Background: Improved understanding of the incidence and risk factors for operative complications and long-term mortality following coronary artery bypass grafting (CABG) is needed to better define the optimal role for CABG in patients with chronic kidney disease (CKD).
Methods: We analysed 2438 patients who underwent CABG at a single centre between 2005 and 2008. Multivariable regression was used to analyse associations and to generate a CKD-specific predictive tool.
Results: Operative mortality was 4.8% in individuals with stage 3 CKD, 7.1% in individuals with stage 4-5 CKD and 2.2% in those without significant CKD (P < 0.001). CKD was associated with post-operative blood transfusion, acute kidney injury, myocardial injury and cardiac arrest, and use of exogenous blood and acute kidney injury were strongly associated with in-hospital death in CKD patients. Patients with stage 3 (HR 1.64, 95% CI 1.30-45.94) and stage 4-5 CKD (HR 2.77, 95% CI 1.00-2.68) were more likely to die during follow-up than those without CKD, but mortality rates were low among patients who survived to discharge-stage 3 (0.006 deaths/year) and stage 4-5 CKD (0.009/year). A scoring system including urgent or emergent surgery (OR 2.30), prior cardiac surgery (OR 3.06), concurrent valve surgery (OR 2.06), preoperative shock (OR 6.18), and prior stroke (OR 1.98) had 96.4% percent specificity for the detection of in-hospital death in patients with CKD.
Conclusions: Perioperative mortality and morbidity remain more frequent in patients with stage 3-5 CKD than patients with preserved renal function, but long-term outcomes in patients surviving hospitalization are favourable. We have developed a predictive tool that holds promise as a means of identifying CKD patients most likely to survive surgery and benefit from CABG.