Outcomes in Dialysis-Dependent Indigenous and Non-Indigenous Patients Undergoing Cardiac Surgery at Townsville University Hospital

PURPOSE:Dialysis-dependent patients have a high risk of cardiovascular death but also a high risk for perioperative mortality in cardiac surgery. Our study examined surgical complications and mortality in Indigenous and non-Indigenous dialysis-dependent patients undergoing cardiac surgery at a single centre. METHODOLOGY:The retrospective study reviewed 72 consecutive dialysis-dependent patients who underwent cardiac surgery between 2008 and 2018. Data was prospectively collected, and follow-up was obtained from physicians and general practitioners. Multivariable analysis was performed to determine predictors of mortality. RESULTS:The median age of Indigenous Australian patients was 60 years, compared with 65 years for non-Indigenous patients. Indigenous Australian patients had a significantly higher rate of return to theatre (43% versus 17%). The predominant reason for return to theatre for the whole cohort was postoperative bleeding (n=16, 22%). The overall early mortality rate was 10%. There were 35 late deaths (49%) and overall survival at 5 years was 40.92±6.8% (95% CI: 28-54%). History of arrhythmia (p=0.019) was a significant risk factor for mortality, whilst patients who underwent isolated coronary artery bypass grafting (p=0.004), and those who received internal mammary artery grafts (p=0.021) had a reduced hazard ratio for mortality. The median follow-up time was 29 months (IQR 10-52 mo). CONCLUSION:Dialysis-dependent Indigenous Australian patients present younger for cardiac surgery, with a higher prevalence of co-morbid diabetes and more extensive coronary artery disease. There was no statistically significant difference in early or late mortality between Indigenous and non-Indigenous patients. However, there was a higher rate of return to theatre amongst the Indigenous Australian cohort.