Computational and Enzymatic Studies of Sartans in SARS-CoV-2 Spike RBD-ACE2 Binding: The Role of Tetrazole and Perspectives as Antihypertensive and COVID-19 Therapeutics.

This study is an extension of current research into a novel class of synthetic antihypertensive drugs referred to as "bisartans", which are bis-alkylated imidazole derivatives bearing two symmetric anionic biphenyltetrazoles. Research to date indicates that bisartans are superior to commercially available hypertension drugs, since the former undergo stronger docking to angiotensin-converting enzyme 2 (ACE2). ACE2 is the key receptor involved in SARS-CoV-2 entry, thus initiating COVID-19 infection and in regulating levels of vasoactive peptides such as angiotensin II and beneficial heptapeptides A(1-7) and Alamandine in the renin-angiotensin system (RAS). In previous studies using in vivo rabbit-iliac arterial models, we showed that Na+ or K+ salts of selected Bisartans initiate a potent dose-response inhibition of vasoconstriction. Furthermore, computational studies revealed that bisartans undergo stable binding to the vital interfacial region between ACE2 and the SARS-CoV-2 "receptor binding domain" (i.e., the viral RBD). Thus, bisartan homologs are expected to interfere with SARS-CoV-2 infection and/or suppress disease expression in humans. The primary goal of this study was to investigate the role of tetrazole in binding and the network of amino acids of SARS-CoV-2 Spike RBD-ACE2 complex involved in interactions with sartans. This study would, furthermore, allow the expansion of the synthetic space to create a diverse suite of new bisartans in conjunction with detailed computational and in vitro antiviral studies. A critical role for tetrazole was uncovered in this study, shedding light on the vital importance of this group in the binding of sartans and bisartans to the ACE2/Spike complex. The in silico data predicting an interaction of tetrazole-containing sartans with ACE2 were experimentally validated by the results of surface plasmon resonance (SPR) analyses performed with a recombinant human ACE2 protein.

[2022 Practice guidelines for the management of arterial hypertension of the Spanish Society of Hypertension]. / Guía práctica sobre el diagnóstico y tratamiento de la hipertensión arterial en España, 2022. Sociedad Española de Hipertensión - Liga Española para la Lucha contra la Hipertensión Arterial (SEH-LELHA).

Hypertension is the most important risk factor for global disease burden. Detection and management of hypertension are considered as key issues for individual and public health, as adequate control of blood pressure levels markedly reduces morbidity and mortality associated with hypertension. Aims of these practice guidelines for the management of arterial hypertension of the Spanish Society of Hypertension include offering simplified schemes for diagnosis and treatment for daily practice, and strategies for public health promotion. The Spanish Society of Hypertension assumes the 2018 European guidelines for management of arterial hypertension developed by the European Society of Cardiology and the European Society of Hypertension, although relevant aspects of the 2017 American College of Cardiology/American Heart Association guidelines and the 2020 International Society of Hypertension guidelines are also commented. Hypertension is defined as a persistent elevation in office systolic blood pressure ≥ 140 and/or diastolic blood pressure ≥ 90 mmHg, and assessment of out-of-office blood pressure and global cardiovascular risk are considered of key importance for evaluation and management of hypertensive patients. The target for treated blood pressure should be < 130/80 for most patients. The treatment of hypertension involves lifestyle interventions and drug therapy. Most people with hypertension need more than one antihypertensive drug for adequate control, so initial therapy with two drugs, and single pill combinations are recommended for a wide majority of hypertensive patients.

Green fluorometric strategy for simultaneous determination of the antihypertensive drug telmisartan (A tentative therapeutic for COVID-19) with Nebivolol in human plasma.

Telmisartan (TEL) and Nebivolol (NEB) are frequently co-formulated in a single dosage form that is frequently prescribed for the treatment of hypertension, moreover, telmisartan is currently proposed to be used to treat COVID19-induced lung inflammation. Green rapid, simple, and sensitive synchronous spectrofluorimetric techniques for simultaneous estimation of TEL and NEB in their co-formulated pharmaceutical preparations and human plasma were developed and validated. Synchronous fluorescence intensity at 335 nm was used for TEL determination (Method I). For the mixture, the first derivative synchronous peak amplitudes (D1) at 296.3 and 320.5 nm were used for simultaneous estimation of NEB and TEL, respectively (Method II). The calibration plots were rectilinear over the concentration ranges of 30-550 ng/mL, and 50-800 ng/mL for NEB and TEL, respectively. The high sensitivity of the developed methods allowed for their analysis in human plasma samples. NEB`s Quantum yield was estimated by applying the single-point method. The greenness of the proposed approaches was evaluated using the Eco-scale, National Environmental Method Index (NEMI), and Green Analytical Procedure Index (GAPI) methods.

