Effect of two-session remote ischaemic preconditioning on myocardial injury after noncardiac surgery in patients undergoing abdominal surgery: randomised clinical trial.

Abstract

Myocardial injury after noncardiac surgery is associated with both short-term and long-term mortality. However, effective preventive strategies remain limited. Remote ischaemic preconditioning (RIPC) confers distinct early and delayed cardioprotection. We hypothesised that a two-session RIPC protocol, targeting both protective phases, would reduce the incidence of myocardial injury. In this prospective, two-centre, observer-blinded, randomised, sham-controlled trial, 766 patients undergoing abdominal surgery were allocated to either a RIPC intervention (four cycles of 5-min ischaemia/5-min reperfusion on the upper limb) or a sham procedure. RIPC was applied twice: 24 h before anaesthesia, and 1 h before anaesthesia. The primary outcome was the incidence of Myocardial Injury after Noncardiac Surgery (MINS), as defined by the American Heart Association. Secondary outcomes included total high-sensitivity cardiac troponin T release and a series of cardiovascular events. Among 766 randomised patients (median age 71 yr; 33.7% female), MINS occurred in 64/368 (17.4%) patients in the RIPC group and 66/368 (17.9%) in the control group (adjusted risk ratio 1.04; 95% confidence interval 0.76-1.41; P=0.808). No significant differences were observed in secondary cardiovascular outcomes between groups. Total high-sensitivity cardiac troponin T release within the first 3 postoperative days was higher in the RIPC group (median difference:32 ng L^-1 (95% confidence interval 12-52; P=0.002). In patients undergoing abdominal surgery, two-session RIPC did not reduce the incidence of MINS. The increased troponin release after RIPC warrants further investigation to determine its long-term clinical significance. NCT05733208.