. 97 (60; 1776) AU*min, p = 0.005) and collagen 1.0 µg/mL (293 (198; 427) vs. 220 (165; 370) AU*min, p = 0.03). Similarly, clot maximum absorbance, a measure of fibrin network density, was increased in patients with ATF (0.48 (0.41; 0.52) vs. 0.42 (0.38; 0.50), p = 0.02), and this was associated with thinner fibres (mean ± SD: 119.7±27.5 vs. 127.8±31.1 nm, p = 0.003) and prolonged lysis time (552 (498; 756) vs. 519 (468; 633) seconds; p = 0.02). Patients with ATF also had increased levels of C-reactive protein (CRP) (1.34 (0.48; 2.94) and 0.88 (0.32; 1.77) mg/L, p = 0.01) compared with the non-MI group. Clot maximum absorbance correlated with platelet aggregation (r = 0.31–0.35, p-values<0.001) and CRP levels (r = 0.60, p<0.001).

Conclusions

Patients with aspirin treatment failure showed increased platelet aggregation and altered clot structure with impaired fibrinolysis compared with stable CAD patients without previous MI. These findings suggest that an increased risk of aspirin treatment failure may be identified by measuring both platelet function and fibrin clot structure.     

Elevated Soluble VEGF Receptor sFlt-1 Correlates with Endothelial Injury in IgA Nephropathy

Background

Endothelial injury, which may present clinically as hypertension, proteinuria and increased von Willebrand Factor (vWF) level, is a common manifestation in IgA nephropathy (IgAN). However, causal factors for endothelial injury in IgAN are not completely understood. An imbalance of vascular endothelial growth factor/Soluble fms-like tyrosine kinase-1 (VEGF/sFlt-1) has been observed in many diseases with endothelial dysfunction, including pre-eclampsia and diabetic retinopathy, but whether it contributes to endothelial injury in IgAN requires further exploration.

Methods

Initially, 96 IgAN patients and 22 healthy volunteers were enrolled as a discovery cohort. VEGF/sFlt-1, sFlt-1 and VEGF levels were compared between patients with IgAN and healthy volunteers to explore the underlying factors that contribute to endothelial injury in IgAN. The identified contributor (sFlt-1) was further confirmed in a replication cohort, which included 109 IgAN patients and 30 healthy volunteers. Correlations of sFlt-1 with hypertension, proteinuria, Oxford-E score and plasma vWF were further evaluated in the combined 205 patients with IgAN.

Results

VEGF/sFlt-1 levels were significantly lower in IgAN patients than healthy volunteers (0.33±0.27 vs. 0.43±0.22, p = 0.02) in the discovery cohort. Within the ratio, plasma sFlt-1 levels were significantly elevated (101.18±25.19 vs. 79.73±18.85 pg/ml, p<0.001), but plasma VEGF levels showed no significant differences. Elevated sFlt-1 levels in the replication cohort were confirmed in IgAN patients (93.40±39.78 vs. 71.92±15.78 pg/ml, p<0.001). Plasma sFlt-1 levels in IgAN patients correlated with proteinuria (severe (>3.5 g/d) vs. moderate (1–3.5 g/d) vs. mild (<1 g/d) proteinuria: 115.95±39.09 vs. 99.89±28.55 vs. 83.24±33.92 pg/ml; severe vs. mild: p<0.001, moderate vs. mild p = 0.001, severe vs. moderate: p = 0.014), hypertension (with vs. without hypertension: 107.87±31.94 vs. 87.32±32.76 pg/ml, p = 0.015) and vWF levels (r = 0.161, p = 0.021).

Conclusions

The present study found elevated sFlt-1 in IgAN patients and further identified its correlation with proteinuria, hypertension and vWF levels. These results suggested that elevated sFlt-1 contributes to endothelial injury in IgAN.     

