Impact of intravenous lidocaine on myocardial injury after off-pump coronary artery surgery

Abstract

Lidocaine has been demonstrated to exert cardioprotective effects against myocardial ischaemia and reperfusion injury. We evaluated whether a continuous i.v. infusion of lidocaine reduced myocardial injury in patients undergoing off-pump coronary artery bypass graft surgery (OPCAB). In this randomized, double-blinded trial, 99 patients received i.v. lidocaine 2% (i.e. a 1.5 mg kg(-1) bolus at induction of anaesthesia followed by a 2.0 mg kg(-1) h(-1) infusion intraoperatively) or an equal volume of saline. Serum creatine kinase-myocardial band (CK-MB) and troponin I (TnI) concentrations were measured before surgery, upon arrival in the intensive care unit, and at 6, 24, 48, and 72 h after surgery. Cardiac enzymes, other biological markers, and rate of postoperative adverse events were compared between the groups. The median (25-75% inter-quartile range) TnI [0.90 (0.43-1.81) vs 1.71 (0.88-3.02) ng ml(-1), P=0.027] and CK-MB [6.5 (3.9-12.3) vs 9.8 (6.0-18.6) ng ml(-1), P=0.005] concentrations 24 h after surgery were significantly lower in the lidocaine group than in the control group. Moreover, lidocaine infusion reduced the total area under the curve of TnI and CK-MB release after surgery by 42% and 27%, respectively, compared with control. Continuous i.v. infusion of lidocaine during surgery reduces myocardial injury in patients undergoing OPCAB.