WHY THIS STUDY?

Current European guidelines advise the use of fractional flow reserve (FFR) for assessing the functional relevance of coronary stenoses and guiding management strategies in patients with chronic coronary syndrome (CCS). To date, evidence from randomized clinical trials (RCTs) supporting these recommendations remains limited. 

HOW WAS IT EXECUTED?

We included CCS patients who underwent functional evaluation of one or more coronary stenoses using FFR and were registered in the Swedish Coronary Angiography and Angioplasty Registry. The primary outcome of interest was the composite of all-cause death and FFR-oriented target vessel revascularization (TVR) by percutaneous coronary intervention at 1 year. A quasi-randomized study design (fuzzy regression discontinuity) was employed in the analysis. This approach has been proven to provide robust implications on causality using observational data. The protocol of this study was registered at clinicaltrials.gov (NCT05592535).

WHAT WERE THE ESSENTIAL RESULTS?

From June 2015 to June 2020, a total of 5,066 individual patients contributing with 6,143 vessels to the analysis were included. 313 (6.2%) patients experienced the primary composite outcome at 1 year. At the FFR cut-off of 0.80, revascularization versus deferral was associated with an increased risk for the primary composite outcome (absolute risk difference and 95% confidence interval of 9.4%, 17.7 to 1.1%, p-value 0.027). No differences in the risk for the composite of all-cause death and re-hospitalization for acute myocardial infarction were encountered.

WHY IT IS IMPORTANT?

At the currently guideline-recommended cut-off of 0.80, the use of FFR to guide revascularization in CCS patients was associated with an increased risk for the composite outcome measure of all-cause death and FFR-oriented TVR at 1 year. These results do not support current guideline recommendations for the use of FFR in CCS. Moreover, these data warrant the conduct of RCTs re-assessing the role of FFR in the contemporary management of patients with CCS.

PLEASE LIST THE DEVICE(S)/TECHNOLOGY(IES) INVOLVED IN THIS TRIAL

All commercially available pressure wires were used in this study.