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

Abstract

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.

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

“…One meta‐analysis showed that post‐PCI FFR < 0.9 is associated with a higher rate of death, MI, and repeated revascularization . The Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) substudy demonstrated that a higher post‐PCI FFR was related to a better clinical outcome; however, no discrete cutoff value was proposed as a prognostic predictor or as a target value for further optimization of PCI. As such, despite a direct relationship between post‐PCI FFR and clinical outcomes, it is still unclear whether post‐PCI FFR predicts the prognosis in DES‐treated patients or whether it is useful to guide further actions to optimize immediate PCI results and long‐term clinical outcomes.…”

“…Measuring coronary pressure and determining FFR may optimize implantation of bare‐metal stents . However, the prognostic value of post‐PCI FFR for predicting clinical outcomes after implantation of a drug‐eluting stent (DES) is controversial …”

“…This “per‐vessel” FFR can be used to assess myocardial ischemia at the target vessel territory in an integrated manner. However, most adverse events predicted by post‐PCI FFR are repeat revascularizations rather than more serious events . Furthermore, post‐PCI FFR could not clearly predict only target lesion revascularization (TLR) due to its inability to discriminate between non‐TLR‐ and TLR‐related target vessel revascularizations.…”

A randomized controlled trial of a physiology‐guided percutaneous coronary intervention optimization strategy: Rationale and design of the TARGET FFR study

“…From a registry of 750 patients receiving bare metal stents, Pijls et al reported that at 6‐month follow‐up, the lowest event rates occurred in patients with post‐PCI FFR ≥0.90 . Studies and related meta‐analyses involving drug‐eluting stents have suggested similar cutoff values of post‐PCI FFR to predict improved clinical outcomes . These range from 0.89 to ≥0.92 with a large systematic review and meta‐analysis of 7470 patients concluding that a post‐PCI FFR ≥0.90 was associated with a significantly lower risk of repeat PCI and major adverse cardiovascular events .…”

“…Published values for overall mean or median final post‐PCI FFR results range from 0.84 to 0.95 . The proportion of patients actually achieving a final FFR ≥0.90 varies widely between studies and ranges from 37% to 93% .…”