The effects of sodium-glucose transporter 2 inhibition on cardiac surgery-associated acute kidney injury: An open-label randomized pilot study

Background: Sodium-glucose transporter-2 (SGLT2) inhibitors reduced the incidence of acute kidney injury in large cardiovascular outcome trials in patients with chronic heart and kidney failure. Acute kidney injury is a common complication following cardiac surgery. We hypothesized that perioperative SGLT2 inhibition could reduce kidney injury after cardiac surgery, measured with the biomarker neutrophil gelatinase-associated (NGAL). Methods: In this open-label phase IV, randomized, parallel-group, pilot study, adult patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomized to receive either an SGLT2 inhibitor, empagliflozin (10 mg; oral) once daily, from three days before surgery until postoperative day two, or standard-of-care. The primary outcome was the between-group difference of serum NGAL on the second postoperative day. Moreover, other biomarkers for acute kidney injury were measured, including serum kidney injury molecule-1 (KIM-1), hypoxia-inducible factor-1 alpha (HIF-1α), and urine NGAL/Creatinine and KIM-1/Creatinine ratios. Additional outcomes included acute kidney injury incidence within the first seven days following cardiac surgery according to Kidney Disease: Improving Global Outcomes criteria and metabolic parameters, including ketone body concentrations and glycemic control. Results: Between March 2022 and April 2023, 55 patients were included (sex: 73 % male, age: 66 ± 10 years, BMI: 28 ± 4 kg/m², empagliflozin n = 25, control n = 30) in the intention-to-treat analysis. There were no significant between-group differences in serum and urine NGAL or KIM-1. However, empagliflozin significantly reduced the incidence of acute kidney injury (20 % vs 66.7 %; absolute difference 46.7 %, 95 % CI, −69.7 – -23.6; P < .001). A significant increase in serum HIF-1α after surgery was solely observed in the control group. We observed no between-group differences in the incidence of (euglycemic) ketoacidosis or hypoglycemic events. Conclusions: In this pilot study, perioperative SGLT2 inhibition was not associated with lower NGAL levels. We observed that SGLT2 inhibition reduced the incidence of acute kidney injury in this small study population. As the results of this pilot study are hypotheses-generating, further validation is needed in a large-scale, double-blind, placebo-controlled, randomized trial, which is currently ongoing.