Diagnostic Performance of On-site Automatic Coronary Computed Tomography Angiography-derived Fractional Flow Reserve

Diagnostic Performance of On-site Automatic Coronary Computed Tomography Angiography-derived Fractional Flow Reserve

The current study evaluated the diagnostic performance for myocardial ischemia of on-site automatic CCTA-derived FFR (CT-FFR) using a commercially available workstation as compared with invasive FFR as a reference. The diagnostic performance of CT-FFR was compared to that of CCTA diameter stenosis.

This is a retrospective, multicenter, comparative, investigator-initiated study to evaluate the diagnostic performance of CT-FFR from routinely acquired CCTA data using the software HeartMedi+ 1.0 (AI Medic, Korea) to detect hemodynamically significant CAD. Patients who underwent CCTA within 90 days before invasive coronary angiography and FFR measurement will be screened in each participating center. After that, invasive coronary angiography, FFR data, and CCTA data will be anonymized and transferred to the independent core laboratories and analyzed in a blind fashion.

The presence of ischemia was defined as FFR ≤0.80. Anatomical obstructive stenosis was defined as diameter stenosis on CCTA ≥50%, and the diagnostic performance of CT-FFR and CCTA stenosis for ischemia was compared.

Inclusion Criteria:

• adults aged 20 years or older
• individuals who had undergone ≥ 64 multidetector row CCTA within 90 days before invasive coronary angiography and FFR measurement
• individuals who had not experienced any clinical events or significant clinical changes between the time of CCTA and invasive coronary angiography

Exclusion Criteria:

• previous coronary intervention or coronary bypass surgery in the target vessel
• invasive coronary angiography under unstable conditions
• previous myocardial infarction at target vessel territory
• congenital heart disease
• moderate or severe valvular heart disease
• previous valvular heart surgery
• left ventricular ejection fraction ≤40% or left ventricular hypertrophy
• previous cardiac device implantation
• body mass index >35 kg/m2
• poor FFR tracing quality
• no information on the position of the FFR pressure wire
• heart rate ≥100 beats/min during CCTA
• CCTA calcium score ≥1000
• no nitroglycerin prior to CCTA
• CCTA slice thickness >1.0 mm
• significant artifacts in CCTA