Oxidative Stress is Associated with Increased Pulmonary Artery Systolic Pressure in Humans

Oxidative stress contributes to the development of pulmonary hypertension in experimental models, but this association in humans is unknown. We investigated the relationship between pulmonary artery systolic pressure measured by echocardiography and plasma aminothiol oxidative stress markers, with the hypothesis that oxidative stress will be higher in those with pulmonary hypertension. A group of 347 patients aged 65±12 years from the Emory Cardiovascular Biobank underwent echocardiographic assessment of left ventricular ejection fraction and pulmonary artery systolic pressure. Plasma aminothiols, cysteine, its oxidized form, cystine; glutathione, and its oxidized disulphide (GSSG) were measured and the redox potentials (Eh) of cysteine/cystine and glutathione/GSSG couples were calculated. Non-normally distributed variables were log transformed (Ln). Univariate predictors of pulmonary artery systolic pressure included age (p\u3c0.001), gender (p=0.002), mitral regurgitation (p\u3c0.001), left ventricular ejection fraction (p\u3c0.001), left atrial size (p\u3c 0.001), diabetes (p=0.03), Plasma Ln cystine (β=9.53, p\u3c0.001), Ln glutathione (β =-5.4, p=0.002), and Eh glutathione (β =0.21, p=0.001). A multivariate linear regression model adjusting for all confounding variables demonstrated that Ln cystine (β=6.56, p=0.007), mitral regurgitation (β= 4.52, P\u3c0.001), statin use (β =-3.39, p=0.03), left ventricular ejection fraction (β=-0.26, p=0.003), and age (β=0.17, p=0.003) were independent predictors of pulmonary artery systolic pressure. For each 1% increase in plasma cystine, pulmonary artery systolic pressure increased by 16%. This association persisted in the subgroup with preserved left ventricular ejection fraction (≥50%) and no significant mitral regurgitation. Whether treatment of oxidative stress will improve pulmonary hypertension requires further study

Response to letter regarding article by Patel et al: A Novel Biomarker of Oxidative Stress is Associated with Risk of Death in Patients with Coronary Artery Disease

We thank Drs Giral and colleagues for their interest in our work.1 They raise the important query of whether our findings would still persist after adjustment for γ-glutamyltransferase (GGT), given that GGT activity hydrolyzes glutathione (GSH) to produce glutamate+cysteinylglycine. This point, however, is not relevant to our description of GSH/cystine as a useful biomarker of cardiovascular disease, because our samples were all collected with a preservation solution containing a GGT

Aggregate Risk Score Based on Markers of Inflammation, Cell Stress, and Coagulation Is an Independent Predictor of Adverse Cardiovascular Outcomes

Objectives: This study sought to determine an aggregate, pathway-specific risk score for enhanced prediction of death and myocardial infarction (MI). Background Activation of inflammatory, coagulation, and cellular stress pathways contribute to atherosclerotic plaque rupture. We hypothesized that an aggregate risk score comprised of biomarkers involved in these different pathways - high-sensitivity C-reactive protein (CRP), fibrin degradation products (FDP), and heat shock protein 70 (HSP70) levels - would be a powerful predictor of death and MI. Methods: Serum levels of CRP, FDP, and HSP70 were measured in 3,415 consecutive patients with suspected or confirmed coronary artery disease (CAD) undergoing cardiac catheterization. Survival analyses were performed with models adjusted for established risk factors. Results: Median follow-up was 2.3 years. Hazard ratios (HRs) for all-cause death and MI based on cutpoints were as follows: CRP ≥3.0 mg/l, HR: 1.61; HSP70 >0.625 ng/ml, HR; 2.26; and FDP ≥1.0 μg/ml, HR: 1.62 (p < 0.0001 for all). An aggregate biomarker score between 0 and 3 was calculated based on these cutpoints. Compared with the group with a 0 score, HRs for all-cause death and MI were 1.83, 3.46, and 4.99 for those with scores of 1, 2, and 3, respectively (p for each: <0.001). Annual event rates were 16.3% for the 4.2% of patients with a score of 3 compared with 2.4% in 36.4% of patients with a score of 0. The C statistic and net reclassification improved (p < 0.0001) with the addition of the biomarker score. Conclusions: An aggregate score based on serum levels of CRP, FDP, and HSP70 is a predictor of future risk of death and MI in patients with suspected or known CAD

A Novel Biomarker of Oxidative Stress is Associated with Risk of Death in Patients with Coronary Artery Disease

Background—Free radical scavengers have failed to improve patient outcomes promoting the concept that clinically important oxidative stress (OS) may be mediated by alternative mechanisms. We sought to examine the association of emerging aminothiol markers of non-free radical mediated oxidative stress with clinical outcomes. Methods and Results—Plasma levels of reduced (cysteine and glutathione) and oxidized (cystine and glutathione disulphide) aminothiols were quantified by high performance liquid chromatography in 1411 patients undergoing coronary angiography (mean age 63 years, male 66%). All patients were followed for a mean of 4.7±2.1 years for the primary outcome of all-cause death (n=247). Levels of cystine (oxidized) and glutathione (reduced) were associated with risk of death (p\u3c0.001 both) before and after adjustment for covariates. High cystine and low glutathione levels (\u3e+1 SD & \u3c-1 SD respectively) were associated with higher mortality (adjusted HR 1.63 (95% CI 1.19-2.21; HR 2.19 (95% CI 1.50-3.19), respectively) compared to those outside these thresholds. Furthermore, the ratio of cystine/glutathione was also significantly associated with mortality (adjusted HR 1.92 (95% CI 1.39-2.64) and was independent of and additive to hs-CRP level. Similar associations were found for other outcomes of cardiovascular death and combined death and myocardial infarction. Conclusions—A high burden of OS, quantified by the plasma aminothiols, cystine, glutathione and their ratio is associated with mortality in patients with CAD, a finding that is independent of and additive to the inflammatory burden. Importantly, this data supports the emerging role of non-free radical biology in driving clinically important oxidative stress

