Role of blood pressure dysregulation on kidney and mortality outcomes in COVID-19. Kidney, blood pressure and mortality in SARS-CoV-2 infection

Background In February 2020 the corona virus disease 2019 (COVID-19) infection started spreading throughout Italy, hitting the Lombardy region very hard. Despite the high diffusion, only a subset of patients developed severe COVID-19: around 25% of them developed acute kidney injury (AKI) and one-third of them died. Elderly patients and patients with high comorbidities were identified as being at higher risk of severe COVID-19. Methods Our prospective observational cohort study includes 392 consecutive patients hospitalized for COVID-19 in Milan (median age 67 years, 75% male). We evaluated the relationship between blood pressure at presentation, presence of AKI at Emergency Department admission and during hospitalization, and total in-hospital mortality (24%). Results Although 58% of our study patients reported a history of hypertension (HYP) (86% on treatment), 30% presented with low blood pressure levels. Only 5.5% were diagnosed with AKI on admission; 75% of hypertensive patients discontinued therapy during hospitalization (only 20% were on treatment at discharge). Gender and hypertension were strongly associated with AKI at admission (odds ratio 11). Blood pressure was inversely correlated with increased risk of AKI upon admission, regardless of the severity of respiratory distress. Age over 65, history of hypertension, and severity of respiratory distress were the main predictors of AKI, which developed in 34.7% of cases during hospitalization. AKI was associated with increased in-hospital mortality. Hypertension and low blood pressure at presentation were the main predictors of in-hospital mortality, together with age over 65, baseline pulmonary involvement, and severity of illness. Conclusions In patients hospitalized for COVID-19, hypertension and low blood pressure at presentation are important risk factors for AKI and mortality. Early reduction of antihypertensive therapy may improve outcomes in patients with SARS-CoV-2 infection.