Endothelial function and left ventricular remodeling in diabetic and non-diabetic patients after acute coronary syndrome

Identifying the Role of Flow-Mediated Dilatation Assessment in Acute Coronary Syndromes: A Systematic Review

In the context of the global burden of cardiovascular disease, the development of novel, patient-targeted diagnostic and therapeutic strategies is of paramount importance. Acute coronary syndromes (ACS) comprise a subset of cardiovascular disease, with constantly increasing prevalence requiring urgent attention. Flow-mediated dilatation (FMD), a noninvasive method for the evaluation of endothelial function, has been previously implemented in patients with ACS. A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted in order to identify all relevant studies assessing the implementation of FMD among patients with ACS. Our review reflects an effort to present all available data regarding the role of FMD to date, a valuable noninvasive and easy accessible diagnostic tool, in the prognosis of patients with ACS. FMD evaluation in patients with ACS reveals a decline in values, indicative of the presence of endothelial function among this distinct patient group. FMD has also been used to assess the response to various treatments, as well as to predict major adverse cardiovascular events. Dynamic responses to interventions highlights its potential in the evolving field of interventional cardiology.

Impact of glycemic control on the association of endothelial dysfunction and coronary artery disease in patients with type 2 diabetes mellitus

Background

We investigated whether glycemic control affects the relation between endothelial dysfunction and coronary artery disease in patients with type 2 diabetes mellitus (T2DM).

Methods

In 102 type 2 diabetic patients with stable angina, endothelial function was evaluated using brachial artery flow-mediated dilation (FMD) with high-resolution ultrasound, and significant stenosis of major epicardial coronary arteries (≥ 50% diameter narrowing) and degree of coronary atherosclerosis (Gensini score and SYNTAX score) were determined. The status of glycemic control was assessed by blood concentration of glycated hemoglobin (HbA1c).

Results

The prevalence of significant coronary artery stenosis (67.9% vs. 37.0%, P = 0.002) and degree of coronary atherosclerosis (Gensini score: 48.99 ± 48.88 vs. 15.07 ± 21.03, P < 0.001; SYNTAX score: 15.88 ± 16.36 vs. 7.28 ± 10.54, P = 0.003) were higher and FMD was lower (6.03 ± 2.08% vs. 6.94 ± 2.20%, P = 0.036) in diabetic patients with poor glycemic control (HbA1c ≥ 7.0%; n = 56) compared to those with good glycemic control (HbA1c < 7.0%; n = 46). Multivariate regression analysis revealed that tertile of FMD was an independent determinant of presence of significant coronary artery stenosis (OR = 0.227 95% CI 0.056–0.915, P = 0.037), Gensini score (β =  − 0.470, P < 0.001) and SYNTAX score (β =  − 0.349, P = 0.004) in diabetic patients with poor glycemic control but not for those with good glycemic control (P > 0.05).

Conclusion

Poor glycemic control negatively influences the association of endothelial dysfunction and coronary artery disease in T2DM patients.

[Impact of endothelial dysfunction on the course of acute ST-elevation myocardial infarction and its correction by remote ischemic preconditioning]

Aim of the study - to assess the effect of remote ischemic preconditioning (RIPC) on the incidence of endothelial dysfunction (ED) and its impact on hospital prognosis in patients with ST segment elevation acute myocardial infarction (STEMI).

MATERIALS AND METHODS

We conducted a single - centre, open - label prospective study that included 173 patients with STEMI who underwent primary percutaneous coronary intervention within the first 24 hours of the symptoms onset. Before the PCI, patients were randomized into two groups. In the first group (n=86) during the preparation for PCI, we performed RIPC procedure by inflation of the cuff of the tonometer to 200 mm Hg and its further deflation on patient's shoulder, thus creating short cycles of controlled ischemia/reperfusion in hand (4 cycles of ischemia/reperfusion for 5/5 minutes respectively). In the second, control group (n=87), the standard primary PCI was performed without the previous RIPC. Evaluation of the endothelial function was performed on the 2-7th day after admission using the endothelium - dependent flow - mediated dilatation test (FMD) of the brachial artery. Primary endpoints in this study included the presence of ED, in - hospital mortality, life - threatening arrhythmias (ventricular fibrillation/ventricular tachycardia after first 24 hours upon admission), stent thrombosis, clinical signs of heart failure, and a combined endpoint consisting of all the listed above.

