Background—: The nonculprit lesion (NCL) management in ST-segment–elevation myocardial infarction patients with multivessel disease is debated. We sought to assess whether quantitative flow ratio (QFR), a noninvasive tool to identify potentially flow-limiting lesions, may be reliable in this scenario. Methods and Results—: The present proof-of-concept study is based on a 3-step process: (1) identification of the QFR reproducibility in NCLs assessment (cohort A, n=31); (2) prospective validation of QFR diagnostic accuracy in respect to fractional flow reserve (cohort B, n=45); and (3) investigation of long-term clinical outcomes of NCLs stratified according to QFR (cohort C, n=110). A blinded core laboratory computed QFR values for all NCLs. Cohort A showed a good correlation and agreement between QFR values at index (acute) and at staged (subacute, 3–4 days later) procedures ( r =0.98; 95% confidence interval, 0.96–0.99; mean difference, 0.004 [−0.027 to 0.34]). The inter-rater agreement was κ=0.9. In cohort B, fractional flow reserve and QFR identified 16 (33%) and 17 (35%) NCLs potentially flow limiting. Sensitivity, specificity, negative, and positive predictive values were 88%, 97%, 94%, and 94%. The area under the receiver operating characteristics curve was 0.96 (95% confidence interval, 0.89–0.99). Finally, in cohort C, we identified 110 ST-segment–elevation myocardial infarction patients where at least 1 NCL was left untreated. Patients with NCLs showing a QFR value ≤0.80 were at higher risk of adverse events (hazard ratio, 2.3; 95% confidence interval, 1.2–4.5; P =0.01). Conclusions—: In a limited and selected study population, our study showed that QFR computation may be a safe and reliable tool to guide coronary revascularization of NCLs in ST-segment–elevation myocardial infarction patients.

BACKGROUND: Diffuse coronary artery disease affects the safety and efficacy of percutaneous coronary intervention (PCI). Pathophysiologic coronary artery disease patterns can be quantified using fractional flow reserve (FFR) pullbacks incorporating the pullback pressure gradient (PPG) calculation. This study aimed to establish the capacity of PPG to predict optimal revascularization and procedural outcomes. METHODS: This prospective, investigator-initiated, single-arm, multicenter study enrolled patients with at least one epicardial lesion with an FFR ≤0.80 scheduled for PCI. Manual FFR pullbacks were used to calculate PPG. The primary outcome of optimal revascularization was defined as an FFR ≥0.88 after PCI. RESULTS: A total of 993 patients with 1044 vessels were included. The mean FFR was 0.68±0.12, PPG 0.62±0.17, and the post-PCI FFR was 0.87±0.07. PPG was significantly correlated with the change in FFR after PCI (r=0.65 [95% CI, 0.61–0.69]; P <0.001) and demonstrated excellent predictive capacity for optimal revascularization (area under the receiver operating characteristic curve, 0.82 [95% CI, 0.79–0.84]; P <0.001). FFR alone did not predict revascularization outcomes (area under the receiver operating characteristic curve, 0.54 [95% CI, 0.50–0.57]). PPG influenced treatment decisions in 14% of patients, redirecting them from PCI to alternative treatment modalities. Periprocedural myocardial infarction occurred more frequently in patients with low PPG (<0.62) compared with those with focal disease (odds ratio, 1.71 [95% CI, 1.00–2.97]). CONCLUSIONS: Pathophysiologic coronary artery disease patterns distinctly affect the safety and effectiveness of PCI. PPG showed an excellent predictive capacity for optimal revascularization and demonstrated added value compared with an FFR measurement. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04789317.

Aims: The aim of this work was to investigate the prognostic impact of revascularization of non-culprit lesions in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease by performing a meta-analysis of available randomized clinical trials (RCTs). Methods and results: Data from six RCTs comparing complete vs. culprit-only revascularization in STEMI patients with multivessel disease were analysed with random effect generic inverse variance method meta-analysis. The endpoints were expressed as hazard ratio (HR) with 95% confidence interval (CI). The primary outcome was cardiovascular death. Main secondary outcomes of interest were all-cause death, myocardial infarction (MI), and repeated coronary revascularization. Overall, 6528 patients were included (3139 complete group, 3389 culprit-only group). After a follow-up ranging between 1 and 3 years (median 2 years), cardiovascular death was significantly reduced in the group receiving complete revascularization (HR 0.62, 95% CI 0.39–0.97, I 2 = 29%). The number needed to treat to prevent one cardiovascular death was 70 (95% CI 36–150). The secondary endpoints MI and revascularization were also significantly reduced (HR 0.68, 95% CI 0.55–0.84, I 2 = 0% and HR 0.29, 95% CI 0.22–0.38, I 2 = 36%, respectively). Needed to treats were 45 (95% CI 37–55) for MI and 8 (95% CI 5–13) for revascularization. All-cause death (HR 0.81, 95% CI 0.56–1.16, I 2 = 27%) was not affected by the revascularization strategy. Conclusion: In a selected study population of STEMI patients with multivessel disease, a complete revascularization strategy is associated with a reduction in cardiovascular death. This reduction is concomitant with that of MI and the need of repeated revascularization.