Hypertension care during the COVID-19 pandemic in an integrated health care system.

Retention in hypertension care, medication adherence, and blood pressure (BP) may have been affected by the COVID-19 pandemic. In a retrospective cohort study of 64 766 individuals with treated hypertension from an integrated health care system, we compared hypertension care during the year pre-COVID-19 (March 2019-February 2020) and the first year of COVID-19 (March 2020-February 2021). Retention in hypertension care was defined as receiving clinical BP measurements during COVID-19. Medication adherence was measured using prescription refills. Clinical care was assessed by in-person and virtual visits and changes in systolic and diastolic BP. The cohort had a mean age of 67.8 (12.2) years, 51.2% were women, and 73.5% were White. In 60 757 individuals with BP measurements pre-COVID-19, 16618 (27.4%) had no BP measurements during COVID-19. Medication adherence declined from 86.0% to 80.8% (p < .001). In-person primary care visits decreased from 2.7 (2.7) to 1.4 (1.9) per year, while virtual contacts increased from 9.5 (12.2) to 11.2 (14.2) per year (both p < .001). Among individuals with BP measurements, mean (SD) systolic BP was 126.5 mm Hg (11.8) pre-COVID-19 and 127.3 mm Hg (12.6) during COVID-19 (p = .14). Mean diastolic BP was 73.5 mm Hg (8.5) pre-COVID-19 and 73.5 mm Hg (8.7) during COVID-19 (p = .77). Even in this integrated health care system, many individuals did not receive clinical BP monitoring during COVID-19. Most individuals who remained in care maintained pre-COVID BP. Targeted outreach may be necessary to restore care continuity and hypertension control at the population level.

School-Based Telemedicine for Hypertension Management in Urban Adolescents.

PURPOSE: The aim of this study is to determine if hypertensive adolescents from impoverished neighborhoods in Rochester, New York have improved blood pressure (BP) control with the use of school-based telemedicine. METHODS: Adolescents receiving antihypertensive medication had monthly study telemedicine visits at school. BP was measured by a telehealth clinical assistant (CTA) at the school using standard procedures, followed in real time by a teleconferencing visit with the study physician. RESULTS: Six participants were enrolled, and all completed school-based telemedicine visits prior to school closure due to the SARS-CoV-2 pandemic. Mean systolic and diastolic BP at baseline were 139 ± 5 and 75 ± 8 mmHg. All six participants had significant improvement in their blood pressure (final school mean BPs, 127 ± 4 and 67 ± 5 mmHg; systolic, baseline vs. final, p = .003). DISCUSSION: In this pilot study, adolescents with very high levels of neighborhood disadvantage had consistent adherence with school-based telemedicine and significant improvement in hypertension (HTN) control.

Newer alternatives for resistant hypertension: Beyond 2022 paradigms.

Given the increased incidence of resistant hypertension and no novel agents to manage hypertension for more than 15 years, there has been an increase in the development of newer agents with unique mechanisms that will hopefully aid in getting this subset of patients under control. More recent classes of agents include nonsteroidal mineralocorticoid receptor blockers, aminopeptidase A inhibitors, dual endothelin A and B antagonists and aldosterone synthetase inhibitors, and novel agents affecting angiotensinogen mRNA in the liver. All these agents are under different levels of development and, if all goes well, should be available to the public within the next 2-5 years. In addition to these agents, renal denervation is anticipated to be approved in the United States within the next 6-9 months, whereas it has already been authorized in certain European countries. Thus, by 2025 and later, we will have a more extensive armamentarium to help quell the rise in resistant hypertension. From early actuarial data associating elevated blood pressure with mortality to the first trials of blood pressure-lowering medications to contemporary American and European hypertension guidelines, the beneficial impact of blood pressure lowering in individuals with hypertension is well established1,2-4. Population-level decreases in incident cardiovascular disease and mortality over the past 50 years reflect this well-established impact. Yet, the year-over-year decline in the incidence of cardiovascular disease has now plateaued, and concomitantly rates of uncontrolled hypertension have increased5,6. Additionally, how the global COVID-19 pandemic impacts cardiovascular disease and hypertension-related outcomes is yet to be determined, but early data suggests population-level increases in blood pressure7.

