SARS-CoV-2 is the virus that causes COVID-19, a pandemic illness. Researchers have learned that the virus can enter cells through a receptor called ACE2. Early on in the disease outbreak, scientists became concerned that certain drugs called ACE inhibitors may increase the chance of infection, or make an infection worse once it happened. Several new studies have shown, however, that those concerns were unfounded.
ACE inhibitors are sometimes prescribed to people that have high blood pressure. Angiotensin II is a molecule that can increase blood pressure by narrowing blood vessels. The level of angiotensin II is controlled by the angiotensin-converting enzyme (ACE), so if that enzyme is inhibited by a drug, there is less angiotensin II and blood pressure goes down.
In a study that included 12,594 individuals, there was no evidence of a link between the likelihood of a positive COVID-19 test and a number of blood pressure-reducing drugs: angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), beta blockers, or calcium channel blockers. There was also no connection between these drugs and a more severe infection, whether it would require a ventilator, intensive care, or result in death. The findings have been reported in the New England Journal of Medicine.
"With nearly half of American adults having high blood pressure, and heart disease patients more vulnerable to COVID-19, understanding the relationship between these commonly used medications and COVID-19 was a critical public health concern," said the lead study investigator Harmony Reynolds, M.D., associate director of the Cardiovascular Clinical Research Center at NYU Langone Health. "Our findings should reassure the medical community and patients about the continued use of these commonly prescribed medications, which prevent potentially severe heart events in their own right."
Incredibly, another new study is now determining whether these drugs may be of some benefit to COVID-19 patients. ACE is part of the renin-angiotensin-aldosterone system (RAAS), which controls blood pressure, and balances the levels of water and sodium in cells and the extracellular environment, ensuring healthy function.
"Our hypothesis is that ACE inhibitor drugs help keep the RAAS system in balance and functioning optimally," said the principal investigator of the study, Rohit Loomba, M.D., professor of medicine and director of the NAFLD Research Center at UC San Diego School of Medicine. "SARS infections create an imbalance, triggering feedback loops that promote inflammation and injury -- a vicious cycle of pathological consequences that wrack the lungs, heart and other organs, and kill."
Loomba noted that there is another factor that is influencing COVID-19 infections in people that are taking ACE inhibitors. "Age appears to be the primary risk factor for COVID-19 and high blood pressure is quite prevalent in people over the age of 60," Loomba said.