Contemporary outcomes of rescue percutaneous coronary intervention for acute myocardial infarction: Comparison with primary angioplasty and the role of distal protection devices (EMERALD trial)

Background The value of distal protection devices during rescue PCI has not been studied. Methods The population enrolled in a prospective, randomized multicenter trial of distal microcirculatory protection in ST-elevation MI, was stratified for those undergoing rescue (n = 93) or primary (n = 408) PCI; we performed the prespecified comparisons of distal protection in rescue and primary PCI. Results Compared to primary PCI, rescue patients had higher baseline rates of TIMI-3 flow, but lower rates of post PCI TIMI-3 flow. However, no differences in the primary endpoints of complete ST-segment resolution (STR) at 30 minutes or infarct size, or 6 month mortality were present. In rescue PCI patients, randomization to distal protection did not significantly affect infarct size, STR, mortality or other clinical events. Conclusion Despite reduced rates of post-procedural TIMI-3 flow, patients undergoing rescue PCI compared to primary PCI have similar myocardial perfusion, infarct size and clinical outcomes. Distal protection did not offer any detectable benefit in this patient population.