Impact of Bisoprolol on Ventricular Arrhythmias in Experimental Myocardial Infarction

Following acute myocardial infarction (AMI), early use of beta-blockers (BBs) reduced the incidences of ventricular arrhythmia (VA) and death in the pre reperfusion era. However, some studies have reported a worsening of clinical outcomes and therefore, this study used a porcine model of AMI to evaluate the efficacy of bisoprolol on VAs and mortality. Twenty pigs were divided into two groups with one group using oral bisoprolol which was given for 3 hours before the experiment and then maintained for 7 days. A loop recorder was implanted, AMI was induced by balloon occlusion for 60 min, and then, reperfusion. One week later, the echocardiography and loop recorder data were analyzed in the surviving animals. Bisoprolol did not increase the heart rate (62.9±14.5 vs 79.0±20.3; p=0.048), lower the rate of premature ventricular contractions (PVC) (0.8±0.8 vs 11.0±12.8; p=0.021) or tend to lower recurrent VA (0.6±0.5 vs 1.1±1.1; p=0.131) during coronary artery occlusion. After reperfusion, bisoprolol did reduce VA in the early AMI period (0.1±0.3 vs 4.2±4.6; p=0.001) and it was not associated with the extent of myocardial recovery. In this porcine model, early oral bisoprolol might help reduce the incidences of PVC and recurrent VA and determine whether effects are more pronounced during the early AMI period. Our results suggest that bisoprolol might help reduce lethal VA and cardiac death following AMI in this reperfusion era.