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 (> or =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 microV/min vs. 6,250 microV/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 STR in Proxis-treated patients, better STR 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).