Prognostic Value of Fractional Flow Reserve Measured Immediately After Drug-Eluting Stent Implantation.

BACKGROUND: The predictive value of fractional flow reserve (FFR) measured immediately after percutaneous coronary intervention (PCI) with drug-eluting stent placement has not been prospectively investigated. We investigated the potential of post-PCI FFR measurements to predict clinical outcome in patients from FAME 1 and 2 trials (Fractional Flow Reserve or Angiography for Multivessel Evaluation).

METHODS AND RESULTS: All patients of FAME 1 and FAME 2 who had post-PCI FFR measurement were included. The primary outcome was vessel-oriented composite end point at 2 years, defined as vessel-related cardiovascular death, vessel-related spontaneous myocardial infarction, and ischemia-driven target vessel revascularization. Eight hundred thirty-eight vessels in 639 patients were analyzed. Baseline FFR values did not differ between vessels with versus without vessel-oriented composite end point (0.66±0.11 versus 0.63±0.14, respectively; P =0.207). Post-PCI FFR was significantly lower in vessels with vessel-oriented composite end point (0.88±0.06 versus 0.90±0.06, respectively; P =0.019). Comparing the 2-year outcome of lower and upper tertiles of post-PCI FFR significant difference was found favoring upper tertile in terms of overall vessel-oriented composite end point (9.2% versus 3.8%, respectively; hazard ratio, 1.46; 95% confidence interval, 1.02-2.08; P =0.037) and target vessel revascularization (7.0% versus 2.4%, respectively; hazard ratio, 1.59; 95% confidence interval, 1.03-2.46; P =0.037). When adjusted to sex, hypertension, diabetes mellitus, target vessel, serial stenosis, and baseline percentage diameter stenosis, a strong trend was preserved in terms of target vessel revascularization (harzard ratio, 1.55; 95% confidence interval, 0.97-2.46; P =0.066), favoring the upper tertile. Post-PCI FFR of 0.92 was found to have the highest diagnostic accuracy; however, the positive likelihood ratio remained low (<1.4).

CONCLUSIONS: A higher post-PCI FFR value is associated with a better vessel-related outcome. However, its predictive value is too low to advocate its use as a surrogate clinical end point.