Baseline plasma adiponectin levels as a predictor of left ventricular systolic dysfunction in patients referred for coronary angiography.

The objective of the present study was to determine the association between plasma adiponectin and left ventricular (LV) systolic function. Baseline plasma adiponectin was measured in 389 patients undergoing coronary angiography for a variety of indications at a Veterans Affairs Medical Center. Detailed demographic, clinical, laboratory, and angiographic data were available for patients. LV systolic function was assessed using ventriculography, and patients were grouped into those with normal or mild dysfunction (ejection fraction > or =45%) versus those with moderate to severe systolic dysfunction (ejection fraction <45%). After adjusting for a variety of clinically relevant covariates known to affect LV systolic function, adiponectin was independently associated with LV systolic function in the entire cohort of patients (p = 0.0002) using multivariate linear regression analysis. In addition, using multivariate logistic regression analysis, adiponectin was an independent predictor of the presence of moderate to severe LV dysfunction (odds ratio 1.54, 95% confidence interval 1.21 to 1.97, p = 0.0005). Moreover, baseline adiponectin was also independently associated with LV function in both the myocardial infarction (MI) and non-MI subpopulations of patients (p = 0.0401 and p= 0.0023, respectively). Finally, in the non-MI subpopulation, baseline adiponectin was an independent predictor of moderate to severe LV systolic dysfunction (odds ratio 1.52, 95% confidence interval 1.15 to 2.02, p = 0.0034). In conclusion, baseline plasma adiponectin was an independent predictor of LV systolic dysfunction in a population of patients referred for coronary angiography.

Usefulness of Complement C1q to Predict 10-Year Mortality in Men With Diabetes Mellitus Referred for Coronary Angiography.

The complement system consists of a family of proteins that play a critical role in the innate immune system. Complement activation has been implicated in many chronic inflammatory diseases, including atherosclerosis. However, a number of experimental studies have highlighted a beneficial role of component C1q in early atherosclerosis and in diabetes mellitus (DM). Despite these data, there have been no studies that have specifically examined the utility of plasma complement C1q as a clinical biomarker in patients with known or suspected coronary artery disease. In this study, baseline plasma complement C1q levels were measured in 159 men with DM who were referred for coronary angiography and who were followed up prospectively for the development of all-cause mortality for 10 years. After adjustment for baseline clinical, angiographic, and laboratory parameters, reduced plasma complement C1q levels were an independent predictor of all-cause mortality at 10 years (hazard ratio 0.66, 95% confidence interval 0.52 to 0.84, p = 0.0006). In additional multivariate models that adjusted for a variety of biomarkers with established prognostic efficacy, complement C1q remained an independent predictor of all-cause mortality at 10 years. In conclusion, reduced levels of complement C1q are associated with an increased risk of all-cause mortality at 10 years in patients with DM referred for coronary angiography. Furthermore, this association is independent of a variety of clinical, angiographic, laboratory variables, including biomarkers with established prognostic efficacy in the prediction of adverse cardiovascular outcomes.

Riboflavin-mediated reduction of oxidant injury, rejection, and vasculopathy after cardiac allotransplantation.

BACKGROUND: Riboflavin is a well-known nutritional supplement that has been shown to exhibit antioxidant properties and protect tissue from oxidative damage. We hypothesized that riboflavin given during cardiac ischemia-reperfusion (I/R) might reduce subsequent acute rejection, after allotransplantation, and coronary allograft vasculopathy (CAV). METHODS: A murine heterotopic cardiac transplantation model was used to test whether riboflavin improves I/R injury and acute/chronic rejection. RESULTS: Riboflavin significantly reduced oxidant production and inflammatory mediator production induced by I/R injury, as evidenced by decreased levels of malondialdehyde, myeloperoxidase activity, and tumor necrosis factor alpha. Administration of riboflavin also improved graft survival and suppressed T-cell infiltration and donor-reactive alloantibody formation during the early period after allotransplantation. A murine long-term cardiac allograft model using immunosuppression (preoperative anti-murine CD4 and anti-CD8) was employed to investigate the effect of riboflavin against CAV at 60 days. Riboflavin-treated grafts exhibited a significant decrease in the severity of coronary artery luminal occlusion as compared with saline-treated grafts (17.4+/-1.8% vs. 43.5+/-5.6%, P=0.0012). However, there was no significant effect of riboflavin to reduce donor-reactive alloantibodies in this chronic model. CONCLUSIONS: These data indicate that riboflavin improves early I/R injury and reduces the development of CAV, most likely due to alloantigen-independent effects such as reduced early graft oxidant stress. Riboflavin administered in the setting of cardiac allograft transplantation appears to be a powerful means to reduce early graft lipid peroxidation, leukocytic infiltration, and cytokine production as well as to suppress the late development of cardiac allograft vasculopathy.