RESULTS

The median values for FMD-test did not differ significantly between the study groups upon admission. Assessment of the FMD of the brachial artery on the 2-7th day after PCI showed that among the patients who underwent RIPC there was a significantly lower percentage of patients with ED than in the patients with STEMI who did not undergo RIPC before PCI (43.1% vs. 75.8% respectively, p=0.0001). We found a significant reduction in the incidence of heart failure and of combined endpoint in the group of patients without ED compared with patients with ED: 0% vs. 9.3% (n=7; p=0.023) and 3.8% (n=2) vs. 16% (n=12; p=0.032) respectively. When assessing the effect of RIPC on hospital prognosis, we also found a significant decrease in the incidence of heart failure and a trend towards a decrease in the combined endpoint in the group of patients who underwent RIPC compared to the control group: 1.5% (n=1) vs. 9.7% (n=6; p=0.045) and 6.2% (n=4) vs. 16.1% (n=10; p=0.073) respectively.

CONCLUSION

Performance of RIPC before the primary PCI significantly reduces the incidence of ED in patients with STEMI on the 2-7th day of the disease onset. The presence of ED in patients with STEMI is associated with a significant increase in the incidence of heart failure and of the combined endpoint during in - hospital period. RIPC significantly reduces the incidence of heart failure in patients with STEMI during in - hospital period.

Serum IL-6 and sIL-6R in type 2 diabetes contribute to impaired capillary-like network formation

We hypothesized that the serum from individuals with type 2 diabetes mellitus (T2DM) and impaired glucose tolerance (IGT) would reduce in vitro capillary-like network formation compared with normal glucose tolerance (NGT) serum and that this would occur along with higher serum concentrations of inflammatory cytokines and lower concentrations of angiogenic growth factors. Subjects were sedentary, older (55-65 yr) adults with NGT, IGT, or T2DM (n = 10/group) matched for body mass index. Human retroviral telomerized endothelial cells (HRVT-ECs) or coronary artery endothelial cells (CECs) were used in a capillary-like network formation assay using endothelial basal medium supplemented with 7.5% serum. Quantification of HRVT-EC network length indicated that serum from the T2DM group resulted in 32 and 35% lower network formation than when using serum from the NGT and IGT groups, respectively (P < 0.05). Serum from T2DM subjects resulted in CEC network formation that was 11 and 8% lower than when using serum from NGT and IGT subjects, respectively (P < 0.05). Analysis of serum cytokines indicated that IL-6 was 41% and 49% higher in the IGT and T2DM groups, respectively, compared with the NGT group (P < 0.05) and there was a trend for higher soluble interleukin-6 receptor (sIL-6R; P = 0.06) and IL-8 (P = 0.08) in the T2DM serum compared with NGT. The use of recombinant IL-6 and sIL-6R at concentrations detected in the T2DM serum also reduced capillary network formation compared with NGT concentrations (P < 0.05). These results suggest that IL-6 and sIL-6R present in the serum of T2DM individuals impair in vitro endothelial cell function across different cell lines. Our findings may have implications for the microvascular complications associated with T2DM.NEW & NOTEWORTHY Higher concentrations of serum factors, specifically Interleukin-6 and its soluble receptor found in individuals with type 2 diabetes (T2DM) appear to impair endothelial cell capillary-like network formation compared with those present in serum from individuals with impaired glucose tolerance and normal glucose tolerance. This may have implications for the vascular complications associated with T2DM.

The effects of pigment epithelium-derived factor on atherosclerosis: putative mechanisms of the process

Cardiovascular disease (CVD) is a leading cause of death worldwide. Atherosclerosis is believed to be the major cause of CVD, characterized by atherosclerotic lesion formation and plaque disruption. Although remarkable advances in understanding the mechanisms of atherosclerosis have been made, the application of these theories is still limited in the prevention and treatment of atherosclerosis. Therefore, novel and effective strategies to treat high-risk patients with atherosclerosis require further development. Pigment epithelium-derived factor (PEDF), a glycoprotein with anti-inflammatory, anti-oxidant, anti-angiogenic, anti-thrombotic and anti-tumorigenic properties, is of considerable interest in the prevention of atherosclerosis. Accumulating research has suggested that PEDF exerts beneficial effects on atherosclerotic lesions and CVD patients. Our group, along with colleagues, has demonstrated that PEDF may be associated with acute coronary syndrome (ACS), and that the polymorphisms of rs8075977 of PEDF are correlated with coronary artery disease (CAD). Moreover, we have explored the anti-atherosclerosis mechanisms of PEDF, showing that oxidized-low density lipoprotein (ox-LDL) reduced PEDF concentrations through the upregulation of reactive oxygen species (ROS), and that D-4F can protect endothelial cells against ox-LDL-induced injury by preventing the downregulation of PEDF. Additionally, PEDF might alleviate endothelial injury by inhibiting the Wnt/β-catenin pathway. These data suggest that PEDF may be a novel therapeutic target for the treatment of atherosclerosis. In this review, we will summarize the role of PEDF in the development of atherosclerosis, focusing on endothelial dysfunction, inflammation, oxidative stress, angiogenesis and cell proliferation. We will also discuss its promising therapeutic implications for atherosclerosis.

