title: Potential impact of clinical use of noninvasive FFRCT on radiation dose exposure and downstream clinical event rate.
abstract: OBJECTIVE
  This study aims to determine the potential impact of introducing noninvasive fractional flow reserve based on coronary computed tomography angiography (CTA) into clinical practice, with respect to radiation dose exposure and downstream event rate.
  
  
  METHODS
  We modeled a population of 1000 stable, symptomatic patients with suspected coronary artery disease, using the disease prevalence from the CONFIRM registry to estimate the pretest likelihood. Four potential clinical pathways were modeled based on the first noninvasive diagnostic test performed: (1) dobutamine echo; (2) single-photon emission computerized tomography (SPECT); (3) coronary CTA; and (4) CTA+FFRCT and leading to possible invasive coronary angiography. The posttest likelihood of testing positive/negative by each test was based on the presenting disease burden and diagnostic accuracy of each test.
  
  
  RESULTS
  The dobutamine echo pathway resulted in the lowest radiation dose of 5.4 mSv, with 4.0 mSv from angiography and 1.4 mSv from percutaneous coronary intervention (PCI). The highest dose was with SPECT, with 26.5 mSv. The coronary computed tomography angiography (cCTA) pathway demonstrated a dose of 14.2 mSv, 3.7 mSv from cCTA, 7.7 mSv from angiography, and 2.8 mSv from PCI. The CTA+FFRCT pathway exhibited a radiation dose of 9.7 mSv, 3.7 mSv for cCTA, 4.2 mSv for angiography, and 1.8 mSv for PCI. Radiation dose exposure for CTA+FFRCT was lower than for SPECT (P<.001). The CTA+FFRCT pathway resulted in the lowest projected death/myocardial infarction rate at 1 year (2.44%) while the dobutamine stress pathway had the highest 1-year event rate (2.84%).
  
  
  CONCLUSIONS
  Our analysis suggests that integrating FFRCT into the CTA clinical pathway may result in reduced cumulative radiation exposure, while promoting favorable clinical outcomes.
authors.affiliation: 1081 Burrard Street, Vancouver, BC, V6Z 1Y6. Electronic address: nbilbey@alumni.ubc.ca.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bilbey
authors.affiliation: 1081 Burrard Street, Vancouver, BC, V6Z 1Y6. Electronic address: phil.blanke@googlemail.com.
authors.forename: Philipp
authors.initials: P
authors.lastname: Blanke
authors.affiliation: 1081 Burrard Street, Vancouver, BC, V6Z 1Y6. Electronic address: chris.naoum@gmail.com.
authors.forename: Christopher
authors.initials: C
authors.lastname: Naoum
authors.affiliation: 1081 Burrard Street, Vancouver, BC, V6Z 1Y6. Electronic address: chesnaldey@gmail.com.
authors.forename: Chesnel Dey
authors.initials: CD
authors.lastname: Arepalli
authors.affiliation: Aarhus University Hospital, Norrebrogade 44, DK 8000 Aarhus C. Electronic address: bnorgaard@dadlnet.dk.
authors.forename: Bjarne Linde
authors.initials: BL
authors.lastname: Norgaard
authors.affiliation: 1081 Burrard Street, Vancouver, BC, V6Z 1Y6. Electronic address: JLeipsic@providencehealth.bc.ca.
authors.forename: Jonathon
authors.initials: J
authors.lastname: Leipsic
mesh_terms: D000072226:Computed Tomography Angiography / Q000009:adverse effects / Q000379:methods*; D017023:Coronary Angiography / Q000009:adverse effects / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005500:Follow-Up Studies; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D011446:Prospective Studies; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000009:adverse effects / Q000517:prevention & control / Q000706:statistics & numerical data*; D012042:Registries; D015899:Tomography, Emission-Computed, Single-Photon
keywords: Computed tomography; FFRCT; Fractional flow reserve; Radiation dose