Clinical Use of CT-Derived Fractional Flow Reserve in the Emergency Department

Kavitha M. Chinnaiyan, Beaumont Health
Robert D. Safian, Beaumont Health
Michael L. Gallagher, Beaumont Health
Julie George, Beaumont Health
Simon R. Dixon, Beaumont Health
Abhay N. Bilolikar, Beaumont Health
Amr E. Abbas, Beaumont Health
Mazen Shoukfeh, Beaumont Health
Marc Brodsky, Beaumont Health
James Stewart, Beaumont Health
Elvis Cami, Beaumont Health
David Forst, Beaumont Health
Steven Timmis, Beaumont Health
Jason Crile, Beaumont Health
Gilbert L. Raff, Beaumont Health


© 2020 American College of Cardiology Foundation Objectives: This study sought to examine the feasibility, safety, clinical outcomes, and costs associated with computed tomography–derived fractional flow reserve (FFRCT) in acute chest pain (ACP) patients in a coronary computed tomography angiography (CTA)–based triage program. Background: FFRCT is useful in determining lesion-specific ischemia in patients with stable ischemic heart disease, but its utility in ACP has not been studied. Methods: ACP patients with no known coronary artery disease undergoing coronary CTA and coronary CTA with FFRCT were studied. FFRCT ≤0.80 was considered positive for hemodynamically significant stenosis. Results: Among 555 patients, 297 underwent coronary CTA and FFRCT (196 negative, 101 positive), whereas 258 had coronary CTA only. The rejection rate for FFRCT was 1.6%. At 90 days, there was no difference in major adverse cardiac events (including death, nonfatal myocardial infarction, and unexpected revascularization after the index visit) between the coronary CTA and FFRCT groups (4.3% vs. 2.7%; p = 0.310). Diagnostic failure, defined as discordance between the coronary CTA or FFRCT results with invasive findings, did not differ between the groups (1.9% vs. 1.68%; p = NS). No deaths or myocardial infarction occurred with negative FFRCT when revascularization was deferred. Negative FFRCT was associated with higher nonobstructive disease on invasive coronary angiography (56.5%) than positive FFRCT (8.0%) and coronary CTA (22.9%) (p < 0.001). There was no difference in overall costs between the coronary CTA and FFRCT groups ($8,582 vs. $8,048; p = 0.550). Conclusions: In ACP, FFRCT is feasible, with no difference in major adverse cardiac events and costs compared with coronary CTA alone. Deferral of revascularization is safe with negative FFRCT, which is associated with higher nonobstructive disease on invasive angiography.