Usefulness of baseline plasma myeloperoxidase levels as an independent predictor of myocardial infarction at two years in patients presenting with acute coronary syndrome.

Baseline plasma myeloperoxidase (MPO) levels have been shown to independently predict the early risk of myocardial infarction (MI) in patients presenting with chest pain. In addition, baseline MPO levels have been demonstrated to predict the development of adverse cardiac events up to 6 months after an acute coronary syndrome (ACS). However, in contrast to other biomarkers, there are no data about the long-term independent predictive value of baseline MPO values in patients with ACS. The present study investigated the long-term prognostic significance of baseline MPO levels in a well-characterized cohort of 193 men with ACS who were referred for coronary angiography at a Veterans Administration Medical Center. All patients were followed prospectively for the development of death and MI, and follow-up data were available for all patients at 24 months. After controlling for different baseline clinical, laboratory, and angiographic variables, baseline plasma MPO values were a strong and independent predictor of MI at 24 months by multivariate analysis. Using the median MPO value of the entire cohort of patients (i.e., 20.34 ng/ml) as a prespecified cutoff, the MI-free survival at 24 months for the group whose baseline MPO values were < or =20.34 ng/ml was 88% compared with 74% in those whose values were >20.34 ng/ml (p = 0.0249 by log-rank test). In conclusion, these data demonstrate that baseline MPO levels independently predict MI at 2 years in patients with ACS.

Usefulness of the serum complement component C4 as a predictor of stroke in patients with known or suspected coronary artery disease referred for coronary angiography.

The complement system has been implicated in the pathogenesis of atherosclerosis. In addition, complement activation and complement-mediated brain injury have been found in a variety of central nervous system diseases, including stroke. However, there are limited data about the value of complement components for prediction of stroke. Complement C3 and C4 levels, in addition to a variety of established biomarkers, were measured in 389 men with known or suspected coronary artery disease referred for coronary angiography for a variety of indications at a Veterans Affairs Medical Center. Patients were followed prospectively for the development of stroke, which was defined and classified according to criteria of the Trial of Org 10172 in Acute Stroke Treatment (TOAST). All strokes were confirmed with magnetic resonance imaging or computed tomography. For the 97% of patients in whom 24-month follow-up data were available, there were 23 strokes (5.9%). By multivariate Cox proportional hazard analysis, complement C4 was an independent predictor of stroke, with a hazard ratio of 1.57 (95% confidence interval 1.03 to 2.39, p = 0.0358). The 24-month stroke-free survival rate for the patients whose complement C4 levels were equal to or below the median value for the entire cohort was 96.1% compared with 90.1% for patients whose complement C4 levels were above the median value, p = 0.0127 by log rank test). In conclusion, in a cohort of men across a spectrum of risk referred for coronary angiography, a single baseline determination of serum complement C4 level is an independent predictor of the future development of stroke.

Relation of baseline plasma phospholipid levels to cardiovascular outcomes at two years in men with acute coronary syndrome referred for coronary angiography.