Renin-Angiotensin-Aldosterone Inhibitors and COVID-19 Infection.

PURPOSE OF REVIEW: This review summarises the literature data and provides an overview of the role and impact of the use of renin-angiotensin-aldosterone system (RAAS) inhibitors in patients with coronavirus disease 2019 (COVID-19) infection. RECENT FINDINGS: The angiotensin-converting enzyme 2 (ACE2) has a key role in the regulation of the RAAS pathway, downregulating angiotensin II and attenuating inflammation, vasoconstriction and oxidative stress. Additionally, it plays an instrumental part in COVID-19 infection as it facilitates the cell entry of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and enables its replication. The use and role of RAAS inhibitors therefore during the COVID-19 pandemic have been intensively investigated. Although it was initially assumed that RAAS inhibitors may relate to worse clinical outcomes and severe disease, data from large studies and meta-analyses demonstrated that they do not have an adverse impact on clinical outcomes or prognosis. On the contrary, some experimental and retrospective observational cohort studies showed a potential protective mechanism, although this effect remains to be seen in large clinical trials.

Research strategies in treatment of hypertension: value of retrospective real-life data.

This review will discuss the limitations of data collected by RCTs in relation to their applicability to daily life clinical management. It will then argue that these limitations are only partially overcome by modifications of RCT design and conduction (e.g. 'pragmatic trials') while being substantially attenuated by real-life-derived research, which can fill many gaps left by trial-collected evidence and have thus an important complementary value. The focus will be on the real-life research approach based on the retrospective analysis of the now widely available healthcare utilization databases (formerly known as administrative databases), which will be discussed in detail for their multiple advantages as well as challenges. Emphasis will be given to the potential of these databases to provide low-cost information over long periods on many different healthcare issues, drug therapies in particular, from the general population to clinically important subgroups, including (i) prognostic aspects of treatments implemented at the medical practice level via hospitalization and fatality data and (ii) medical practice-related phenomena such as low treatment adherence and therapeutic inertia (unsatisfactorily evaluated by RCTs). It will also be mentioned that thanks to the current availability of these data in electronic format, results can be obtained quickly, helping timely decisions under emergencies. The potential shortcomings of this approach (confounding by indication, misclassification, and selection bias) will also be discussed along with their possible minimization by suitable analytic means. Finally, examples of the contributions of studies on hypertension and other cardiovascular risk factors will be offered based on retrospective healthcare utilization databases that have provided information on real-life cardiovascular treatments unavailable via RCTs.

Rationale and design of the Effects of intensive Systolic blood Pressure lowering treatment in reducing RIsk of vascular evenTs (ESPRIT): A multicenter open-label randomized controlled trial.

BACKGROUND: Lowering blood pressure (BP) effectively reduces the risk of cardiovascular (CV) events in high CV risk individuals. The optimal target of BP lowering among high CV risk individuals remains unclear. METHODS: The Effects of intensive Systolic blood Pressure lowering treatment in reducing RIsk of vascular evenTs (ESPRIT) trial is a multi-center, open-label, randomized controlled trial to compare the efficacy and safety of intensive BP lowering strategy (Systolic BP target <120 mm Hg) and standard BP lowering strategy (Systolic BP target <140 mm Hg). Participants aged at least 50 years old with baseline systolic BP within 130 to 180 mm Hg at high CV risk, defined by established CV diseases or 2 major CV risk factors, were enrolled. The primary outcome is a composite CV outcome of myocardial infarction, coronary or non-coronary revascularization, hospitalization or emergency department visit from new-onset heart failure or acute decompensated heart failure, stroke, or death from CV diseases. Secondary outcomes include components of the primary composite outcome, all-cause death, a composite of the primary outcome or all-cause death, kidney outcomes, as well as cognitive outcomes. RESULTS: Despite of the interruption of COVID-19 outbreak, the ESPRIT trial successfully enrolled and randomized 11,255 participants from 116 hospitals or primary health care institutions. The mean age of the participants was 64.6 (standard deviation [SD], 7.1) years, 4,650 (41.3%) were women. Among them 28.9%, 26.9% and 38.7% had coronary heart disease, prior stroke and diabetes mellitus, respectively. COVID-19 outbreak affected the BP lowering titration process of the trial, and delayed the reach of BP target. CONCLUSIONS: The ESPRIT trial will address the important question on the optimal BP lowering target for individuals with high CV risk, and generate high quality evidence for treating millions of patients from East Asian countries.

