BACKGROUND: Little is known about the association of kidney dysfunction and outcome in acute severe hypertension. This study aimed to measure the association between baseline chronic kidney disease (estimated glomerular filtration rate), acute kidney injury (AKI, decrease in estimated glomerular filtration rate > or =25% from baseline) and outcome in patients hospitalized with acute severe hypertension.

METHODS AND RESULTS: The Studying the Treatment of Acute Hypertension (STAT) registry enrolled patients with acute severe hypertension, defined as > or =1 blood pressure measurement >180 mm Hg systolic and/or >110 mm Hg diastolic and treated with intravenous antihypertensive therapy. Data were compared across groups categorized by admission estimated glomerular filtration rate and AKI during admission. On admission, 79% of the cohort (n=1566) had at least mild chronic kidney disease (estimated glomerular filtration rate/min in 46%,/min in 22%). Chronic kidney disease patients were more likely to develop heart failure (P

CONCLUSIONS: Chronic kidney disease is a common comorbidity among patients admitted with acute severe hypertension, and AKI is a frequent form of acute target organ dysfunction, particularly in those with baseline chronic kidney disease. Any degree of AKI is associated with a greater risk of morbidity and mortality.