Heart Surgery in Patients on Dialysis: Who is at High Risk?

METHODS: Records of the patients who underwent cardiac surgery at Kitasato University Hospital between 2011 and 2017 were retrospectively reviewed.

RESULTS: During the study period, a total of 1046 operations of heart surgery utilizing cardiopulmonary bypass or off-pump coronary artery bypass were performed. Among these, 72 patients (6.9%; 67 ± 10 (40 – 83) years, 52 men) were on hemodialysis. 40 were diabetic, 9 were preoperatively on intra-aortic balloon pump, 16 were emergency, 27 had aortic valve replacement for aortic stenosis and 53 operations included coronary artery surgery. In-hospital mortality occurred in 9 (12.5%). Age (P = 0.047), preoperative serum albumin level (P = 0.042) and cardiopulmonary bypass time (P = 0.0009) were associated with in-hospital mortality. Patients were followed up for 2.3 ± 1.9 years (2 days – 6.6 years). Late death occurred in 15. Body weight (P = 0.037) and body surface area (P = 0.034) were associated with late death. Age (P = 0.028), body weight (P = 0.005), body surface area (P = 0.008), regional cerebral oxygen saturation (cerebral rSO2) measured with near-infrared spectroscopy after induction of anesthesia (P = 0.023) were associated with combined early and late death. Multivariate logistic regression analysis revealed that low cerebral rSO2 after induction of anesthesia and emergency surgery were associated with combined early and late death and that the cutoff value for rSO2 was 46% (OR 3.4, 95%CI 1.1–11.0).

CONCLUSION: Low cerebral rSO2 after induction of anesthesia and emergency operation were associated with poor outcome in patients on dialysis undergoing cardiac surgery. These factors can be used to trigger intensive early and late postoperative management in this patient group.