RAAS inhibitors are associated with a better chance of surviving of inpatients with Covid-19 without a diagnosis of diabetes mellitus, compared with similar patients who did not require antihypertensive therapy or were treated with other antihypertensives.

Purpose: The effect of renin-angiotensin-aldosterone system (RAAS) inhibitors in combination with COVID-19 and diabetes mellitus (DM) remains unknown. We assessed the risk of death in COVID-19 inpatients based on the presence or absence of DM, arterial hypertension (AH) and the use of RAAS inhibitors or other antihypertensives. Methods: The results of treatment of all adult PCR-confirmed COVID-19 inpatients (n = 1097, women 63.9%) from 02/12/2020 to 07/01/2022 are presented. The presence of DM at the time of admission and the category of antihypertensive drugs during hospital stay were noted. Leaving the hospital due to recovery or death was considered as a treatment outcome. Multivariable logistic regression analysis was used to assess the risk of death. Patients with COVID-19 without AH were considered the reference group. Results: DM was known in 150 of 1,097 patients with COVID-19 (13.7%). Mortality among DM inpatients was higher: 20.0% vs. 12.4% respectively (p=0.014). Male gender, age, fasting plasma glucose (FPG) and antihypertensives were independently associated with the risk of dying in patients without DM. In DM group such independent association was confirmed for FPG and treatment of AH. We found a reduction in the risk of death for COVID-19 inpatients without DM, who received RAAS inhibitors compared with the corresponding risk of normotensive inpatients, who did not receive antihypertensives: OR 0.22 (95% CI 0.07-0.72) adjusted for age, gender and FPG. Conclusion: This result raises a question about the study of RAAS inhibitors effect in patients with Covid-19 without AH.

COVID-19: Understanding the impact of anti-hypertensive drugs and hydroxychloroquine on the ACE1 and ACE2 in lung and adipose tissue in SHR and WKY rats.

Hypertensive individuals taking anti-hypertensive drugs from renin-angiotensin system inhibitors may exhibit a more severe evolution of the disease when contracting the SARS-CoV-2 virus (COVID-19 disease) due to potential increases in ACE2 expression. The study investigated ACE1 and ACE2 axes and hydroxychloroquine in the lungs and adipose tissue of male and female normotensive Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHRs). SHRs were treated with losartan (10 mg/kg/day) or captopril (10 mg/kg/day) for 14 days or 7 days with hydroxychloroquine (200 mg/kg/day) in drinking water. WKY rats were also treated for 7 days with hydroxychloroquine. Blood pressure (BP), protein, and mRNA expression of ACE1 and ACE2 were analyzed in serum, adipose, and lung tissues. Losartan and captopril reduced BP in both sexes in SHR, whereas hydroxychloroquine increased BP in WKY rats. Losartan reduced ACE2 in serum and lungs in both sexes and in adipose tissue of male SHRs. Captopril decreased ACE2 protein in the lung of females and in adipose tissue in both sexes of SHRs. Hydroxychloroquine decreased ACE1 and ACE2 proteins in the lungs in both sexes and adipose tissue in male SHRs. In female WKY rats, ACE2 protein was lower only in the lungs and adipose tissue. Losartan effectively inhibited ACE2 in male and captopril in female SHRs. Hydroxychloroquine inhibited ACE2 in male SHRs and female WKY rats. These results further our understanding of the ACE2 mechanism in patients under renin-angiotensin anti-hypertensive therapy and in many trials using hydroxychloroquine for COVID-19 treatment and potential sex differences in response to drug treatment.

Medical Telemonitoring for the Management of Hypertension in Older Patients in Japan.

