FLOW Evaluation to Guide Revascularization in Multi-vessel ST-elevation Myocardial Infarction

Although current guidelines recommend fractional flow reserve (FFR) to identify haemodynamically relevant coronary lesion(s) in stable patients when evidence of ischaemia is not available (Class I, Level of Evidence: A), no published study has assessed the usefulness of FFR to guide percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI) patients with multi-vessel disease (MVD).

The main objective of this study is to determine whether, in STEMI patients with MVD amenable to PCI, the use of FFR in addition to angiography will improve cardiovascular outcomes, compared with the current practice of angiography- guided PCI, by improving the appropriateness of revascularisations by assessing the relevance of non-culprit lesions in the context of STEMI with multivessel coronary artery disease.

The secondary objective is to assess the safety and the cost-effectiveness of the FFR-guided strategy compared to the angiography-guided strategy.

The optimal revascularisation strategy in STEMI patients with MVD is currently debated. Recent data suggest that MV-PCI may be the most appropriate option for treating such patients. Consequently, the real challenge becomes to define what MVD is, in the context of acute MI, in order to limit revascularisation by PCI to vessels that truly need it. Visual estimation of the degree of coronary stenoses is a poor indicator of their haemodynamic severity. FFR is precisely designed and recommended in current guidelines to provide objective guidance for the functional assessment of lesion severity during coronary angiography in stable patients, but it has not been validated in STEMI patients with MVD. The purpose of the present trial will therefore be to investigate the relevance of FFR to guide the revascularisation management of patients at the acute stage of STEMI.

STEMI patients with successful culprit lesion PCI (primary, rescue or pharmaco-invasive) and ≥ 50% diameter stenosis by visual estimate, in which revascularization is contemplated and judged amenable to PCI in at least one additional non-culprit lesion will be randomized into two groups: angiography-guided PCI or FFR-guided PCI.

If the patient is randomized to the angiography-guided PCI, all the lesions indicated beforehand will be treated. If the patient is randomized to the FFR-guided PCI, measurements of FFR of non-infarct related lesion(s) will be performed and only those lesions with a FFR ≤ 0.80 will be treated.

The use of drug-eluting stents is encouraged in both strategies. All patients will receive optimal medical therapy (including dual antiplatelet therapy, beta-blockers, statins, ACE-I or ARB) as recommended in international guidelines in both strategies.

Clinical follow-up will be performed at discharge, 30-day, 6 month and one-year. Rates of major adverse cardiac events, functional class and number of anti-anginal medications used will be collected. If the patient has been rehospitalized since index hospital discharge, the discharge summary and all relevant information will be collected.

Eligibility Criteria:
Inclusion Criteria:

* STEMI patients ≥ 18 years old with successful culprit lesion PCI (primary, rescue or pharmaco-invasive) and ≥ 50% stenosis judged amenable to PCI in at least one additional non-culprit lesion
* Written informed consent

Exclusion Criteria:

* Patients with cardiogenic shock (SBP \< 90 mmHg with clinical signs of low output or patients requiring inotropic agents)
* Patients with MVD referred to surgery for CABG or treatment of acute complications (e.g. ventricular septal rupture)
* Patients with one-vessel disease
* Previous coronary bypass surgery
* Extremely tortuous, calcified coronary vessels or chronic total occlusion (CTO)
* Life expectancy \< 2 years
* Patients with known hypersensitivity to adenosine
* Pregnancy
* Participation in another interventional therapeutic study at the same time or within 3 months prior to the beginning of the present study