The impact of fractional flow reserve measurement on clinical outcomes after transradial coronary stenting

Aims: Fractional flow reserve (FFR) ≥0.96 after stenting correlates well with an optimal stent expansion, but outcomes based on FFR after drug eluting stents (DES) have not been studied. This study sought to investigate the proportion of patients in whom an FFR ≥0.96 can be achieved after transradial stenting using primarily DES and to determine outcomes based on a post-stent FFR ≥0.96 vs. an FFR<0.96. Methods and results: A total of 66 patients with single-vessel disease and FFR<0.75 underwent transradial stenting. After stenting, FFR was <0.96 in 34 patients and there was a hyperaemic trans-stent gradient across the edges of stent in five patients; after high-pressure balloon inflation, FFR increased to ≥0.96 in three patients and an FFR ≥ 0.96 was achieved in 35 patients (53%, group 1), but FFR remained <0.96 in 31 patients (47%, group 2). There was no correlation between FFR and minimum lumen diameter in group 1 or group 2 (r=0.03; p=0.72 and r=0.02; p=0.22, respectively). The 24-month event-free survival estimate defined as freedom from death, MI, and target vessel revascularisation (PCI or CABG) was significantly greater in group 1 than in group 2 (94% versus 72%, respectively; p=0.02). Conclusions: After transradial stenting with predominately DES, an FFR ≥0.96 was achieved in only 53% of patients and event rates among patients with a post-stent FFR ≥0.96 were significantly lower than those with an FFR<0.96.