Abstract: SA-PO014

Racial Differences in the Risk for AKI after Cardiac Surgery

Session Information

Category: Acute Kidney Injury

  • 003 AKI: Clinical and Translational

Authors

  • George, James F, University of Alabama at Birmingham , Birmingham, Alabama, United States
  • Xie, Rongbing, University of Alabama at Birmingham , Birmingham, Alabama, United States
  • Tresler, Margaret, University of Alabama at Birmingham , Birmingham, Alabama, United States
  • Kirklin, James K, University of Alabama at Birmingham , Birmingham, Alabama, United States
  • Agarwal, Anupam, University of Alabama at Birmingham, Birmingham, Alabama, United States
Background

The effects of race on developing AKI following cardiac surgery are unknown. To determine the extent of this disparity, we studied risk factors for AKI after cardiac surgery at a tertiary referral center.

Methods

AKI was defined using the KDIGO working group definition. Pre-op or baseline creatinine (CRE) was defined as the minimum value within 30 days before surgery. Post-op CRE was defined as the maximum value within 48 hours after surgery. Post-operative risk factors for AKI were determined using multivariable logistic analysis to predict the probability of AKI KDIGO stage >1.

Results

Among 5347 patients (pts) who underwent cardiac surgery between July 1, 2010 and December 31, 2015, the study included 2175 pts who had coronary artery bypass grafts (CABG, 1309, 60%), valve procedure (585, 27%), or combined CABG and valve procedures (279, 13%). The remaining
3172 pts were excluded due to concomitant other surgeries, assist devices, a prior dialysis, race other than black or white, death or discharge within 48 hours, or missing CRE values. 1791 of included pts were white (82%) and 382 were black (18%). 1589 pts were KDIGO=0, 522 were KDIGO=1, and 62 were KDIGO>=2. By multivariable analysis, factors predictive (p<0.001) of KDIGO stage >1 included black race (OR 1.57, p=0.0005), increased BMI at time of surgery (OR 1.02, p<0.0001), older age (OR 1.02, p<0.0001), higher number of diseased vessels (OR 1.21, p=0.0002), and mitral valve procedure (OR 2.05, p=0.0007). Mean pre-op CRE among blacks was 1.21 (0.9-1.3, 25th to 75th percentile) and 1.07 (0.8-1.2) in whites, a difference of 0.14 (p<0.0001). Mean post-op CRE among blacks was 1.45 (1.0-1.6) and 1.22 (0.9-1.4) in whites. Notably, the mean difference between post-op and pre-op CRE was significantly larger in blacks at 0.24 (0.0-0.3) versus 0.15 (0.0-0.3) in whites (p=0.0011). Review of Medicare billing data showed 53 (3%) whites and 20 (5%) blacks received a Nephrology consult during hospitalization (p=0.03). Only 16 (1%) of white and 9 (2%) of blacks required dialysis (p=0.02).

Conclusion

Black race was a significant risk factor for AKI after cardiac surgery, with blacks exhibiting larger increases in CRE after surgery. These results indicate that a larger, multicenter study examining race and AKI post-cardiac surgery is clearly warranted and tailored interventions to prevent AKI in blacks are needed.

Funding

  • Clinical Revenue Support