Randomized Comparison of Primary Percutaneous Coronary Intervention With Combined Proximal Embolic Protection and Thrombus Aspiration Versus Primary Percutaneous Coronary Intervention Alone in ST-Segment Elevation Myocardial Infarction The PREPARE (PRoximal Embolic Protection in Acute myocardial infarction and Resolution of ST-Elevation) Study

Objectives The purpose of this study was to evaluate the effectiveness of combined proximal embolic protection with thrombus aspiration (Proxis Embolic Protection System [St. Jude Medical, St. Paul, Minnesota]) in ST-segment elevation myocardial infarction patients. Background Embolization during primary percutaneous coronary intervention (PCI) may result in microvascular obstruction, reduced myocardial perfusion, and impaired prognosis. Methods Two hundred eight-four patients were randomized to primary PCI with the Proxis system versus primary PCI alone after angiography. The primary end point was the occurrence of complete (>= 70%) ST-segment resolution (STR) at 60 min measured by continuous ST-segment Holter. Results There was no significant difference in the occurrence of the primary end point (80% vs. 72%, p = 0.14). However, immediate complete STR (at time of last contrast) occurred in 66% of Proxis-treated patients and 50% in control patients (absolute difference, 16.3%; 95% confidence interval: 4.3% to 28.2%; p = 0.009). A significant lower ST-segment curve area (0 to 3 h after primary PCI) was observed in the Proxis arm (5,192 mu V/min vs. 6,250 mu V/min, p = 0.037). Major adverse cardiac and cerebral events at 30 days occurred with similar frequency in both groups (6 vs. 10). Conclusions There was no significant difference in complete STR at 60 min in this proof-of-concept study. However, we observed a significant difference in immediate complete SIR in Proxis-treated patients, better SIR at later time points, and a reduction of electrocardiogram injury current over time, compared with control patients. The results suggest that primary PCI with the Proxis system may lead to better immediate microvascular flow in ST-segment elevation myocardial infarction patients. (The PREPARE Study; ISRCTN71104460) (J Am Coll Cardiol Intv 2009;2:934-43) (c) 2009 by the American College of Cardiology Foundation