The intravascular administration of iodinated contrast media for diagnostic imaging is a common cause of acute kidney injury (AKI) and a leading cause of iatrogenic renal disease. Contrast-induced AKI is associated with serious adverse outcomes including death, need for dialysis, prolonged hospitalization, and acceleration in the rate of progression of underlying chronic kidney disease. The benefit of IV isotonic bicarbonate compared to IV isotonic saline and of N-acetylcysteine for the prevention of contrast-induced AKI and associated adverse outcomes remains unclear. The purpose of the PRESERVE trial was to compare the effectiveness of IV isotonic sodium bicarbonate with IV isotonic sodium chloride and oral NAC with placebo for the prevention of serious adverse outcomes in high-risk participants scheduled to undergo coronary or non-coronary angiography.

The Biomarker Collection and Analysis sub-study collected, banked, and analyzed the blood and urine of participants from the VA-funded PRESERVE trial. Blood and urine proteins and other markers may predict the development of contrast-induced acute kidney injury and diagnose the very early stages of this condition following angiography. In addition, these biomarkers may predict which patients that develop acute kidney injury following angiography are likely to experience serious longer-term complications such as death, need for dialysis, and/or progressive loss of kidney function.

The aim of the Biomarker Collection and Analysis sub-study was to establish a biorepository of blood and urine samples from the PRESERVE trial participants to allow for future analyses of known and yet-to-be identified biomarkers that may predict and diagnose contrast-induced acute kidney injury.

The primary outcome included a composite of serious, adverse, patient-centered events, such as death, need for acute dialysis, and persistent decline in kidney function.

All sub-study participants were from the PRESERVE trial. Recruitment for the sub-study occurred when participants enrolled in the PRESERVE trial. No additional inclusion or exclusion criteria were applied for participation.

Pre-angiography measurements of plasma biomarkers and urine biomarkers modestly predicted the development of major adverse kidney events and death. Measurement of these injury and repair biomarkers can be used to improve the efficiency of future contrast-associated acute kidney injury trials.