COVID-19 first and delta waves in relation to ACEI, ARB, Influenza vaccination, and comorbidity in a North Metropolitan Barcelona Health Consortium

BACKGROUNDSome authors have reported that angiotensin converter enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) improve clinical outcomes in hypertensive COVID-19 patients, and others have proposed cross-protection for influenza vaccination. This study explores the impact of these variables on the evolution of hospitalized patients, focusing in the first wave and the Delta wave. METHODSHospitalizations (n=1888) from March 1, 2020, to July 31, 2021, in the Hospital of Terrassa, the referral center for the free access Terrassa Health Consortium in the North Metropolitan Barcelona Health Region (population=167,386) were studied. The number of chronic treatments and conditions of patients from the initial outbreak (n=184) and the Delta outbreak (n=158) were recorded. RESULTSOf the non-survivors, 96.3% were aged >60 years in the first wave and 100% were aged >70 years in the Delta wave. In non-survival hospitalized patients aged >60 years, the percentage treated with ACEI was similar to general population but was significantly different for ARB treatments of influenza vaccination, although associated to a higher comorbidity and age. In July 2021, the number of hospitalizations for patients aged <50 years was higher than March 2020 and 22% of hospitalized patients without chronic treatments and conditions needed admission to the intensive care unit. Mortality was reduced in the groups with most comorbidities who received influenza and SARS-CoV2 vaccination. CONCLUSIONSIn COVID-19 infection, age and comorbidity are related to survival, ACEI use is safe. A high proportion of patients without comorbidity require hospitalization and intensive care.