Anatomical and Functional Computed Tomography for Diagnosing Hemodynamically Significant Coronary Artery Disease: A Meta-Analysis

Abstract

Objectives: This meta-analysis determined the diagnostic performance of coronary computed tomography (CT) angiography (CTA), CT myocardial perfusion (CTP), fractional flow reserve CT (FFR_CT), the transluminal attenuation gradient (TAG), and their combined use with CTA versus FFR as a reference standard for detection of hemodynamically significant coronary artery disease (CAD).

Background: CTA provides excellent anatomic, albeit limited functional information for the evaluation of CAD. Recently, various functional CT techniques emerged to assess the hemodynamic consequences of CAD.

Methods: This meta-analysis was performed in adherence to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed, EMBASE, and Web of Science were searched from inception until September 7, 2017. Bayesian random effects analysis was used to compute pooled sensitivity, specificity, and the summary receiver-operating characteristic curve of the index tests and compare them with the FFR as a reference standard. Analyses were performed on vessel and patient levels. Because CTA has excellent sensitivity, specificity was considered most relevant. Individual FFR_CT values were collected.

Results: Overall, 54 articles and 5,330 patients were included. At vessel level, pooled specificity of CTP (0.86; 95% confidence interval [CI]: 0.76 to 0.93), FFR_CT (0.78; 95% CI: 0.72 to 0.83) and TAG (0.77; 95% CI: 0.61 to 0.89) were substantially higher than that of CTA (0.61; 95% CI: 0.54 to 0.68). The addition of FFR_CT, CTP, and TAG to CTA resulted in high to excellent specificities (0.80 to 0.92). The summary receiver-operating characteristic curve at vessel level yielded superior diagnostic accuracy for CTP, FFR_CT, and combined CTA and CTP, compared with CTA. A subanalysis of on-site versus off-site FFR_CT revealed no substantial differences between the sensitivity (0.84 vs. 0.85) and specificity (0.80 vs. 0.73) of the 2 techniques. In a second subanalysis, dynamic CTP showed higher sensitivity (0.85 vs. 0.72), but had a lower specificity (0.81 vs. 0.90) than static CTP.

Conclusions: CTP and FFR_CT demonstrated a substantial improvement in the identification of hemodynamically significant CAD compared with CTA; therefore, their integration to clinical workflow before revascularization is recommended.

Keywords: computed tomography; coronary artery disease; fractional flow reserve; meta-analysis; myocardial perfusion imaging.