Virus World

Men have higher concentrations of ACE2 in their blood than women. As ACE2 enables coronavirus to infect cells, the findings may explain why men are more susceptible to COVID-19 infection than women. The study, published in the European Heart Journal today, also found that heart failure patients taking drugs targeting the renin-angiotensin-aldosterone system (RAAS), such as angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), did not have higher concentrations of ACE2 in their blood. 

Dr Adriaan Voors (MD-PhD), Professor of Cardiology at the University Medical Center Groningen (The Netherlands), who led the study, said: “Our findings do not support the discontinuation of these drugs in COVID-19 patients as has been suggested by earlier reports.” Some recent research suggested that RAAS inhibitors might increase concentrations of ACE2 in plasma – the liquid part of blood – thereby increasing the risk of COVID-19 for cardiovascular patients taking these drugs. The current study indicates that this is not the case, although it looked only at ACE2 concentrations in plasma, not in tissues such as lung tissue. In addition, the study cannot provide definitive evidence on the effects of RAAS inhibitors in patients with COVID-19. Its conclusions are mainly restricted to heart failure patients, and the patients did not have COVID-19, so the researchers cannot provide a direct link between the course of the disease and ACE2 plasma concentrations. Prof Voors said: “ACE2 is a receptor on the surface of cells. It binds to the coronavirus and allows it to enter and infect healthy cells after it is has been modified by another protein on the surface of the cell, called TMPRSS2. High levels of ACE2 are present in the lungs and, therefore, it is thought to play a crucial role in the progression of lung disorders related to COVID-19.”

The researchers measured ACE2 concentrations in blood samples taken from two groups of heart failure patients from 11 European countries. There were 1485 men and 537 women in the first group, the index cohort, which was designed to test the researchers’ hypotheses and research questions. Then the researchers validated their findings in a second group of 1123 men and 575 women, the validation cohort. The median (average) age of the participants in the index cohort was 69 years for men and 75 years for women, and in the validation cohort it was 74 and 76 years, respectively. When the researchers looked at a number of clinical factors that could play a role in ACE2 concentrations, including the use of ACE inhibitors, ARBs and mineralocorticoid receptor antagonists (MRAs), as well as a history of chronic obstructive pulmonary disease, coronary artery by-pass graft and atrial fibrillation, they found that male sex was the strongest predictor of elevated ACE2 concentrations. In the index cohort, ACE inhibitors, ARBS and MRAs were not associated with greater ACE2 plasma concentrations, and in the validation cohort, ACE inhibitors and ARBs were associated with lower ACE2 concentrations, while MRAs were only weakly associated with higher concentrations.

Published in European Heart J. (May 10, 2020):

https://doi.org/10.1093/eurheartj/ehaa373

Background: Effect of angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) on outcomes in patients with coronavirus disease 2019 (COVID-19) is uncertain. Available evidence is limited to a few retrospective observational studies with small number of patients.

Methods: We did a meta-analysis to assess the effect of ACEi/ARB in patients with COVID-19 on severity of disease, risk for hospitalisation, and death compared to those not on ACEi/ARB. We searched the Cochrane library, PubMed, Embase, ClinicalTrial.gov and medRxiv for studies published until 21.04.2020. Inclusion criteria included all studies with patients with confirmed COVID-19 either taking, or not taking, ACEi/ARB. Depending on degree of heterogeneity, fixed or random effect model was selected to calculate effect size (Odds ratio).

Findings: Five studies were eligible for meta-analysis. These included 308 patients on ACEi/ARB, and 1172 not on ACEi/ARB. Compared to patients with COVID-19 not on ACEi/ARB, there was a statistically significant 44% reduction in odds of developing severe disease (OR: 0.56; 95% CI: 0.34-1.89, I2=68.15), and 62% reduction in odds of death (OR: 0.38; 95% CI: 0.19-0.74, I2=0.000) in those on ACEi/ARB. There was a non-significant 19% (OR 0.81; 95% CI: 0.42-1.55, I2: 0.000) reduction in odds of hospitalisation among those on ACEi/ARB.

Interpretation: It is safe to use ACEi/ARB in patients with COVID-19 requiring these medications for associated comorbidities. Although limited by confounding factors typical of a meta-analysis of retrospective observational studies, our data suggests that use of these medications may reduce risk of developing severe disease and death.

Preprint Available at medRxiv (April 28, 2020):

https://www.medrxiv.org/content/10.1101/2020.04.23.20076661v1

Background:

The SARS-Cov2 virus binds to the ACE2 receptor for cell entry. It has been suggested that ACE-inhibitors, which are commonly used in patients with hypertension or diabetes and which raise ACE2 levels, may increase the risk of severe COVID-19 infection.

Methods:

We evaluated this hypothesis in an early cohort of 205 acute inpatients with COVID-19 at King’s College Hospital and Princess Royal University Hospital, London, UK with the primary endpoint being death or transfer to a critical care unit for organ support within 7-days of symptom onset.

Findings:

53 patients out of 205 patients reached the primary endpoint. Contrary to the hypothesis, treatment with ACE-inhibitors was associated with a reduced risk of rapidly deteriorating severe disease. There was a lower rate of death or transfer to a critical care unit within 7 days in patients on an ACE-inhibitor OR 0·29 (CI 0·10-0·75, p<0·01), adjusting for age, gender, comorbidities (hypertension, diabetes mellitus, ischaemic heart disease and heart failure).

Interpretation:

Although a small sample size, we do not see evidence for ACE-inhibitors increasing the short-term severity of COVID-19 disease and patients on treatment with ACE-inhibitors should continue these drugs during their COVID-19 illness. A potential beneficial effect needs to be explored as more data becomes available.