ACEI beneficial against SARS-CoV-2 infections
European Medicines Agency. (2020). EMA Advises Continued Use of Medicines for Hypertension, Heart or Kidney Disease During COVID-19 Pandemic.
https://www.ema.europa.eu/en/news/ema-advises-continued-use-medicines-hypertension-heart-kidney-disease-during-covid-19-pandemic
European Society of Cardiology. (2020). Position statement of the ESC Council on Hypertension on ACE-inhibitors and angiotensin receptor blockers. ESC.
https://www.escardio.org/Councils/Council-on-Hypertension-(CHT)/News/position-statement-of-the-esc-council-on-hypertension-on-ace-inhibitors-and-ang
Hubei by Patel and Verma (2020) show that mortality rates are greatly reduced when ACE inhibitors are used.
Guzik, T. J., Mohiddin, S. A., Dimarco, A., Patel, V., Savvatis, K., Marelli-Berg, F. M., ... & Nicklin, S. A. (2020). COVID-19 and the cardiovascular system: implications for risk assessment, diagnosis, and treatment options. Cardiovascular research.
Article COVID-19 and the cardiovascular system: implications for ris...
ACEI worsens SARS-CoV-2 infections
ACE inhibitors and angiotensin II blockers (ARBs) may worsen COVID-19 infections since they upregulate the expression of ACE2. (Diaz, 2020)
Diaz, J. H. (2020). Hypothesis: angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may increase the risk of severe COVID-19. Journal of Travel Medicine.
https://academic.oup.com/jtm/article/27/3/taaa041/5809509
There is no harm in using ACE inhibitors or ARBs in patients with COVID-19 if clinically indicated.
To see why and how, please have a look at these articles:
1. Article Association of Renin-Angiotensin System Inhibitors With Seve...
2. Article Renin-Angiotensin System Inhibitors and COVID-19: Potential ...
3. Article Renin-angiotensin system inhibition in COVID-19 patients
Early in the COVID-19 Pandemic condition, it was confusingly thought that ACE inhibitors and ARB had deleterious effects on COVID-19 due to the ACE enzymes up regulation. Because SARS-CoV 2 uses ACE enzymes ti enter into the host cells. It is also evident that the manifestation of COVID-19 depends on the ACE 2 receptors presence in the involving organs like lung, kidney, liver, brain and vascular endothelial cells. Subsequently these hypothesis has been proved wrong which you may find in Muhammad Yousuf sir's answer section. There is no harmful effects of using ACE inhibitors or ARB in COVID-19 patients which is supported by ESC, AHA, ACC and American Heart Failure Association; and many more hypertension and cardiac societies across the world. Moreover these agents have well established role on reno and cardio protection; even widely used in de novo heart failure caused by COVID-19.