Impact of timing of urgent coronary artery bypass grafting following coronary angiography on acute kidney injury.

OBJECTIVES: Prior studies have examined the association between timing of cardiac surgery after coronary angiography with risk of acute kidney injury, but this remains controversial. The purpose of this study was to investigate the association between interval from coronary angiography to urgent coronary artery bypass grafting with acute kidney injury, and to examine this possible effect in patients with preexisting kidney disease. METHODS: Patients from a single institution undergoing urgent, isolated coronary artery bypass grafting within 7 days of coronary angiography were included. Patients were subdivided by chronic kidney disease stage and angiography-to-surgery interval. Locally estimated scatterplot smoothing was used to evaluate the functional relationship of the probability of acute kidney injury and time interval. Adjusted odds ratios were calculated for each time interval group compared against the Day 0 to 1 interval group, controlling for multiple covariates. Analyses were repeated for each chronic kidney disease subgroup. RESULTS: A total of 2249 patients were included in this study. There were 271 (12.0%) patients with postoperative acute kidney injury. Plots demonstrated a decreasing risk of kidney injury from Day 0 to 1 to Day 3 following coronary angiography. Adjusted odds ratios also showed a significant decrease in risk of kidney injury on Day 3 compared with Day 0 to 1. Analyses repeated for each chronic kidney disease stage showed similar trends. CONCLUSIONS: For patients undergoing urgent coronary artery bypass grafting, there is a decreased risk of kidney injury in those having surgery on day 3 after coronary angiography compared with those having surgery on Day 0 to 1, regardless of preexisting kidney disease.