National Trends in Mortality and Urgent Dialysis after Admission for Acute Hypertension in Japan from 2010 through 2019

Background Despite increasing incidences of hypertension, recent trends in mortality and urgent dialysis following acute hypertension (AHT) remain undetermined. Methods This retrospective observational cohort study evaluated 50,316 hospitalized AHT patients from 2010 to 2019, using an administrative claims database in Japan. We examined trends in incidence, urgent dialysis, mortality and its risk factors using logistic regression models. Using ICD-10 codes, AHT was categorized into five spectrums: malignant hypertension (MHT) ( n = 1,792), hypertensive emergency ( n = 17,907), hypertensive urgency ( n = 1,562), hypertensive encephalopathy ( n = 6,593), and hypertensive heart failure (HHF) ( n = 22,462). Results The median age of the patients was 76 years and 54.9% were female. The total AHT incidence was 70 cases per 100,000 admission year. The absolute death rate increased from 1.83% [95% confidence intervals (CI), 1.40–2.40] to 2.88% (95%CI, 2.42–3.41) [Cochran-Armitage trend test (CA), P < 0.0001]. Upward trends were observed in patients aged ≥80, with lean body mass index ≤18.4, and with HHF. Urgent dialysis rates increased from 1.52% (95%CI, 1.12–2.06) to 2.60% (2.17–3.1) (CA, P = 0.0071) in 48,235 patients, excluding maintenance dialysis patients. Older age, male, lean body mass, MHT, HHF, and underlying chronic kidney disease (CKD) correlated with higher mortality risk; greater hospital volume correlated with lower mortality risk; and MHT, HHF, diabetes mellitus, CKD, and scleroderma correlated with a higher risk of urgent dialysis. Conclusions Mortality and urgent dialysis rates following AHT have increased. Aging, complex comorbidities, and HHF-type AHT contributed to the rising trend of mortality.