Serum cystatin C levels are strongly associated with development of acute kidney injury (AKI) and short-term prognosis among coronary care unit (CCU) patients, according to a new study published in Kidney & Blood Pressure Research (2017;42:961-973).
In a prospective, observational study of 412 CCU patients, Yugang Hu, MD, and colleagues at Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China, found that patients in the highest quartile of serum cystatin C (greater than 1.69 mg/L) had a significant 9.6-fold increased risk of incident AKI compared with those in the lowest quartile (less than 0.93 mg/L) in adjusted analyses.
Based on KDIGO (Kidney Disease: Improving Global Outcomes) AKI criteria, AKI developed in 130 patients (31.6%).
Among patients with pre-existing chronic kidney disease (CKD), those in the highest quartile of serum cystatin C (greater than 2.86 mg/L) had a 27-fold increased risk of incidence AKI compared with those in the lowest quartile (less than 1.30 mg/L). Among patients without pre-existing CKD, those in the highest quartile of cystatin C (greater than 1.27 mg/L) had a 4.7-fold higher risk of incidence AKI than those in the lowest quartile (less than 0.89 mg/L).
After a median 19.8 month follow-up, 112 patients (27.2%) died within 2 years after admission. Serum cystatin C independently predicted the risk of 2-year mortality, rehospitalization, and renaCyl recovery failure. A serum cystatin C level of 1.255 mg/L or higher on the first day of admission was associated with a significant 3-fold increased risk of mortality and 1.8-fold increase risk of rehospitalization at 2 years. Among patients with incident AKI, the rate of failure of renal function recovery was 3.4% for those who had a serum cystatin C level less than 1.255 mg/L on admission compared with 31.4% in those with serum cystatin C levels of 1.255 mg/L or higher.
“If confirmed further, [serum cystatin C] may provide a unique opportunity to impact dramatically the management of AKI by delivering diagnostic, severity, and prognostic information at an early time-point following a renal insult,” the authors concluded.
Hu Y, Liu H, Du L, et al. Serum cystatin C predicts AKI and the prognosis of patients in coronary care unit: a prospective, observational study. Kidney Blood Press Res 2017;42:961-973.