Preprocedural computed tomography (CT) workup with assessment of virtual transcatheter heart valve-to-coronary ostia (VTC) distance and transcatheter heart valve-to-sinus (VTS) distances is recommended to assess the risk of coronary obstruction following valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR).
The authors sought to investigate the agreement of predicted VTC and VTS distances and observed post-TAVR anatomy on CT and their relationship with transcatheter heart valve (THV) expansion and deployment conditions.
Fifty-one patients who underwent a balloon-expandable ViV procedure were included in this study. The expansion of the THV stent frame was evaluated at 4 levels: THV inflow, surgical heart valve (SHV) sewing ring, SHV outflow, and THV outflow. Assessment of the VTC/VTS distances was performed on the pre-TAVR CT, and THV-to-coronary ostia and THV-to-sinus distances were assessed on the post-TAVR CT.
Following the ViV procedure, the THV stent frame flared toward the outflow but was generally underexpanded at all levels, particularly at the SHV sewing ring level. Postdilatation impacted the extent of THV expansion, resulting in greater expansion than nominal balloon filling at all 4 THV levels (P < 0.001). Observed THV-to-coronary ostia distances were systematically larger than predicted by the VTC distance (mean difference 1.25 ±1.28 mm) in patients with nominal balloon filling but systematically smaller in case of postdilatation (mean difference -0.45 ± 0.52 mm). A similar relationship was observed between VTS and THV-to-sinus distance measurements.
With nominal balloon filling, VTC and VTS distances underestimate postprocedural distances due to THV frame underexpansion. However, postdilatation may lead to distances smaller than predicted due to THV overexpansion at the outflow level.