Hypertension is the most frequent modifiable risk factor associated with cardiovascular disease (CVD) morbidity and mortality. Even in older people, strict blood pressure (BP) control has been recommended to reduce CVD event risks. However, caution should be exercised since older hypertensive patients have increased physical vulnerability due to frailty and multimorbidity, and older patients eligible for clinical trials may not represent the general population. Medical telemonitoring systems, which enable us to monitor a patient's medical condition remotely through digital communication, have become much more prevalent since the coronavirus pandemic. Among various physiological parameters, BP monitoring is well-suited to the use of such systems, which enable healthcare providers to deliver accurate and safe BP management, even in the presence of frailty and/or living in geographically remote areas. Furthermore, medical telemonitoring systems could help reduce nonadherence to antihypertensive medications and clinical inertia, and also enable multi-professional team-based management of hypertension. However, the implementation of medical telemonitoring systems in clinical practice is not easy, and substantial barriers, including the development of user-friendly devices, integration with existing clinical systems, data security, and cost of implementation and maintenance, need to be overcome. In this review, we focus on the potential of medical telemonitoring for the management of hypertension in older people in Japan.

Effect of continuing the use of renin-angiotensin system inhibitors on mortality in patients hospitalized for coronavirus disease 2019: a systematic review, meta-analysis, and meta-regression analysis.

BACKGROUND: The effect of angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) on mortality was preliminarily explored through the comparison of ACEIs/ARBs with non-ACEIs/ARBs in patients with coronavirus disease 2019 (COVID-19). Reaching a conclusion on whether previous ACEI/ARB treatment should be continued in view of the different ACE2 levels in the comparison groups was not unimpeachable. Therefore, this study aimed to further elucidate the effect of ACEI/ARB continuation on hospital mortality, intensive care unit (ICU) admission, and invasive mechanical ventilation (IMV) in the same patient population. METHODS: We searched PubMed, the Cochrane Library, Ovid, and Embase for relevant articles published between December 1, 2019 and April 30, 2022. Continuation of ACEI/ARB use after hospitalization due to COVID-19 was considered as an exposure and discontinuation of ACEI/ARB considered as a control. The primary outcome was hospital mortality, and the secondary outcomes included 30-day mortality, rate of ICU admission, IMV, and other clinical outcomes. RESULTS: Seven observational studies and four randomized controlled trials involving 2823 patients were included. The pooled hospital mortality in the continuation group (13.04%, 158/1212) was significantly lower than that (22.15%, 278/1255) in the discontinuation group (risk ratio [RR] = 0.45; 95% confidence interval [CI], 0.28-0.72; P = 0.001). Continuation of ACEI/ARB use was associated with lower rates of ICU admission (10.5% versus 16.2%, RR = 0.63; 95% CI 0.5-0.79; P < 0.0001) and IMV (8.2% versus 12.5%, RR = 0.62; 95% CI 0.46-0.83, P = 0.001). Nevertheless, the effect was mainly demonstrated in the observational study subgroup (P < 0.05). Continuing ACEI/ARB had no significant effect on 30-day mortality (P = 0.34), acute myocardial infarction (P = 0.08), heart failure (P = 0.82), and acute kidney injury after hospitalization (P = 0.98). CONCLUSION: Previous ACEI/ARB treatment could be continued since it was associated with lower hospital deaths, ICU admission, and IMV in patients with COVID-19, although the benefits of continuing use were mainly shown in observational studies. More evidence from multicenter RCTs are still needed to increase the robustness of the data. Trial registration PROSPERO (CRD42022341169). Registered 27 June 2022.

Disruption in Blood Pressure Control With the COVID-19 Pandemic: The PCORnet Blood Pressure Control Laboratory.

