Multicenter randomized trial and a systematic overview of lidocaine in acute myocardial infarction

Background More than 20 randomized trials and 4 meta-analyses have been con ducted on the use of prophylactic lidocaine in acute myocardial infarction (MI). The results suggest that lidocaine reduces ventricular fibrillation ( VF) hut increases mortality rates in acute MI. Methods and Results Patients with ST-elevation MI who were examined <6 hour s after symptom onset (n = 903) were randomly assigned to either lidocaine or no lidocaine and to either streptokinase and heparin or heparin alone. L idocaine was given as 4 boluses of 50 mg each every 2 minutes, then an infu sion of 3 mg/min for 12 hours, then 2 mg/min for 36 hours. We compared the incidence of in-hospital death and ventriculor arrhythmias. We then perform ed a meta analysis of prophylactic lidocaine in acute MI that included thes e and prior trial results. The rates of VF and death with and Without lidoc aine were calculated For each trial, then odds ratios (OR) with confidence intervals (Cl) were calculated for the risk of these events; overall with a nd without lidocaine. Patients given lidocaine in the randomized study had significantly less VF (2.0% vs 5.7% without lidocaine, P = .004) and a tren d toward increased mortality rates (9.7% vs 70%, P = .145). Metaanalysis re vealed nonsignificant trends toward reduced VF (OR 0.71,95% Cl 0.47 to 1.09 ) and increased mortality rates (OR 1.12, 95% Cl 0.91 to 1.36) with lidocai ne. Conclusions Lidocaine reduces VF but may adversely affect mortality rates. The routine use of prophylactic lidocaine in acute MI is not recommended.