The contribution of angiotensin peptides to cardiovascular neuroregulation in health and disease

The brain renin–angiotensin system (RAS) is critically involved in the cardiovascular regulation and energy homeostasis. The overwhelming evidence indicates that the central RAS closely cooperates with the systemic RAS by means of interactions with the autonomic nervous system and hormonal and humoral factors linking RAS with regulation of blood pressure, water–electrolyte equilibrium, and energy balance. Particularly significant roles in these interactions are played by aldosterone and vasopressin;however, other factors such as proinflammatory cytokines, growth factors, nitric oxide, prostaglandins, and ROS appear to be also essential players, especially during challenges (stress, hypoxia), and under pathological conditions (hypertension, heart failure, metabolic syndrome, atherosclerosis, COVID-19). Current pharmacotherapies of cardiovascular diseases are focused on the angiotensin-converting enzyme inhibitors and angiotensin type 1 receptor blockers and their effects on systemic RAS. A better understanding of neuroanatomical and neurochemical connections between central RAS and other regulatory systems should advance pharmacological interventions aimed at central RAS. © 2023 Elsevier Inc. All rights reserved.

Headache medication and the COVID-19 pandemic.

The world is currently dominated by the Corona Virus Disease 2019 (COVID-19) pandemic. Besides the obvious concerns about limitation of virus spread and providing the best possible care to infected patients, a concomitant concern has now arisen in view of a putative link between the use of certain drugs, such as Renin-Angiotensin System (RAS) inhibitors and ibuprofen, and an increased risk for COVID-19 infection. We here discuss this concern in relation to headache treatment and conclude that, based on current evidence, there is no reason to abandon treatment of headache patients with RAS inhibitors or ibuprofen.

COVID-19 pandemic and hypertension: an updated report from the Japanese Society of Hypertension project team on COVID-19.

The number of reported cases with coronavirus disease 2019 (COVID-19) has exceeded 620 million worldwide, still having a profound impact on people's health and daily lives since its occurrence and outbreak in December 2019. From the early phase of the COVID-19 pandemic, there has been a concern that the rapid spread of this communicable disease can negatively influence non-communicable diseases. Accumulating data indicate that the restriction on the access to medical care, psychological distress, and life-style changes triggered by the pandemic have indeed affected blood pressure control in hypertensive patients. Since our previous report in 2020 that summarized the findings of the literature related to COVID-19 and hypertension, there has been a considerable progress in our understanding of the association between these two disorders; nonetheless, there are remaining challenges and emerging questions in the field. In this article, we aim to summarize the latest information on the impact of the pandemic on blood pressure control, the use of the renin-angiotensin system inhibitors in patients with COVID-19, and the blood pressure changes as one of the possible post-acute sequelae of COVID-19 (also known as long COVID). We also summarize the evidence of telemedicine and COVID-19 vaccination in hypertensive subjects, based on data available as of June 2022.

Drugs Modulating Renin-Angiotensin System in COVID-19 Treatment.

A massive worldwide vaccination campaign constitutes the main tool against the COVID-19 pandemic. However, drug treatments are also necessary. Antivirals are the most frequently considered treatments. However, strategies targeting mechanisms involved in disease aggravation may also be effective. A major role of the tissue renin-angiotensin system (RAS) in the pathophysiology and severity of COVID-19 has been suggested. The main link between RAS and COVID-19 is angiotensin-converting enzyme 2 (ACE2), a central RAS component and the primary binding site for SARS-CoV-2 that facilitates the virus entry into host cells. An initial suggestion that the susceptibility to infection and disease severity may be enhanced by angiotensin type-1 receptor blockers (ARBs) and ACE inhibitors (ACEIs) because they increase ACE2 levels, led to the consideration of discontinuing treatments in thousands of patients. More recent experimental and clinical data indicate that ACEIs and, particularly, ARBs can be beneficial for COVID-19 outcome, both by reducing inflammatory responses and by triggering mechanisms (such as ADAM17 inhibition) counteracting viral entry. Strategies directly activating RAS anti-inflammatory components such as soluble ACE2, Angiotensin 1-7 analogues, and Mas or AT2 receptor agonists may also be beneficial. However, while ACEIs and ARBs are cheap and widely used, the second type of strategies are currently under study.

Which ones, when and why should renin-angiotensin system inhibitors work against COVID-19?

