Three-year follow-up optical coherence tomography of under-expanded drug-eluting stent in-stent restenosis treated with ABSORB bioresorbable vascular scaffold following ultra-high pressure pre-dilatation

Optical Coherence Tomography: An Eye Into the Coronary Artery

Optical coherence tomography (OCT) is slowly but surely gaining a foothold in the hands of interventional cardiologists. Intraluminal and transmural contents of the coronary arteries are no longer elusive to the cardiologist's probing eye. Although the graduation of an interventionalist in imaging techniques right from naked eye angiographies to ultrasound-based coronary sonographies to the modern light-based OCT has been slow, with the increasing regularity of complex coronary cases in practice, such a transition is inevitable. Although intravascular ultrasound (IVUS) due to its robust clinical data has been the preferred imaging modality in recent years, OCT provides a distinct upgrade over it in many imaging and procedural aspects. Better image resolution, accurate estimation of the calcified lesion, and better evaluation of acute and chronic stent failure are the distinct advantages of OCT over IVUS. Despite the obvious imaging advantages of OCT, its clinical impact remains subdued. However, upcoming newer trials and data have been encouraging for expanding the use of OCT to wider indications in clinical utility. During percutaneous coronary intervention (PCI), OCT provides the detailed information (dissection, tissue prolapse, thrombi, and incomplete stent apposition) required for optimal stent deployment, which is the key to successfully reducing the major adverse cardiovascular event (MACE) and stent-related morbidities. The increasing use of OCT in complex bifurcation stenting involving the left main (LM) is being studied. Also, the traditional pitfalls of OCT, such as additional contrast load for image acquisition and stenting involving the ostial and proximal LM, have also been overcome recently. In this review, we discuss the interpretation of OCT images and its clinical impact on the outcome of procedures along with current barriers to its use and newer paradigms in which OCT is starting to become a promising tool for the interventionalist and what can be expected for the immediate future in the imaging world.

Multimodality intravascular imaging of bioresorbable vascular scaffolds implanted in vein grafts

INTRODUCTION

There are no data presenting a serial assessment of vein graft healing after bioresorbable vascular scaffold (BVS) implantation at long-term follow-up.

AIM

To describe ABSORB BVS healing in vein grafts by optical coherence tomography (OCT) and high-definition intravascular imaging (HD-IVUS) at long-term follow-up.Material and methods: The study group consisted of 6 patients. The first patient had serial OCT assessment of BVS implanted in the saphenous vein grafts (SVG) at baseline and at 3-, 6-, 18-month follow-up and the second patient had OCT assessment of BVS implanted in the SVG at baseline and 24-, 48-month follow-up. The second and the third patients had OCT and HD-IVUS imaging at baseline and 48-month follow-up. The last 3 patients had OCT imaging of BVS implanted in the native coronary artery at 48-month follow-up.

RESULTS

There were no differences in neointimal hyperplasia after BVS implantation between each time point. However, complete scaffold coverage was observed only 48 months after implantation. Out of 202 analyzed scaffold struts, there were 67 (33%) black boxes detectable at 48-month follow-up. HD-IVUS presented plaque burden up to 67% at the segment of BVS implantation at 48-months follow-up. There was a difference in neointimal hyperplasia thickness (1.27 (0.953-1.696) vs. 0.757 (0.633-0.848), p < 0.001) between a native coronary artery and BVS scaffolds at 48-month follow-up.

CONCLUSIONS

Bioresorbable vascular scaffold implanted in SVG characterized moderate neointimal hyperplasia as excessive as compared to native coronary arteries at long-term follow-up. The complete scaffold coverage was observed only 48 months after implantation.