Correlation between OCT-derived intrastent dimensions and fractional flow reserve measurements after coronary stent implantation and impact on clinical outcome.

BACKGROUND: Insufficient stent expansion, vessel wall injury, and tissue prolapse, all frequently unrecognized by coronary angiography, are predictors of future major adverse cardiac event (MACE) after percutaneous coronary intervention (PCI). Optical coherence tomography (OCT) provides accurate visualization of these features of inadequate stent deployment, whereas reduced fractional flow reserve (FFR) values after PCI indicate functional significance of a residual intrastent stenosis.

OBJECTIVE: To investigate the relationship of OCT-derived intrastent lumen dimensions and FFR-derived hemodynamic relevance immediately after coronary stent implantation and to evaluate the clinical impact of these parameters at follow-up.

METHODS: In 66 stable patients with a coronary de novo lesion, treated by stent implantation, post-stenting FFR and OCT data were compared and related to MACE at follow-up.

RESULTS: There was a significant correlation between remaining OCT-derived intrastent percent area stenosis (%AS) and post-stent FFR (r² = 0.491; P<.001). According to receiver operating characteristic (ROC) analysis, both final FFR and intrastent %AS predicted MACE at 20 months (FFR: area under the curve [AUC] = 0.768; 95% confidence interval [CI], 0.562-0.973; and optimal cut-off = 0.905; %AS: AUC = 0.807; 95%CI, 0.613-1.000; and optimal cut-off = 16.85%) with moderate diagnostic efficiency. Intrastent %AS (16.60 ± 4.75% vs 7.01 ± 3.49%; P<.001) and the 20-month cumulative incidence of MACE (35.9% vs 5.3%; P=.01) were significantly greater in patients with FFR ≤0.905 (n = 26; 39.4%) compared with FFR >0.905 (n = 40; 60.6%).

CONCLUSION: OCT-derived residual intrastent %AS is associated with decreased FFR following stent implantation and both are predictors for clinical outcome at follow-up.