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Abstract: SA-PO143

AKI Risk Stratification in Cardiac Surgery Patients: Is SPARK Index an Option?

Session Information

Category: Acute Kidney Injury

  • 102 AKI: Clinical, Outcomes, and Trials

Authors

  • Koratala, Abhilash, University of Texas Health science center, San Antonio, Texas, United States
  • Bejjanki, Harini, University of Florida, Gainesville, Florida, United States
  • Alquadan, Kawther Farouk, University of Florida, Gainesville, Florida, United States
  • Ejaz, A. Ahsan, Centra Medical Group Nephrology Center, Farmville, Virginia, United States
Background

The Simple Postoperative AKI Risk (SPARK) index has been proposed as a preoperative AKI risk score for patients undergoing “non” cardiac surgery, which is a summation of the integer scores of the following variables: age, sex, expected surgery duration, emergency operation, diabetes mellitus, use of renin-angiotensin-aldosterone inhibitors, baseline eGFR, albuminuria hypoalbuminemia, anemia, and hyponatremia. Based on the score, 4 SPARK classes were defined, A, B, C and D in the order of increasing score/AKI risk. Since the index incorporates many of the risk factors common to cardiac surgery (CS) patient, albeit with major differences, we investigated its usefulness in this cohort.

Methods

We utilized data from a previously published study where we reported that serum uric acid (SUA) is an independent risk factor for AKI in patients undergoing CS. SPARK scores were calculated for all patients (N=190). Odds ratio (OR) for AKI was calculated and AUC of SPARK scores, preoperative SUA, creatinine (SCR) and eGFR were compared.

Results

SPARK class A (score <20), B (>20 to <40), C (>40 to <60) and D (>60) consisted of 18, 98, 45 and 9 patients, respectively. OR with CI95% and p-value for AKI were: raw SPARK score, 1.0 (1.0-1.0, 0.603); class A, 1.1 (0.8-1.4, 0.286); class B, 1.1 (2.0-1.2, 0.878); class C, 1.0 (0.9-1.1. 0.788); class D, unable to calculate due to small sample size. Pair-wise comparison of AUCs revealed significant differences between SUA and SCR (Z=3.6, <0.0003), GFR (Z=4.1, <0.0003) and SPARK score (Z=3.8, <0.0001). SPARK score did not demonstrate significant differences with GFR (Z=0.7=6, 0.552) or SCR (Z=1.2, 0.229). Receiver Operating Characteristics (ROC) curves shown in Figure 1.

Conclusion

Our data suggests that the SPARK Index is not a good predictor of AKI in CS where SCR, eGFR and SUA outperform its discriminatory capabilities and require only a single, cost-effective laboratory test.