Plasma Levels of Soluble Urokinase-Type Plasminogen Activator Receptor Associate with the Clinical Severity of Acute Puumala Hantavirus Infection

Objectives

Urokinase-type plasminogen activator receptor is a multifunctional glycoprotein, the expression of which is increased during inflammation. It is known to bind to β₃-integrins, which are elementary for the cellular entry of hantaviruses. Plasma soluble form of the receptor (suPAR) levels were evaluated as a predictor of severe Puumala hantavirus (PUUV) infection and as a possible factor involved in the pathogenesis of the disease.

Design

A single-centre prospective cohort study.

Subjects and Methods

Plasma suPAR levels were measured twice during the acute phase and once during the convalescence in 97 patients with serologically confirmed acute PUUV infection using a commercial enzyme-linked immunosorbent assay (ELISA).

Results

The plasma suPAR levels were significantly higher during the acute phase compared to the control values after the hospitalization (median 8.7 ng/ml, range 4.0–18.2 ng/ml vs. median 4.7 ng/ml, range 2.4–12.2 ng/ml, P<0.001). The maximum suPAR levels correlated with several variables reflecting the severity of the disease. There was a positive correlation with maximum leukocyte count (r = 0.475, p<0.001), maximum plasma creatinine concentration (r = 0.378, p<0.001), change in weight during the hospitalization (r = 0.406, p<0.001) and the length of hospitalization (r = 0.325, p = 0.001), and an inverse correlation with minimum platelet count (r = −0.325, p = 0.001) and minimum hematocrit (r = −0.369, p<0.001).

Conclusion

Plasma suPAR values are markedly increased during acute PUUV infection and associate with the severity of the disease. The overexpression of suPAR possibly activates β₃-integrin in PUUV infection, and thus might be involved in the pathogenesis of the disease.     

The Relationship between the Severity of Coronary Artery Disease and Epicardial Adipose Tissue Depends on The Left Ventricular Function

Background

Epicardial adipose tissue (EAT) is an active metabolic and endocrine organ. Previous studies focusing mainly on patients with preserved left ventricular function (LVF) could show a correlation between increased amounts of EAT and the extent and activity of coronary artery disease (CAD). However, to date, there are no data available about the relationship between EAT and the severity of CAD with respect to the whole spectrum of LVF impairment. Therefore, we evaluated this relationship in patients with CAD.

Methods

250 patients with CAD and 50 healthy controls underwent CMR examination to assess EAT. The severity of CAD was defined using the angiographic Gensini score (GSS).

Results

The GSS ranged from 2–364. Linear regression analysis revealed a significant correlation between EAT and GSS (r = 0.177, p = 0.01). Patients with mild (GSS≤10) and moderate CAD (GSS>10−≤40) showed comparable EAT to healthy controls. However, in patients with severe CAD (GSS>40) EAT was significantly reduced (p<0.0001) compared to healthy controls. Interestingly, patients with the same GSS revealed different EAT depending on the left ventricular function (LVF). Patients with preserved LVF (LVF≥50%) showed more EAT mass compared to those with reduced LVF (LVF<50%) regardless of the GSS. In patients with preserved LVF and mild CAD, EAT was comparable to healthy controls (61.8±19.4 g vs. 62.9±14.4 g, p = 0.8). In patients with moderate CAD, EAT rose significantly to 83.1±24.9 g (p = 0.01) and started to decline to 66.4±23.6 g in patients with severe CAD (p = 0.03). Contrary, in CAD patients with reduced LVF, EAT was already significantly reduced in patients with mild CAD as compared to healthy controls (p = 0.001) and showed a stepwise decline with increasing CAD severity.

Conclusion

The relationship between EAT and the severity of CAD depends on LVF. These findings emphasize the multifactorial interaction between EAT and the severity of CAD.     

The Vitamin D Status in Inflammatory Bowel Disease

Context

There is no consensus on the vitamin D status of children and adolescents with inflammatory bowel disease (IBD).

Aim

To determine the vitamin D status of patients with IBD by comparing their serum 25(OH)D concentration to that of healthy controls.

