Intravenous Beta Blockers in Primary PCI: New Hope for an Old Therapy
Primary percutaneous coronary intervention (PCI) is the preferred strategy of reperfusion for patients with ST-segment elevation myocardial infarction (STEMI). With contemporary PCI techniques and adjunctive pharmacological therapy, primary PCI restores optimal epicardial flow in as many as 95% of patients with STEMI.1 However despite remarkable improvement in the outcomes of patients with STEMI, mortality and morbidity remain significant.2 To further improve the efficacy of reperfusion, considerable efforts are being made on 2 fronts: development of systems to provide timely access to PCI for patients with STEMI in order to reduce time to reperfusion3 and investigation of therapies to minimize reperfusion injury (i.e., to render myocardial cells more resistant to detrimental effects of ischemia/reperfusion cycle).4 The restoration of blood flow to the ischemic myocardium is associated with reperfusion injury manifested as myocardial stunning, no-reflow, arrhythmias and myocardial hemorrhage. Experimental studies in animals suggest that reperfusion injury may account for up to 50% of the final infarct size.5 Despite decades of research, understanding of reperfusion injury remains elusive and remarkably little success has been achieved with translational research in cardioprotective therapeutics.6
- Received August 26, 2013.
- Accepted August 26, 2013.