IMPORTANCE: It has been hypothesized that angiotensin-converting enzyme 
inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) may make patients more 
susceptible to coronavirus disease 2019 (COVID-19) and to worse outcomes through 
upregulation of the functional receptor of the virus, angiotensin-converting 
enzyme 2.
OBJECTIVE: To examine whether use of ACEI/ARBs was associated with COVID-19 
diagnosis and worse outcomes in patients with COVID-19.
DESIGN, SETTING, AND PARTICIPANTS: To examine outcomes among patients with 
COVID-19, a retrospective cohort study using data from Danish national 
administrative registries was conducted. Patients with COVID-19 from February 22 
to May 4, 2020, were identified using ICD-10 codes and followed up from day of 
diagnosis to outcome or end of study period (May 4, 2020). To examine 
susceptibility to COVID-19, a Cox regression model with a nested case-control 
framework was used to examine the association between use of ACEI/ARBs vs other 
antihypertensive drugs and the incidence rate of a COVID-19 diagnosis in a 
cohort of patients with hypertension from February 1 to May 4, 2020.
EXPOSURES: ACEI/ARB use was defined as prescription fillings 6 months prior to 
the index date.
MAIN OUTCOMES AND MEASURES: In the retrospective cohort study, the primary 
outcome was death, and a secondary outcome was a composite outcome of death or 
severe COVID-19. In the nested case-control susceptibility analysis, the outcome 
was COVID-19 diagnosis.
RESULTS: In the retrospective cohort study, 4480 patients with COVID-19 were 
included (median age, 54.7 years [interquartile range, 40.9-72.0]; 47.9% men). 
There were 895 users (20.0%) of ACEI/ARBs and 3585 nonusers (80.0%). In the 
ACEI/ARB group, 18.1% died within 30 days vs 7.3% in the nonuser group, but this 
association was not significant after adjustment for age, sex, and medical 
history (adjusted hazard ratio [HR], 0.83 [95% CI, 0.67-1.03]). Death or severe 
COVID-19 occurred in 31.9% of ACEI/ARB users vs 14.2% of nonusers by 30 days 
(adjusted HR, 1.04 [95% CI, 0.89-1.23]). In the nested case-control analysis of 
COVID-19 susceptibility, 571 patients with COVID-19 and prior hypertension 
(median age, 73.9 years; 54.3% men) were compared with 5710 age- and sex-matched 
controls with prior hypertension but not COVID-19. Among those with COVID-19, 
86.5% used ACEI/ARBs vs 85.4% of controls; ACEI/ARB use compared with other 
antihypertensive drugs was not significantly associated with higher incidence of 
COVID-19 (adjusted HR, 1.05 [95% CI, 0.80-1.36]).
CONCLUSIONS AND RELEVANCE: Prior use of ACEI/ARBs was not significantly 
associated with COVID-19 diagnosis among patients with hypertension or with 
mortality or severe disease among patients diagnosed as having COVID-19. These 
findings do not support discontinuation of ACEI/ARB medications that are 
clinically indicated in the context of the COVID-19 pandemic.