Endothelial dysfunction, arterial stiffness, and heart failure

Endothelial dysfunction is a marker of systemic response to the cardiac resynchronization therapy in heart failure

BACKGROUND

Cardiac resynchronization therapy (CRT) induces a significant improvement in patients with heart failure (HF), who are often characterized by the presence of endothelial dysfunction (ED) with impaired flow-mediated vasodilation (FMD). We aimed to study the ED in patients with HF candidates to CRT with defibrillator (CRT-D).

METHODS AND RESULTS

We studied 57 consecutive patients affected by HF and undergoing CRT-D. At the baseline we recorded a high prevalence of ED (64.9%) with impaired FMD (4.1 ± 3.8%). After 12 months of CRT, we reported a marked increase of the mean FMD (8.8 ± 4.8% vs 4.1 ± 3.8%; P < .05) along with significant improvement of left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), New York Heart Association (NYHA) functional class, and 6-minute walk test (6MWT); 42 patients (73.7%) were classified as responders according to standard criteria. FMD was related to LVEF (r = 0.169; P < .05), LVESV (r = -0.169; P < .05), NYHA functional class (r = -0.27; P < .051), and 6MWT (r = 0.360; P < .01).

CONCLUSIONS

ED is not an independent predictor of CRT response, but it is able to intercept the systemic effects of CRT and is an affordable marker of response to CRT, especially in patients unable to perform the 6MWT.

The role of tissue Renin-Angiotensin-aldosterone system in the development of endothelial dysfunction and arterial stiffness

Epidemiological studies support the notion that arterial stiffness is an independent predictor of adverse cardiovascular events contributing significantly to systolic hypertension, impaired ventricular-arterial coupling and diastolic dysfunction, impairment in myocardial oxygen supply and demand, and progression of kidney disease. Although arterial stiffness is associated with aging, it is accelerated in the presence of obesity and diabetes. The prevalence of arterial stiffness parallels the increase of obesity that is occurring in epidemic proportions and is partly driven by a sedentary life style and consumption of a high fructose, high salt, and high fat western diet. Although the underlying mechanisms and mediators of arterial stiffness are not well understood, accumulating evidence supports the role of insulin resistance and endothelial dysfunction. The local tissue renin-angiotensin-aldosterone system (RAAS) in the vascular tissue and immune cells and perivascular adipose tissue is recognized as an important element involved in endothelial dysfunction which contributes significantly to arterial stiffness. Activation of vascular RAAS is seen in humans and animal models of obesity and diabetes, and associated with enhanced oxidative stress and inflammation in the vascular tissue. The cross talk between angiotensin and aldosterone underscores the importance of mineralocorticoid receptors in modulation of insulin resistance, decreased bioavailability of nitric oxide, endothelial dysfunction, and arterial stiffness. In addition, both innate and adaptive immunity are involved in this local tissue activation of RAAS. In this review we will attempt to present a unifying mechanism of how environmental and immunological factors are involved in this local tissue RAAS activation, and the role of this process in the development of endothelial dysfunction and arterial stiffness and targeting tissue RAAS activation.

Effect of tobacco smoking and smoking cessation on plasma lipoproteins and associated major cardiovascular risk factors: a narrative review

Cigarette smoking, active or passive, kills about 6 million people each year worldwide. Cardiovascular disease (CVD) is responsible for 40% of all smoking-related deaths, lung cancer accounts for 20% of all smoking-related deaths, and chronic obstructive pulmonary disease is related to another 20% of deaths. In this narrative review we consider the relationship between cigarette smoking and CVD. We discuss disease states and/or CVD risk factors related to smoking, such as dyslipidaemia, vascular inflammation, endothelial dysfunction, arterial stiffness, insulin resistance, type 2 diabetes mellitus (T2DM), chronic kidney disease (CKD), and non-alcoholic fatty liver disease (NAFLD) as well as their complex interrelations. Smoking cessation can correct abnormalities related to smoking; however, success rates are relatively low. In cases of inability to quit, measures to minimize the adverse effects of smoking specifically related to CVD should be taken. Smokers should receive best practice treatment, according to guidelines, as for non-smokers.

