Phd in ANGIO-CARDIO-THORACIC PATHOPHYSIOLOGY AND IMAGING

Thesis title: Instantaneous wave-free ratio-guided revascularization of non-culprit lesions in patients with ST-elevation myocardial infarction and multivessel disease: the multicenter WAVE registry

Objectives: We aimed to describe clinical outcomes of a cohort of patients undergoing instantaneous wave-free ratio (iFR)-guided complete revascularization for ST-elevation myocardial infarction (STEMI) and multivessel coronary artery disease (MVD). Background: Complete revascularization of non-culprit lesions (NCL) is strongly recommended in patients with STEMI) and MVD, but no definitive evidence is available regarding which diagnostic strategy should be preferred, and iFR has never been investigated in this setting. Methods: Following primary percutaneous coronary intervention (PCI), consecutive patients with STEMI and intermediate NCL were enrolled in the WAVE study and destinated to an iFR-guided CR. NCL with iFR <0.89 underwent PCI while NCL with iFR >0.89 were deferred. Primary endpoint was NC target lesion failure (NC-TLF) and secondary endpoint were major adverse cardiovascular events (MACE), at one-year follow up. Results: Overall, 209 patients were enrolled (ischemic iFR <0.89=83; non-ischemic iFR>0.89=126). Patients with iFR <0.89 showed a higher prevalence of traditional cardiovascular risk factors and angiographically-determined three vessels disease. In the entire cohort, NC-TLF and MACE occurred in 6.7% and 10.5% of patients respectively. Compared to the deferred group, patients with iFR<0.89 experienced significantly higher rates of both NC-TLF (3.2% vs 12.1%; p=0.021) and MACE (7.1% vs 16.9%; p= 0.041). This result was mostly driven by increased rates of NC-TLF PCI and further revascularizations in this latter group, while no differences were evident in terms of non-fatal myocardial infarction or death. At multivariable analysis, the strongest predictor of MACE was symptom onset to balloon time [hazard ratio=1.17 (95% confidence interval: 1.04-1.31), p=0.008]). Conclusions: In STEMI and MVD iFR assessment is feasible and safe, and could represent a valid option to effectively select those NCL needing revascularization and safely deferring those that do not. Further randomized studies are however needed to confirm the WAVE study findings.