Renin-angiotensin-aldosterone system (RAAS) inhibitors, including 
angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor 
blockers (ARBs) are one of the most prescribed antihypertensive medications. 
Previous studies showed RAAS inhibitors increase the expression of ACE2, a 
cellular receptor for severe acute respiratory syndrome coronavirus 2 
(SARS-CoV-2), which provokes a concern that the use of ACEI and ARB in 
hypertensive individuals might lead to increased mortality and severity of 
coronavirus disease 2019 (COVID-19). To further investigate the effects of 
ACEI/ARB on COVID-19 patients, we systematically reviewed relevant studies that 
met predetermined inclusion criteria in search of PubMed, Embase, Cochrane 
Library databases, medRxiv, and bioRxiv. The search strategy included clinical 
data published through October 12, 2020. Twenty-six studies involving 8104 
hypertensive patients in ACEI/ARB-treated group and 8203 hypertensive patients 
in non-ACEI/ARB-treated group were analyzed. Random-effects meta-analysis showed 
ACEI/ARB treatment was significantly associated with a lower risk of mortality 
in hypertensive COVID-19 patients (odds ratio [OR] = 0.624, 95% confidence 
interval [CI] = 0.457-0.852, p = .003, I2  = 74.3%). Meta-regression analysis 
showed that age, gender, study site, Newcastle-Ottawa Scale scores, 
comorbidities of diabetes, coronary artery disease, chronic kidney disease, or 
cancer has no significant modulating effect of ACEI/ARB treatment on the 
mortality of hypertensive COVID-19 patients (all p > .1). In addition, the 
ACEI/ARB treatment was associated with a lower risk of ventilatory support 
(OR = 0.682, 95% CI = 0.475-1.978, p = .037, I2  = 0.0%). In conclusion, these 
results suggest that ACEI/ARB medications should not be discontinued for 
hypertensive patients in the context of COVID-19 pandemic.