Hypothesis

Serum 25(OH)D concentration will be lower in patients with IBD compared to controls.

Subjects and Methods

A case-controlled retrospective study of subjects with IBD (n = 58) of 2–20 years (male n = 31, age 16.38±2.21 years; female n = 27, age16.56±2.08 years) and healthy controls (n = 116; male n = 49, age 13.90±4.59 years; female n = 67, age 15.04±4.12years). Study subject inclusion criteria: diagnosis of Crohn’s disease (CD) or ulcerative colitis (UC). Vitamin D deficiency was defined as 25(OH)D of (<20 ng/mL) (<50 nmol/L), overweight as BMI of ≥85^th but <95^th percentile, and obesity as BMI ≥95^th percentile. Data were expressed as mean ± SD.

Results

Patients with CD, UC, and their controls had mean serum 25(OH)D concentrations of 61.69±24.43 nmol/L, 53.26±25.51, and 65.32±27.97 respectively (ANOVA, p = 0.196). The overweight/obese controls had significantly lower 25(OH)D concentration compared to the normal-weight controls (p = 0.031); whereas 25(OH)D concentration was similar between the normal-weight and overweight/obese IBD patients (p = 0.883). There was no difference in 25(OH)D between patients with UC and CD, or between subjects with active IBD and controls. However, IBD subjects with elevated ESR had significantly lower 25(OH)D than IBD subjects with normal ESR (p = 0.025), as well as controls (65.3±28.0 nmol/L vs. 49.5±25.23, p = 0.045).

Conclusion

There is no difference in mean serum 25(OH)D concentration between children and adolescents with IBD and controls. However, IBD subjects with elevated ESR have significantly lower 25(OH)D than controls. Therefore, IBD subjects with elevated ESR should be monitored for vitamin D deficiency.     

Identification of Altered Plasma Proteins by Proteomic Study in Valvular Heart Diseases and the Potential Clinical Significance

Background

Little is known about genetic basis and proteomics in valvular heart disease (VHD) including rheumatic (RVD) and degenerative (DVD) valvular disease. The present proteomic study examined the hypothesis that certain proteins may be associated with the pathological changes in the plasma of VHD patients.

Methods and Results

Differential protein analysis in the plasma identified 18 differentially expressed protein spots and 14 corresponding proteins or polypeptides by two-dimensional electrophoresis and mass spectrometry in 120 subjects. Two up-regulated (complement C4A and carbonic anhydrase 1) and three down-regulated proteins (serotransferrin, alpha-1-antichymotrypsin, and vitronectin) were validated by ELISA in enlarging samples. The plasma levels (n = 40 for each) of complement C4A in RVD (715.8±35.6 vs. 594.7±28.2 ng/ml, P = 0.009) and carbonic anhydrase 1 (237.70±15.7 vs. 184.7±10.8 U/L, P = 0.007) in DVD patients were significantly higher and that of serotransferrin (2.36±0.20 vs. 2.93±0.16 mg/ml, P = 0.025) and alpha-1-antichymotrypsin (370.0±13.7 vs. 413.0±11.6 µg/ml, P = 0.019) in RVD patients were significantly lower than those in controls. The plasma vitronectin level in both RVD (281.3±11.0 vs. 323.2±10.0 µg/ml, P = 0.006) and DVD (283.6±11.4 vs. 323.2±10.0 µg/ml, P = 0.011) was significantly lower than those in normal controls.

Conclusions

We have for the first time identified alterations of 14 differential proteins or polypeptides in the plasma of patients with various VHD. The elevation of plasma complement C4A in RVD and carbonic anhydrase 1 in DVD and the decrease of serotransferrin and alpha-1-antichymotrypsin in RVD patients may be useful biomarkers for these valvular diseases. The decreased plasma level of vitronectin – a protein related to the formation of valvular structure – in both RVD and DVD patients might indicate the possible genetic deficiency in these patients.     