In addition to cholesterol and triglycerides, plasma also contains phospholipids. The choline-containing phospholipids constitute >90% of total plasma phospholipids. To date, no studies have looked specifically at the prognostic significance of total phospholipids in patients with known or suspected coronary artery disease. The present study investigated the long-term prognostic significance of total choline-containing phospholipid levels in a well-characterized cohort of 193 men with acute coronary syndromes who were referred for coronary angiography at a Department of Veterans Affairs Medical Center. All patients were followed prospectively for the development of vascular outcomes. After controlling for a variety of baseline variables (including established biomarkers such high-sensitivity C-reactive protein and fibrinogen), plasma phospholipid values (analyzed as a continuous variable) were a strong and independent predictor of each of the individual end points of all-cause mortality (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.41 to 0.90, p = 0.0126), cardiac mortality (HR 0.49, 95% CI 0.29 to 0.81, p = 0.0057), and myocardial infarction (HR 0.71, 95% CI 0.52 to 0.98, p = 0.0342) when using a Cox proportional-hazards model. In addition, baseline phospholipid values were also an independent predictor of the composite outcome of all-cause mortality, fatal or nonfatal myocardial infarction, or stroke (HR 0.66, 95% CI 0.49 to 0.90, p = 0.0075). In conclusion, these data demonstrate that low baseline levels of total choline-containing phospholipid are a strong and independent predictor of cardiovascular outcomes (including mortality) in patients with acute coronary syndromes.

Usefulness of Plasma Tissue Inhibitor of Matrix Metalloproteinase-4 to Predict Death and Myocardial Infarction in Patients With Diabetes Mellitus Referred for Coronary Angiography.

TIMP-4 is the newest member of a family of secreted proteins known as the tissue inhibitors of metalloproteases that selectively inhibit matrix metalloproteases. TIMP-4 is abundantly expressed in human cardiovascular structures and has been implicated in cardiovascular disease. Furthermore, it has also been shown to be a novel target of peroxisome proliferator-activated receptor gamma in rat smooth muscle cells, suggesting a potential role in diabetes mellitus as well. However, there have been no studies that have specifically examined the utility of baseline plasma TIMP-4 levels for the prediction of long-term adverse cardiovascular outcomes. In this study, baseline plasma TIMP-4 levels were measured in 162 male patients with diabetes mellitus who were referred for coronary angiography and followed prospectively for the development of all-cause mortality and enzymatically confirmed myocardial infarction (MI) out to 5 years. After adjustment for a variety of baseline clinical, angiographic and laboratory parameters, plasma TIMP-4 levels were an independent predictor of all-cause mortality (hazard ratio 1.60, 95% CI 1.13 to 2.26; p = 0.0082) and MI (hazard ratio 1.61, 95% CI 1.19 to 2.18; p = 0.0021) at 5 years. Furthermore, in additional multivariate models that adjusted for a variety of biomarkers with established prognostic efficacy, TIMP-4 remained an independent predictor of adverse outcomes. In conclusion, elevated levels of TIMP-4 are associated with an increased risk of long-term all-cause mortality and MI in patients with diabetes mellitus referred for coronary angiography. Moreover, this association is independent of a variety of clinical, angiographic, and laboratory variables, including biomarkers with established prognostic efficacy in the prediction of adverse cardiovascular outcomes.

Tissue inhibitor of metalloproteinase-1 (TIMP-1) is an independent predictor of all-cause mortality, cardiac mortality, and myocardial infarction.

BACKGROUND: Matrix metalloproteinases and their inhibitors have been implicated in both vascular and ventricular remodeling, and in atherosclerotic plaque rupture. The prognostic value of plasma tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in patients with established or suspected coronary artery disease is unknown. METHODS: Tissue inhibitor of metalloproteinase-1 and matrix metalloproteinase-9 (MMP-9) levels, along with a number of other established biomarkers, were measured in 389 male patients undergoing coronary angiography at a Veterans Administration Medical Center. The patients were then followed prospectively for the occurrence of all-cause mortality, cardiac mortality, and myocardial infarction (MI). RESULTS: Follow-up data at 24 months were available for 97% of the patients. For the entire cohort of patients, TIMP-1 was the only biomarker to independently predict all-cause mortality and MI. In addition, the ratio of TIMP-1 to matrix metalloproteinase-9 was independently predictive of cardiac mortality at 24 months. The 24-month survival rates for patients in the lower quartile (< 66.5 ng/mL), interquartile (66.5-100 ng/mL), and upper quartile (> 100 ng/mL) of plasma TIMP-1 values were 95.3%, 89.3%, and 72.2%, respectively (P < .001). Furthermore, when patients with chest pain were risk stratified into those with and without an acute coronary syndrome, TIMP-1 remained an independent predictor of all-cause mortality in both subgroups. CONCLUSIONS: In a cohort of male patients undergoing coronary angiography, a single baseline determination of plasma TIMP-1 is independently predictive of the subsequent risk of death and MI.

