Impact of the estimated glomerular filtration rate on long-term mortality in patients with hypertensive crisis visiting the emergency department

Abstract

Background The association between renal function and all-cause mortality in patients with hypertensive crisis remains unclear. We aimed to identify the impact of estimated glomerular filtration rate (eGFR) on all-cause mortality in patients with hypertensive crisis visiting the emergency department (ED).

Methods This retrospective study included patients aged ≥18 years admitted to the ED between 2016 and 2019 for hypertensive crisis (systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥110 mmHg). They were classified into four groups according to the eGFR at admission to the ED: ≥90, 60–89, 30–59, and <30 mL/min/1.73 m2.

Results Among the 4,821 patients, 46.7% and 5.8% had an eGFR of ≥90 and <30 mL/min/1.73 m2, respectively. Patients with lower eGFR were older and more likely to have comorbidities. The 3-year all-cause mortality rates were 7.7% and 41.9% in those with an eGFR ≥90 and <30 mL/min/1.73 m2, respectively. After adjusting for confounding variables, those with an eGFR of 30–59 (hazard ratio [HR], 1.93; 95% confidence interval [CI], 1.47–2.54) and <30 mL/min/1.73 m2 (HR, 2.35; 95% CI, 1.71–3.24) had significantly higher 3-year all-cause mortality risks than those with an eGFR of ≥90 mL/min/1.73 m2. Patients with an eGFR of 60–89 mL/min/1.73 m2 had a higher mortality (21.1%) than those with an eGFR of ≥90 mL/min/1.73 m2 (7.7%); however, the difference was not significant (HR, 1.21; 95% CI, 0.94–1.56).

Conclusions Renal impairment is common in patients with hypertensive crisis who visit the ED. A strong independent association was observed between decreased eGFR and all-cause mortality in these patients. eGFR provides useful prognostic information and permits the early identification of patients with hypertensive crisis with an increased mortality risk. Intensive treatment and follow-up strategies are needed for patients with a decreased eGFR who visit the ED.