Changes in circulating progenitor cells are associated with outcome in heart failure patients: a longitudinal study

BACKGROUND

Circulating progenitor cells (CPCs) are involved in the process of endothelial repair and are a prognostic factor in cardiovascular diseases. We evaluated the association between serial measurements of CPCs and functional capacity and outcomes in heart failure (HF).

METHODS

We included 156 consecutive consenting ambulatory HF patients (left ventricular ejection fraction < 40%). We evaluated CPCs and functional capacity (peak VO2) every 6 months for up to 2 years. CPCs were measured as early-outgrowth colony-forming units (EO-CFUs) and circulating CD34+, VEGFR2+ and/or CD133+ cells. We recorded mortality, HF hospital admissions, transplant, and ventricular assist device.

RESULTS

The mean age was 55 ± 15 years. A decrease in CD34+VEGFR2+ cells was independently associated with increased functional capacity; a 10-cell decrease in CD34+VEGFR2+ cells was associated with an increase of 0.2 mL/kg/min in peak VO2 (P < 0.05). We found an interaction effect (P = 0.02) between EO-CFUs and diabetes: in patients without diabetes, a 10-EO-CFU increase was independently associated with increased peak VO2 of 0.28 mL/kg/min (P = 0.01), and in patients with diabetes, a decrease in EO-CFUs was associated with an increased peak VO2 (P < 0.05). Higher EO-CFUs were associated with reduced mortality (hazard ratio, 0.25; 95% confidence interval, 0.09-0.69).

CONCLUSIONS

We noted differential relations between CPCs and outcomes in patients with vs without diabetes. Higher EO-CFUs and lower CD34+VEGFR2+ cells were associated with improved functional capacity and reduced mortality in nondiabetic patients. In patients with diabetes, lower EO-CFUs were associated with improved functional capacity. The basis for these differences requires further examination.

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.

Macrophage migration inhibitory factor is associated with vascular dysfunction in patients with end-stage renal disease

BACKGROUND

Patients with end-stage renal disease (ESRD) show a high prevalence of cardiovascular disease with arterial stiffness, atherosclerosis and endothelial dysfunction, leading to increased morbidity and mortality. The cytokine macrophage migration inhibitory factor (MIF) exhibits proinflammatory and proatherogenic functions and has recently emerged as a major regulator of atherogenesis. Studies examining the relationship between circulating MIF levels and vascular dysfunction in this high-risk population do not exist.

METHODS

In patients with ESRD (n = 39) and healthy controls (n = 16) we assessed endothelial function by flow-mediated dilation of the brachial artery and arterial stiffness (augmentation pressure, augmentation index and pulse pressure) using applanation tonometry. High-sensitive Troponin and subendocardial viability ratio were determined to assess myocardial injury.

RESULTS

Patients with ESRD had impaired endothelial function and higher plasma MIF levels. MIF levels negatively correlated with endothelial function (r = -0.345, P = 0.031) and positively with arterial stiffness indices in patients with ESRD (pulse pressure r = -0.374, P = 0.019 and augmentation pressure r = -0.423, P = 0.025). In multivariate regression models besides age, gender, weight, and heart rate, MIF was an independent predictor for arterial stiffness. Impact on myocardial end-organ damage was reflected by correlation with high-sensitive Troponin I (r = 0.43, P = 0.009).

CONCLUSION

Our findings show that high MIF plasma levels are associated with diminished endothelial function and arterial stiffness and are correlated with myocardial injury. Further studies are necessary to investigate whether modulation of MIF might have an impact on atherosclerotic disease in this high-risk population.

