Temporal trends in fractional flow reserve use in patients undergoing coronary angiography: a population-based study

Background — Invasive fractional flow reserve (FFR) has emerged as an important tool to identify a subset of patients in whom coronary revascularization may be beneficial. Our objective was to evaluate temporal trends in FFR use.

Methods — We identified all coronary angiograms in the CorHealth Ontario Cardiac Registry between the years 2010 to 2015. The primary and secondary outcomes were the age- and sex-adjusted monthly rate of FFR per 100,000 population and per 100 angiograms, respectively. Piecewise regression analyses were used to evaluate the temporal trends in FFR use, for the entire cohort, and then stratified by indication (stable coronary artery disease [CAD]) versus acute coronary syndrome [ACS]).

Results — The study cohort included 379,688 angiograms, of which 122,571 were for stable CAD (32%), 134,769 were for ACS (36%). Monthly age- and sex-adjusted 
FFR use rates increased significantly over the study period, from 0.4 to 2.3 per 100,000 people per month. The monthly FFR use rate per 100 angiograms increased from 0.9 to 4.9 per 100 angiograms per month; however, the proportion of positive FFR (<0.8) results was relatively constant at 28%. There was a more dramatic increase in the use of FFR in the stable CAD (1.1 to 8.0 per 100 angiograms/month) compared with the population with ACS (0.6 to 4.5 per 100 angiograms/month).

Conclusions — There was a >5-fold increase in the use of FFR in patients across Ontario, which was predominantly driven by use in stable CAD. Case selection for FFR use was relatively unchanged with approximately one-quarter of FFR cases being positive over time.