Kidney Week

Abstract: FR-PO075

Platelet Count Is a Novel Independent Predictor of Major Adverse Kidney Events

Session Information

• AKI: Epidemiology, Risk Factors, Prevention
  November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 101 AKI: Epidemiology‚ Risk Factors‚ and Prevention

Authors

• Park, Isabel, Brigham and Women's Hospital, Boston, Massachusetts, United States

Isabel Park,

• Short, Samuel, University of Vermont College of Medicine, Burlington, Vermont, United States

Samuel Short,

• Thomas, Charlotte, Brigham and Women's Hospital, Boston, Massachusetts, United States

Charlotte Thomas,

• Kim, Helena, Brigham and Women's Hospital, Boston, Massachusetts, United States

Helena Kim,

• Ali, Rafia W., Brigham and Women's Hospital, Boston, Massachusetts, United States

Rafia W. Ali,

• Leaf, David E., Brigham and Women's Hospital, Boston, Massachusetts, United States

David E. Leaf,

Background

Thrombocytopenia is associated with increased mortality in patients with established acute kidney injury (AKI). We investigated whether lower platelet count is independently associated with incident AKI.

Methods

We performed a retrospective cohort study in two groups of patients: those admitted to the ICU (n=71,749) and those who underwent cardiac surgery (CS; n=21,981) at two academic medical centers in Boston, MA between 2005 and 2018. Patients with end-stage kidney disease and those who already had AKI at study entry were excluded. The primary exposure was platelet count, assessed on ICU admission and preoperatively in the ICU and CS cohorts, respectively. Platelet count was assessed categorically (<30, 30–49, 50–99, 100–149, 150–450, and >450 x 10⁹/L in the ICU cohort, and <100, 100–149, 150–450, and >450 x 10⁹/L in the CS cohort). In both cohorts, platelet counts of 150–450 x 10⁹/L served as the reference group. The primary outcome was Major Adverse Kidney Events within 7 days (MAKE7) following ICU admission or CS, defined as doubling of creatinine, dialysis, or death. We used multivariable logistic regression to adjust for confounders.

Results

In both the ICU and CS cohorts, we observed a monotonic increase in risk of MAKE7 with platelet counts below the reference range of 150–450 x 10⁹/L. In the ICU cohort, patients with a platelet count <30 vs. 150–450 x 10⁹/L had a 3.58-fold (95% CI, 3.05–4.19) higher risk of MAKE7 in fully adjusted models (Figure 1A). In the CS cohort, patients with a platelet count <100 vs. 150–450 x 10⁹/L had a 2.28-fold (95% CI, 1.62–3.22) higher risk of MAKE7 in fully adjusted models (Figure 1B).

Conclusion

Lower platelet count is strongly and independently associated with a higher risk of MAKE7 in patients admitted to the ICU and in those undergoing CS.