Long-term prognosis of acute kidney injury after first acute stroke.

BACKGROUND AND OBJECTIVES: Acute kidney injury (AKI) has been associated with increased mortality in a variety of clinical settings. We studied the incidence, predictors, and effect of AKI on long-term overall mortality and cardiovascular events after stroke.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This was a prospective outcome study of 2155 patients who sustained an acute first-ever stroke and were followed for 10 yr. Patients were divided in two groups: (1) Those with an acute increase (over 48 h) in serum creatinine >or=0.3 mg/dl or a percentage increase of >or=50% and (2) those with a change <0.3 mg/dl, no change at all, or even a reduction.

RESULTS: Twenty-seven percent of patients developed AKI after acute stroke. Stroke severity, baseline estimated GFR, heart failure, and stroke subtype predict the occurrence of AKI. The probability of 10-yr mortality for patients with AKI was 75.9 and 57.7 in the patients without AKI (log rank test 45.0; P = 0.001). When patients with AKI were subdivided into three groups according to AKI severity, the probability of 10-yr mortality increased: 73.7, 86.5, and 89.2 in stages 1, 2, and 3, respectively. In Cox proportional hazard analysis, AKI was an independent predictor of 10-yr mortality (P < 0.01) and for the occurrence of new composite cardiovascular events (P < 0.05) after adjustment for available confounding variables.

CONCLUSIONS: AKI after stroke is a powerful and independent predictor of 10-yr mortality and new composite cardiovascular events.