International guidelines recommend performing percutaneous coronary intervention (PCI) on stable coronary lesions with a positive fractional flow reserve (FFR) to improve clinical outcomes. It remains unclear if FFR positive lesions with preserved coronary flow reserved (CFR) might be better treated medically.
This study compared clinical outcomes between PCI and medical therapy for stable FFR-positive lesions with preserved CFR.
We performed a substudy of the randomized, multicenter COMPARE-ACUTE trial in which treated ST-elevation myocardial infarction patients with stable non-culprit lesions were randomized to either FFR-guided PCI or medical therapy. Based on baseline and hyperaemic pressure gradients, we computed the so-called pressure bounded-CFR (pb-CFR) and classified lesions as low (<2) or preserved (=2). Our primary end point was a composite of death from any cause, non-fatal myocardial infarction, revascularization, or cerebrovascular events (MACCE) at 12 months.
A total of 980 lesions from 885 subjects were included in this sub-study due to availability of baseline and hyperaemic pressure gradients. For the 462 lesions with FFR=0.80, 249 had a pb-CFR<2 while 29 had a preserved CFR (pb-CFR=2). The rate of MACCE at 1 year did not differ significantly between subjects with FFR=0.80 and pb-CFR<2 versus FFR=0.80 and pb-CFR=2 (24% vs. 30%, p=0.44). Because of randomization, baseline characteristics were well balanced between subjects with FFR=0.80 and pb-CFR=2 who were treated by PCI or medical therapy. Importantly for subjects with FFR=0.80 and pb-CFR=2, MACCE occurred more frequently when treated medically compared with PCI (50% vs. 0% respectively, p=0.01).
In this post-hoc substudy from a large randomized controlled trial of 885 subjects with 980 lesions, a preserved pb-CFR=2 did not associate with an improved clinical outcome when FFR=0.80. Subjects with FFR-positive coronary lesions but a preserved pb-CFR experienced significantly worse clinical outcomes when treated medically instead of with PCI. These data suggest that a stenosis with a FFR=0.80, even when pb-CFR remains preserved, benefits from treatment with PCI.