Soluble Urokinase Plasminogen Activator Receptor Level Is an Independent Predictor of the Presence and Severity of Coronary Artery Disease and of Future Adverse Events

Introduction Soluble urokinase plasminogen activator receptor (suPAR) is an emerging inflammatory and immune biomarker. Whether suPAR level predicts the presence and the severity of coronary artery disease (CAD), and of incident death and myocardial infarction (MI) in subjects with suspected CAD, is unknown. Methods and Results We measured plasma suPAR levels in 3367 subjects (67% with CAD) recruited in the Emory Cardiovascular Biobank and followed them for adverse cardiovascular (CV) outcomes of death and MI over a mean 2.1±1.1 years. Presence of angiographic CAD (≥50% stenosis in ≥1 coronary artery) and its severity were quantitated using the Gensini score. Cox\u27s proportional hazard survival and discrimination analyses were performed with models adjusted for established CV risk factors and C-reactive protein levels. Elevated suPAR levels were independently associated with the presence of CAD (P\u3c0.0001) and its severity (P\u3c0.0001). A plasma suPAR level ≥3.5 ng/mL (cutoff by Youden\u27s index) predicted future risk of MI (hazard ratio [HR]=3.2; P\u3c0.0001), cardiac death (HR=2.62; P\u3c0.0001), and the combined endpoint of death and MI (HR=1.9; P\u3c0.0001), even after adjustment of covariates. The C-statistic for a model based on traditional risk factors was improved from 0.72 to 0.74 (P=0.008) with the addition of suPAR. Conclusion Elevated levels of plasma suPAR are associated with the presence and severity of CAD and are independent predictors of death and MI in patients with suspected or known CAD

Circulating CD34+ Progenitor Cells and Risk of Mortality in a Population with Coronary Artery Disease

RATIONALE: Low circulating progenitor cell (PC) numbers and activity may reflect impaired intrinsic regenerative/reparative potential, but it remains uncertain whether this translates into a worse prognosis. OBJECTIVES: To investigate whether low numbers of PCs associate with a greater risk of mortality in a population at high cardiovascular risk. METHODS & RESULTS: Patients undergoing coronary angiography were recruited into two cohorts (1, n=502 and 2, n=403) over separate time periods. PCs were enumerated by flow cytometry as CD45(med+) blood mononuclear cells expressing CD34, with additional quantification of subsets co-expressing CD133, VEGFR2 and CXCR4. Coefficient of variation for CD34 cells was 2.9% and 4.8%, 21.6% and 6.5% for the respective subsets. Each cohort was followed for a mean of 2.7 and 1.2 years, respectively, for the primary endpoint of all-cause death. There was an inverse association between CD34+ and CD34+/CD133+ cell counts and risk of death in Cohort 1 (β=−0.92, p=0.043 and β=−1.64, p=0.019, respectively) that was confirmed in Cohort 2 (β=−1.25, p=0.020 and β=−1.81, p=0.015, respectively). Covariate adjusted HRs in the pooled cohort (n=905) were 3.54 (1.67-7.50) and 2.46 (1.18-5.13), respectively. CD34+/CD133+ cell counts improved risk prediction metrics beyond standard risk factors. CONCLUSION: Reduced circulating PC counts, identified primarily as CD34+ mononuclear cells or its subset expressing CD133 are associated with risk of death in individuals with coronary artery disease, suggesting that impaired endogenous regenerative capacity is associated with increased mortality. These findings have implications for biological understanding, risk prediction and cell selection for cell based therapies

Primary Prevention of Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of death worldwide. This article focuses on current guidelines for the primary prevention of CVD and addresses management of key risk factors. Dietary modification, weight loss, exercise, and tobacco use cessation are specific areas where focused efforts can successfully reduce CVD risk on both an individual and a societal level. Specific areas requiring management include dyslipidemia, hypertension, physical activity, diabetes, aspirin use, and alcohol intake. These preventive efforts have major public health implications. As the global population continues to grow, health care expenditures will also rise, with the potential to eventually overwhelm the health care system. Therefore it is imperative to apply our collective efforts on CVD prevention to improve the cardiovascular health of individuals, communities, and nations

Raising HDL cholesterol in women

Danny J Eapen1, Girish L Kalra1, Luay Rifai1, Christina A Eapen2, Nadya Merchant1, Bobby&amp;nbsp;V Khan11Emory University School of Medicine, Atlanta, GA, USA; 2University of South Florida School of Medicine, Tampa, FL, USAAbstract: High-density lipoprotein cholesterol (HDL-C) concentration is essential in the determination of coronary heart disease (CHD) risk in women. This is especially true in the postmenopausal state, where lipid profiles and CHD risk mimic that of age-matched men. Thus, interventions designed to reduce CHD risk by raising HDL-C levels may have particular significance during the transition to menopause. This review discusses HDL-C-raising therapies and the role of HDL in the primary prevention of CHD in women. Lifestyle-based interventions such as dietary change, aerobic exercise regimens, and smoking cessation are initial steps that are effective in raising HDL-C, and available data suggest women respond similarly to men with these interventions. When combined with pharmacotherapy, the effects of these lifestyle alterations are further amplified. Though studies demonstrating gender-specific differences in therapy are limited, niacin continues to be the most effective agent in raising HDL-C levels, especially when used in combination with fibrate or statin therapy. Emerging treatments such as HDL mimetic therapy show much promise in further raising HDL-C levels and improving cardiovascular outcomes.Keywords: high-density lipoprotein, HDL, women, cholesterol, heart diseas