Percutaneous coronary intervention for delayed coronary obstruction due to endothelialization of self-expandable transcatheter heart valve: a case report

BACKGROUND: Coronary obstruction is one of the serious complications associated with transcatheter aortic valve implantation (TAVI). Delayed coronary obstruction (DCO) is a rare manifestation of coronary obstruction. CASE SUMMARY: A 91-year-old woman was diagnosed with severe aortic stenosis. She underwent TAVI with a self-expandable valve, without any complications. After 8 months, she was readmitted to our hospital for effort angina. Transthoracic echocardiogram and myocardial scintigraphy suggested left coronary artery ischaemia. Computed tomography revealed that the transcatheter heart valve (THV) frame was covered with a low-density mass that occluded the left coronary sinus (LCS). Transoesophageal echocardiogram showed a Doppler signal flowing from the non-coronary sinus to the LCS through the roundabout route between the aortic wall and the THV. Percutaneous coronary intervention was performed for the roundabout route. Although intravascular ultrasound after the implantation of one drug-eluting stent showed the underexpansion of the stent, another stent deployment improved the expansion. After the procedure, her symptom improved. DISCUSSION: Reportedly, the mechanism of DCO occurring months or years after TAVI is thought to be thrombus formation or THV endothelialization. In our case, the low-density mass was considered to be endothelium which developed along the THV frame. Low sinotubular junction height and higher THV position could be the underlying mechanisms of DCO. Percutaneous coronary intervention is a possible treatment option for DCO caused by THV endothelialization.