Considerations on the use of antihypertensive blockers of the renin-angiotensin system in adults and children in the face of the COVID-19 pandemic / Consideraciones sobre el uso de antihipertensivos bloqueadores del sistema renina-angiotensina en adultos y niños ante la pandemia de COVID-19

Abstract As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients with hypertension and other cardiovascular comorbidities develop more severe coronavirus disease (COVID)-19 and are at high risk of death, a controversy arose about the use of antihypertensives as angiotensin-converting enzyme inhibitors (ACEis) and angiotensin II receptor blockers (ARBs). Such drugs might increase the expression of the fundamental receptor of this new infectious agent: the angiotensin-converting enzyme 2 (ACE2). Preclinical observations indicate that the increase of ACE2 expression or the activity by ACEis and ARBs leads to a greater transformation of angiotensin (Ang)-II to Ang-(1-7), which is associated with positive effects on cardiovascular and pulmonary pathophysiology. This association has been demonstrated in observational studies in patients with cardiovascular pathology and pneumonia. It has not been possible to confirm whether users of ACEis or ARBs are more infected by the new coronavirus, due to methodological issues in studies with patients infected with SARS-CoV-2. However, the use of such antihypertensive treatments in both children and adults might reduce the virulence of infection. Therefore, changes in the antihypertensive therapy of patients at risk of contracting COVID-19 are not recommended.

Resumen Los pacientes con hipertensión y otra comorbilidad cardiovascular infectados con SARS-CoV-2 desarrollan cuadros más graves de COVID-19 y con mayor frecuencia fallecen. Este hecho ha originado una controversia acerca del uso de antihipertensivos inhibidores de la enzima convertidora de la angiotensina (IECA) y de antagonistas de los receptores de la angiotensina II (ARA-II), pues tales medicamentos pueden incrementar la expresión del receptor funcional de este nuevo agente infeccioso: la enzima convertidora de la angiotensina 2 (ECA2). Las observaciones preclínicas indican que el aumento de la expresión o de la actividad de la ECA2 por uso de IECA o ARA-II conduce a una mayor transformación de angiotensina 2 a a angiotensina 1-7, la cual se asocia con efectos positivos sobre la fisiopatología pulmonar y cardiovascular. En estudios observacionales de pacientes con patología cardiovascular y neumonía se ha confirmado esta asociación. La falta de evidencia contundente debida a aspectos metodológicos en estudios con pacientes infectados con SARS-CoV-2 no permite confirmar si los usuarios de IECA o ARA-II se contagian más con el nuevo coronavirus. Sin embargo, continuar con tales medicamentos antihipertensivos, tanto en adultos como en niños, podría reducir la virulencia de la infección. Por ello, no se recomienda cambiar la terapia antihipertensiva en los pacientes susceptibles a la COVID-19.

Eje Renina Angiotensina, Enzima Convertidora de Angiotensina 2 y Coronavirus / Renin Angiotensin Axis, Angiotensin Converting Enzyme 2 and Coronavirus

Resumen: El sistema renina angiotensina aldosterona (SRAA) es el principal regulador del volumen plasmático, manteniendo la homeostasis cardiovascular e hidrosalina. En la vía clásica, la enzima convertidora de angiotensina (ECA) genera Angiotensina II (AngII), de potente efecto inflamatorio y vasoconstrictor. Esta vía clásica es a su vez regulada por la ECA2, que convierte AngII a Ang 1-7, cuyas acciones vaso dilatadoras y antiinflamatorias dan balance a los efectos de AngII. La ECA2 se ha relacionado con la patogenia de infecciones respiratorias como el virus respiratorio sincicial y el síndrome respiratorio agudo grave por coronavirus (SARS-CoV y SARS-CoV-2). Estudios recientes han demostrado que la ECA2 corresponde al principal receptor del SARS-CoV-2, que en conjunto con otros receptores como la serin proteasa TMPRSS2, permiten la fijación, fusión y entrada del virus a la célula huésped. En animales infectados por SARS-CoV se produce una caída de la concentración tisular de ECA2 y Ang 1-7, con la consiguiente sobreexpresión de AngII, y sus efectos vasoconstrictores e inflamatorios. Experimentos con ECA2 recombinante han mostrado un efecto protector frente a la sobreexpresión del SRAA en animales infectados por SARS-CoV, efecto similar al demostrado con el uso de bloquea- dores del receptor de AngII, AT1. La evidencia sobre el rol protector de ECA2 parece respaldar las recomendaciones respecto a no suspender estos medicamentos en la infección SARS-CoV-2. En este artículo presentamos el conocimiento actual sobre el rol del SRAA en la infección por SARS-CoV, a partir de conceptos fisiopatológicos, bases moleculares, y evidencia experimental y clínica.

