A meta-analysis of randomized controlled trials evaluating CCTA versus usual care for triaging patients in the emergency room setting documented efficiencies of CCTA for discharge disposition but increased downstream invasive coronary angiography and revascularization [32]. Hemodynamic assessment using flow indexes, derived from biophysical modeling of CTA-derived data, is a recent development. A small, single-center study was validated in animals (with CT-documented flow correlated with microsphere-determined flow; R-squared = 0.90, P < . 001) and also explored in 39 human participants with acute chest pain and normal coronaries, documenting excellent interobserver correlation (R = 0.96, P < . 0001) and agreement [33]. Although a report on the initial 1,000 participants in the international, multicenter, prospective, real-world registry, ADVANCE (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Care), has documented that CTA stenosis severity had an increased likelihood of an abnormal fractional flow reserve-CT, the utility of this measure was limited in practice, given that mild lesions could result in ischemia whereas intermediate to severe lesions could be nonflow limiting [34]. In addition, in common with the preponderant focus of other leading existing clinical trials exploring the utility of fractional flow reserve-CT, these studies were evaluated in stable chest pain cohorts, as opposed to the acute chest pain setting of the present discussion. Alternate approaches use concurrent CT perfusion (CTP) assessment to augment the anatomic data with functional characterization. In a subanalysis of 183 ROMICAT I (Rule Out Myocardial Infarction by Computer Assisted Tomography) participants, rest CTP predicted ACS independently of obstructive anatomic assessment, and sensitivity for detection of Acute Nonspecific Chest Pain
Acute Nonspecific Chest Pain Low Probability of Coronary Artery Disease PCAs. A meta-analysis of randomized controlled trials evaluating CCTA versus usual care for triaging patients in the emergency room setting documented efficiencies of CCTA for discharge disposition but increased downstream invasive coronary angiography and revascularization [32]. Hemodynamic assessment using flow indexes, derived from biophysical modeling of CTA-derived data, is a recent development. A small, single-center study was validated in animals (with CT-documented flow correlated with microsphere-determined flow; R-squared = 0.90, P < . 001) and also explored in 39 human participants with acute chest pain and normal coronaries, documenting excellent interobserver correlation (R = 0.96, P < . 0001) and agreement [33]. Although a report on the initial 1,000 participants in the international, multicenter, prospective, real-world registry, ADVANCE (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Care), has documented that CTA stenosis severity had an increased likelihood of an abnormal fractional flow reserve-CT, the utility of this measure was limited in practice, given that mild lesions could result in ischemia whereas intermediate to severe lesions could be nonflow limiting [34]. In addition, in common with the preponderant focus of other leading existing clinical trials exploring the utility of fractional flow reserve-CT, these studies were evaluated in stable chest pain cohorts, as opposed to the acute chest pain setting of the present discussion. Alternate approaches use concurrent CT perfusion (CTP) assessment to augment the anatomic data with functional characterization. In a subanalysis of 183 ROMICAT I (Rule Out Myocardial Infarction by Computer Assisted Tomography) participants, rest CTP predicted ACS independently of obstructive anatomic assessment, and sensitivity for detection of Acute Nonspecific Chest Pain