Simplified rapid hydration and contrast-associated acute kidney injury among CKD patients stratified by Mehran score: sub-analysis from the TIME Trial.

Simplified rapid hydration has been proven to be non-inferior to standard hydration in preventing contrast-associated acute kidney injury among chronic kidney disease patients undergoing coronary angiography. The current investigation aimed to further confirm the feasibility and safety of the newly proposed hydration method-simplified rapid hydration (SH) in each risk stratification by Mehran risk score (MRS). Eligible patients (n = 954) randomized to the SH group and standard hydration group were allocated into 2 groups based on MRS: low to moderate-risk and high to very high-risk groups. Primary endpoints were the incidence of contrast-associated acute kidney injury (CA-AKI) and acute heart failure (AHF) (SH vs standard hydration). Secondary endpoints included serum creatinine (Scr), blood urea nitrogen (BUN), cystatin-C (Cys-C), and C-reactive protein (CRP) at 24 h, 48 h, and 72 h after PCI procedure, and the incidence of major adverse cardiac events (MACE). MRS was associated with a higher incidence of CA-AKI (OR = 1.101, 95%CI 1.049-1.156, P < 0.001). In the low to moderate-risk and high to very-high-risk groups, the incidence of CA-AKI in the SH and standard hydration group was 3.3% versus 4.9% (P = 0.5342), 10% versus 12% (P = 0.6392), respectively. Meanwhile, there might be subtle differences in renal function indexes and inflammatory indicators between SH and the control group at different time points. The preventive effect of SH in CA-AKI was similar to standard hydration regardless of MRS-guided risk stratification.