Abstract 13587: Long-Term Outcomes of CT-Derived Fractional Flow Reserve in the Emergency Department

Abstract

Introduction: In acute chest pain (ACP) patients, CT-derived fraction flow reserve (FFRCT) is feasible and adjudicates need for immediate coronary revascularization. There are no long-term outcome studies of FFRCT in ACP. Hypothesis: In ACP patients, FFRCT is safe and associated with favorable outcomes when negative. Methods: ACP patients with no known coronary artery disease or definitive acute coronary syndrome undergoing coronary CTA with FFRCT were compared to those having CTA alone for the composite major adverse cardiac event (MACE) endpoint of death, nonfatal myocardial infarction, unplanned percutaneous (PCI) or surgical (CABG) revascularization over 2 years. FFRCT ≤ 0.80 was considered positive for hemodynamically significant stenosis. Results: From September 2015 to July 2018, 2,568 ACP patients (mean age 55 years, 52% female) underwent CTA of which 236 (10%) had FFRCT (156 negative, 80 positive). Of the total, 1629 (63.2%) had normal coronaries, and 43 (1.7%) were uninterpretable. FFRCT patients were older (p<0.001) with more diabetes mellitus (18.2% vs. 12.2%, p = 0.009), hypertension (50.8% vs. 38.2%, p<0.001), hyperlipidemia (43.6% vs. 25.4%, p<0.001), and >25% stenosis on CTA (93% vs. 13.6%, p<0.001). Positive FFRCT was associated with higher MACE (10% vs. 2.1%, p<0.001). With comparable stenosis on CTA, positive FFRCT had higher MACE compared to negative FFRCT or CTA alone (Table 1). Conclusions: In ACP patients, negative FFRCT and CTA alone are comparable for MACE. Positive FFRCT portends higher MACE at 2 years within similar stenosis categories. FFRCT can provide incremental value to ACP evaluation with coronary CTA.