The article describes the possible pathophysiological origin of COVID-19 and the crucial role of renin-angiotensin system (RAS), providing several "converging" evidence in support of this hypothesis. SARS-CoV-2 has been shown to initially upregulate ACE2 systemic activity (early phase), which can subsequently induce compensatory responses leading to upregulation of both arms of the RAS (late phase) and consequently to critical, advanced and untreatable stages of COVID-19 disease. The main and initial actors of the process are ACE2 and ADAM17 zinc-metalloproteases, which, initially triggered by SARS-CoV-2 spike proteins, work together in increasing circulating Ang 1-7 and Ang 1-9 peptides and downstream (Mas and Angiotensin type 2 receptors) pathways with anti-inflammatory, hypotensive and antithrombotic activities. During the late phase of severe COVID-19, compensatory secretion of renin and ACE enzymes are subsequently upregulated, leading to inflammation, hypertension and thrombosis, which further sustain ACE2 and ADAM17 upregulation. Based on this hypothesis, COVID-19-phase-specific inhibition of different RAS enzymes is proposed as a pharmacological strategy against COVID-19 and vaccine-induced adverse effects. The aim is to prevent the establishment of positive feedback-loops, which can sustain hyperactivity of both arms of the RAS independently of viral trigger and, in some cases, may lead to Long-COVID syndrome.

Biologia Futura: is ADAM 17 the reason for COVID-19 susceptibility in hyperglycemic and diabetic patients?

COVID-19 is a disease-causing current pandemic. It prevails in patients with pre-existing conditions such as diabetes and hypertension. Renin-angiotensin system was identified as a center of COVID-19 pathophysiology. There is a current controversy concerning the usage of ACE inhibitors and AR blockers in patients with COVID-19. Multiple clinical trials are on the way to determine the effect of RAS blockers in patients with COVID-19. ACE2 receptor is thought to be the point of entry utilized by a coronavirus. However, other factors have been identified which potentially facilitate SARS-CoV-2 entry into the cell. ADAM17 could facilitate viral entry in hyperglycemic and diabetic patients. Insulin is an ADAM17 inhibitor. Heme oxygenase (HO)-1 level is reduced in diabetic patients, contributing to the worst outcome for patients with poor glycemic control. The combined therapy of glycemic control and antioxidant response to oxidative stress could be explored in patients with COVID-19.

Angiotensin-Converting-Enzyme 2 and Renin-Angiotensin System Inhibitors in COVID-19: An Update.

Ever since its outbreak, Corona Virus Disease 2019(COVID-19) caused by SARS-CoV-2 has affected more than 26 million individuals in more than 200 countries. Although the mortality rate of COVID-19 is low, but several clinical studies showed, patients with diabetes mellitus (DM) or other major complication at high risk of COVID-19 and reported more severe disease and increased fatality. The angiotensin-converting-enzyme 2 (ACE2), a component of renin-angiotensin-system (RAS); acts on ACE/Ang-II/AT1recptor axis, and regulates pathological processes like hypertension, cardiac dysfunction, Acute Respiratory Distress Syndrome (ARDS) etc. The progression of T2DM and hypertension show decreased expression and activity of ACE2. There are several treatment strategies for controlling diabetes, hypertension, etc; like ACE2 gene therapies, endogenous ACE2 activators, human recombinant ACE2 (hrACE2), Angiotensin-II receptor blockers (ARBs) and ACE inhibitors (ACEi) medications. ACE2, the receptors for SARS-CoV2, facilitates virus entry inside host cell. Clinicians are using two classes of medications for the treatment of COVID-19; one targets the SARS-CoV-2-ACE2 interaction, while other targets human immune system. The aim of this review is to discuss the role of ACE2 in diabetes and in COVID-19 and to provide an analysis of data proposing harm and benefit of RAS inhibitor treatment in COVID-19 infection as well as showing no association whatsoever. This review also highlights some candidate vaccines which are undergoing clinical trials.

Renin-angiotensin system inhibitors and mortality in patients with COVID-19.

Association of renin-angiotensin system inhibitors with risk of death in patients with hypertension (HTN) and coronavirus disease 2019 (COVID-19) is not well characterized. The aim of this study was to evaluate the outcomes of patients with HTN and COVID-19 with respect to different chronic antihypertensive drug intake. We performed a retrospective, observational study from a large cohort of patients with HTN and with a laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection admitted to the Emergency Rooms (ER) of the Piacenza Hospital network from February 21, 2020 to March 20, 2020. There were 1050 patients admitted to the ERs of the Piacenza Hospital network with COVID-19. HTN was present in 590 patients [median age, 76.2 years (IQR 68.2-82.6)]; 399 (66.1%) patients were male. Of them, 248 patients were chronically treated with ACEi, 181 with ARBs, and 161 with other drugs (O-drugs) including beta blockers, diuretics and calcium-channel inhibitors. With respect to the antihypertensive use, there was no difference between comorbid conditions. During a follow-up of 38 days (IQR 7.0-46.0), 256 patients (43.4%) died, without any difference stratifying for antihypertensive drugs. Of them, 107 (43.1%) were in ACEi group vs 67 (37%) in ARBs group vs 82 (50.7%) in O-drugs group, (log-rank test: p = 0.066). In patients with HTN and COVID-19, neither ACEi nor ARBs were independently associated with mortality. After adjusting for potential confounders in risk prediction, the rate of death was similar. Our data confirm Specialty Societal recommendations, suggesting that treatment with ACEIs or ARBs should not be discontinued because of COVID-19.

Renin-Angiotensin System Inhibitors and COVID-19: a Systematic Review and Meta-Analysis. Evidence for Significant Geographical Disparities.

