P. D. Kohtz1, B. R. Griffin2, S. Faubel2, S. Ambruso2, J. Teixeira2, M. Bronsert3, M. Wells1, C. Matter1, M. J. Weyant1, T. Reece1, J. D. Pal1, D. A. Fullerton1, J. C. Cleveland1, M. Aftab1 1University Of Colorado Denver,Cardiothoracic Surgery,Aurora, CO, USA 2University Of Colorado Denver,Division Of Nephrology,Aurora, CO, USA 3University Of Colorado Denver,Adult And Child Consortium For Health Outcomes Research And Delivery Science And Surgical Outcomes And Applied Research,Aurora, CO, USA
Objective: Patients with End Stage Renal Disease (ESRD) requiring hemodialysis are increasing worldwide. Cardiac surgery is reluctantly offered to these patients. ESRD is an established risk factor for patients undergoing surgery requiring cardiopulmonary bypass. Acute Kidney Injury (AKI) after cardiac surgery leads to a significant increase in post-operative mortality and morbidity. The objective of this study is to evaluate the influence of ESRD on post-operative outcomes. We further compared adjusted complications rates in ESRD patients to matched counterparts without any kidney disease, as well as to those who develop severe AKI following cardiac surgery.
Method: Using our local STS database from 2011-2016, we identified 2,536 surgical cases, of which 1,584 met inclusion criteria (Figure 1A).Within this group, 35 patients had ESRD at the time of surgery and 102 patients developed severe AKI (doubling of creatinine) following surgery. We performed unadjusted, multivariate, and propensity matched analyses comparing ESRD patients to those without renal injury and those who developed severe AKI following surgery. A 2:1 greedy match was used. All statistical tests were considered to be significant at a 2-sided p < .05.
Results: The in-hospital mortality was 2.9%. vs 2.5% (p = 0.9) in patients with and without ESRD. On bivariate analysis, there were no significant differences in preoperative cardiogenic shock (p=0.5), mean Charlson comorbidity index (p=0.9) and cardiopulmonary bypass time (p=0.7) between the groups. In both models, propensity matching was successful, as defined by standard error values < 0.1 in all variables. There was no difference in propensity matched post-surgical infection (p=0.46), intensive care unit (ICU) length of stay (p=0.77), or 30-day readmission rate (p=0.58) in the ESRD patients compared to those with normal renal function. When compared to patients with severe AKI following surgery, on propensity-matched analysis, ESRD patients had dramatically lower risks of post-surgical infection (p=0.005) and ICU LOS (p=0.03) (Figure 1B-C). Median follow up of ESRD group was 21.5 months (Range: 1-71 months) and 5-year KM-estimated survival for ESRD patients was 61% (Figure 1D).
Conclusion: In dialysis dependent patients with ESRD, major cardiac surgery procedures can be performed with acceptable perioperative risks and early mortality. There is no significant difference in post-surgical complications compared to those with normal renal function or post-operative AKI. ESRD patients had much lower rates of infections and ICU length of stay compared to those who developed severe post-operative AKI following surgery.
