Assessment of bystander coronary artery disease in transcatheter aortic valve replacement (TAVR) patients using noncoronary-dedicated planning computed tomography angiography (CTA): diagnostic accuracy in a retrospective real-world cohort.

Aim: To assess the diagnostic potential of a noncoronary-dedicated pre-TAVR CT angiography (CTA) conducted as a prospective ECG-gated scan without premedication and standard cardiac reconstructions in evaluating bystander coronary artery disease (CAD) against invasive coronary angiography (ICA) as the gold standard.

Materials and methods: This retrospective study included 232 patients who underwent both CTA and ICA as part of their pre-TAVR evaluation. Exclusion criteria included prior stent, pacemaker, coronary artery bypass, or valve surgery. Coronary arteries were analysed solely through thin-slice axial reconstructions, with observers blinded to ICA results. Stenosis was categorised as mild (< 50%), moderate (50%-69%), or severe (≥70%). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for 50% and 70% diameter stenosis (DS) thresholds.

Results: At the 50% DS threshold, CTA demonstrated 71% sensitivity, 74% specificity, 92% NPV, and 38% PPV. At the 70% DS threshold, results included 46% sensitivity, 91% specificity, 93% NPV, and 41% PPV. The highest vessel-specific NPV at 50% DS was for the left main (98%) and left anterior descending (LAD) (91%); at 70% DS, left main (LM) (98%) and left circumflex (LCX) (94%) showed the highest NPV. Image quality impacted NPV, with excellent or very good image quality linked to higher diagnostic performance.

Conclusion: Noncoronary-dedicated pre-TAVR CTA shows promise for ruling out significant CAD effectively and may act as a gatekeeper for ICA, aligning with typical coronary CT angiography (CCTA) outcomes.