Distal Myocardial Protection During Percutaneous Coronary Intervention With an Intracoronary β-Blocker

Abstract

Background— Experimental studies have demonstrated that intravenous β-blocker administration before coronary artery occlusion significantly reduces myocardial injury. Clinical studies have shown that intracoronary (IC) propranolol administration before percutaneous coronary intervention (PCI) delays myocardial ischemia. The present study tested the hypothesis that IC propranolol treatment protects ischemic myocardium from myocardial damage and reduces the incidence of myocardial infarction (MI) and short-term adverse outcomes after PCI. Methods and Results— Patients undergoing PCI (n=150) were randomly assigned in a double-blind fashion to receive IC propranolol (n=75) or placebo (n=75). Study drug was delivered before first balloon inflation via an intracoronary catheter with the tip distal to the coronary lesion. Biochemical markers were evaluated through the first 24 hours and clinical outcomes to 30 days. Evidence of MI with creatine kinase–MB elevation after PCI was seen in 36% of placebo and 17% of propranolol patients ( P =0.01). Troponin T elevation was seen in 33% of placebo and 13% of propranolol patients ( P =0.005). At 30 days, the composite end point of death, postprocedural MI, non–Q-wave MI after PCI hospitalization, or urgent target-lesion revascularization occurred in 40% of placebo versus 18% of propranolol patients (hazard ratio 2.14, 95% CI 1.24 to 3.71, P =0.004). Conclusions— IC administration of propranolol protects the myocardium during PCI, significantly reducing the incidence of MI and improving short-term clinical outcomes.