Functional and Angiography-Derived Strain Guided Multi-Vessel/Lesion Revascularization Strategy in Patients With Acute ST-Segment Elevation Myocardial Infarction (FAVOR V AMI)

The FAVOR V AMI study is a prospective, multicenter, blinded, randomized, sham-controlled trial comparing the long-term clinical outcome of the two PCI strategies, the FAST guided strategy (test group) versus standard treatment strategy (control group), in a high-risk population with STEMI and MVD who underwent successful primary PCI of the infarct-related artery. The primary endpoint is major adverse cardiac events (MACE), defined as a composite of all-cause death, myocardial infarction (MI), or ischemia-driven revascularization when the last patient reaches 6-month follow-up. The major secondary endpoint is cardiovascular death and MI when at least 395 total events have accrued. The study hypothesis is the FAST (μQFR+RWS) guided PCI strategy is superior to a standard treatment strategy by the primary and major secondary endpoint.

For the patients randomized to μQFR+RWS group, μQFR will be measured in all non-infarct related arteries containing any non-culprit lesion with visually-assessed percentage diameter stenosis (DS%) ≥50% and ≤90% with reference vessel diameter (RVD) ≥2.5 mm. If μQFR ≤0.80 or RWS ≥13%, PCI will be performed; if μQFR >0.80 and RWS <13%, the procedure will deferral; if DS% >90%, PCI should be performed without the need of μQFR or RWS. For all patients undergoing PCI, post-PCI μQFR measurement is recommended; if μQFR <0.90, if the reason is obvious post-dilation with a non-compliant balloon or bail-out stenting should be considered; if the reason is not obvious intravascular imaging should be considered. For the patients randomized to standard treatment group, PCI should be performed of all non-culprit lesions with visual DS% ≥70% in all non-infarct related arteries with RVD ≥2.5 mm; for a non-culprit lesion with visually DS% 50-70%, PCI can be performed if fractional flow reserve (FFR) ≤0.80 or instantaneous wave-free ratio (iFR) ≤0.89. All patients will be followed by either telephone or clinic visit at 1 month, 6 months,1 year, 2 years, 3 years, 4 years and 5 years.

The sample size will be about 5,000 using an event-driven sample calculation. An adaptive design will be implemented for sample size re-estimation when 90% of patients have been enrolled. All principal analyses will take place in the intention-to-treat (ITT) population. The primary and major secondary endpoints will be analyzed in prespecified subgroups, including age (≥65 vs. <65), sex (men vs. women), diabetes (yes vs. no), time from symptom onset to primary PCI (≤ vs. > median), planned number of NCLs for PCI in the control arm (0/1 vs. 2 vs. 3), infarct related artery (LM/LAD vs, others), untreated CTOs with RVD ≥2.5 mm in non-infarct related artery (yes vs. no), timing of elective PCI (same hospitalization as the emergency PCI vs. during an elective readmission), P2Y12 inhibitor therapy (Clopidogrel vs. Ticagrelor), treatment of any non-infarct lesion with DS >90% prior to randomization (yes vs. no), LVEF (echo post primary PCI, prior to randomization) (>40% vs. ≤40%), Killip Class (I vs. ≥II), lesion location of non-culprit lesion (LM/LAD vs. others), diseased vessels (two-vessel disease vs. LM/three-vessel disease), moderate or severe calcification in any NCL (yes vs. no), bifurcation lesion with planned main vessel and SB treatment in any NCL (yes vs. no), intravascular guidance during the randomized procedure (yes vs. no), μQFR grayzone (μQFR < 0.75 vs. = 0.75-0.85 vs. > 0.85 [by core laboratory]), μQFR-based functional SYNTAX score (FSSQFR, low tertile vs. mid tertile vs. high tertile [by core laboratory]), post-PCI μQFR (≥0.90 vs. <0.90 [by core laboratory]), angiography-derived IMR (≥2.5 mmHgs/cm vs. <2.5 mmHgs/cm [by core laboratory]), residual physiology pattern (PPG diffuse vs. local [by core laboratory]), μQFR-based residual functional SYNTAX score (rFSSQFR, 0 vs. ≥ 1 [by core laboratory]), learning experience of μQFR/RWS (first half vs. second half of enrolled cases in each center).