Comparison of Clinical Outcomes Between Fractional Flow Reserve-guided Strategy and Angiography-guided Strategy in Treatment of Non-Infarction Related Artery Stenosis in Patients With Acute Myocardial Infarction

The presence of ischemia is a prerequisite for the improvement of clinical outcomes with percutaneous coronary intervention (PCI). It is well-known that the discrepancy exists between angiographic stenosis severity and the presence of myocardial ischemia. This discrepancy cannot completely overcome with even more precise invasive imaging modalities such as intravascular ultrasound or optical coherence tomography.

Currently, fractional flow reserve (FFR) is regarded as a gold-standard invasive method to define lesion-specific ischemia and FFR-guided PCI has been proven to reduce unnecessary revascularization and to enhance patient's clinical outcomes. Therefore, current guidelines recommend FFR measurement for intermediate coronary stenosis when there is no definite evidence of lesion-specific ischemia.

However, previous evidences which well demonstrated the benefit of FFR-guided strategy were mostly generated from non-acute myocardial infarction patients.1, 3-5 Recently FAMOUS-NAMI trial evaluated 176 patients with acute non-ST elevation myocardial infarction (NSTEMI) with multivessel disease, and demonstrated feasibility of FFR measurement in acute NSTEMI patients and also presented that FFR-guided decision making for non-infarct related artery (IRA) stenosis was significantly reduced unnecessary stent implantation without any difference in major adverse cardiovascular events at 1-year as well as medical cost, compared with angiography-only guided decision making process.

Nevertheless, there have been no evidence in clinical setting of acute myocardial infarction (AMI). Since about 30-50% of patients with AMI possess multivessel disease, the ability to accurately assess the functional significance of non-IRA stenoses at the time of initial primary PCI would potentially facilitate revascularization decisions with potential for health and economic benefit. Moreover, avoiding unnecessary stent implantation for non-IRA stenoses in patients with AMI with multivessel disease would reduce the possibility of stent- or procedure related complications, and enhance long-term prognosis of patients.

Therefore, the FRAME-AMI trial will compare clinical outcomes after index primary PCI between FFR-guided strategy versus angiography only-guided strategy for management of non-IRA stenoses in AMI with multivessel disease patients.