The very operation of these drugs raised concerns that they would make it easier for the virus to penetrate the cells of the body. However, numerous medical societies recommended that patients continue their medication.
The possibility of a second wave made research on the safety of continuing with these drugs in a pandemic context essential. For this reason, our team of researchers from the University of East Anglia (UK) set out to analyze what effects these drugs had on the advancement of COVID-19.
What we discovered was that these drugs, far from increasing the risk for patients, reduced the risk of death or serious diseases caused by COVID-19.
Reduction of medical damages in a third of patients
We collected data from 19 relevant virus studies that looked at patients taking two specific types of blood pressure medication: angiotensin converting enzyme (ACEI) inhibitors and angiotensin receptor blockers ( ARB). This allowed us to work with the forecasts of more than 28,000 COVID-19 patients, which in turn made it possible for us to analyze the effect of these drugs on the virus.
ACEIs and ARBs act on the renin-angiotensin-aldosterone system (RAAS), which is essential for regulating both blood pressure and fluid and electrolyte balance. The possibility of using these drugs to enhance the expression of a protein found on the surface of cells, the angiotensin-converting enzyme 2 (ACE2), was also considered.
The ACE2 protein not only helps regulate blood pressure, but it also allows the coronavirus to enter the cells of the body. So it was a concern that patients continued to take these drugs. And it is that if these drugs increased the amount of ACE2 present in the cells, it was assumed that in the same way they would make it easier for the virus to infect them, which would worsen the patient’s condition.
But when we compared the status of the patients who had taken ACEI and ARB with that of those who had not, the results indicated otherwise.
We found no evidence that these drugs could increase the harm caused by COVID-19 or the risk of death from this disease. On the contrary: patients who had been prescribed ACEI and ARB to treat high blood pressure had a significantly lower risk of death, admission to the ICU or need for intubation. The frequency of this type of event was a third lower in this group of patients.
This pointed to the possibility that these drugs could provide real protection against the virus, especially in patients with high blood pressure.
How is this effect explained?
It is not clear why patients taking ACEI and ARB resist the disease better, but there are a couple of issues that should be discussed.
The first point is that, although in theory these drugs were designed to increase ACE2 levels, there is no strong evidence that they actually do so. We do not have clinical data on the effects of this medicine on the expression of ACE2 in human tissues.
But even if these drugs increased ACE2 levels in cells, not all of this increase would be concentrated on their surface. There would be additional ACE2 that could appear in other parts of the cell, which would lead to it not functioning as an entry point for SARS-CoV-2.
There is a second relevant piece of information. SARS-CoV-2 infections can also cause an overreaction of the RAAS sequence (which is precisely what these drugs fight) and inflammation. It is believed that this acceleration of the inflammatory process can cause severe lung damage and thus worsen damage caused by conditions such as pneumonia or severe acute respiratory syndrome. Therefore, taking these drugs, which inhibit the RAAS system, could avoid this chain of events and, thus, improve clinical outcomes against COVID-19.
What we do know is that our study provides strong evidence that patients with high blood pressure should continue to take their medications during the pandemic, as this has been shown to be safe. What we haven’t investigated is whether prescribing these pills to critically ill COVID-19 patients could be beneficial. This is something that is currently undergoing randomized clinical checks.
Vassilios Vassiliou, Senior Clinical Lecturer in Cardiovascular Medicine, University of East Anglia and Ranu Baral, Visiting Researcher (Academic Foundation Doctor FY2), University of East Anglia
This article was originally published on The Conversation. Read the original.