Early peripheral endothelial dysfunction predicts myocardial infarct extension and microvascular obstruction in patients with ST-elevation myocardial infarction

INTRODUCTION AND OBJECTIVES

The role of endothelial dysfunction (ED) in patients with ST-elevation myocardial infarction (STEMI) is poorly understood. Peripheral arterial tonometry (PAT) allows non-invasive evaluation of ED, but has never been used for this purpose early after primary percutaneous coronary intervention (P-PCI). Our purpose was to analyze the relation between ED assessed by PAT and both the presence of microvascular obstruction (MVO) and infarct extension in STEMI patients.

METHODS

ED was assessed by the reactive hyperemia index (RHI), measured by PAT and defined as RHI <1.67. Infarct extension was assessed by troponin I (TnI) release and contrast-enhanced cardiac magnetic resonance (ceCMR). MVO was assessed by ceCMR and by indirect angiographic and ECG indicators. An echocardiogram was also performed in the first 12 h.

RESULTS

We included 38 patients (mean age 60.0±13.7 years, 29 male). Mean RHI was 1.87±0.60 and 16 patients (42.1%) had ED. Peak TnI (median 118 mg/dl, IQR 186 vs. 67/81, p=0.024) and AUC of TnI (median 2305, IQR 2486 vs. 1076/1042, p=0.012) were significantly higher in patients with ED, who also showed a trend for more transmural infarcts (63.6% vs. 22.2%, p=0.06) and larger infarct mass on ceCMR (median 17.5%, IQR 15.4 vs. 10.1/10.3, p=0.08). Left ventricular ejection fraction (LVEF) was lower and wall motion score index (WMSI) was higher on both echocardiogram and ceCMR in patients with ED. On ceCMR, MVO was more frequent in patients with RHI <1.67 (54.5% vs. 11.1%, p=0.03). ECG and angiographic indicators of MVO all showed a trend toward worse results in these patients.

CONCLUSIONS

The presence of ED assessed by PAT 24 h after P-PCI in patients with STEMI is associated with larger infarcts, lower LVEF, higher WMSI and higher prevalence of MVO.

Endothelial dysfunction evaluated by peripheral arterial tonometry is related with peak TnI values in patients with ST elevation myocardial infarction treated with primary angioplasty

PURPOSE

The role of endothelial-dependent function in patients with acute ST elevation myocardial infarction (STEMI) is not clear. Endothelial dysfunction may contribute to the pathophysiological processes occurring after STEMI and influence the extension of myocardial necrosis. Endothelial-dependent dysfunction evaluated by peripheral arterial tonometry (PAT) has already showed to be correlated with microvascular coronary endothelial dysfunction. Our purpose was to evaluate the impact of endothelial dysfunction on peak Troponin I (TnI) values, as a surrogate for the extension of myocardial infarction, in patients with STEMI treated with primary angioplasty (P-PCI).

METHODS

58 patients with STEMI treated with P-PCI (mean age 59.0 ± 14.0 years, 46 males) were included. Endothelial function was assessed by reactive hyperaemia index (RHI) determined by PAT. Patients were divided in two groups according to the previously reported RHI threshold for high risk (1.67). The extension of myocardial necrosis was evaluated by peak TnI levels.

RESULTS

RHI median value was 1.78 (IQR0.74);25 patients had endothelial dysfunction (RHI b 1.67). The two groups had no significant differences in age, gender, main risk factors and pain-to-balloon time. Patients with an RHI b 1.67 had significant larger infarcts: TnI 73.5 ng/mL (IQR 114.42 ng/mL) versus TnI 33.2 ng/mL (IQR 65.2 ng/mL); p = 0.028. On multivariate analysis, the presence of an RHI b 1.67 kept significant impact on TnI peak values (p=0.02).

