Renin-angiotensin system inhibitors in management of hypertension during the COVID-19 pandemic.

COVID-19, which is caused by the single-stranded RNA severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has introduced significant therapeutic dilemmas in several areas. One of these is concern regarding the use of renin-angiotensin system (RAS) inhibitors. Dysfunction of the RAS has been observed in COVID-19 patients, but whether RAS inhibitors, such as angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type-1 receptor blockers (ARBs), are associated with improved or worse clinical outcomes, remains unclear. RAS inhibitors are currently widely used in the treatment of hypertension. Emerging data suggest an increased association and a heightened mortality in patients of COVID-19 with co-morbidities such as hypertension, coronary heart disease, and diabetes mellitus, particularly in the elderly. Therefore, several recently published research papers have focused on the management of hypertension during the COVID-19 pandemic, as this co-morbidity was found to be the most common in patients with coronavirus infections. SARS-CoV-2 viral surface protein is known to attach angiotensin converting enzyme-2 (ACE-2) on the cell membrane to facilitate viral entry into the cytoplasm. While the SARS-CoV-2 viral load remains the highest in upper respiratory tract of COVID-19 patients, it has also been reported in multiple sites in COVID-19, and patients not infrequently require the Intensive Care Units (ICU) admission. However, despite the theoretical concerns of possible increased ACE2 expression by RAS blockade, there is no evidence that RAS inhibitors are harmful during COVID-19 infection, and indeed they have been shown to be beneficial in some animal studies. In this review we summarise the pathophysiology of the interaction between RAS, ACEIs/ARBs inhibitors and COVID-19, and conclude, on the basis of current data, that RAS blockade should be maintained during the current coronavirus pandemic.