Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers in Patients With Coronavirus Disease 2019 Friend or Foe?

When the coronavirus disease 2019 (COVID-19) wreaked an unprecedented havoc of an escalating number of deaths and hospitalization in the United States, clinicians were faced with a myriad of unanswered questions, one of the them being the implication of the renin-angiotensin-aldosterone system in patients with COVID-19. Animal data and human studies have shown that angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) increase the expression of ACE2. ACE2 is an enzyme found in the heart, kidney, gastrointestinal tract, and lung and is a coreceptor for severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV2), the virus responsible for COVID-19. Therefore, one can speculate that discontinuing ACE inhibitor or ARB therapy may lead to decreased ACE2 expression, thereby attenuating the infectivity of SARS-CoV-2, and mitigating the disease progression of COVID-19. However, several studies have also shown that ACE2 exhibits reno- and cardioprotection and preserves lung function in acute respiratory distress syndrome, which would favor ACE inhibitor or ARB therapy. This article is to examine and summarize the 2 opposing viewpoints and provide guideline recommendations to support the use or discontinuation of ACE inhibitors and ARBs in patients with COVID-19.