Relation between endothelial dysfunction and the acute coronary syndrome: implications for therapy

Hospitalization for acute coronary syndrome increases the long-term risk of pneumonia: a population-based cohort study

It is well established that the risk of acute coronary syndrome (ACS) increases after respiratory infection. However, the reverse association has not been evaluated. We tested the hypothesis that the long-term risk of pneumonia is increased after a new ACS event. A matched-cohort study was conducted using a nationally representative dataset. We identified patients with admission for ACS between 2004 and 2014, without a previous history of ACS or pneumonia. Incidence density sampling was used to match patients, on the basis of age and sex, to 3 controls who were also free from both ACS and pneumonia. We examined the incidence of pneumonia after ACS until the end of the cohort observation (Dec 31, 2014). The analysis cohort consisted of 5469 ACS cases and 16,392 controls (median age, 64 years; 68.3% men). The incidence rate ratios of the first and the total pneumonia episodes in the ACS group relative to the control group was 1.25 (95% confidence interval [CI], 1.11–1.41) and 1.23(95% CI 1.11–1.36), respectively. A significant ACS-related increase in the incidence of pneumonia was observed in the Cox-regression, shared frailty, and joint frailty model analyses, with hazard ratios of 1.25 (95% CI 1.09–1.42), 1.35 (95% CI 1.15–1.58), and 1.24 (95% CI 1.10–1.39), respectively. In this population-based cohort of patients who were initially free from both ACS and pneumonia, we found that hospitalization for ACS substantially increased the long term risk of pneumonia. This should be considered when formulating post-discharge care plans and preventive vaccination strategies in patients with ACS.

Relation of vascular dilator function and cardiac autonomic function with coronary angiography findings in patients with non-ST segment elevation acute coronary syndrome

BACKGROUND

A sizeable number of patients with a diagnosis of non-ST segment elevation acute coronary syndrome show non-obstructive coronary artery disease. In this study we assessed whether differences in vascular and cardiac autonomic function exist between non-ST segment elevation acute coronary syndrome patients with obstructive or non-obstructive coronary artery disease.

METHODS AND RESULTS

Systemic endothelium-dependent and independent vascular dilator function (assessed by flow-mediated dilation and nitrate-mediated dilation of the brachial artery, respectively) and cardiac autonomic function (assessed by time-domain and frequency-domain heart rate variability parameters) were assessed on admission in 120 patients with a diagnosis of non-ST segment elevation acute coronary syndrome. Patients were divided into two groups according to coronary angiography findings: (a) 59 (49.2%) with obstructive coronary artery disease (≥50% stenosis in any epicardial arteries); (b) 61 (50.8%) with non-obstructive coronary artery disease. No significant differences between the two groups were found in both flow-mediated dilation (5.03 ± 2.6 vs. 5.40 ± 2.5%, respectively; P = 0.37) and nitrate-mediated dilatation (6.79 ± 2.8 vs. 7.30 ± 3.4%, respectively; P = 0.37). No significant differences were also observed between the two groups both in time-domain and frequency-domain heart rate variability variables, although the triangular index tended to be lower in obstructive coronary artery disease patients (30.2 ± 9.5 vs. 33.9 ± 11.6, respectively; P = 0.058). Neither vascular nor heart rate variability variables predicted the recurrence of angina, requiring emergency room admission or re-hospitalisation, during 11.3 months of follow-up.

CONCLUSIONS

Among patients admitted with a diagnosis of non-ST segment elevation acute coronary syndrome we found no significant differences in systemic vascular dilator function and cardiac autonomic function between those with obstructive coronary artery disease and those with non-obstructive coronary artery disease.

Transforming Growth Factor Beta (TFG-β) Concentration Isoforms are Diminished in Acute Coronary Syndrome

Acute coronary syndrome (ACS) is the leading cause of death in elderly patients worldwide. Due its participation in apoptosis, fibrosis, and angiogenesis, transforming growth factor-β (TGF-β) isoforms had been categorized as risk factors for cardiovascular diseases. However, due their contradictory activities, a cardioprotective role has been suggested. The aim was to measure the plasma levels of TGF-β1, 2, and 3 proteins in patients with ACS. This was a case-control study including 225 subjects. The three activated isoforms were measured in serum using the Bio-Plex Pro TGF-β assay by means of magnetic beads; the fluorescence intensity of reporter signal was read in a Bio-Plex Magpix instrument. We observed a significant reduction of the three activated isoforms of TGF-β in patients with ACS. The three TGF-β isoforms were positively correlated with each other in moderate-to-strong manner. TGFβ-2 was inversely correlated with glucose and low-density lipoprotein (LDL)-cholesterol, whereas TGF-β3 was inversely correlated with the serum cholesterol concentration. The production of TGF-β1, TGF-β2, and TGF-β3 are decreased in the serum of patients with ACS. Further follow-up controlled studies with a larger sample size are needed, in order to test whether TGF-β isoforms could be useful as biomarkers that complement the diagnosis of ACS.