Usefulness of the white blood cell count as a predictor of angiographic findings in an unselected population referred for coronary angiography.

There are limited data about the relative importance of the many different but inter-related inflammatory markers with respect to their ability to independently predict the presence and extent of coronary artery disease (CAD). In addition, studies demonstrating such associations have often been conducted in well-defined populations and have excluded patients with or not adjusted for co-morbidities associated with CAD. In a cohort of 389 men who underwent coronary angiography for a variety of clinical indications and across a spectrum of risk, the following inflammatory markers were measured at baseline to determine their relative abilities to predict angiographic outcomes: C-reactive protein, myeloperoxidase, tissue inhibitor of metalloproteinase-1, erythrocyte sedimentation rate, and white blood cell (WBC) count. This analysis was done in the context of traditional CAD risk factors and other co-morbidities associated with CAD (such as morbid obesity, renal dysfunction, heart failure, and so forth). WBC count was the only marker that was independently associated with angiographically documented CAD (p = 0.0184). Further, WBC count (odds ratio 1.31, 95% confidence interval 1.05 to 1.64, p = 0.0157) and plasma myeloperoxidase (odds ratio 1.35, 95% confidence interval 1.08 to 1.69, p = 0.0090) were the only inflammatory markers that were independently predictive of the presence of multivessel disease on coronary angiography. In conclusion, these data demonstrate that a simple baseline WBC count is independently associated with angiographic CAD, and that it can predict the presence of multivessel disease, even in the context of clinical CAD risk factors and other established inflammatory markers.

Usefulness of Plasma Matrix Metalloproteinase-3 Levels to Predict Myocardial Infarction in Men With and Without Acute Coronary Syndrome.

Matrix metalloproteinase-3 (MMP-3), or stromelysin-1, is a matrix metalloproteinase which is expressed in atherosclerotic plaques and which has been implicated in the pathogenesis of acute coronary syndrome (ACS). Functional polymorphisms in the promoter region of the human MMP-3 gene resulting in an increased expression of MMP-3 have been shown to predict the risk of incident myocardial infarction (MI). However, there have been no studies that have specifically examined the utility of baseline plasma MMP-3 levels for the prediction of long-term MI. In this study, baseline plasma MMP-3 levels were measured in 355 male patients who were referred for coronary angiography and followed prospectively for the development of enzymatically confirmed MI out to 5 years. After adjustment for a variety of baseline clinical, angiographic, and laboratory parameters, plasma MMP-3 levels were an independent predictor of MI at 5 years (hazards ratio 1.42, 95% CI 1.13 to 1.79; p = 0.0023). Furthermore, in 5 additional multivariate models that included a variety of contemporary biomarkers associated with adverse outcomes and MI, MMP-3 remained an independent predictor of MI at 5 years. Similar results were obtained when the analyses were restricted to the subpopulation of patients presenting with ACS. In conclusion, elevated levels of MMP-3 are associated with an increased risk of long-term MI in patients with and without ACS referred for coronary angiography. Furthermore, this association is independent of a variety of clinical, angiographic, laboratory variables, including biomarkers with established prognostic efficacy for the prediction of MI.

Caloric restriction promotes genomic stability by induction of base excision repair and reversal of its age-related decline.

