Remote ischaemic preconditioning reduces myocardial injury in patients undergoing heart valve surgery: randomised controlled trial
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\pm179.3 μg/l) compared with the control group (708.4\pm242.5 μg/l). Mean difference was 309.7\pm50.8 (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.