OBJECTIVE: To explore trends in blood pressure (BP) control before and during the COVID-19 pandemic. PATIENTS AND METHODS: Health systems participating in the National Patient-Centered Clinical Research Network (PCORnet) Blood Pressure Control Laboratory Surveillance System responded to data queries, producing 9 BP control metrics. Averages of the BP control metrics (weighted by numbers of observations in each health system) were calculated and compared between two 1-year measurement periods (January 1, 2019, through December 31, 2019, and January 1, 2020, through December 31, 2020). RESULTS: Among 1,770,547 hypertensive persons in 2019, BP control to <140/<90 mm Hg varied across 24 health systems (range, 46%-74%). Reduced BP control occurred in most health systems with onset of the COVID-19 pandemic; the weighted average BP control was 60.5% in 2019 and 53.3% in 2020. Reductions were also evident for BP control to <130/<80 mm Hg (29.9% in 2019 and 25.4% in 2020) and improvement in BP (reduction of 10 mm Hg in systolic BP or achievement of systolic BP <140 mm Hg; 29.7% in 2019 and 23.8% in 2020). Two BP control process metrics exhibited pandemic-associated disruption: repeat visit in 4 weeks after a visit with uncontrolled hypertension (36.7% in 2019 and 31.7% in 2020) and prescription of fixed-dose combination medications among those with 2 or more drug classes (24.6% in 2019 and 21.5% in 2020). CONCLUSION: BP control decreased substantially during the COVID-19 pandemic, with a corresponding reduction in follow-up health care visits among persons with uncontrolled hypertension. It is unclear whether the observed decline in BP control during the pandemic will contribute to future cardiovascular events.

Association of Baseline Adherence to Antihypertensive Medications With Adherence After Shelter-in-Place Guidance for COVID-19 Among US Adults.

Importance: Adherence to selected antihypertensive medications (proportion of days covered [PDC]) declined after guidance to shelter in place for COVID-19. Objectives: To determine whether PDC for all antihypertensive medications collectively fell from the 6 months before sheltering guidance (September 15, 2019, to March 14, 2020 [baseline]) compared with the first (March 15 to June 14, 2020) and second (June 15 to September 14, 2020) 3 months of sheltering and to assess the usefulness of baseline PDC for identifying individuals at risk for declining PDC during sheltering. Design, Setting, and Participants: This retrospective cohort study included a random sample of US adults obtained from EagleForce Health, a division of EagleForce Associates Inc. Approximately one-half of the adults were aged 40 to 64 years and one-half were aged 65 to 90 years, with prescription drug coverage, hypertension, and at least 1 antihypertensive medication prescription filled at a retail pharmacy during baseline. Main Outcomes and Measures: Prescription claims were used to assess (1) PDC at baseline and changes in PDC during the first and second 3 months of sheltering and (2) the association of good (PDC ≥ 80), fair (PDC 50-79), and poor (PDC < 50) baseline adherence with adherence during sheltering. Results: A total of 27 318 adults met inclusion criteria (mean [SD] age, 65.0 [11.7] years; 50.7% women). Mean PDC declined from baseline (65.6 [95% CI, 65.2-65.9]) during the first (63.4 [95% CI, 63.0-63.8]) and second (58.9 [95% CI, 58.5-59.3]) 3 months after sheltering in all adults combined (P < .001 for both comparisons) and both age groups separately. Good, fair, and poor baseline adherence was observed in 40.0%, 27.8%, and 32.2% of adults, respectively. During the last 3 months of sheltering, PDC declined more from baseline in those with good compared with fair baseline adherence (-13.1 [95% CI, -13.6 to -12.6] vs -8.3 [95% CI, -13.6 to -12.6]; P < .001), whereas mean (SD) PDC increased in those with poor baseline adherence (mean PDC, 31.6 [95% CI, 31.3-31.9] vs 34.4 [95% CI, 33.8-35.0]; P < .001). However, poor adherence during sheltering occurred in 1034 adults (9.5%) with good baseline adherence, 2395 (31.6%) with fair baseline adherence, and 6409 (72.9%) with poor baseline adherence. Conclusions and Relevance: These findings suggest that individuals with poor baseline adherence are candidates for adherence-promoting interventions irrespective of sheltering guidance. Interventions to prevent poor adherence during sheltering may be more useful for individuals with fair vs good baseline adherence.

Angiotensin-converting enzyme 2 in human plasma and lung tissue.

