Acute kidney injury following coronary artery bypass grafting and control angiography: a comprehensive analysis of 221 patients.

Abstract

Postoperative coronary angiography offers the basis for prompt management of ischemic complications after coronary artery bypass grafting (CABG). Little is known about the effects of postoperative angiography on renal function. The current study aims to assess the incidence and risk factors for acute kidney injury (AKI) following postoperative coronary angiography. A total of 221 CABG patients (mean age, 67 ± 8years) underwent postoperative coronary angiography due to perioperative myocardial infarction (PMI). AKI was defined according to the KDIGO criteria. Logistic regression analyses were performed to find out risk factors responsible for AKI and to ascertain significant associations between AKI and in-hospital death. Mean delay from CABG operation to postoperative angiography was 1.4 ± 1.0days. AKI occurred in 79/221 (36%) patients. Mean serum-creatinine (sCr) values peaked on the first day after the angiography and reached the lowest level at the fourth day. In the multivariable analysis, the following variables were independent predictors for AKI: postoperative peak values of CK-MB (p = 0.049, OR 1.03, 95% CI 1.00-1.06 per 10 U/l), EuroSCORE I (p = 0.011, OR 1.18, 95% CI 1.04-1.35), and AKI before re-angiography (p = 0.004, OR 3.50, 95% CI 1.51-8.16), whereas a delayed angiography (p = 0.031, OR 0.69, 95% CI 0.49-0.97) was protective against AKI. Patients with post-angiography AKI had a significantly higher mortality after multivariable adjustment than patients without AKI (15.5% vs. 2.11%, p = 0.001, OR 5.42, 95% CI 1.35-21.75). Over one-third of patients who undergo postoperatively angiography develop AKI. The occurrence of AKI must be considered during the decision-making prior to coronary angiography, especially in patients presenting the identified risk factors for AKI.