Increased Risk of Acute Coronary Syndrome in Patients With Chronic Pancreatitis: A Nationwide Cohort Analysis

Chronic inflammation may promote development of coronary heart disease. Studies on the relationship between chronic pancreatitis (CP) and cardiovascular diseases are scant.We conducted a nationwide retrospective cohort study to determine the risk of acute coronary syndrome (ACS) in patients with CP.We randomly selected a comparison cohort of individuals without CP from the Taiwan National Health Insurance Research Database (N = 23.74 million) and frequency-matched them with patients with CP from 2000 to 2010 in a 1:4 ratio according to age, sex, and index year. The follow-up period lasted from the index date of the new CP diagnosis to the date of ACS diagnosis, censoring, or the end of 2011. We analyzed the risk of ACS by using Cox proportional-hazard models.In total, 17,405 patients with CP and 69,620 individuals without CP were followed for 84,430 and 417,426 person-years. Most patients with CP were men, and the mean age of the patients was 48.3 ± 15.0 years. The overall ACS incidence was 2.15-fold higher in the CP cohort than in the non-CP cohort (4.89 vs 2.28 per 10,000 person-years) with an adjusted hazard ratio (aHR) of 1.40 (95% confidence interval [CI] 1.20-1.64). Compared with individuals without CP, patients with CP aged ≤39 years exhibited the highest risk of ACS (aHR 2.14, 95% CI 1.13-4.02), followed by those aged 40 to 54 years (aHR 1.66, 95% CI 1.23-2.24) and those aged 55 to 69 years (aHR 1.53, 95% CI 1.15-2.03).CP may become an independent risk factor for ACS.

Impact of oxidative stress during pregnancy on fetal epigenetic patterns and early origin of vascular diseases

Epidemiological studies have led scientists to postulate the developmental origins of health and disease hypothesis for noncommunicable diseases such as diabetes, cardiovascular diseases, hypertension, and obesity. However, the cellular and molecular mechanisms involved in the development of these diseases are not well understood. In various animal models, it has been observed that oxidative stress during pregnancy is associated with the early development of endothelial dysfunction in offspring. This phenomenon suggests that endothelial dysfunction may initiate in the uterus and could lead to increased risk of cardiovascular disease later in life. Currently, it is known that many of the fetal adaptive responses to environmental factors are mediated by epigenetic changes in the genome, especially by the degree of methylation in cytosines in the promoter regions of genes. These findings suggest that the establishment of a particular epigenetic pattern in the genome may be generated by oxidative stress.

Vitamin D plasma levels and in-hospital and 1-year outcomes in acute coronary syndromes: a prospective study

Deficiency in 25-hydroxyvitamin D (25[OH]D), the main circulating form of vitamin D in blood, could be involved in the pathogenesis of acute coronary syndromes (ACS). To date, however, the possible prognostic relevance of 25 (OH)D deficiency in ACS patients remains poorly defined. The purpose of this prospective study was to assess the association between 25 (OH)D levels, at hospital admission, with in-hospital and 1-year morbidity and mortality in an unselected cohort of ACS patients.We measured 25 (OH)D in 814 ACS patients at hospital presentation. Vitamin D serum levels >30 ng/mL were considered as normal; levels between 29 and 21 ng/mL were classified as insufficiency, and levels < 20 ng/mL as deficiency. In-hospital and 1-year outcomes were evaluated according to 25 (OH)D level quartiles, using the lowest quartile as a reference.Ninety-three (11%) patients had normal 25 (OH)D levels, whereas 155 (19%) and 566 (70%) had vitamin D insufficiency and deficiency, respectively. The median 25 (OH)D level was similar in ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) patients (14.1 [IQR 9.0-21.9] ng/mL and 14.05 [IQR 9.1-22.05] ng/mL, respectively; P = .88). The lowest quartile of 25 (OH)D was associated with a higher risk for several in-hospital complications, including mortality. At a median follow-up of 366 (IQR 364-379) days, the lowest quartile of 25 (OH)D, after adjustment for the main confounding factors, remained significantly associated to 1-year mortality (P < .01). Similar results were obtained when STEMI and NSTEMI patients were considered separately.In ACS patients, severe vitamin D deficiency is independently associated with poor in-hospital and 1-year outcomes. Whether low vitamin D levels represent a risk marker or a risk factor in ACS remains to be elucidated.

