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

Abstract Objectives The study sought to examine the feasibility, safety, clinical outcomes, and costs associated with computed tomography–derived fractional flow reserve (FFR CT ) in acute chest pain (ACP) patients in a coronary computed tomography angiography (CTA)–based triage program. Background FFR CT 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 FFR CT were studied. FFR CT  ≤0.80 was considered positive for hemodynamically significant stenosis. Results Among 555 patients, 297 underwent coronary CTA and FFR CT (196 negative, 101 positive), whereas 258 had coronary CTA only. The rejection rate for FFR CT 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 FFR CT groups (4.3% vs. 2.7%; p = 0.310). Diagnostic failure, defined as discordance between the coronary CTA or FFR CT 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 FFR CT when revascularization was deferred. Negative FFR CT was associated with higher nonobstructive disease on invasive coronary angiography (56.5%) than positive FFR CT (8.0%) and coronary CTA (22.9%) (p  CT groups ($8,582 vs. $8,048; p = 0.550). Conclusions In ACP, FFR CT is feasible, with no difference in major adverse cardiac events and costs compared with coronary CTA alone. Deferral of revascularization is safe with negative FFR CT , which is associated with higher nonobstructive disease on invasive angiography.