Renin-angiotensin-aldosterone system (RAAS) inhibitors include angiotensin-converting enzyme (ACE) inhibitors, angiotensin-receptor blockers (ARBs), and direct renin inhibitors. They act by inhibiting the RAAS system. Recent studies have indicated an increased risk of COVID-19 in patients taking medications that act on the RAAS system. This study aims to evaluate the association between the use of RAAS inhibitors and the risk of COVID-19.

This study included a total of 12,594 participants who had previously undergone treatment with ACE inhibitors, calcium-channel blockers, thiazide diuretics, angiotensin-receptor blockers, or beta-blockers. The participants were tested for COVID-19, and Bayesian methods were used to compare the outcomes of those who were treated with RAAS inhibitors versus untreated patients. The previous history of hypertension was also considered. The primary outcome was the incidence of COVID-19.

Of 12,594 participants who underwent testing, 5,894 (46.8%) were positive for COVID-19, and 1,002 (17%) of them had severe illness. A total of 4,357 patients (34.6%) had a history of hypertension, and 2,573 patients (59.1%) among them were tested positive. However, none of the medications included in the study exhibited a significant association with the risk of severe illness.

The research concluded that the use of RAAS inhibitors was not associated with the risk of severe COVID-19 in patients who tested positive.