Impact of renal dysfunction on early outcomes of coronary artery bypass grafting surgery

• Published in: Laeknabladid Vol. 108; no. 5; p. 231
• Main Authors: Sveinsdottir, Nanna, Heidarsdottir, Sunna Run, Steinthorsson, Arni Steinn, Johannesdottir, Hera, Heimisdottir, Alexandra Aldis, Kristjansson, Tomas Thor, Einarsson Long, Thorir, Gudmundsdottir, Ingibjorg, Sigurdsson, Martin Ingi, Gudbjartsson, Tomas
• Format: Journal Article
• Language: Icelandic
• Published: Iceland 01-05-2022
• Subjects: Coronary Artery Bypass - adverse effects; Coronary Artery Disease - complications; Coronary Artery Disease - diagnostic imaging; Coronary Artery Disease - surgery; Female; Humans; Male; Renal Insufficiency - complications; Renal Insufficiency, Chronic - complications; Renal Insufficiency, Chronic - diagnosis; Retrospective Studies; Stroke Volume; Ventricular Function, Left; chronic kidney disease; complications; Coronary artery bypass grafting (CABG); short-term; reduced kidney function; outcome
• ISSN: 1670-4959

Impaired renal function as seen in chronic kidney disease (CKD) is a known risk factor for coronary artery diseases and has been linked to inferior outcome after myocardial revascularization. Studies on the outcome of coronary bypass grafting (CABG) in CKD-patients are scarce. We aimed to study this subgroup of patients following CABG in a well defined whole-nation cohort, focusing on short term complications and 30 day mortality.
A retrospective study on 2300 consecutive patients that underwent CABG at Landspítali University Hospital 2001-2020. Patients were divided into four groups according to preoperative estimated glomerular filtration rate (GFR), and the groups compared. GFR 45-59 mL/mín/1.73m2, GFR 30-44 mL/mín/1.73m2, GFR <30 mL/mín/1.73m2 and controls with normal GFR (≥60 mL/mín/1.73m2). Clinical information was gathered from medical records and logistic regression used to estimate risk factors of 30-day mortality.
Altogether 429 (18.7%) patients had impaired kidney function; these patients being more than six years older, having more cardiac symptoms and a higher mean EuroSCORE II (5.0 vs. 1.9, p<0.001) compared to controls. Furthermore, their left ventricular ejection fraction was also lower, their median hospital stay extended by two days and major short-term complications more common, as was 30 day mortality (24.4% vs. 1.4%, p<0.001). In multivariate analysis advanced age, ejection fraction <30% and GFR <30 mL/min/1.73m2 were independent predictors of higher 30-day mortality (OR=10.4; 95% CI: 3.98-25.46).
Patients with impaired renal function are older and more often have severe coronary artery disease. Early complications and 30-day mortality were much higher in these patients compared to controls and advanced renal failure and the strongest predictor of 30-day mortality.