Real-world application of CCTA with CT-FFR for coronary assessment pre-TAVI: the CT2TAVI study

This study aims to evaluate the implementation of concomitant CAD assessment on pre-TAVI (transcatheter aortic valve implantation) planning CTA (CT angiography) aided by CT-FFR (CT-fractional flow reserve) [The CT2TAVI protocol] and investigates the incremental value of CT-FFR to coronary CT angiography (CCTA) alone in the evaluation of patients undergoing CT2TAVI. This is a prospective observational real-world cohort study at an academic health system on consecutive patients who underwent CTA for TAVI planning from 1/2021 to 6/2022. This represented a transition period in our health system, from not formally reporting CAD on pre-TAVI planning CTA (Group A) to routinely reporting CAD on pre-TAVI CTA (Group B; CT2TAVI protocol). All CTAs were retrospective ECG-gated using a dual source 192 slice CT scanner without nitrate or intravenous beta blocker premedication. We assessed downstream ICA and revascularization pre-TAVI and clinical outcomes 30 days and 1 year post-TAVI in both groups. 307 patients were included with 199 patients in Group A and 108 patients in Group B. In Group B, ICA was performed pre-TAVI in only 40.7% of patients. The use of CT-FFR, which was primarily aimed at identifying hemodynamically significant proximal vessel disease, helped avoid downstream invasive testing for 60.5% (23/38) of patients who were deemed to have obstructive proximal vessel disease using CCTA alone or had one or more uninterpretable proximal segments using CCTA. All-cause mortality, cardiovascular mortality, myocardial infarction and need for revascularization at 1-year post-TAVI were comparable between groups with a higher trend toward heart failure hospitalizations in Group A. Routine ICA can safely be deferred pre-TAVI, with the CT2TAVI strategy using modern CT scanners aided by CT-FFR analysis.