Utilization of cardiac computed tomography angiography and outpatient invasive coronary angiography in Ontario, Canada

- We performed a real-world analysis of 10.1 million adults in Ontario, Canada.
- CCTA utilization patterns revealed slow and steady diffusion across the population.
- Elective angiography and revascularization rates were significantly lower after CCTA funding initiation.
- 1044 fewer annual invasive angiograms were performed after CCTA funding initiation.
- Suggest a potentially significant, population level, real-world impact of CCTA.

BackgroundCardiac computed tomography angiography (coronary CTA) has emerged as a non-invasive method of diagnosing coronary artery disease. The extent of utilization and uptake of this technology since initiation of its funding by the government of Ontario is unknown.ObjectivesThe aim of our study was to examine coronary CTA utilization and the rates of elective invasive coronary angiography and revascularization before and after funding initiation.MethodsWe studied all coronary CTAs performed on adults in Ontario after initiation of funding. We also used an interrupted time series analysis to compare the average monthly rates of invasive angiography and revascularization before and after initiation of funding.ResultsThere was an initial steep increase in age-and sex-standardized rates of coronary CTA from 5.0 to 11.4/100,000 over the first two quarters after funding initiation. Afterwards, there was a gradual increase in utilization from 11.4 to 17.1/100,000 over two subsequent calendar years. There was a significant reduction in both the mean monthly outpatient invasive coronary angiography (from 20.7 to 19.9 per 100,000 (p = 0.0004)) and revascularization (from 4.9 to 4.4 per 100,000 (p < 0.0001)) rates in the three years following introduction of the coronary CTA billing code as compared to the three prior to its introduction.ConclusionsSince the introduction of coronary CTA funding in Ontario, there has been a steady and controlled increase in its utilization. The increasing use of coronary CTA was associated with a reduction in both the rates of invasive angiography and revascularization.