Caloric restriction is a potent experimental manipulation that extends mean and maximum life span and delays the onset and progression of tumors in laboratory rodents. While caloric restriction (CR) clearly protects the genome from deleterious damage, the mechanism by which genomic stability is achieved remains unclear. We provide evidence that CR promotes genomic stability by increasing DNA repair capacity, specifically base excision repair (BER). CR completely reverses the age-related decline in BER capacity (P<0.01) in all tissues tested (brain, liver, spleen and testes) providing aged, CR animals with the BER phenotype of young, ad libitum-fed animals. This CR-induced reversal of the aged BER phenotype is accompanied by a reversal in the age-related decline in DNA polymerase beta (beta-pol), a rate-limiting enzyme in the BER pathway. CR significantly reversed the age-related loss of beta-pol protein levels (P<0.01), mRNA levels (P<0.01) and enzyme activity (P<0.01) in all tissues tested. Additionally, in young (4-6-month-old) CR animals a significant up-regulation in BER capacity, beta-pol protein and beta-pol mRNA is observed (P<0.01), demonstrating an early effect of CR that may provide insight in distinguishing the anti-tumor from the anti-aging effects of CR. This up-regulation in BER by caloric restriction in young animals corresponds to increased protection from carcinogen exposure, as mutation frequency is significantly reduced in CR animals exposed to either DMS or 2-nitropropane (2-NP) (P<0.01). Overall the data suggest an important biological consequence of moderate BER up-regulation and provides support for the hormesis theory of caloric restriction.

Potential role of MLH1 in the induction of p53 and apoptosis by blocking transcription on damaged DNA templates.

Defects in DNA mismatch repair (MMR) are common in human cancers, confer tolerance to certain types of chemotherapeutic agents, and lead to genomic instability. In addition to their mismatch-correcting roles during DNA replication, MMR proteins can bind to certain DNA lesions and signal p53 and apoptosis by an unknown mechanism. To further study the mechanism by which the MMR protein MLH1 is involved in the induction of p53 and apoptosis, we exposed the colon carcinoma cell line HCT116 (MLH1-deficient) and mlh1-corrected HCT116 sublines to alkylating agents or hydrogen peroxide (H2O2). It was found that while alkylating agents induced both apoptosis and phosphorylation of the Ser-15 site of p53 in a MLH1-dependent manner, induction of apoptosis, but not p53 phosphorylation, was MLH1 dependent following treatment with H2O2. The MLH1-dependent induction of p53 phosphorylation by alkylating agents did not appear to be cell cycle dependent, arguing against a futile repair mechanism operating during S phase as the sole mechanism for the MLH1-dependent DNA damage signaling. Importantly, we found that both alkylating agents and H2O2 caused significant inhibition of mRNA synthesis in MLH1-expressing but not in MLH1-deficient cells. These findings suggest a novel mechanism of MLH1 in the induction p53 and apoptosis by inhibiting RNA polymerase II-dependent transcription on damaged DNA templates.

Elevated baseline plasma phospholipid protein (PLTP) levels are an independent predictor of long-term all-cause mortality in patients with diabetes mellitus and known or suspected coronary artery disease.

OBJECTIVES: To investigate the long-term prognostic significance of baseline plasma PLTP levels in a group of well-characterized male patients with diabetes mellitus and known or suspected coronary artery disease referred for coronary angiography. BACKGROUND: PLTP is a plasma protein that mediates the net transfer and exchange of phospholipids between lipoproteins. It has been implicated in the pathogenesis of atherosclerosis and elevated plasma levels have been reported in patients with diabetes mellitus. METHODS: Baseline plasma PLTP levels were measured in 154 male patients with diabetes mellitus who were referred for coronary angiography and followed prospectively for 5 years for the development of all-cause mortality. RESULTS: After adjustment for a variety of baseline clinical, angiographic and laboratory parameters, plasma PLTP levels (analyzed as a continuous variable) were an independent predictor of all-cause mortality at 5 years (HR, 1.55; 95% CI, 1.22-2.00; P = 0.0009). Furthermore, in 3 additional multivariate models that also included a wide variety of contemporary biomarkers with established prognostic efficacy (i.e., ST2, GDF-15, Cystatin C, Fibrinogen, and NT-proBNP), PLTP remained an independent predictor of all-cause mortality at 5 years. CONCLUSIONS: Elevated baseline plasma levels of PLTP are associated with an increased risk of long-term all-cause mortality in patients with diabetes and known or suspected coronary disease. Furthermore, this association is independent of a variety of clinical, angiographic, and laboratory variables, including a whole host of contemporary biomarkers with established prognostic efficacy.

