Remote ischaemic preconditioning reduces myocardial injury in patients undergoing heart valve surgery: Randomised controlled trial

Abstract

Objective: To determine whether remote ischaemic preconditioning (RIPC) is cardioprotective in patients undergoing heart valve replacement. Design: Single-blinded, randomised controlled trial. Setting :Tertiary referral hospital in China. Patients: Adult patients (31-72 years) undergoing mitral valve, aortic valve or tricuspid valve surgery. Interventions: Patients were randomised to either the RIPC (n=38) or control (n=35) group. After induction of anaesthesia, patients in the RIPC group underwent three 5 min cycles of right upper limb ischaemia, induced by an automated cuff-inflator placed on the upper arm and inflated to 200 mm Hg. Each cycle was interrupted by a 5 min period of reperfusion during which time the cuff was deflated. The control group had only a deflated cuff placed on the upper arm for 30 min. Main outcome measures: Serum troponin I concentration was measured before surgery and at 6, 12, 24, 48, and 72 h postoperatively. The cardiac function of all patients was followed postoperatively. Results: Troponin I concentration was reduced in the RIPC group (398.7±179.3 μg/l) compared with the control group (708.4±242.5 μg/l). Mean difference was 309.7±50.8 (95% CI 210.1 to 409.3, p<0.0001). A greater improvement in postsurgical cardiac function was noted in the RIPC group than in the control group. Conclusions: These data indicate that RIPC reduces myocardial injury and improves cardiac function in patients undergoing heart valve surgery. Trial registration number: NCT01175681.