Usefulness of the trans-stent fractional flow reserve gradient for predicting clinical outcomes.

Objectives: We evaluated the usefulness of a fractional flow reserve (FFR) gradient across the stent (ΔFFR ) for long-term clinical outcomes after percutaneous coronary intervention (PCI) with a drug-eluting stent (DES).

Background: The clinical meaning of a trans-stent pressure gradient after DES implantation has not been estimated adequately.

Methods: FFR pull-back and intravascular ultrasound (IVUS) were performed after successful PCI in 135 left anterior descending artery lesions. ΔFFR was defined as the FFR gradient across the stent. The ΔFFR was defined as the ΔFFR value divided by the total stent length multiplied by 10. Major adverse cardiac events (MACEs) were the composite of all-cause death, target vessel-related myocardial infarction, and target lesion revascularization.

Results: Despite successful PCI, ΔFFR > 0 was observed in 98.5% of cases. ΔFFR ≥ 0.04 and ΔFFR  ≥ 0.009 predicted suboptimal stenting defined as final minimal stent area < 5.5 mm . During 2,183 ± 898 days, the MACE-free survival rate was significantly lower in patients with ΔFFR ≥ 0.04 and ΔFFR  ≥ 0.009 compared to those with lower values (69.6 vs. 93.4%, log-rank p = .031; 72.1 vs. 97.7%, log-rank p = .003, respectively). ΔFFR  ≥ 0.009 (hazard ratio 10.1, p = .032) was an independent predictor of MACE.

Conclusion: A trans-stent FFR gradient was frequently observed. ΔFFR and ΔFFR are related to long-term outcomes in DES-treated patients.