The prevalence of endothelial dysfunction in patients with and without coronary artery disease

BACKGROUND

Endothelial dysfunction (ED) is frequently present in patients presenting with acute or stable coronary artery disease (CAD), but it is also found in patients presenting with chest pain without angiographic coronary lesions.

HYPOTHESIS

We hypothesized that even in patients without CAD, the presence of cardiovascular (CV) risk factors will correlate with the presence of ED.

METHODS

Our study included a total of 341 consecutive patients referred for coronary angiography. We used pulse wave analysis with a finger plethysmograph (peripheral arterial tonometry) to determine endothelial function. Hyperemia ratio was calculated as the ratio of the postischemic hyperemia response relative to baseline measurement.

RESULTS

The hyperemia ratio was significantly higher in patients without CAD (2.02 ± 0.52) compared with patients with chronic CAD (1.81 ± 0.44, P = 0.001) or acute CAD (1.74 ± 0.49, P < 0.001). Prevalence of ED was 33%, 46%, and 58%, respectively. In multivariate analysis, the presence of CAD, diabetes, and cigarette smoking, and the total number of CV risk factors, were strong predictors of ED. In 67% of the patients without CAD but with ≥3 CV risk factors, ED was present.

CONCLUSIONS

Prevalence of ED in patients with chest pain depends on the presence of CAD and CV risk factors. Patients without CAD but with ≥3 risk factors frequently presented with ED. Such patients may be at increased risk for future CV events and may profit from intensified therapy to control CV risk factors.

Endothelial dysfunction in post-myocardial infarction patients with various expressions of risk factors

It has not been established yet whether patients who suffer myocardial infaction (MI) in the absence of classic risk factors also have endothelial dysfunction (ED), as has been shown for patients with risk factors, and if so, to what extent it is manifested. Young male patients in the stable phase after MI were included in the study. At the time of MI, 20 patients had high and 21 patients low expression of risk factors. The control group consisted of 35 healthy age-matched males. ED was estimated by ultrasound measurement of the endothelium-dependent dilation of the brachial artery, induced by the reactive hyperemia test. Compared to the control group, the level of endothelium-dependent vasodilation was significantly reduced in both groups of patients (controls: 9.1% +/- 5.6%; patients with high risk: 5.5% +/- 5.1%; patients with low risk: 5.6 +/- 3.5 %; ANOVA, p<.01). There was no difference between both groups of patients. These results showed that ED is not associated or due only to classic risk factors. It appears that ED may occur and precede development of atherosclerosis in the absence of classic risk factors. These novel findings can have important clinical implications.

Interleukin-6 Correlates with Endothelial Dysfunction in Young Post-Myocardial Infarction Patients

BACKGROUND

The estimation of coronary risk based on consideration of classical risk factors is insufficient in young patients with myocardial infarction who have low expressions of classical risk factors. Endothelial dysfunction (ED) and markers of vascular inflammation may be more appropriate for risk estimation. The relations among ED and inflammation markers in such patients have not yet been explored.

PATIENTS AND METHODS

Twenty-one patients (on average 44 years old) in the stable phase after myocardial infarction, with low expressions of risk factors, were included in the study. The control group consisted of 25 healthy age-matched males. ED was estimated by ultrasound measurement of the endothelium-dependent dilatation of the brachial artery. The following inflammation markers were measured: hsCRP, interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha), ICAM-1, VCAM-1, selectin-P and selectin-E.

RESULTS

Patients had a significantly reduced level of endothelium-dependent vasodilatation (5.6 +/- 3.5 vs. 8.8 +/- 6.5%, p < 0.05), and an increased level of IL-6 (3.2 [1.5-8.4] vs. 1.4 [0.9-2.3] ng/ml; p < 0.01). All other inflammation markers were comparable to controls. We found a significant negative correlation between ED and the levels of IL-6 (r = -0.54, p = 0.012).