PURPOSE OF REVIEW: While the COVID-19 pandemic is constantly evolving, it remains unclear whether the use of angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) affects the clinical course of SARS-CoV-2 infection. For this meta-analysis, PubMed, CENTRAL, and grey literature were searched from their inception to 19 May 2020 for randomized, controlled trials or observational studies that evaluate the association between the use of either ACE inhibitors or ARBs and the risk for major clinical endpoints (infection, hospitalization, admission to ICU, death) in adult patients during the COVID-19 pandemic. In addition, a subgroup geographical analysis of outcomes was performed. Studies including less than 100 subjects were excluded from our analysis. RECENT FINDINGS: In total, 25 observational studies were included. ACE inhibitors and ARBs were not associated with increased odds for SARS-CoV-2 infection, admission to hospital, severe or critical illness, admission to ICU, and SARS-CoV-2-related death. In Asian countries, the use of ACE inhibitors/ARBs decreased the odds for severe or critical illness and death (OR = 0.37, 95% CI 0.16-0.89, I2 = 83%, and OR = 0.62, 95% CI 0.39-0.99, I2 = 0%, respectively), whereas they increased the odds for ICU admission in North America and death in Europe (OR = 1.75, 95% CI 1.37-2.23, I2 = 0%, and OR = 1.68, 95% CI 1.05-2.70, I2 = 82%, respectively). ACE inhibitors might be marginally protective regarding SARS-CoV-2-related death compared with ARBs (OR = 0.86, 95% CI 0.74-1.00, I2 = 0%). Randomized controlled trials are needed to confirm the aforementioned associations between ACE inhibitors, ARBs, and SARS-CoV-2.

Renin-Angiotensin System and Coronavirus Disease 2019: A Narrative Review.

Although clinical manifestations of the 2019 novel coronavirus disease pandemic (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), are mainly respiratory symptoms, patients can also develop severe cardiovascular damage. Therefore, understanding the damage caused by SARS-COV-2 to the cardiovascular system and the underlying mechanisms is fundamental. The cardiovascular damage may be related to the imbalance of the renin-angiotensin-system (RAS) as this virus binds the Angiotensin-Converting-Enzyme 2 (ACE2), expressed on the lung alveolar epithelial cells, to enter into cells. Virus internalization may cause a downregulation of ACE2 on host cell surface that could lead to a local increased level of angiotensin II (AII) and a reduced level of angiotensin 1-7 (A1-7). An imbalance between these angiotensins may be responsible for the lung and heart damage. Pharmacological strategies that interfere with the viral attachment to ACE2 (umifenovir and hydroxychloroquine/chloroquine) or that modulate the RAS (analogous of A1-7 and ACE2, losartan) are in clinical development for COVID-19. The use of RAS inhibitors has also become a matter of public concern as these drugs may increase the mRNA expression and levels of ACE2 and impact the virulence and transmission of SARS-COV-2. Data on the effect of RAS inhibitors on ACE2 mRNA expression are scarce. Scientific societies expressed their opinion on continuing the therapy with RAS inhibitors in patients with COVID-19 and underlying cardiovascular diseases. In conclusion, RAS may play a role in SARS-COV-2-induced cardiac and pulmonary damage. Further studies are needed to better understand the role of RAS in COVID-19 and to guide decision on the use of RAS inhibitors.

Angiotensin-converting enzyme 2: a double-edged sword in COVID-19 patients with an increased risk of heart failure.

The coronavirus disease (COVID-19) pandemic is a global health priority. Given that cardiovascular diseases (CVD) are the leading cause of morbidity around the world and that several trials have reported severe cardiovascular damage in patients infected with SARS-CoV-2, a substantial number of COVID-19 patients with underlying cardiovascular diseases need to continue their medications in order to improve myocardial contractility and to prevent the onset of major adverse cardiovascular events (MACEs), including heart failure. Some of the current life-saving medications may actually simultaneously expose patients to a higher risk of severe COVID-19. Angiotensin-converting enzyme 2 (ACE2), a key counter regulator of the renin-angiotensin system (RAS), is the main entry gate of SARS-CoV-2 into human host cells and an established drug target to prevent heart failure. In fact, ACE inhibitors, angiotensin II receptor blockers, and mineralocorticoid antagonists may augment ACE2 levels to protect organs from angiotensin II overload. Elevated ACE2 expression on the host cell surface might facilitate viral entrance, at the same time sudden nonadherence to these medications triggers MACEs. Hence, safety issues in the use of RAS inhibitors in COVID-19 patients with cardiac dysfunction remain an unsolved dilemma and need paramount attention. Although ACE2 generally plays an adaptive role in both healthy subjects and patients with systolic and/or diastolic dysfunction, we conducted a literature appraisal on its maladaptive role. Understanding the exact role of ACE2 in COVID-19 patients at risk of heart failure is needed to safely manage RAS inhibitors in frail and non-frail critically ill patients.