Association between Plasma Neutrophil Gelatinase Associated Lipocalin Level and Obstructive Sleep Apnea or Nocturnal Intermittent Hypoxia

Background

Both obstructive sleep apnea (OSA) and a novel lipocalin, neutrophil gelatinase associated lipocalin (Ngal), have been reported to be closely linked with cardiovascular disease and loss of kidney function through chronic inflammation. However, the relationship between OSA and Ngal has never been investigated.

Objectives

To evaluate the relationship between Ngal and OSA in clinical practice.

Methods

In 102 patients, polysomnography was performed to diagnose OSA and plasma Ngal levels were measured. The correlations between Ngal levels and OSA severity and other clinical variables were evaluated. Of the 46 patients who began treatment with continuous positive airway pressure (CPAP), Ngal levels were reevaluated after three months of treatment in 25 patients.

Results

The Ngal level correlated significantly with OSA severity as determined by the apnea hypopnea index (r = 0.24, p = 0.01) and 4% oxygen desaturation index (ODI) (r = 0.26, p = 0.01). Multiple regression analysis showed that the Ngal level was associated with 4%ODI independently of other clinical variables. Compliance was good in 13 of the 25 patients who used CPAP. Although the OSA (4%ODI: 33.1±16.7 to 1.1±1.9/h, p<0.01) had significantly improved in those with good compliance, the Ngal levels were not significantly changed (60.5±18.1 before CPAP vs 64.2±13.9 ng/ml after CPAP, p = 0.27).

Conclusions

Plasma Ngal levels were positively associated with the severity of OSA. However, the contribution rate of OSA to systemic Ngal secretion was small and changes in Ngal levels appeared to be influenced largely by other confounding factors. Therefore, it does not seem reasonable to use the Ngal level as a specific biomarker of OSA in clinical practice.     

Growth Differentiation Factor-15 (GDF-15) Levels Are Associated with Cardiac and Renal Injury in Patients Undergoing Coronary Artery Bypass Grafting with Cardiopulmonary Bypass

Objective

Growth differentiation factor-15 (GDF-15) has been identified as a strong marker of cardiovascular disease; however, no data are available concerning the role of GDF-15 in the occurrence of organ dysfunction during coronary artery bypass grafting (CABG) associated with cardiopulmonary bypass (CPB).

Methods

Five arterial blood samples were taken sequentially in 34 patients from anesthesia induction (IND) until 24 h after arrival at the intensive care unit (ICU). Plasma levels of GDF-15, follistatin-like 1 (FLST1), myeloperoxidases (MPO), hydroperoxides and plasma antioxidant status (PAS) were measured at each time-point. Markers of cardiac (cardiac-troponin I, cTnI) and renal dysfunction (neutrophil gelatinase-associated lipocalin, NGAL) and other classical biological factors and clinical data were measured.

Results

Plasma GDF-15 levels increased gradually during and after surgery, reaching nearly three times the IND levels in the ICU (3,075±284 ng/L vs. 1,061±90 ng/L, p<0.001). Plasma MPO levels increased dramatically during surgery, attaining their highest level after unclamping (UNCLAMP) (49±11 ng/mL vs. 1,679±153 ng/mL, p<0.001) while PAS significantly decreased between IND and UNCLAMP (p<0.05), confirming the high oxidative status induced by this surgical procedure. ICU levels of GDF-15 correlated positively with cTnI and NGAL (p = 0.006 and p = 0.036, respectively), and also with hemoglobin and estimated glomerular filtration rate (eGFR). Among all the post-operative biomarkers available, only eGFR, NGAL and GDF-15 measured at ICU arrival were significantly associated with the onset of acute kidney injury (AKI). Patients with a EuroSCORE >3 were shown to have higher GDF-15 levels.

Conclusions

During cardiac surgery associated with CPB, GDF-15 levels increased substantially and were associated with markers of cardiac injury and renal dysfunction.