Abstract: The renin-angiotensin-aldosterone system (RAAS) is the main plasma volume regulator, which maintains cardiovascular and hydrosaline homeostasis. In the classical pathway, the angiotensin converting enzyme (ACE) generates Angiotensin II (AngII), which is powerfully inflammatory and vasoconstrictive. This classical pathway is also regulated by ACE2, which converts AngI to Ang 1-9, and degrades AngII to Ang 1-7, whose vasodilatory and anti-inflammatory functions balance out the effects of AngII. ACE2 has been associated with the pathogenesis of respiratory infections such as RSV and severe acute respiratory syndrome coronavirus (SARS-CoV and SARS-CoV-2). Recent studies have shown that ACE2 corresponds to the main SARS-CoV-2 receptor, which together with other receptors such as the TMPRSS2, allows the virus to attach, fuse, and enter the host cell. These studies have shown that in animals infected with coronavirus there is a drop in tissue concentration of ACE2 and Ang 1-7, leading to overexpression of AngII and its vasoconstrictive and inflammatory effects. Experiments with recombinant ACE2 have shown a protective effect against overexpression of RAAS in coronavirus-infected animals, which is similar to that demonstrated with the use of AnglI receptor blockers (AT1). Evidence on the protective role of ACE2 seems to support the recommendations re garding not discontinuing these drugs in COVID-19 infection. In this article, we present the current knowledge about the role of RAAS in coronavirus infection, based on physiopathological concepts, molecular bases, and experimental and clinical evidence.

Un novedoso agente en el tratamiento de la insuficiencia cardiaca con función sistólica deprimida / A novel agent in the treatment of heart failure with depressed systolic function

Resumen Introducción: Se revisará la evolución del tratamiento farmacológico de la insuficiencia cardiaca (IC) en los últimos 25 an˜os, desde el concepto de tratamiento con vasodilatadores, pasando por el bloqueo o inhibición del sistema renina-angiotensina-aldosterona y la inhibición betaadrenérgica y su importante contribución en la disminución de la morbimortalidad por IC, el papel de los péptidos natriuréticos y, finalmente, se conocerá uno de los estudios más importantes en el área cardiológica y específicamente en el manejo de la IC, en el cual se demuestra un enfoque modulador de los sistemas neuro humorales que se activan en estos pacientes. Objetivos: La IC constituye la etapa final de la mayoría de las enfermedades cardiovasculares, con una alta tasa de hospitalización y de morbimortalidad cardiovascular, siendo, por lo tanto, de interés constante la necesidad de encontrar un agente terapéutico innovador que disminuya significativamente estas complicaciones y también que mejore la calidad de vida de los que la presentan. Metodología: Se realizará una descripción del PARADIGM-HF Clinical Trial, que utilizó un compuesto sacubitrilo/valsartán para el manejo de la IC con un mecanismo modulador diferente del concepto de bloqueador de sistemas deletéreos que se activan cuando un paciente presenta síntomas y signos de IC. Conclusiones: La muerte por causas cardiovasculares u hospitalización por IC (el punto final primario) se produjo en 914 pacientes (21.8%) en el grupo sacubitrilo/valsartán y 1,117 pacientes (26.5%) en el grupo de enalapril (razón de riesgo en el grupo sacubitrilo/valsartán, 0.80; intervalo de confianza (IC) del 95%: 0.73 a 0.87; p < 0.001 (exacta p = 4.0 × 10 - 7)). De los pacientes que recibieron sacubitrilo/valsartán, 537 (12.8%) fueron hospitalizados por IC, en comparación con los 658 pacientes (15.6%) que recibieron enalapril (razón de riesgo, 0.79; IC del 95%, 0.71 a 0.89; p < 0.001). Un total de 711 pacientes (17.0%) en el grupo sacubitrilo/valsartán y 835 pacientes (19.8%) en el grupo de enalapril murió (razón de riesgo de muerte por cualquier causa, 0.84; IC del 95%, 0.76 a la 0.93; p < 0.001).