CONCLUSIONS

The presence of endothelial-dependent dysfunction, assessed by PAT, is related with higher peak TnI values in STEMI patients treated with P-PCI. These results strength the possibility that endothelial-dependent dysfunction may be a marker of poor prognosis and eventually a therapeutic target in patients with STEMI.

The effect of autoimmunity on the development time of microvascular complications in patients with type 1 diabetes mellitus

Background

Type 1 diabetes mellitus (DM) is an autoimmune disease with chronic complications that is becoming more frequent as life expectancy of diabetics has increased owing to improved methods of detection and better management. In this study, we investigated whether the presence of autoimmunity can be used in predicting the development time of microvascular complications.

Material/Methods

Our study included 52 patients with type 1 diabetes mellitus (DM). The subjects had developed microvascular complications and they had been tested for anti-GAD (glutamic acid decarboxylase) antibodies and/or islet-cell antibodies (ICA). In the assessment of microvascular complications, we used ocular fundus examination, electromyography (EMG), and 24-h urine microalbuminuria tests.

Results

Of the patients included in the study, 30 were female and 22 were male. Of all patients characterized for the existence of diabetic complications, 36 of 52 had both diabetic retinopathy and diabetic nephropathy, 5 patients had diabetic neuropathy, and 11 patients had diabetic retinopathy only. At the diagnosis of diabetes, 20 in 52 patients tested negative for autoantibodies (anti-GAD and anti-ICA), while 32 of 52 tested positive for anti-GAD and/or anti-ICA. The mean HbA1C level of autoantibody-negative patients was 7.7%, while antibody-positive patients had slightly higher HbA1c levels (7.9%). However, this difference was not statistically significant (p>0.05). The mean development time of microvascular complications in autoantibody-positive patients was calculated as 11: 40±6.46 years, and in patients with negative autoimmunity results it was 10.91±6.70 years.

Conclusions

The presence of diabetes-related autoantibodies (DRAs) in patients with type 1 diabetes mellitus does not have a significant effect on the development time of diabetic microvascular complications.

Evaluation of the Associations between Vascular Endothelial Function and Coronary Artery Stenosis in Patients with Elevated Blood Pressure during Coronary Angiography

<p><b>Objectives:</b> The aim of the present study is to explore the correlation between vascular endothelial function and coronary artery stenosis in non-hypertensive patients with elevated blood pressure under stress.</p><p><b>Methods:</b> This study included 1141 patients suspected of having coronary artery disease (CAD) without hypertension. Coronary arteriography and ultrasonic detection were used to measure the flow-mediated dilatation (FMD) function in the brachial artery. Patients were divided into 2 groups according to coronary angiography: experiment group, patients with blood pressure ? 140/90 mm Hg; control group, patients with blood pressure <140/90 mm Hg. The correlation between vascular endothelial function and coronary artery stenosis was observed.</p><p><b>Results:</b> The majority of the patients in the control group were found to have either normal coronary arteries or stenosis <50%. Patients in the experiment group (those with invasive blood pressure [IBP] >140/90) were more likely to have some degree of coronary artery stenosis. Specifically, there were significantly more patients with >50% stenosis in the experiment when compared with the control group (<i>P</i> < .05). The FMD in the experiment group was significantly lower than that in the control group (<i>P</i> < .05).</p><p><b>Conclusion:</b> The non-hypertensive patients with elevated blood pressure under stress had coronary artery stenosis, which was associated with vascular endothelial dysfunction.</p>

Comparison of TIMI and Gensini score in patients admitted to the emergency department with chest pain, who underwent coronary angiography

Background

In patients admitted to the emergency department with complaints of chest pain and unstable angina pectoris, ST-elevation MI scoring is done according to risk factors used to calculate risks of urgent revascularization, MI, and death within 14 days. For this calculation, the most widely used scoring system is TIMI risk score.

Materila/Methods

In this prospective, cross-sectional descriptive study, we evaluated and compared the effectiveness of TIMI and Gensini scores of patients with chest pain who were admitted to Hacettepe University Hospitals Emergency Department between March 2011 and September 2011 and who underwent coronary angiography.

