cqvip:Context: Atheromatous and thrombotic embolization during percutaneous coronary intervention (PCI) in acute myocardial infarction is common and may result in m icrocirculatory dysfunction, the prevention of which may improve reperfusion suc cess, reduce infarct size, and enhance event-free survival. Objective: To deter mine whether protection of the distal microcirculation from thromboembolic debri s liberated during primary PCI results in improved reperfusion and decreased inf arct size.Design, Setting, and Patients: Prospective randomized controlled trial at 38 academic and community-based institutionsin 7 countries enrolling 501 pa tients aged 18 years or older with ST-segment elevation myocardial infarction(S TEMI) presenting within 6 hours of symptom onset and undergoing primary PCI or r escue intervention after failed thrombolysis. Interventions: Patients were rando mized between May 20, 2002, and November 21, 2003, to receive PCI with a balloon occlusion and aspiration distal microcirculatory protection system vs angioplas ty without distal protection. Main Outcome Measures:Coprimary end points were ST -segment resolution(STR) measured 30 minutes after PCI by continuous Holter mon itoring and infarct size measured by technetium Tc 99m sestamibi imaging between days 5 and 14. Secondary end points included major adverse cardiac events. Resu lts: Among 252 patients assigned to distal protection, aspiration was performed in 97%(242/251), all angioplasty balloon inflations were fully protected in 79 %(193/245), and visible debris was retrieved from 73%(182/250). Complete STR w as achieved in a similar proportion reperfused with vs without distal protection (63.3%[152/240] vs 61.9%[148/239], respectively; absolute difference,1.4%[95 %confidence interval, -7.7%to 10.5%;P = .78]), and left ventricular infarct size was similar in both groups (median, 12.0%[n = 229] vs 9.5%[n = 208],respe ctively; P = .15). Major adverse cardiac events at 6 months occurred with simila r frequency in the distal protection and control groups (10.0%vs 11.0%, respec tively;P = .66). Conclusions: A distal balloon occlusion and aspiration system e ffectively retrieves embolic debris in most patients with acute STEMI undergoing emergent PCI.Nonetheless, distal embolic protection did not result in improved microvascularflow, greater reperfusion suc cess,reduced infarct size, or enhanced event-free survival.
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