Randomized Comparison of Distal Protection Versus Conventional Treatment in Primary Percutaneous Coronary Intervention

OBJECTIVES: The purpose of this study was to evaluate the use of distal protection during percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) in native coronary vessels. BACKGROUND: Embolization of material from the infarct-related lesion during PCI may result in impaired myocardial perfusion and worsen the prognosis. Previous attempts to protect the microcirculation during primary PCI have had conflicting results. METHODS: We randomly assigned 626 patients with STEMI referred within 12 h to have PCI performed with (n = 312) or without (n = 314) distal protection. The primary end point was complete (>or=70%) ST-segment resolution detected by continuous ST-segment monitoring. Blood levels of troponin-T and creatine kinase-MB were monitored before and after the procedure, and echocardiographic determination of the left ventricular wall motion index (WMI) was performed before discharge. RESULTS: Patients were well matched in terms of demographic and angiographic baseline characteristics. There was no significant difference in the occurrence of the primary end point (76% vs. 72%, p = 0.29), no difference in maximum troponin-T (4.8 microg/l and 5.0 microg/l, p = 0.87) or maximum creatine kinase-MB (185 microg/l and 184 microg/l, p = 0.99), and no difference in median WMI (1.70 vs. 1.70, p = 0.35). The rate of major adverse cardiac and cerebral events (MACCE) 1 month after PCI was 5.4% with distal protection and 3.2% with conventional treatment (p = 0.17). CONCLUSIONS: The routine use of distal protection by a filterwire system during primary PCI does not seem to improve microvascular perfusion, limit infarct size, or reduce the occurrence of MACCE.