Abstract
ObjectivesFractional flow reserve (FFR) has been suggested to have value in acute coronary syndromes (ACSs). The clinical and prognostic value of ischaemia reduction assessed by post-percutaneous coronary intervention (PCI) FFR has not been studied in this population.MethodsConsecutive stable ischaemic heart disease (SIHD) (N=390) and patients with ACS (N=189) who had pre-PCI FFR and post-PCI FFR were followed for 2.4±1.5 years. Primary endpoint was major adverse cardiac events (MACE) (composite of myocardial infarction, target vessel revascularisation and death).ResultsIn patients with ACS, PCI led to significant improvement in FFR from 0.62±0.15 to post-PCI FFR 0.88±0.08 (p<0.0001). Post-PCI FFR identified 29 patients (15%) who had persistently low FFR<0.80 (0.75±0.06) despite angiographically optimal results prompting subsequent interventions improving repeat FFR (0.85±0.06; p<0.0001). The difference in MACE events between patients with ACS and patients with SIHD varied according to the post-PCI FFR value (interaction p=0.044). Receiver operator curve analysis identified a final FFR cut-off of ≤0.91 as having the best predictive accuracy for MACE in the ACS study population (30% vs 19%; p=0.03). Patients with ACS achieving final FFR of >0.91 had similar outcomes compared with patients who had SIHD (19% vs 16%; p=0.51). However, in patients with final FFR of ≤0.91 there was increased MACE versus patients with SIHD (30% vs 16%; p<0.01).ConclusionsPost-PCI FFR is valuable in assessing the functional outcome of PCI in patients with ACS. Use of post-PCI FFR in patients with ACS allows for functional optimisation of PCI results and is predictive of long-term outcomes in patients with ACS.