Sinus sequestration due to transcatheter heart valve endothelialization after transcatheter aortic valve replacement

An 85-year-old woman underwent transcatheter aortic valve replacement (TAVR) using a 26 mm Evolut FX (Medtronic Inc.). The transcatheter heart valve (THV) was implanted relatively high (Panels A, B, Supplementary data online, Video S1). The inflow to the sinus of Valsalva (SOV) was narrowed by the ST junction and the THV frame; however, the THV struts remained open. Six months later, she developed exertional angina. Multidetector computed tomography (MDCT) revealed an endothelialized THV sequestered in the SOV (Panels C–E). Single-photon emission computed tomography revealed ischaemia in the LAD area (Panels F, G). Coronary angiography (CAG) confirmed the MDCT findings (Panel H, Supplementary data online, Video S2); therefore, PCI was performed. The challenging procedure necessitated the use of a guide extension catheter, microcatheters, and a 3 g tip load hydrophilic wire to penetrate the endothelialized THV strut (Panel I). Initially, a 3.5 mm stent was deployed from the LAD to the SOV. Despite high-pressure inflation, the initial stent was significantly under-expanded. An additional 4.5 mm stent was positioned within the initial stent, extending from the left main trunk (LMT) to the SOV, increasing the radial force, but both stents exhibited suboptimal expansion due to the constrained space between the ST junction and THV frames. Therefore, we considered the under-expansion fixed, not due to a recoil phenomenon, and more repetitive post-dilation would be ineffective (Panels J, K, Supplementary data online, Video S3). Post-procedural MDCT revealed stenotic stents (Panel L). Nonetheless, she experienced immediate relief from her symptoms. This report highlights that THV endothelialization can result in sinus sequestration, culminating in delayed coronary occlusion (DCO) following TAVR. Although endothelialization is recognized as a potential mechanism for DCO,1 this case underscores that high THV placement may necessitate bailout PCI due to sinus sequestration and can lead to inadequate expansion of rescue stenting. Supplementary data are available at European Heart Journal online. Dr Yashima is a clinical proctor of Medtronic. The other authors have no relationships to disclose. The data underlying this article will be shared on reasonable request by the corresponding author. All authors declare no funding for this contribution.