Certain conditions are linked to the more serious cases of coronavirus infection, aka COVID-19. These include high blood pressure (hypertension), diabetes, and heart disease. Classes of drugs that are OFTEN used to treat ALL these conditions are ACEIs (angiotensin-converting enzyme inhibitors) and ARBs (angiotensin receptor blockers.
I’ve never understood why or how hypertension would predispose to serious COVID-19 disease, especially if blood pressure is well controlled. A new theory suggests why that may be: The drugs used to treat hypertension—ACEIs and ARBs—allow the virus to flourish.
From JAMA Network:
The increased mortality and morbidity of COVID-19 in patients with hypertension is an association that has been observed in a number of initial epidemiological studies outlining the characteristics of the COVID-19 epidemic in China. Wu et al2 found hypertension to have a hazard ratio of 1.70 for death and 1.82 for acute respiratory distress syndrome in 201 patients with COVID-19. Zhou et al found hypertension to have a hazard ratio of 3.05 for in-hospital mortality in 191 patients with COVID-19.
Neither of these studies adjusted for confounding variables and thus it remains unclear if this association is related to the pathogenesis of hypertension or another associated comorbidity or treatment. There has been a growing concern that this association with hypertension is confounded by treatment with specific antihypertensive medications: angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs).
The link with ACEIs and ARBs is because of the known association between angiotensin-converting enzyme 2 (ACE2) and SARS-CoV-2. ACE2 has been shown4 to be a co-receptor for viral entry for SARS-CoV-2 with increasing evidence that it has a protracted role in the pathogenesis of COVID-19. ACE2 has a broad expression pattern in the human body with strong expression noted in the gastrointestinal system, heart, and kidney with more recent data identifying expression of ACE2 in type II alveolar cells in the lungs. The concern that ACEIs and ARBs affect the severity and mortality of COVID-19 is 2-fold. One suggestion is that ACEIs could directly inhibit ACE2; however, ACE2 functions as a carboxypeptidase and is not inhibited by clinically prescribed ACEIs.
In addition, there is concern that the use of ACEIs and ARBs will increase expression of ACE2 and increase patient susceptibility to viral host cell entry and propagation.
In response, the Council on Hypertension of the European Society of Cardiology, the American Heart Association, the Heart Failure Society of America, and the American College of Cardiology all recommend that patients continue their ACE inhibitors and ARBs until we have better evidence that they may be harmful in the setting of this coronavirus pandemic.
One of my patients with hypertension was concerned about his ACEI promoting serious COVID-19 illness, and I had no hesitation about switching him to another class of drug, chlorthalidone in this instance. Calcium channel blockers like amlodipine are another good choice for hypertension that requires just one drug.
As usual, we need more hard data.
Steve Parker, M.D.
PS: Loss of excess weight also helps control high blood pressure.