PURPOSE: We investigated plasma angiotensin-converting enzyme 2 (ACE2) concentration in a population sample and the ACE2 expression quantitated with the diaminobenzidine mean intensity in the lung tissue in patients who underwent lung surgery. MATERIALS AND METHODS: The study participants were recruited from a residential area in the suburb of Shanghai for the plasma ACE2 concentration study (n = 503) and the lung tissue samples were randomly selected from the storage in Ruijin Hospital (80 men and 78 age-matched women). RESULTS: In analyses adjusted for covariables, men had a significantly higher plasma ACE2 concentration (1.21 vs. 0.98 ng/mL, p = 0.027) and the mean intensity of ACE2 in the lung tissue (55.1 vs. 53.9 a.u., p = 0.037) than women. With age increasing, plasma ACE2 concentration decreased (p = 0.001), while the mean intensity of ACE2 in the lung tissue tended to increase (p = 0.087). Plasma ACE2 concentration was higher in hypertension than normotension, especially treated hypertension (1.23 vs. 0.98 ng/mL, p = 0.029 vs. normotension), with no significant difference between users of RAS inhibitors and other classes of antihypertensive drugs (p = 0.64). There was no significance of the mean intensity of ACE2 in the lung tissue between patients taking and those not taking RAS inhibitors (p = 0.14). Neither plasma ACE2 concentration nor the mean intensity of ACE2 in the lung tissue differed between normoglycemia and diabetes (p ≥ 0.20). CONCLUSION: ACE2 in the plasma and lung tissue showed divergent changes according to several major characteristics of patients.Plain language summary What is the context? • The primary physiological function of ACE2 is the degradation of angiotensin I and II to angiotensin 1-9 and 1-7, respectively. • ACE2 was found to behave as a mediator of the severe acute respiratory syndrome coronavirus (SARS) infection. • There is little research on ACE2 in humans, especially in the lung tissue. • In the present report, we investigated plasma ACE2 concentration and the ACE2 expression quantitated with the diaminobenzidine mean intensity in the lung tissue respectively in two study populations. What is new? • Our study investigated both circulating and tissue ACE2 in human subjects. The main findings were: • In men as well as women, plasma ACE2 concentration was higher in younger than older participants, whereas the mean intensity of ACE2 in the lung tissue increase with age increasing. • Compared with normotension, hypertensive patients had higher plasma ACE2 concentration but similar mean intensity of ACE2 in the lung tissue. • Neither plasma ACE2 concentration nor lung tissue ACE2 expression significantly differed between users of RAS inhibitors and other classes of antihypertensive drugs. What is the impact? • ACE2 in the plasma and lung tissue showed divergent changes according to several major characteristics, such as sex, age, and treated and untreated hypertension. • A major implication is that plasma ACE2 concentration might not be an appropriate surrogate for the ACE2 expression in the lung tissue, and hence not a good predictor of SARS-COV-2 infection or fatality.

Protocol for a 30-day randomised, parallel-group, non-inferiority, controlled trial investigating the effects of discontinuing renin-angiotensin system inhibitors in patients with and without COVID-19: the RASCOVID-19 trial.

INTRODUCTION: The COVID-19 pandemic caused by the virus SARS-CoV has spread rapidly and caused damage worldwide. Data suggest a major overrepresentation of hypertension and diabetes among patients experiencing severe courses of COVID-19 including COVID-19-related deaths. Many of these patients receive renin-angiotensin system (RAS) inhibiting therapy, and evidence suggests that treatment with angiotensin II receptor blockers (ARBs) could attenuate SARS-CoV-induced acute respiratory distress syndrome, and ACE inhibitors and ARBs have been suggested to alleviate COVID-19 pulmonary manifestations. This randomised clinical trial will address whether RAS inhibiting therapy should be continued or discontinued in hospitalised patients with COVID-19. METHODS AND ANALYSIS: This trial is a 30-day randomised parallel-group non-inferiority clinical trial with an embedded mechanistic substudy. In the main trial, 215 patients treated with a RAS inhibitor will be included. The participants will be randomly assigned in a 1:1 ratio to either discontinue or continue their RAS inhibiting therapy in addition to standard care. The patients are included during hospitalisation and followed for a period of 30 days. The primary end point is number of days alive and out of hospital within 14 days after recruitment. In a mechanistic substudy, 40 patients treated with RAS inhibition, who are not in hospital and not infected with COVID-19 will be randomly assigned to discontinue or continue their RAS inhibiting therapy with the primary end point of serum ACE2 activity. ETHICS AND DISSEMINATION: This trial has been approved by the Scientific-Ethical Committee of the Capital Region of Denmark (identification no. H-20026484), the Danish Medicines Agency (identification no. 2020040883) and by the Danish Data Protection Agency (P-2020-366). The results of this project will be compiled into one or more manuscripts for publication in international peer-reviewed scientific journals. TRIAL REGISTRATION NUMBER: 2020-001544-26; NCT04351581.