Frequency, correlates, and clinical implications of myocardial perfusion after primary angioplasty and stenting, with and without glycoprotein IIb/IIIa inhibition, in acute myocardial infarction.

Abstract

We sought to determine the prognostic importance of myocardial reperfusion after various contemporary interventional strategies in patients with acute myocardial infarction (AMI). The frequency, correlates, and clinical implications of myocardial perfusion after primary angioplasty in AMI have not been examined in a large-scale prospective study. Similarly, whether glycoprotein (GP) IIb/IIIa inhibitors and/or stents improve myocardial perfusion beyond balloon angioplasty has not been investigated. Tissue-level perfusion assessed by the myocardial blush grade was evaluated in 1,301 patients with AMI randomized to balloon angioplasty versus stenting, each with or without abciximab. Despite Thrombolysis In Myocardial Infarction flow grade 3 restoration in 96.1% of patients, myocardial perfusion was normal in only 17.4% of patients, reduced in 33.9%, and absent in 48.7%. Myocardial perfusion status post-coronary intervention stratified patients into three distinct risk categories, with 1-year mortality rates of 1.4% (normal blush), 4.1% (reduced blush), and 6.2% (absent blush) (p = 0.01). Among patients randomized to angioplasty, angioplasty + abciximab, stenting, and stenting + abciximab, normal myocardial perfusion was restored in 17.7%, 17.0%, 17.5%, and 17.6%, respectively (p = 0.95), which was associated with similar 1-year rates of mortality in patients randomized to stenting versus angioplasty (4.5% vs. 4.8%, p = 0.91) and abciximab versus no abciximab (4.3% vs. 5.0%, p = 0.63). Restoration of normal tissue-level perfusion is a powerful determinate of survival after primary PCI in AMI and is achieved in a minority of patients. Neither stents nor GP IIb/IIIa inhibitors significantly enhance myocardial perfusion compared to balloon angioplasty alone, underlying the similar long-term mortality with these different mechanical reperfusion strategies.