2017 Cardiovascular Research Day Abstract Book

87
Perioperative high density lipoprotein particle changes and the risk of acute kidney injury
after cardiac surgery
Loren Smith, MD, PhD 1 • Derek Smith, PhD 2 • Alan Remaley, MD, PhD 3 • MacRae Linton, MD 4 •
Frederic Billings IV, MD 5
1Anesthesiology, Vanderbilt University Medical Center • 2 Biostatistics, Vanderbilt University
Medical Center • 3 National Heart, Lung, and Blood Institute, National Institutes of Health •
4Medicine and Pharmacology, Vanderbilt University Medical Center • 5 Anesthesiology and
Medicine, Vanderbilt University Medical Center
Faculty
Acute kidney injury (AKI) after cardiac surgery occurs in up to 30% of patients and increases the
risk of postoperative myocardial infarction and death. No effective treatments exist. Increased
intraoperative oxidative stress independently predicts AKI after cardiac surgery. High density
lipoproteins (HDL) have anti-oxidant capacity. We hypothesize that perioperative HDL cholesterol
concentration (HDL-C), HDL particle concentration (HDL-P) and HDL composition are associated
with the risk of postoperative AKI.
We analyzed data from a prospective, 393-subject trial of perioperative atorvastatin to prevent AKI
after cardiac surgery. Statin-using patients were randomized to placebo or 80mg atorvastatin the
morning of surgery and 40mg on postoperative day 1. Stain-naïve patients were randomized to
placebo or 80mg the day prior to surgery and 40mg daily thereafter during hospitalization. The
associations between 1) HDL-C, 2) small HDL particle concentration, and 3) the change in HDL-P
from anesthetic induction to postoperative day two with maximum serum creatinine change from
baseline in the first 48 postoperative hours were assessed using two-component latent variable
mixture models adjusted for known AKI risk factors. Regression analyses assessed interactions of
chronic statin use, perioperative atorvastatin treatment, and HDL-C on AKI risk. We quantified HDL
particle size by NMR Lipoprofile test in 90 subjects. HDL-C and HDL-P change over time were
assessed with mixed effects models adjusted for AKI risk factors. We quantified myeloperoxidase
(MPO) activity of apolipoprotein B-depleted serum in 30 subjects using a bioluminescence assay.
A higher preoperative HDL-C was independently associated with a decreased postoperative serum
creatinine change (p=0.02). The association between a high HDL-C and an attenuated increase in
serum creatinine was strongest in chronic statin-using patients (p=0.008) and was enhanced with
perioperative atorvastatin treatment (p=0.004) and increasing chronic statin dose (p=0.003). HDL-
C did not change during the perioperative period (p=0.60), however, HDL-P decreased (p