FFR Versus Angiography-Guided Strategy for Management of AMI With Multivessel Disease

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.

(1) Inclusion Criteria

• Subject must be at least 19 years of age
• Acute ST-segment elevation myocardial infarction (STEMI) A. ※ STEMI: "ST-segment elevation ≥0.1 mV in ≥2 contiguous leads B. or documented newly developed left bundle-branch block "
• Acute non-ST-segment elevation myocardial infarction (NSTEMI)

A. ※ NSTEMI: NSTEMI is defined as a combination of criteria with mandated elevation of a cardiac biomarker, preferably high-sensitive cardiac troponin with at least one value above 99th percentile of the upper reference limit and at least one of the following:

• Symptoms of ischaemia.
• New or presumed new significant ST-T wave changes
• Development of pathological Q waves on electrocardiography (ECG).
• Imaging evidence of new or presumed new loss of viable myocardium or regional wall motion abnormality.
• Intracoronary thrombus detected on angiography.
• Primary percutaneous coronary intervention (PCI) in < 12 h after the onset of symptoms for STEMI patients (In case of NSTEMI, PCI should be performed within 72 hours of symptom onset)
• Multivessel disease (at least one stenosis of >50% in a non-culprit vessel ≥ 2.0 mm by visual estimation)
• Subject is able to verbally confirm understandings of risks, benefits and treatment alternatives of receiving invasive physiologic evaluation and PCI and he/she or his/her legally authorized representative provides written informed consent prior to any study related procedure.

(2) Exclusion criteria

• Severe stenosis with TIMI flow ≤ II of the non-IRA artery
• Unprotected left main coronary artery disease (stenosis > 50% by visual estimation)
• Non-IRA stenosis not amenable for PCI treatment by operators' decision)
• Chronic total occlusion in non-IRA
• Cardiogenic shock (Killip class IV) already at presentation or the completion of IRA PCI
• Intolerance to Aspirin, Clopidogrel, Plasugrel, Ticagrelor, Heparin, Bivaluridin, or Everolimus, Zotarolimus
• Known true anaphylaxis to contrast medium (not allergic reaction but anaphylactic shock)
• Pregnancy or breast feeding
• Non-cardiac co-morbid conditions are present with life expectancy <1 year or that may result in protocol non-compliance (per site investigator's medical judgment).
• Other primary valvular disease with severe degree: severe mitral regurgitation, mitral stenosis, severe aortic regurgitation, or aortic stenosis
• Patients with a history of Coronary Artery Bypass Graft (CABG) or treated with fibrinolytic Therapy
• Unwillingness or inability to comply with the procedures described in this protocol.