Incidence and risk factors of acute kidney injury after maze operation in patients with rheumatic mitral valve disease

BACKGROUND: Acute kidney injury (AKI) is one of the most common complications after cardiac surgery. While current guidelines indicate that surgical ablation does not increase the risk of renal failure, recent studies have produced conflicting results. This study was conducted to evaluate the incidence of AKI after maze procedure in patients with rheumatic mitral valve disease and atrial fibrillation, and to elucidate risk factors associated with postoperative AKI. METHODS: Between 2011 and 2020, 203 patients with rheumatic mitral valve disease and atrial fibrillation (61.4±8.7 years, male:female =67:136) who underwent concomitant maze procedure and mitral valve replacement were retrospectively reviewed. Other combined procedures included aortic valve operations (n=64, 31.5%) and tricuspid valve procedures (n=149, 73.4%). The AKI was defined as an increase of serum creatinine level by 1.5 times after surgery based on the RIFLE (Risk, Injury, Failure, Loss, and End stage) criteria. A multivariable logistic regression analysis was performed to evaluate risk factors associated with postoperative AKI. RESULTS: Postoperative AKI developed in 76 patients (37.4%). The multivariable analysis demonstrated that age [odds ratio (OR), 95% confidence interval (CI): 1.065, 1.025–1.107; P=0.001], cardiopulmonary bypass (CPB) time (1.007, 1.002–1.013; P=0.009) and nadir hematocrit during CPB (0.854, 0.740–0.985; P=0.031) were associated with postoperative AKI. CONCLUSIONS: Postoperative AKI occurred in more than one thirds of patients with rheumatic mitral valve disease and atrial fibrillation who underwent combined mitral valve replacement and maze procedure. Optimization of CPB management might be needed to prevent postoperative AKI after maze procedure.