Abstract Introduction: A review is presented on the evolution of the pharmacological treatment of heart failure (HF) in the last 25 years, from the concept of treatment with vasodilators to the blocking or inhibition of the renin angiotensin aldosterone system. Beta-adrenergic inhibition and its important contribution in the reduction of morbidity and mortality due to HF will be discussed along with the role of the natriuretic peptides. One of the most important studies in the cardiology area, and specifically in the management of HF, is presented, in which an approach is demonstrated of the modulator of the neurohumoral systems that are activated in these patients. Objectives: HF is the final stage of most cardiovascular diseases, and has a high rate of hospital admission, as well as cardiovascular morbidity and mortality. Therefore, there is constant interest in the need to find an innovative therapeutic agent that significantly reduces these complications and that improves the quality of life of those who suffer from it. Methods: A description will be presented of the PARADIGM-HF Clinical Trial using a sacubitril/valsartán compound for the management of HF with a modulating mechanism different from the concept of a deleterious system blocker that is activated when a patient has symptoms and signs of heart failure. Conclusions: Death due to cardiovascular causes, or hospital admission due to heart failure (the primary endpoint) occurred in 914 patients (21.8%) in the Sacubitril / valsartán group, and 1117 patients (26.5%) in the enalapril group (risk ratio in the sacubitril / valsartán group, 0.80, with a 95% confidence interval [CI]: 0.73 to 0.87, P<0.001 ;exact P= 4.0 × 10 --7;). Of the patients receiving sacubitril / valsartán, 537 (12.8%) were hospitalised due to heart failure, compared with 658 patients (15.6%) receiving enalapril (hazard ratio 0.79, 95% CI: 0.71 to 0.89, P<.001). A total of 711 patients (17.0%) in the sacubitril / valsartán group, and 835 patients (19.8%) in the enalapril group, died (all-cause death rate, 0.84, 95% CI: 0.76 to 0.93, P<.001)

Participation of hepatic α/β-adrenoceptors and AT1 receptors in glucose release and portal hypertensive response induced by adrenaline or angiotensin II

It has been previously demonstrated that the hemodynamic effect induced by angiotensin II (AII) in the liver was completely abolished by losartan while glucose release was partially affected by losartan. Angiotensin II type 1 (AT1) and adrenergic (∝1- and β-) receptors (AR) belong to the G-proteins superfamily, which signaling promote glycogen breakdown and glucose release. Interactive relationship between AR and AT1-R was shown after blockade of these receptors with specific antagonists. The isolated perfused rat liver was used to study hemodynamic and metabolic responses induced by AII and adrenaline (Adr) in the presence of AT1 (losartan) and ∝1-AR and β-AR antagonists (prazosin and propranolol). All antagonists diminished the hemodynamic response induced by Adr. Losartan abolished hemodynamic response induced by AII, and AR antagonists had no effect when used alone. When combined, the antagonists caused a decrease in the hemodynamic response. The metabolic response induced by Adr was mainly mediated by ∝1-AR. A significant decrease in the hemodynamic response induced by Adr caused by losartan confirmed the participation of AT1-R. The metabolic response induced by AII was impaired by propranolol, indicating the participation of β-AR. When both ARs were blocked, the hemodynamic and metabolic responses were impaired in a cumulative effect. These results suggested that both ARs might be responsible for AII effects. This possible cross-talk between β-AR and AT1-R signaling in the hepatocytes has yet to be investigated and should be considered in the design of specific drugs.