Instantaneous Wave-Free Ratio for the Assessment of Intermediate Left Main Coronary Artery Stenosis: Correlations With Fractional Flow Reserve/Intravascular Ultrasound and Prognostic Implications: The iLITRO-EPIC07 Study

Abstract

BACKGROUND:There is little information available on agreement between fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) in left main coronary artery (LMCA) intermediate stenosis. Besides, several meta-analyses support the use of FFR to guide LMCA revascularization, but limited information is available on iFR in this setting. Our aims were to establish the concordance between FFR and iFR in intermediate LMCA lesions, to evaluate with intravascular ultrasound (IVUS) in cases of FFR/iFR discordance, and to prospectively validate the safety of deferring revascularization based on a hybrid decision-making strategy combining iFR and IVUS.METHODS: Prospective, observational, multicenter registry with 300 consecutive patients with intermediate LMCA stenosis who underwent FFR and iFR and, in case of discordance, IVUS and minimal lumen area measurements. Primary clinical end point was a composite of cardiovascular death, LMCA lesion-related nonfatal myocardial infarction, or unplanned LMCA revascularization.RESULTS: FFR and iFR had an agreement of 80% (both positive in 67 and both negative in 167 patients); in case of disagreement (31 FFR+/iFR-and 29 FFR−/iFR+) minimal lumen area was ≥6 mm 2 in 8.7% of patients with FFR+ and 14.6% with iFR+. Among the 300 patients, 105 (35%) underwent revascularization and 181 (60%) were deferred according to iFR and IVUS. At a median follow-up of 20 months, major adverse cardiac events incidence was 8.3% in the defer group and 13.3% in the revascularization group (hazard ratio, 0.71 [95% CI 0.30-1.72]; P=0.45). CONCLUSIONS:In patients with intermediate LMCA stenosis, a physiology-guided treatment decision is feasible either with FFR or iFR with moderate concordance between both indices. In case of disagreement, the use of IVUS may be useful to indicate revascularization. Deferral of revascularization based on iFR appears to be safe in terms of major adverse cardiac events.

Fractional flow reserve and non-hyperemic indices: Essential tools for percutaneous coronary interventions

“…Considering the critical prognostic importance of left main (LM) stem disease and its difficult angiographic assessment, the revascularization of intermediate LM should be guided by FFR or intravascular imaging[ 44 ]. Generally, LM disease is frequently associated with other stenoses of the coronary artery tree.…”

“…In discordant FFR/iFR measurements, IVUS showed an MLA < 6 mm 2 in 69% of the cases of FFR+/iFR-, while in FFR-/iFR+ cases, 40% only had an MLA< 6 mm 2 . The patients deferred from revascularization with discordant hemodynamic measurements and a negative IVUS evaluation had a low incidence of MACE at follow-up, leading to an iFR-guided LMCA revascularization strategy combined with IVUS in the discordant cases (hybrid approach)[ 44 ].…”

“…The ILITRO-EPIC07 study showed that FFR and iFR had an average agreement of 80%, while IVUS was more likely to match FFR’s classification of stenosis significance in discrepant cases. Therefore, from a clinician's viewpoint, the best approach for determining if revascularization can be safely deferred in intermediate left main coronary artery lesions is a combination of IVUS and physiology[ 44 ].…”

Evidence-based Management of Left Main Coronary Artery Disease

“…In a prospective multicentre registry with 300 patients with intermediate LM stenosis, a deferred revascularisation guided by the instantaneous wave-free ratio (iFR) was feasible, but with moderate concordance with FFR (80%). [ 39 ] In cases of disagreement, IVUS was useful to indicate revascularisation. [ 39 ]…”

Compunction: The Present Tense of Physiology to Guide Coronary Revascularization in Severe Aortic Stenosis

“…1 Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are workhorse physiology tools in contemporary interventional cardiology for the assessment of intermediate-severity coronary atherosclerotic stenoses to guide revascularization (class I), 2,3 though discordance between iFR and FFR has been reported in up to 20% of patients. 4…”