Relation of baseline plasma MMP-1 levels to long-term all-cause mortality in patients with known or suspected coronary artery disease referred for coronary angiography.

OBJECTIVES: To investigate the long-term prognostic significance of baseline plasma MMP-1 levels in a group of well-characterized male patients with known or suspected coronary artery disease, including those presenting with acute coronary syndrome. BACKGROUND: MMP-1 is an interstitial collagenase that is considered the primary enzyme responsible for collagen degradation. In addition, MMP-1 can lead to platelet activation through the PAR1 pathway that is independent of thrombin. METHODS: Baseline plasma MMP-1 levels were measured in 364 male patients who were referred for coronary angiography and followed prospectively for five years for the development of all-cause mortality. RESULTS: After adjustment for a variety of baseline clinical, angiographic and laboratory parameters, baseline plasma MMP-1 levels (analyzed as a continuous variable) were an independent predictor of all-cause mortality at 5 years (HR, 1.49; 95% CI, 1.23-1.80; P < 0.0001). Furthermore, in 3 additional multivariate models that included a wide variety of contemporary biomarkers with established prognostic efficacy (i.e., ST2, GDF-15, Cystatin C, hs-CRP, Myeloperoxidase, NT-proBNP, TIMP-1, Adiponectin, RDW, hemoglobin, and Erythropoietin), MMP-1 remained an independent predictor of all-cause mortality at 5 years. Similar results were obtained when the analyses were restricted to the subpopulation of patients presenting with acute coronary syndrome. CONCLUSIONS: Elevated levels of MMP-1 are associated with an increased risk of long-term all-cause mortality in patients with known or suspected coronary disease that is independent of a variety of clinical, angiographic, and laboratory variables, including a whole host of contemporary biomarkers with established prognostic efficacy representing multiple different pathophysiologic processes.

Elevated baseline plasma IL-8 levels are an independent predictor of long-term all-cause mortality in patients with acute coronary syndrome.

OBJECTIVES: To investigate the long-term prognostic significance of baseline plasma IL-8 levels in a group of well-characterized male patients presenting with acute coronary syndrome. BACKGROUND: IL-8 is a cytokine that has been implicated in the pathogenesis of atherosclerosis and acute coronary syndrome. Elevated plasma levels have been reported in patients with acute coronary syndrome. METHODS: Baseline plasma IL-8 levels were measured in 180 male patients with acute coronary syndrome who were referred for coronary angiography and followed prospectively for the development of all-cause mortality for 5 years. RESULTS: In a multivariate model that included a wide variety of baseline clinical, laboratory and angiographic parameters in the selection process, baseline plasma IL-8 levels (analyzed as a continuous variable) emerged as a significant predictor of all-cause mortality at 5 years (HR, 1.43; 95% CI, 1.08-1.88; p = 0.0123). Furthermore, in 3 additional multivariate models that also included in the selection process a number of contemporary biomarkers with established prognostic efficacy in ACS (i.e., NT-proBNP, hs-CRP, hemoglobin and RDW), IL-8 remained an independent predictor of all-cause mortality at 5 years. CONCLUSION: Elevated baseline plasma levels of IL-8 are associated with an increased risk of long-term all-cause mortality in patients with acute coronary syndrome. Furthermore, this association is independent of a variety of clinical, laboratory and angiographic variables, including contemporary biomarkers with established prognostic efficacy in acute coronary syndrome.

Attenuation of DNA polymerase beta-dependent base excision repair and increased DMS-induced mutagenicity in aged mice.