Cardiovascular biomarkers and subclinical brain disease in the atherosclerosis risk in communities study

BACKGROUND AND PURPOSE

Cerebrovascular and cardiovascular disease share common risk factors. Our goal was to determine whether levels of N-terminal brain natriuretic peptide (NT-proBNP) and cardiac troponin T measured with a highly sensitive assay (hs-cTnT) are associated with silent brain infarcts (BIs) and white matter lesions (WMLs) on MRI in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS

At ARIC visit 3 (1993-1995), 1920 participants had brain MRI. NT-proBNP and hs-cTnT were measured in all individuals at ARIC visit 4 (1996-1998). Of 1920 individuals, 1112 had a follow-up MRI [2004-2006]). We analyzed the association of NT-proBNP and hs-cTnT with MRI-defined BI and WML on the initial MRI and incident BI and WML progression on the follow-up MRI in participants without heart failure, coronary heart disease, or stroke.

RESULTS

In the adjusted model, individuals in the highest NT-proBNP quartile had significantly more BI (odds ratio, 3.50; 95% confidence interval, 2.03-6.20), and WML (β-coefficient, 0.09; SE, 0.03) on the baseline MRI and more incident BI (odds ratio, 2.18; 95% confidence interval, 1.38-3.47) and WML progression (β-coefficient, 0.22; SE, 0.10) on the follow-up MRI. Individuals in the highest hs-cTnT category had more BI (odds ratio, 3.03; 95% confidence interval, 1.57-5.82) and WML (β-coefficient, 0.11; SE, 0.04) on the initial MRI and more WML progression (β-coefficient, 0.43; SE, 0.17) on the follow-up MRI.

CONCLUSIONS

NT-proBNP and hs-cTnT are independently associated with silent MRI-defined BI and WML, suggesting that cardiovascular biomarkers may be useful to identify individuals with subclinical cerebral injury.

Genetic prediction of heart failure incidence, prognosis and beta-blocker response

Heart failure (HF) is a widespread syndrome due to left ventricular dysfunction with high mortality, morbidity and health-care costs. Beta-blockers, together with diuretics and ACE-inhibitors or angiotensin receptor blockers, are a cornerstone of HF therapy, as they reduce mortality and morbidity. Nevertheless, their efficacy varies among patients, and genetics is likely to be one of the modifying factors. In this article, literature on the role of candidate genes on the development of HF, its prognosis and pharmacogenomics of β-blockers in patients with HF is reviewed. The available findings do not support, at the present time, a role for genetic tests in the treatment of HF. More large-scale genome-wide studies with adequate methodology and statistical analysis are required before considering genetic tailoring of HF therapy in patients with systolic HF.

Hemopexin therapy improves cardiovascular function by preventing heme-induced endothelial toxicity in mouse models of hemolytic diseases

BACKGROUND

Hemolytic diseases are characterized by enhanced intravascular hemolysis resulting in heme-catalyzed reactive oxygen species generation, which leads to endothelial dysfunction and oxidative damage. Hemopexin (Hx) is a plasma heme scavenger able to prevent endothelial damage and tissue congestion in a model of heme overload. Here, we tested whether Hx could be used as a therapeutic tool to counteract heme toxic effects on the cardiovascular system in hemolytic diseases.

METHODS AND RESULTS

By using a model of heme overload in Hx-null mice, we demonstrated that heme excess in plasma, if not bound to Hx, promoted the production of reactive oxygen species and the induction of adhesion molecules and caused the reduction of nitric oxide availability. Then, we used β-thalassemia and sickle cell disease mice as models of hemolytic diseases to evaluate the efficacy of an Hx-based therapy in the treatment of vascular dysfunction related to heme overload. Our data demonstrated that Hx prevented heme-iron loading in the cardiovascular system, thus limiting the production of reactive oxygen species, the induction of adhesion molecules, and the oxidative inactivation of nitric oxide synthase/nitric oxide, and promoted heme recovery and detoxification by the liver mainly through the induction of heme oxygenase activity. Moreover, we showed that in sickle cell disease mice, endothelial activation and oxidation were associated with increased blood pressure and altered cardiac function, and the administration of exogenous Hx was found to almost completely normalize these parameters.

CONCLUSIONS

Hemopexin treatment is a promising novel therapy to protect against heme-induced cardiovascular dysfunction in hemolytic disorders.