Increased pre-procedural urinary microalbumin is associated with a risk for renal functional deterioration after coronary computed tomography angiography

Background Urinary microalbumin is a marker for preclinical nephropathy. A percentage change in cystatin C (%CyC) of ≥ 10% for 24 h after tests with contrast media is reportedly an independent predictor for developing contrast-induced nephropathy. We investigated the relationship between the presence of urinary microalbumin and changes in CyC after coronary computed tomography angiography (CCTA). Methods Three hundred and thirty-three patients with known or suspected coronary artery disease who scheduled for CCTA using a 70 mL of Iopamidol were enrolled. Serum creatinine and CyC levels were measured at baseline and 24 h post-procedure. The %CyC, absolute changes in estimated glomerular filtration rate (ΔeGFR), and oral fluid volume from pre- to post-procedure were calculated. The patients were dichotomized into 2 groups as follows: group A comprised 83 patients showing a %CyC of ≥ 10%; and group B comprised 250 patients showing a %CyC of < 10%. Results The ΔeGFR, fasting plasma glucose levels, HbA1c, and pre-procedural urinary microalbumin levels were significantly greater in group A than in group B. Oral fluid intake volume was significantly less in group A than in group B. The urinary microalbumin significantly correlated with %CyC (r = 0.504, P < 0.0001). Multivariate logistic regression analysis revealed that pre-procedural urinary microalbumin and oral fluid volume were independent predictors for %CyC ≥ 10%. The optimal cut-off value of a pre-procedural urinary microalbumin level was 58 mg/g·creatinine for predicting a %CyC ≥ 10% using receiver-operating-characteristic analysis. Conclusions Renal functional changes should be carefully paid attention to after CCTA, particularly in patients exhibiting increased pre-procedural urinary microablumin levels.