The biological mechanisms responsible for aging remain poorly understood. We propose that increases in DNA damage and mutations that occur with age result from a reduced ability to repair DNA damage. To test this hypothesis, we have measured the ability to repair DNA damage in vitro by the base excision repair (BER) pathway in tissues of young (4-month-old) and old (24-month-old) C57BL/6 mice. We find in all tissues tested (brain, liver, spleen and testes), the ability to repair damage is significantly reduced (50-75%; P<0.01) with age, and that the reduction in repair capacity seen with age correlates with decreased levels of DNA polymerase beta (beta-pol) enzymatic activity, protein and mRNA. To determine the biological relevance of this age-related decline in BER, we measured spontaneous and chemically induced lacI mutation frequency in young and old animals. In line with previous findings, we observed a three-fold increase in spontaneous mutation frequency in aged animals. Interestingly, lacI mutation frequency in response to dimethyl sulfate (DMS) does not significantly increase in young animals whereas identical exposure in aged animals results in a five-fold increase in mutation frequency. Because DMS induces DNA damage processed by the BER pathway, it is suggested that the increased mutagenicity of DMS with age is related to the decline in BER capacity that occurs with age. The inability of the BER pathway to repair damages that accumulate with age may provide a mechanistic explanation for the well-established phenotype of DNA damage accumulation with age.

Plasma interleukin-10 levels and adverse outcomes in acute coronary syndrome.

UNLABELLED: PURPOSE OR BACKGROUND: Interleukin (IL)-10 is an immunoregulatory cytokine that is produced by a variety of cell types, such as macrophages and activated monocytes. IL-10 possesses numerous anti-inflammatory, anti-thrombotic and anti-atherosclerotic properties. Furthermore, patients with acute coronary syndrome have been demonstrated to have reduced levels of IL-10 compared to their stable counterparts. For these reasons, it has been proposed that IL-10 plays a protective role in both atherogenesis and plaque vulnerability. However, 2 short-term studies on the prognostic utility of IL-10 in patients with acute coronary syndrome have provided conflicting results, with one study showing that reduced levels of IL-10 were predictors of adverse outcomes and another showing that elevated levels predicted poor outcomes. The objective of the present study was to investigate the long-term prognostic significance of baseline IL-10 levels in patients with acute coronary syndrome. METHODS: Baseline plasma IL-10 levels were measured in 193 well-characterized male patients with acute coronary syndrome who were referred for coronary angiography and followed prospectively for 5 years for the development of major adverse cardiovascular events. RESULTS: After controlling for a variety of baseline variables (including established biomarkers such as high-sensitivity C-reactive protein and N-terminal-pro-B-type natriuretic peptide), plasma IL-10 levels (whether analyzed as a continuous variable or as a categorical variable using receiver operating characteristic-derived cut point) were a strong and independent predictor of the composite outcome of death or non-fatal myocardial infarction when using a Cox proportional hazards model. CONCLUSIONS: These data demonstrate that, despite biologic plausibility for IL-10 as being a cardioprotective cytokine, elevated baseline plasma levels of IL-10 are a strong and independent predictor of long-term adverse cardiovascular outcomes in patients with acute coronary syndrome.

Relation of baseline plasma ADMA levels to cardiovascular morbidity and mortality at two years in men with diabetes mellitus referred for coronary angiography.

BACKGROUND: Patients with diabetes mellitus (DM) have been shown to have higher levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of endothelial nitric oxide (NO) synthase. Higher plasma levels of ADMA have been implicated in the pathogenesis of endothelial dysfunction and atherosclerosis by lowering NO levels. High baseline plasma levels of ADMA in patients with DM have been shown to predict diabetes related complications. However, there are limited data on the prognostic significance of baseline ADMA levels in patients with established DM. METHODS: The present study investigated the long-term prognostic significance of baseline plasma ADMA levels in a well-characterized cohort of 170 high-risk diabetic men with known or suspected coronary artery disease who were referred for coronary angiography. All patients were followed prospectively for the development of vascular outcomes, including all-cause mortality. RESULTS: After controlling for a variety of baseline variables (including established biomarkers such as hs-CRP and fibrinogen), plasma ADMA levels (analyzed as the upper tertile of baseline values compared with the lower two tertiles) were a strong and independent predictor of all-cause mortality (HR 2.63, 95% CI 1.13-6.11, p=0.0247) when using a Cox proportional hazards model. In addition, baseline ADMA values were also an independent predictor of the composite outcome of all-cause mortality or MI (fatal or non-fatal) (HR 2.44, 95% CI 1.26-4.72, p=0.0079), as well as the composite outcome of all-cause mortality, MI (fatal or nonfatal), or stroke (HR 2.00, 95% CI 1.10-3.62, p=0.0232). CONCLUSION: These data demonstrate that elevated baseline levels of ADMA are a strong and independent predictor of cardiovascular outcomes (including all-cause mortality) in patients with DM.

