Revascularization Deferral of Nonculprit Stenoses on the Basis of Fractional Flow Reserve: 1-Year Outcomes of 8,579 Patients

Background: Intracoronary physiology is increasingly used in nonculprit stenoses of patients with acute coronary syndromes (ACS). However, evidence regarding the safety of fractional flow reserve-based deferral in patients with ACS, compared with patients with stable angina pectoris (SAP), is scarce. Objectives: The aim of this study was to evaluate the safety of revascularization deferral on the basis of fractional flow reserve interrogation of nonculprit lesions in patients with ACS. Methods: A pooled analysis was performed of individual patient data included in 5 large international published studies on physiology-guided revascularization. The primary endpoint was major adverse cardiac events (MACE) (a composite of death, nonfatal myocardial infarction, or unplanned revascularization) at 1-year follow-up. Clinical outcomes of patients with ACS and SAP were compared in both the deferred and the revascularized groups. Results: A total of 8,579 patients were included in the analysis, 6,461 with SAP and 2,118 with ACS and nonculprit stenoses. Using fractional flow reserve, revascularization was deferred in 5,129 patients (59.8%) and performed in 3,450 patients (40.2%). In the deferred ACS group, a higher MACE rate was observed compared with the deferred SAP group (4.46% vs. 2.83%; adjusted hazard ratio [HR]: 1.72; 95% confidence interval [CI]: 1.17 to 2.53; p < 0.01). In particular, early unplanned revascularization (3.34% and 2.04% in ACS and SAP; adjusted HR: 1.81; 95% CI: 1.09 to 3.00; p = 0.02) contributed to this excess in MACE but the difference between the ACS and SAP groups did not reach statistical significance. On the contrary, no differences in outcomes linked to clinical presentation were found in treated patients (MACE rate 6.51% vs. 6.20%; adjusted HR: 1.21; 95% CI: 0.88 to 1.26; p = 0.24). Conclusions: Patients with ACS in whom revascularization of nonculprit lesions was deferred on the basis of fractional flow reserve have more MACE at 1 year compared with patients with SAP with deferred revascularization. Unplanned revascularization mainly contributed to this excess of MACE.