The question boils down to does increasing the number of ACE2 receptors increase or lower your risk of severe disease with Covid-19. Increasing the number of receptors might increase the number of attack points for the virus, or, increasing the number of receptors might reduce the risk of lung damage as ACE2 acts to protect the lung. We know that the ACE2 receptor is encoded on the X chromosome and women, who have more ACE2 receptors, do better than men in the mortality statistics.
We now have some observational data to suggest that ARBI help protect the lungs against SARS-CoV-2, approximately 34% less likely to have severe disease (OR=0.343, 95% CI 0.128-0.916, p=0.025). There wasn't enough data to inform about ACEI.
Summary Background The novel coronavirus (CoV) severe acute respiratory syndrome (SARS)-CoV-2 outbreak started at the end of 2019 in Wuhan, China, and spread over 100 countries. SARS-CoV-2 uses the membrane protein Angiotensin I converting enzyme 2(ACE2) as a cell entry receptor. Indeed, it was reported that the balance of Renin-Angiotensin System (RAS), regulated by both ACE and ACE2, was altered in COVID-19 patients. It is controversial, however, whether commonly used anti-hypertensive drugs Angiotensin I converting enzyme inhibitor (ACEI) and Angiotensin II receptor blocker (ARB) shall be continued in the confirmed COVID-19 patients. This study was designed to investigate any difference in disease severity between COVID-19 patients with hypertension comorbidity. The included COVID-19 patients used ACEI, ARB, calcium channel blockers (CCB), beta blockers (BB), or thiazide to treat preexisting hypertension prior to the hospital were compared to patients who did not take any of those drugs. Methods In this multicentre retrospective study, clinical data of 511 COVID-19 patients were analyzed. Patients were categorized into six sub-groups of hypertension comorbidity based on treatment using one of anti-hypertension drugs (ACEI, ARB, CCB, BB, thiazide), or none. A meta-analysis was performed to evaluate the use of ACEI and ARB associated with pneumonia using published studies. Findings Among the elderly (age>65) COVID-19 patients with hypertension comorbidity, the risk of COVID-19-S (severe disease) was significantly decreased in patients who took ARB drugs prior to hospitalization compared to patients who took no drugs (OR=0.343, 95% CI 0.128-0.916, p=0.025). The meta-analysis showed that ARB use has positive effects associated with morbidity and mortality of pneumonia. Interpretation Elderly (age>65) COVID-19 patients with hypertension comorbidity who are taking ARB anti-hypertension drugs may be less likely to develop severe lung disease compared to patients who take no anti-hypertension drugs. Funding National Natural Science Foundation of China, Chinese Academy of Medical Sciences
Update 7 May 2020
An observational study of 8,910 patients in hospitals in Asia, Europe, and North America who had either died in the hospital (5.8%) or survived to hospital discharge (94.2%). This showed an advantage with the use of ARBs but no ACEI
No increased risk of in-hospital death was found to be associated with the use of ACE inhibitors (2.1% vs. 6.1%; odds ratio, 0.33; 95% CI, 0.20 to 0.54) or the use of ARBs (6.8% vs. 5.7%; odds ratio, 1.23; 95% CI, 0.87 to 1.74).
1 May 2020: Cardiovascular Disease, Drug Therapy, and Mortality in Covid-19
Anti-hypertensive Angiotensin II receptor blockers associated to mitigation of disease severity in elderly COVID-19 patients