Effects of Remote Ischaemic Pre-conditioning in Patients undergoing Off-pump Coronary Artery Bypass Grafting Procedure: A Randomised Controlled Study

Introduction: Remote Ischaemic Pre-conditioning (RIPC) is a simple, non invasive, cost-effective intervention using brief cycles of limb ischaemia/reperfusion that may reduce Perioperative Myocardial Injury (PMI) in patients undergoing Coronary Artery Bypass Grafting (CABG) surgery. Aim: To study the effects of remote ischaemic pre-conditioning in cardiac patients undergoing off-pump CABG procedure. Materials and Methods: A double-blinded, randomised controlled study was conducted at the Department of Anaesthesiology, SRM Medical College Hospital and Research Centre, Tamil Nadu, India from November 2023 to July 2024. Among a total of 140 patients, 69 patients received RIPC (group A), and 71 patients were free of RIPC (group B). Total of 134 patients were included for final analysis. Preoperatively, the patient's routine laboratory investigations, including cardiac Troponin I (cTnI), were measured. cTnI is the primary endpoint used here to assess PMI. Post-procedure, the patient's cTnI level as well as the renal function tests were evaluated at 24, 48, and 72 hours (hrs). Secondary endpoints included short-term clinical outcomes. The Student’s t-test, and Pearson’s Chisquared test were used, and p-values<0.05 were considered statistically significant. Results: The groups were comparable concerning demographic data and baseline haemodynamic parameters. Compared with the control group B at 24, 48, and 72 hrs, the cTnI was shown to be lower in the RIPC group throughout the trial (1.66±2.02, 2.52±1.92, 2.34±1.85, p-value: 0.001, 0.001, and 0.001, respectively). Acute renal injury was measured by comparing serum creatinine levels at 24, 48, and 72 hours, which were lower in the RIPC group A (1.07±0.44, 1.06±0.48, 1.08±0.48, p values: 0.001, 0.001, and 0.001, respectively). Conversely, the RIPC group remained a shorter stay in the Intensive Care Unit (ICU) (p-value <0.0001). Conclusion: Remote ischaemic pre-conditioning in off-pump CABG procedure has been shown to reduce the severity of perioperative myocardial injury, as evidenced by lower cTnI levels at 24, 48, and 72 hrs post-intervention. RIPC also reduced the incidence of acute kidney injury, resulting in consistently lower serum creatinine levels. Additionally, patients in the RIPC group had a significantly shorter ICU, suggesting improved postoperative recovery