Association Between 3D-Angiography Based Fractional Flow Reserve and Non-Invasive Myocardial Ischemia Testing: The FAST ISCHEMIA Study

Background. In order to facilitate fractional flow reserve (FFR)-guided lesion assessment, several 3-dimensional (3D)-angiog-raphy-based physiological indices have been recently validated. Thus far, limited data are available on the association of these indices with conventional forms of ischemia testing. Aim. The aim of the study was to determine the association between 3D-angiography-based vessel-FFR (vFFR) and myocardial ischemia as assessed by exercise electrocardiography (ECG) testing, dobutamine stress echocardiography, single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), and stress cardiovascular magnetic resonance imaging (stress CMR). Methods. FAST ISCHEMIA is a retrospective, single-center cohort study including patients who underwent non-invasive myocardial ischemia testing and subsequent coronary angiography (≤3 months). A total of 145 patients (340 vessels) were analyzed. The overall patient-based sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) of vFFR ≤0.80 in any vessel for ischemia was 64% (95% confidence interval [CI], 53-74), 71% (95% CI, 54-84), 83% (95% CI, 72-91), 46% (95% CI, 33-60), 2.16 (95% CI, 1.25-3.74), and 0.52 (95% CI, 0.36-0.74), respectively. Multivariable logistic regression showed that vFFR ≤0.80 was significantly associated with ischemia on a patient level (odds ratio, 8.13; 95% CI, 2.51-30.06; P<.001) and on a vascular territory level (odds ratio, 2.75; 95% CI, 1.17-6.44; P<.01). Conclusion. Our study suggests that vFFR ≤0.80 has a modest association with non-invasive myocardial ischemia testing using either exercise ECG or stress imaging modalities. After correcting for independent confounders, vFFR was independently associated with ischemia on a non-invasive myocardial ischemia detection test.