Diagnostic performance of quantitative coronary artery disease assessment using computed tomography in patients with aortic stenosis undergoing transcatheter aortic-valve implantation

Fig. 1. Examples of patients undergoing pre-TAVI CT with “evaluable” coronary artery segments. On the left side a patient is presented where in the pre-TAVI CTA all coronary segments were evaluable. There was no obstructive CAD present in CTA analysis, confirmed by invasive QCA. On the right hand side, a patient is presented, where CTA showed obstructive CAD, confirmed by invasive QCA in the distal left main stem and in the LAD. CAD coronary artery disease, CTA computed tomography angiography, RCA right coronary artery, LCA left coronary artery

Fig. 2. Examples of patients undergoing pre-TAVI CT with “non-evaluable” coronary artery segments and consecutive application of CACS. On the left side a patient is presented where pre-TAVI CTA coronary segments were non- evaluable, however CACS was 0 and no obstructive CAD was confirmed by invasive QCA. On the right hand side, a patient is presented, where CTA was non-evaluable, but CACS was above 400 and invasive QCA confirmed obstructive CAD (i.e. high grade stenosis in the LAD/1.diagnoal branch). CACS coronary artery calcium score, CAD coronary artery disease, CTA computed tomography angiography, RCA right coronary artery, LCA left coronary artery

Fig. 3. Sensitivity and specificity of CACS in the detection of CAD. In this figure the sensitivity and specificity of different CACS in detecting obstructive CAD (i.e. ≥ 50% stenosis) by invasive QCA as the reference standard is depicted. CACS coronary artery calcium score

Fig. 4. Patient based ROC curve analysis of CACS for the prediction of CAD. Receiver-operator characteristic (ROC) curve identifying the cut-off CACS for prediction of obstructive (50% CAD stenosis in QCA as the reference standard) on a per-patient patient- based analysis. CACS coronary artery calcium score

Fig. 5. Proposed algorithm for the assessment for CAD in TAVI patients using CTA with CACS. Patients with a known diagnosis of CAD should be considered for ICA to clarify coronary anatomy. In patients with no known CAD and evaluable segments from CTA, the decision to pursue ICA will depend on the presence or absence of a 50% stenosis (left side of figure). In patients with no known CAD and evidence of non-evaluable segments on CTA, CACS thresholds can be incorporated into the decision making process. Decision towards further downstream testing using ICA can be considered in patients with CACS cut-off of 100 with high sensitivity and low specificity (or alternatively 400 with a lower sensitivity and higher specificity) respectively. CACS coronary artery calcium score, CAD coronary artery disease, ICA invasive coronary angiography