Vessel fractional flow reserve-based non-culprit lesion reclassification in patients with ST-segment elevation myocardial infarction: Impact on treatment strategy and clinical outcome (FAST STEMI I study)

Background: Complete revascularization in patients with ST-segment elevation myocardial (STEMI) improves clinical outcome. Vessel fractional flow reserve (vFFR) has been validated as a non-invasive physiological technology to evaluate hemodynamic lesion significance without need for a dedicated pressure wire or hyperemic agent. This study aimed to assess discordance between vFFR reclassification and treatment strategy in intermediate non-culprit lesions of STEMI patients and to assess the clinical impact of this discordance. Methods: This was a single-center, retrospective cohort study. From January 2018 to December 2019, consecutive eligible STEMI patients were screened based on the presence of a non-culprit vessel with an intermediate lesion (30–80% angiographic stenosis) feasible for offline vFFR analysis. The primary outcome was the percentage of non-culprit vessels with discordance between vFFR and actual treatment strategy. The secondary outcome was two-year vessel-oriented composite endpoint (VOCE), a composite of vessel-related cardiovascular death, vessel-related myocardial infarction, and target vessel revascularization. Results: A total of 441 patients (598 non-culprit vessels) met the inclusion criteria. Median vFFR was 0.85 (0.73–0.91). Revascularization was performed in 34.4% of vessels. Discordance between vFFR and actual treatment strategy occurred in 126 (21.1%) vessels. Freedom from VOCE was higher for concordant vessels (97.5%) as compared to discordant vessels (90.6%)(p = 0.003), particularly due to higher adverse event rates in discordant vessels with a vFFR ≤0.80 but deferred revascularization. Conclusions: In STEMI patients with multivessel disease, discordance between vFFR reclassification and treatment strategy was observed in 21.1% of non-culprit vessels with an intermediate lesion and was associated with increased vessel-related adverse events.