['Cardiac catheterization shortly before coronary artery bypass grafting or valve surgery has been associated with increased postoperative acute kidney injury. The relationship between catheterization timing and acute kidney injury after proximal aortic surgery remains unknown.', 'Between August 2005 and February 2011, a total of 285 consecutive patients underwent cardiac catheterization before elective proximal aortic surgery with cardiopulmonary bypass at a single institution. The association between timing of catheterization and postoperative acute kidney injury (defined as postoperative increase in serum creatinine ≥ 50% of baseline) was assessed using logistic regression analysis.', 'Of 285 patients, 152 (53%) underwent catheterization on preoperative days 1 to 3 and 133 (47%) underwent catheterization on preoperative day 4 or before. Acute kidney injury occurred in 88 (31%) patients, 3 (1.1%) requiring dialysis. Acute kidney injury occurred in 37 (24%) patients catheterized on preoperative days 1 to 3, and 51 (38%) patients catheterized on preoperative day 4 or before. Catheterization on preoperative days 1 to 3 was not associated with an increased risk of acute kidney injury relative to catheterization on preoperative day 4 or before (unadjusted odds ratio, 0.52; 95% confidence interval, 0.31-0.86; P = .01; adjusted odds ratio, 0.35; 95% confidence interval, 0.17-0.73; P = .005).'] Is cardiac catheterization within 1 to 3 days of proximal aortic surgery associated with increased postoperative acute kidney injury?