CONCLUSION

It appears that IL-6 is the most valuable circulating marker of ED, and consequently a useful marker of coronary risk.

Statins and the endothelium

Statins have been shown to have pleiotropic effects apart from serum lipid-lowering effect in human. One of the major target organs for the effects of statins is the vascular endothelium, which plays an important role in the development of atherosclerosis and angiogenesis. Recent numerous studies have shown that the statins' cholesterol-independent vascular effects appear to involve directly restoring or improving endothelial function by increasing NO production, promoting re-endothelialization after arterial injury, and inhibiting inflammatory responses within the vessel wall that are thought to contribute to atherosclerosis. This review provides an update of the unique effects of statins on endothelial cells including endothelial progenitor cells as well as highlighting the therapeutic potential of statins beyond their established lipid-lowering effects.

Influence of coenzyme Q(10) and cerivastatin on the flow-mediated vasodilation of the brachial artery: results of the ENDOTACT study

AIM

Endothelial dysfunction (ED) is the functional prestep in atherosclerosis. Aim of the present study was to evaluate the effects of a potent antioxidant (coenzyme Q(10), CoQ(10)) and of cerivastatin on ED of the brachial artery.

METHODS AND RESULTS

Twenty-five male patients with manifest ED (flow-mediated vasodilation [FMD%]<4.5%) were included in this prospective, randomized, cross-over study. ED of the brachial artery was assessed by the use of high-resolution ultrasound. Each patient had to pass through three treatment phases ((1) single therapy with cerivastatin (C), (2) single therapy with CoQ(10), (3) combination therapy). FMD% significantly improved throughout all treatment phases ((1) 3.50+/-4.05% vs. 8.80+/-6.39%, p=0.009; (2) -0.25+/-4.0% vs. 7.06%+/-4.39%, p=0.004; (3) 3.14+/-3.54% vs. 8.82+/-5.78%, p=0.011). C led to a significant decrease of CoQ(10) plasma levels (1.23+/-0.34 vs. 0.87+/-0.39 microg/ml, p=0.004).

CONCLUSION

Our results indicate a positive influence of CoQ(10) supplementation on human ED, which appears to be independent of lipid lowering. Although large-scale studies evaluating other antioxidants failed to demonstrate a positive prognostic effect, Q(10) has never been evaluated in larger trials. Experimental as well as clinical results indicate that CoQ(10) warrants further attention in atherosclerosis research.

Beyond lipid-lowering: effects of statins on endothelial nitric oxide

Endothelial dysfunction is now recognised as an important process in the pathogenesis of atherosclerosis. Nitric oxide (NO) release by the endothelium regulates blood flow, inflammation and platelet aggregation, and consequently its disruption during endothelial dysfunction can decrease plaque stability and encourage the formation of atherosclerotic lesions and thrombi. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) are often utilised in the prevention of coronary heart disease due to their efficacy at lowering lipid levels. However, statins may also prevent atherosclerotic disease by non-lipid or pleiotropic effects, for example, improving endothelial function by promoting the production of NO. There are various mechanisms whereby statins may alter NO release, such as inhibiting the production of mevalonate and important isoprenoid intermediates, thereby preventing the isoprenylation of the small GTPase Rho, which negatively regulates the expression of endothelial nitric oxide synthase (eNOS). Furthermore, statins may also increase eNOS activity via post-translational activation of the phosphatidylinositol 3-kinase/protein kinase Akt (PI3 K/Akt) pathway and/or through an interaction with the molecular chaperone heat-shock protein 90 (HSP90). Data suggest that statins may vary in their efficacy for enhancing the release of NO, and the mechanisms dictating these differences are not yet clear. By increasing NO production, statins may interfere with atherosclerotic lesion development, stabilise plaque, inhibit platelet aggregation, improve blood flow and protect against ischaemia. Therefore, the ability of statins to improve endothelial function through the release of NO may partially account for their beneficial effects at reducing the incidence of cardiovascular events.

