The clinical utility of remote ischemic preconditioning in protecting against cardiac surgery-associated acute kidney injury: A pilot randomized clinical trial

Abstract

Background: Cardiac surgery-associated acute kidney injury (CSA-AKI) is a well-known, serious complication and a well-recognized independent risk factor for higher morbidity and mortality among patients undergoing cardiac surgery.

Objectives: The aim of the study was to assess the efficacy of remote ischemic preconditioning (RIPC) in reducing the incidence of CSA-AKI, measured with the standard creatinine technique and using neutrophil gelatinase-associated lipocalin (NGAL) serum concentrations as a potential new biomarker of kidney damage. The ethics committee of the Medical University of Lodz prospectively approved the protocol (approval No. RNN/286/13/KE). The study was retrospectively registered with the U.S. National Institutes of Health - NIH (29 June 2017; ClinicalTrials.gov identifier: NCT03205410).

Material and methods: We conducted a prospective single-center double-blind randomized and controlled tudy. Data was collected from patients admitted to the Cardiosurgery Clinic at the Medical University of Lodz (Poland) between January and December 2014, scheduled for elective cardiac surgery (an off-pump coronary artery bypass). A total of 28 patients were randomized to receive either RIPC (n = 14) or sham RIPC (n = 14). After the induction of anesthesia, the patients assigned to the RIPC group underwent 3 cycles of five-minute inflation to 200 mm Hg and five-minute deflation of the upper-arm cuff. The control group had a deflated cuff placed on the upper arm for 30 min. The authors measured the patients' serum creatinine concentration to check for the occurrence of a CSA-AKI within 48 h after cardiac surgery, and NGAL serum concentration to check its level within 3 h after the operation.

Results: Fewer patients in RIPC group developed CSA-AKI within 48 h after cardiac surgery than in the control group (29% vs 93%; p = 0.003). Fewer patients in the RIPC group presented an increase in NGAL 3 h after surgery (medians: 124 vs 176.7; p = 0.0003).

Conclusions: In patients undergoing an off-pump coronary artery bypass, RIPC significantly reduces the occurrence of CSA-AKI and protects against increased postoperative NGAL levels.

Keywords: cardiac surgery-associated acute kidney injury; neutrophil gelatinase-associated lipocalin; remote ischemic preconditioning.