Hypertension and Excess Risk for Severe COVID-19 Illness Despite Booster Vaccination

Demographic and clinical characteristics of the cohort are shown in the Figure. In multivariable analyses, factors significantly associated with risk of hospitalization for Omicron infection included older age, hypertension, CKD, and MI or HF, as well as longer duration between the last vaccination and infection (Figure). Notably, the presence of hypertension was associated with the greatest magnitude of risk, which remained significant in sensitivity analyses excluding patients with a history of CKD, MI, or HF. Results were similar when ACE inhibitor/angiotensive receptor blocker use was removed from the model. Our findings reveal a persistent and marked associa-tion between hypertension and risk for severe COVID-19 illness, even among a fully vaccinated patient population. The Omicron variant of SARS-CoV-2 has led to overall less severe COVID-19 illness in most affected individuals when compared with prior vari-ants—with morbidity and mortality even further reduced by receiving 3 doses of vaccine. Our findings were con-sistent with prior studies demonstrating greater hospitalization risk with advanced age and time since the last vaccine dose. 2 Even when controlling for these and other clinical variables, the risk of hospitalization related to breakthrough Omicron infection was more than dou-bled by the presence of hypertension. Recognizing that hypertension is quite prevalent in the setting of high-risk conditions such as CKD, MI, and HF, we repeated our analyses excluding patients with these diagnoses and found still substantial and significant risks associated with hypertension. Our findings extend from prior reports of equivocal or potentially confounded associations of hypertension with COVID-19 illness sever-ity that were based on analyzing early pandemic and particularly pre-Omicron outcomes data. 3 In the con-text of shifts in the risk factors associated with more severe forms of COVID-19 during the course of the pandemic, 4 our results indicate persistence and even accentuation of hypertension-related risk in the setting of a more transmissible albeit generally less viru-lent strain of SARS-CoV-2 and in the era of multidose