Relationship of baseline plasma ADMA levels to cardiovascular outcomes at 2 years in men with acute coronary syndrome referred for coronary angiography.

BACKGROUND: Nitric oxide (NO) is produced from L-arginine by NO synthase and is an important molecule with antiatherogenic properties. Asymmetric dimethylarginine (ADMA) acts as an endogenous inhibitor of endothelial NO synthase. As such, it has been associated with endothelial dysfunction and elevated circulating levels of ADMA have been found in patients with cardiovascular risk factors. In addition, high baseline plasma levels of ADMA have been shown to be an independent predictor of adverse outcomes in a variety of patient populations. However, there are very limited data in patients with acute coronary syndromes (ACS). METHODS: This study investigated the long-term prognostic significance of baseline plasma ADMA levels in a well-characterized cohort of 193 men with ACS who were referred for coronary angiography. All patients were followed up prospectively for the development of vascular outcomes. RESULTS: After controlling for a variety of baseline variables (including established biomarkers such as high-sensitivity C-reactive protein and fibrinogen), plasma ADMA levels (analyzed as the upper tertile of baseline values compared with the lower two tertiles) were a strong and independent predictor of each of the individual endpoints of all-cause mortality [hazard ratio (HR): 2.45, 95% confidence interval (CI): 1.08-5.57; P=0.0325] and myocardial infarction (HR: 2.28, 95% CI: 1.14-4.57; P=0.0204) when using a Cox proportional hazards model. In addition, baseline ADMA values were also an independent predictor of the composite outcome of all-cause mortality, fatal or nonfatal myocardial infarction, or stroke (HR: 1.81, 95% CI: 1.01-3.25; P=0.0482). CONCLUSION: These data show that elevated baseline levels of ADMA are a strong and independent predictor of cardiovascular outcomes (including mortality) in patients with ACS.

Relation of baseline serum potassium levels to angiographic findings in patients with known or suspected coronary artery disease.

BACKGROUND: In experimental animal studies, potassium has been demonstrated to protect against the development of atherosclerosis through a variety of mechanisms. Data regarding the role of potassium in the development of human atherosclerosis are sparse. The objective of this study was to determine the association between plasma potassium levels and angiographically defined coronary artery disease (CAD). METHODS: In a cohort of 389 male patients undergoing coronary angiography for a variety of clinical indications, the association between baseline serum potassium levels and the extent of angiographically defined atherosclerosis was analyzed. Adjustments were made for clinical and laboratory variables (including inflammatory markers) known to be associated with atherosclerosis. RESULTS: By multivariate logistic regression analysis, baseline serum potassium levels were an independent predictor of the presence of multivessel disease (odds ratio (OR) 1.31, 95% confidence interval (CI) 1.01-1.69; P < 0.05). In addition, in the non-myocardial infarction subpopulation of patients, serum potassium was also an independent predictor of the presence of multivessel disease by multivariate logistic regression analysis (OR 1.34, 95% CI, 1.02-1.76; P < 0.05). In the myocardial infarction (MI) subpopulation, serum potassium was not a predictor of multivessel disease, possibly due to the confounding effect of hypokalemia known to be present during MI. CONCLUSIONS: These data demonstrate that a simple baseline serum potassium level is independently associated with the presence of multivessel disease, even in the context of clinical CAD risk factors and other established inflammatory markers.