TY - JOUR

T1 - Prognostic Value and Risk Continuum of Noninvasive Fractional Flow Reserve Derived from Coronary CT Angiography

AU - Ihdayhid, Abdul Rahman

AU - Norgaard, Bjarne L

AU - Gaur, Sara

AU - Leipsic, Jonathan

AU - Nerlekar, Nitesh

AU - Osawa, Kazuhiro

AU - Miyoshi, Toru

AU - Jensen, Jesper M

AU - Kimura, Takeshi

AU - Shiomi, Hiroki

AU - Erglis, Andrejs

AU - Jegere, Sanda

AU - Oldroyd, Keith G

AU - Botker, Hans Erik

AU - Seneviratne, Sujith K

AU - Achenbach, Stephan

AU - Ko, Brian S

N1 - https://doi.org/10.1148/radiol.2019182264

PY - 2019/8

Y1 - 2019/8

N2 - Background: Coronary CT angiography with noninvasive fractional flow reserve (FFR) predicts lesion-specific ischemia when compared with invasive FFR. The longer term prognostic value of CT-derived FFR (FFR CT) is unknown. Purpose: To determine the prognostic value of FFR CT when compared with coronary CT angiography and describe the relationship of the numeric value of FFR CT with outcomes. Materials and Methods: This prospective subanalysis of the NXT study (Clinicaltrials.gov: NCT01757678) evaluated participants suspected of having stable coronary artery disease who were referred for invasive angiography and who underwent FFR, coronary CT angiography, and FFR CT. The incidence of the composite primary end point of death, myocardial infarction, and any revascularization and the composite secondary end point of major adverse cardiac events (MACE: cardiac death, myocardial infarction, unplanned revascularization) were compared for an FFR CT of 0.8 or less versus stenosis of 50% or greater on coronary CT angiograms, with treating physicians blinded to the FFR CT result. Results: Long-term outcomes were obtained in 206 individuals (age, 64 years 6 9.5), including 64% men. At median follow-up of 4.7 years, there were no cardiac deaths or myocardial infarctions in participants with normal FFR CT. The incidence of the primary end point was more frequent in participants with positive FFR CT compared with clinically significant stenosis at coronary CT angiography (73.4% [80 of 109] vs 48.7% [91 of 187], respectively; P , .001), with the majority of outcomes being planned revascularization. Corresponding hazard ratios (HRs) were 9.2 (95% confidence interval [CI]: 5.1, 17; P , .001) for FFR CT and 5.9 (95% CI: 1.5, 24; P = .01) for coronary CT angiography. FFR CT was a superior predictor compared with coronary CT angiography for primary end point (C-index FFR CT, 0.76 vs coronary CT angiography, 0.54; P , .001) and MACE (FFR CT, 0.71 vs coronary CT angiography, 0.52; P = .001). Frequency of MACE was higher in participants with positive FFR CT compared with coronary CT angiography (15.6% [17 of 109] vs 10.2% [19 of 187], respectively; P = .02), driven by unplanned revascularization. MACE HR was 5.5 (95% CI: 1.6, 19; P = .006) for FFR CT and 2.0 (95% CI: 0.3, 14; P = .46) for coronary CT angiography. Each 0.05-unit FFR CT reduction was independently associated with greater incidence of primary end point (HR, 1.7; 95% CI: 1.4, 1.9; P , .001) and MACE (HR, 1.4; 95% CI: 1.1, 1.8; P , .001). Conclusion: In stable patients referred for invasive angiography, a CT-derived fractional flow reserve (FFR CT) value of 0.8 or less was a predictor of long-term outcomes driven by planned and unplanned revascularization and was superior to clinically significant stenosis on coronary CT angiograms. Additionally, the numeric value of FFR CT was an independent predictor of outcomes.

AB - Background: Coronary CT angiography with noninvasive fractional flow reserve (FFR) predicts lesion-specific ischemia when compared with invasive FFR. The longer term prognostic value of CT-derived FFR (FFR CT) is unknown. Purpose: To determine the prognostic value of FFR CT when compared with coronary CT angiography and describe the relationship of the numeric value of FFR CT with outcomes. Materials and Methods: This prospective subanalysis of the NXT study (Clinicaltrials.gov: NCT01757678) evaluated participants suspected of having stable coronary artery disease who were referred for invasive angiography and who underwent FFR, coronary CT angiography, and FFR CT. The incidence of the composite primary end point of death, myocardial infarction, and any revascularization and the composite secondary end point of major adverse cardiac events (MACE: cardiac death, myocardial infarction, unplanned revascularization) were compared for an FFR CT of 0.8 or less versus stenosis of 50% or greater on coronary CT angiograms, with treating physicians blinded to the FFR CT result. Results: Long-term outcomes were obtained in 206 individuals (age, 64 years 6 9.5), including 64% men. At median follow-up of 4.7 years, there were no cardiac deaths or myocardial infarctions in participants with normal FFR CT. The incidence of the primary end point was more frequent in participants with positive FFR CT compared with clinically significant stenosis at coronary CT angiography (73.4% [80 of 109] vs 48.7% [91 of 187], respectively; P , .001), with the majority of outcomes being planned revascularization. Corresponding hazard ratios (HRs) were 9.2 (95% confidence interval [CI]: 5.1, 17; P , .001) for FFR CT and 5.9 (95% CI: 1.5, 24; P = .01) for coronary CT angiography. FFR CT was a superior predictor compared with coronary CT angiography for primary end point (C-index FFR CT, 0.76 vs coronary CT angiography, 0.54; P , .001) and MACE (FFR CT, 0.71 vs coronary CT angiography, 0.52; P = .001). Frequency of MACE was higher in participants with positive FFR CT compared with coronary CT angiography (15.6% [17 of 109] vs 10.2% [19 of 187], respectively; P = .02), driven by unplanned revascularization. MACE HR was 5.5 (95% CI: 1.6, 19; P = .006) for FFR CT and 2.0 (95% CI: 0.3, 14; P = .46) for coronary CT angiography. Each 0.05-unit FFR CT reduction was independently associated with greater incidence of primary end point (HR, 1.7; 95% CI: 1.4, 1.9; P , .001) and MACE (HR, 1.4; 95% CI: 1.1, 1.8; P , .001). Conclusion: In stable patients referred for invasive angiography, a CT-derived fractional flow reserve (FFR CT) value of 0.8 or less was a predictor of long-term outcomes driven by planned and unplanned revascularization and was superior to clinically significant stenosis on coronary CT angiograms. Additionally, the numeric value of FFR CT was an independent predictor of outcomes.

KW - ARTERY-DISEASE

KW - CARE

KW - DESIGN

KW - DIAGNOSTIC PERFORMANCE

KW - FFRCT

KW - OUTCOMES

KW - PHYSIOLOGICAL SEVERITY

KW - RATIONALE

KW - STENOSES

U2 - 10.1148/radiol.2019182264

DO - 10.1148/radiol.2019182264

M3 - Journal article

C2 - 31184558

VL - 292

SP - 343

EP - 351

JO - Radiology

JF - Radiology

SN - 0033-8419

IS - 2

ER -