Dual renin-angiotensin-aldosterone blockade: promises and pitfalls

Eight weeks of treatment with mineralocorticoid receptor blockade does not alter vascular function in individuals with and without type 2 diabetes

Aldosterone has been suggested to be involved in the microvascular complications observed in type 2 diabetes. We aimed to investigate the effect of mineralocorticoid receptor (MR) blockade on endothelial function in individuals with type 2 diabetes compared to healthy controls. We included 12 participants with type 2 diabetes and 14 controls. We measured leg hemodynamics at baseline and during femoral arterial infusion of acetylcholine and sodium nitroprusside before and 8 weeks into treatment with MR blockade (eplerenone). Acetylcholine infusion was repeated with concomitant n-acetylcysteine (antioxidant) infusion. No difference in leg blood flow or vascular conductance was detected before or after the treatment with MR blockade in both groups and there was no difference between groups. Infusion of n-acetylcysteine increased baseline blood flow and vascular conductance, but did not change the vascular response to acetylcholine before or after treatment with MR blockade. Skeletal muscle eNOS content was unaltered by MR blockade and no difference between groups was detected. In conclusion, we found no effect of MR blockade endothelial function in individuals with and without type 2 diabetes. As the individuals with type 2 diabetes did not have vascular dysfunction, these results might not apply to individuals with vascular dysfunction.

Nephrotic syndrome: pathophysiology and consequences

In patients with kidney disease, nephrotic syndrome can lead to several complications including progressive kidney dysfunction. Proteinuria may lead to the formation of cellular or fibrous crescents with reciprocal development of rapidly progressive glomerulonephritis or focal glomerulosclerosis. Proteinuria may also cause overload and dysfunction of tubular epithelial cells, eventually resulting in tubular atrophy and interstitial fibrosis. Hypoalbuminemia is usually associated with increased risk of mortality and kidney dysfunction. Dyslipidemia may increase the risk of atherosclerotic complications, cause podocyte dysfunction and contribute to vascular thrombosis. Urinary loss of anticoagulants and overproduction of coagulation factors may facilitate a hypercoagulable state. Edema, hypogammaglobulinemia, loss of complement factors, and immunosuppressive therapy can favor infection. Treatment of these complications may reduce their impact on the severity of NS. Nephrotic syndrome is a kidney disorder that can worsen the quality of life and increase the risk of kidney disease progression.

Nutritional Treatment as a Synergic Intervention to Pharmacological Therapy in CKD Patients

Nutritional and pharmacological therapies represent the basis for non-dialysis management of CKD patients. Both kinds of treatments have specific and unchangeable features and, in certain cases, they also have a synergic action. For instance, dietary sodium restriction enhances the anti-proteinuric and anti-hypertensive effects of RAAS inhibitors, low protein intake reduces insulin resistance and enhances responsiveness to epoetin therapy, and phosphate restriction cooperates with phosphate binders to reduce the net phosphate intake and its consequences on mineral metabolism. It can also be speculated that a reduction in either protein or salt intake can potentially amplify the anti-proteinuric and reno-protective effects of SGLT2 inhibitors. Therefore, the synergic use of nutritional therapy and medications optimizes CKD treatment. Quality of care management is improved and becomes more effective when compared to either treatment alone, with lower costs and fewer risks of unwanted side effects. This narrative review summarizes the established evidence of the synergistic action carried out by the combination of nutritional and pharmacological treatments, underlying how they are not alternative but complementary in CKD patient care.

Control of blood pressure levels in patients with premature coronary artery disease: Results from the Genetics of Atherosclerotic Disease study

High blood pressure (BP) is the major cardiovascular-risk factor for coronary artery disease (CAD), principally in young patients who have an important and increasing socioeconomic burden. Despite the Seventh Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7), recommended BP target <140/90 mm Hg for patients with stable CAD, in 2017 the American College of Cardiology and the American Heart Association (ACC/AHA) updated BP target to <130/80 mm Hg. We aimed to analyze the prevalence of BP control in patients with premature CAD using both criteria. In addition, antihypertensive therapy, lifestyle, clinical, and sociodemographic characteristics of the patients were evaluated in order to identify factors associated with the achievement of BP targets. The present study included 1206 patients with CAD diagnosed before 55 and 65 years old in men and women, respectively. Sociodemographic, clinical, and biochemical data were collected. The results indicate that 85.6% and 77.5% of subjects with premature CAD achieved JNC-7 non-strict and ACC/AHA strict BP target, respectively. Consistently, number of antihypertensive drugs and hypertension duration >10 years were inversely associated with BP targets, whereas total physical activity and smoking were directly associated with BP targets, regardless of BP criteria. Considering that age, gender, and hypertension duration are non-modifiable cardiovascular-risk factors, our results highlight the need for more effective strategies focused on increase physical activity and smoking cessation in young patients with CAD. These healthier lifestyles changes should favor the BP target achievement and reduce the socioeconomic and clinical burden of premature CAD.

The pathophysiology of myocardial infarction-induced heart failure

Heart failure (HF) is a multifactorial disorder and is usually the end stage of many cardiovascular diseases (CVD). HF presents one of the highest morbidity and mortality indices worldwide and high costs to public health organizations. Myocardial infarction (MI) is the most prevalent CVD in the Western world and leads to HF when its management is inadequate. It has a destructive potential for heart cells and abruptly reduces the cardiac output, a clinical condition known as heart dysfunction that might progress to HF. Many acute and chronic adaptations occur due to MI that progress to HF, e.g., neurohumoral hyperactivity, inflammatory response and cardiac remodeling. Herein, we reviewed in simplistic manner the processes involved in setting of MI until the establishment of HF.

New agents modulating the renin-angiotensin-aldosterone system-Will there be a new therapeutic option?

The renin-angiotensin-aldosterone system (RAAS) is more complex than it was originally regarded. According to the current subject knowledge, there are two main axes of the RAAS: (1) angiotensin-converting enzyme (ACE)-angiotensin II-AT₁ receptor axis and (2) ACE2-angiotensin-(1-7)-Mas receptor axis. The activation of the first axis leads to deleterious effects, including vasoconstriction, endothelial dysfunction, thrombosis, inflammation, and fibrosis; therefore, blocking the components of this axis is a highly rational and commonly used therapeutic procedure. The ACE2-Ang-(1-7)-Mas receptor axis has a different role, since it often opposes the effects induced by the classical ACE-Ang II-AT₁ axis. Once the positive effects of the ACE2-Ang-(1-7)-Mas axis were discovered, the alternative ways of pharmacotherapy activating this axis of RAAS appeared. This article briefly describes new molecules affecting the RAAS, namely: recombinant human ACE2, ACE2 activators, angiotensin-(1-7) peptide and non-peptide analogs, aldosterone synthase inhibitors, and the third and fourth generation of mineralocorticoid receptor antagonists. The results of the experimental and clinical studies are encouraging, which leads us to believe that these new molecules can support the treatment of cardiovascular diseases as well as cardiometabolic disorders.