Fabian Plank, Presenter: Nothing to Disclose

Tobias De Zordo MD, Abstract Co-Author: Nothing to Disclose

Moritz Kummann, Abstract Co-Author: Nothing to Disclose

Andrea Klauser MD, Abstract Co-Author: Nothing to Disclose

Werner R. Jaschke MD, PhD, Abstract Co-Author: Nothing to Disclose

Gudrun Feuchtner MD, Abstract Co-Author: Nothing to Disclose

Coronary CTA is validated to rule out coronary artery disease (CAD), however, false positive high-grade lesions result in lower sensitivity. Additional mean lumen area (MLA) measurements may increase accuracy by identifying hemodynamic relevance of a stenosis. Therefore the purpose was to evaluate the added value of MLA quantification by CTA to predict hemodynamic significance of coronary stenosis by invasive angiography (ICA) requiring coronary revascularization procedure.  

45 patients (mean age 63.9) who underwent 128- or 64-slice CTA presented with at least one high-grade stenosis (> 50%) in a proximal coronary vessel (right coronary artery (RCA), left main (LM), left anterior descending (LAD) or circumflex artery (CX)) and subsequently underwent invasive angiography (ICA). The minimal lumen area (MLA) was quantified by CT. Results were evaluated for hemodynamic relevance in ICA (defined as fractional flow reserve <0.8) and followed by percutaneous intervention or coronary bypass grafting. ROC–Analysis with stepwise testing (0.1 mm² MLA increments) was performed.

Overall, 50 high-grade stenosis (6 RCA, 7 LM, 37 LAD) in 156 proximal segments were evaluated. Mean lumen diameter was 4.7 mm² ±3.05. Mean MLA was 2.75 mm² (range 2.18-3.27) for high grade stenosis and 5.51 mm² (range 4.93-6.09) for no or mild stenosis. The MLA for LM was 7.13 mm², LAD 2.90 mm², CX 3.84 mm², RCA 5.13 mm². A threshold of 1.9 mm² MLA was identified as optimal cut-off, area under the curve (AUC) was 0.90 (p<0.0001). Sensitivity: 81.8% (59.7 – 94.8) and specificity: 91.04% (84.9 – 95.3). Twenty seven high-grade stenosis (>50%) in CT had no hemodynamic relevance. Of those, 24 (88.9%) lesions had MLA >1.9 mm².  

A minimal lumen area cut-off of 1.9 mm² or less showed highest accuracy for prediction of significantly increased hemodynamic relevance and may add important value to CTA.

The added value of MLA measurements may help identify hemodynamically relevant coronary stenosis.

Plank, F, De Zordo, T, Kummann, M, Klauser, A, Jaschke, W, Feuchtner, G, Predictive Value of Coronary Artery Lumen Area Quantification for Prediction of Hemodynamically Relevant Coronary Stenosis by Computed Tomography (CT) Angiography.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14008167.html