Results

The mean (range) age of 165 patients was 62 (31–88) years. Moderate correlation between TIMI and Gensini scores was detected (mean values of Gensini score for TIMI 1 is 53.50, for TIMI 2 it is 52.09, for TIMI 3 it is 102.77, for TIMI 4 it is 113.70, and for TIMI 5 it is 115.43). There was also a positive correlation between TIMI score and the results.

Conclusions

TIMI risk stratification score is safe and easy to use for rapid assessment of mortality and MI risk, despite its low possibility of predicting the outcome.

L-arginine, asymmetric dimethylarginine, and symmetric dimethylarginine in plasma and synovial fluid of patients with knee osteoarthritis

BACKGROUND

The aim of this study was to investigate the involvement of the nitric oxide (NO) pathway in osteoarthritis (OA).

MATERIAL AND METHODS

The study groups consisted of 32 patients with knee OA and 31 healthy controls. In peripheral venous blood samples (from the OA patients and the controls) and in synovial fluid samples (from the OA patients), the concentrations of L-arginine (ARN), asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) were evaluated. In plasma samples, thiobarbituric acid reactive substances (TBARS) were also measured.

RESULTS

Plasma ARN concentrations were lower in the OA patients than in controls (53.55 ± 16.37 vs. 70.20 ± 25.68 µmol/l) (P<0.05), while plasma ADMA concentrations were similar. Accordingly, the ARN/ADMA ratio was lower in the OA patients than in the control group (80.85 ± 29.58 vs. 110.51 ± 30.48, P<0.05). Plasma SDMA and TBARS concentrations were higher in the OA patients than in controls (0.69 ± 0.15 vs. 0.60 ± 0.10 µmol/l, P<0.05 and 1.21 ± 0.29 vs. 0.55 ± 0.12, respectively) (P<0.001). In the OA patients, ADMA concentrations were significantly higher in the synovial fluid than in plasma (0.75 ± 0.09 vs. 0.69 ± 0.14 µmol/l, P<0.05), as were ARN concentrations (76.96 ± 16.73 vs. 53.55 ± 16.73 µmol/l) (P<0.00001). Conclusions These results indicate a poor availability of NO in the synovial fluid of the OA patients, which may contribute to the progression of OA. The decreased ARN/ADMA ratio and the increased SDMA and TBARS in the plasma of the OA patients suggest an impairment of endothelial function in these subjects.

Endothelial dysfunction over the course of coronary artery disease

The vascular endothelium regulates blood flow in response to physiological needs. Endothelial dysfunction is closely related to atherosclerosis and its risk factors, and it constitutes an intermediate step on the progression to adverse events throughout the natural history of coronary artery disease (CAD), often affecting clinical outcomes. Understanding the relation of endothelial function with CAD provides an important pathophysiological insight, which can be useful both in clinical and research management. In this review, we summarize the current knowledge on endothelial dysfunction and its prognostic influence throughout the natural history of CAD, from early atherosclerosis to post-transplant management.

Optimizing HgA1C and glucose monitoring frequency in patients with Type 2 diabetes

BACKGROUND

The primary objective of our study is to compare HgA1C to self monitoring frequency in diabetes subjects. A secondary objective is to evaluate the influence of family support and gender on glucose monitoring frequency and HgA1C.

MATERIAL/METHODS

We studied the glucose monitoring frequency and HgA1c outcome of 67 subjects treated with diet alone, 350 subjects treated with tablets, 155 subjects treated with insulin, and 228 subjects treated with both tablets and insulin.

RESULTS

Eleven percent of the subjects monitoring 4-7 times per week produced a positive significant coefficient (p<.05). Self monitoring less than 4 times per week showed no statistical significance and self monitoring more than 8 times per week showed no statistical significance. Forty-eight percent of subjects treating with insulin alone and tablet plus insulin produced positive significant coefficients (p<.05). The percentage lowering of HgA1C of tablet plus insulin is 15.64% as the mean HgA1C at the first visit was 9.35 compared to 7.89. The percentage lowering of HgA1C for insulin alone was 12.24% as the mean HgA1C at the first visit was 9.37 compared to 8.23 at the later visit.

CONCLUSIONS

We conclude that (1) frequency of self monitoring should be based on individualized goals and willingness to participate, (2) both insulin alone and tablet plus insulin levels of medication are effective at lowering HgA1C levels; however, using the tablet and insulin combined produced lower HgA1C levels than using insulin alone; (3) family support and gender have no effect on glucose monitoring frequency and lowering HgA1C levels.