Early use of statins in acute coronary syndromes

This review examines the use of statin medications early in the clinical course of acute coronary syndrome (ACS). Available data demonstrate that there are clear clinical benefits to this practice. Numerous previous studies have documented the primary and secondary benefits of statins in the prevention of coronary events. Recent trials show that when statins are used during hospital admissions for ACS, patients experience decreased recurrent myocardial infarction, lower death rates, and fewer repeat hospitalizations for ischemia or revascularization. Several studies suggest that the positive effects of statins on plaque stabilization, inflammation, thrombosis, and endothelial function may be independent of lipid levels. There is also an emerging view that beneficial lipid-lowering with statins in high-risk patients has no lower limit. This information suggests that all patients admitted for ACS should be treated with statins, regardless of cholesterol levels.

Health effects and time course of particulate matter on the cardiopulmonary system in rats with lung inflammation

Recent epidemiological studies associate health effects and particulate matter in ambient air. Exacerbation of the particle-induced inflammation can be a mechanism responsible for increased hospitalization and death due to cardiopulmonary events in high-risk groups of the population. Systems regulating blood pressure that depend on lung integrity can be involved in progression of cardiovascular diseases. This study focused on the expression levels of various genes involved in cardiovascular and pulmonary diseases to assess their role in the onset of cardiovascular problems due to ambient particulate matter and compared these with the corresponding products. Rats with ozone-induced (1600 microg/m(3); 8 h) pulmonary inflammation were exposed to 0.5 mg, 1.5 mg, or 5 mg of particulate matter (PM) from Ottawa Canada (EHC-93) by intratracheal instillation. mRNA levels of various genes and their products were measured 2, 4, and 7 d after instillation. At 2 d after exposures to PM, tumor necrosis factor (TNF)-alpha levels in bronchoalveolar lavage fluid (BALF) were elevated approximately 4 times for the highest EHC-93 dose. MIP-2 protein levels in BALF were elevated approximately three times during the entire time period studied, whereas IL-6 levels were not affected compared to control groups. The MIP-2 mRNA levels revealed a similar pattern of induction. A twofold increase in endothelin (ET)-1 levels at d 2 and a 20% decrease in angiotensin-converting enzyme (ACE) activity at d 7 were measured in plasma. A 60% decrease of ACE and ET-1 mRNA levels suggested a possible endothelial damage in the lung blood vessels. Inducible nitric oxide synthase (iNOS) mRNA was found to be increased 3.5 times 2 d after instillation of the particles. Therefore, the endothelial damage could have been caused by large amounts of the free radical NO. Also, plasma levels of fibrinogen were elevated (20%), which could presumably increase blood viscosity, leading to decreased tissue blood flow. These changes in hematological and hemodynamic parameters observed in our study are in line with heart failure in high-risk groups of the population after high air pollution episodes.

Early use of statins in acute coronary syndromes

This review examines the use of HMG-CoA reductase inhibitor (statin) medications early in the clinical course of acute coronary syndrome. Available data demonstrate that there are clear clinical benefits to this practice. Numerous previous studies have documented the primary and secondary benefits of statins in the prevention of coronary events. Recent trials show that when statins are used during hospital admissions for acute coronary syndrome (ACS), patients experience decreased recurrent myocardial infarction, lower death rates, and fewer repeat hospitalizations for ischemia or revascularization. Several studies suggest that the positive effects of statins on plaque stabilization, inflammation, thrombosis, and endothelial function may be independent of lipid levels. There is also an emerging view that beneficial lipid-lowering with statins in high-risk patients has no lower limit. This information suggests that all patients admitted for ACS should be treated with statins, regardless of cholesterol levels.

Atherothrombosis: plaque instability and thrombogenesis

Hemostasis involves a carefully regulated balance between circulating and endothelium-derived prothrombotic and antithrombotic factors. The unstable or vulnerable plaque facilitates thrombosis, clinically manifest as an acute coronary syndrome (ACS), by creating an environment that favors thrombus formation over prevention of lysis. Endothelial cell dysfunction is integral to both the development of the atherosclerotic lesion as well as its destabilization. The transformation of a stable plaque to an unstable one involves complex interactions among T lymphocytes, macrophages, endothelial cells, and smooth muscle cells. Degradation of the fibrous cap of the atherosclerotic lesion as well as the overexpression of prothrombotic and underexpression of antithrombotic factors by cells within the plaque precede thrombus formation. Accordingly, pharmacological interventions for the treatment of ACS are directed against the initiation and propagation of thrombosis, as well as toward improvement of endothelial function.