Risk Factors and Blood Pressure Control Targets Associated With the Clinical Outcome of Elderly COVID-19 Patients With Hypertension: a Retrospective Cohort Study

Abstract

Background: COVID-19 is a global pandemic, especially among the elderly. Our study aimed to explore the risk factors and identify the blood pressure control targets associated with the clinical outcome of elderly COVID-19 patients with hypertension. Methods: In this retrospective cohort study, elderly COVID-19 patients who were admitted to Wuhan Huoshenshan Hospital from February 8 to 17, 2020 was included. Demographic, medical history, clinical data, and laboratory test data were collected from medical records. The adverse clinical outcomes were intensive care unit (ICU) admission and death. Difference between hypertension and non-hypertension groups were compared. Hypertension group were further divided into 3 subgroups according to their maximum blood pressures. Kaplan–Meier (K–M) method was used to find the differences both between hyperntesion and non-hypertension groups, and among the 3 hypertension subgroups. Univariable and multivariable Cox proportional hazards regression model were used to find risk factors.Results: All 133 elderly COVID-19 patients (79 patients with hypertension) were included. (1) Univariate analysis between hypertension and non-hypertension patients showed most laboratory tests were significantly (P < 0.05, or P < 0.01), particularly in adverse clinical outcomes (32.91% vs 7.41% at 30 days, P < 0.05). (2) Multivariate Cox proportional hazards models confirmed hypertension (HR 3.202, 95% CI:1.164 - 8.807) were the most important independent risk factors of outcomes in elderly patients, as well as low lymphocyte count, while the statistical difference of other values diminished. (3) Hypertension group were further divided into 3 subgroups according to their maximum blood pressures. K-M analysis showed maximum systolic blood pressure (SBP) ≥160mmHg subgroup (P < 0.01) and maximum blood pressure (DBP) ≥90mmHg subgroup (P < 0.05) experienced more adverse outcomes than others. (4) Multivariate Cox-proportional hazard model confirmed that maximum SBP≥160mmHg and maximum DBP ≥90mmHg were risk factors (HR 8.279, 95% CI: 1.346, 50.914; HR 5.080, 95% CI: 1.606,16.071; respectively). Conclusions: Hypertension is the most important independent risk factor of adverse outcomes in elderly COVID-19 patients, controlling the maximum blood pressure levels under 160/90 mmHg will decrease large part risks of adverse outcomes, the first week are key treatment period for patient prognosis.