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


Background — Cardiac 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.

Objectives — The 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.

Methods — We 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.

Results — There 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.

Conclusions — Since 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.



Roifman I, Rezai MR, Wijeysundera HC, Chow BJ, Wright GA, Tu JV. J Cardiovasc Comput Tomogr. 2015; 9(6):567-71. Epub 2015 Jul 22.

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