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BVS restenosis: “Reappearance of the disappeared stent”

The Absorb Bioresorbable Vascular Scaffold (BVS) (Abbott Vascular, Santa Clara, USA) was voluntarily withdrawn from commercial use in September of 2017 due to poor uptake amid safety concerns. Yet, it continues to hold the fascination and imagination of the interventional cardiology community like a “pot of gold at the end of a rainbow.” A temporary implant which treats coronary artery disease and disappears, is physiologically logical and intuitively attractive; on the other hand, lifelong permanent metallic Drug Eluting Stents (DES) are nonideal solutions for the treatment of some of the “real world” coronary artery lesions especially in younger patients. Because the knowledge and science of today will create the safe and effective therapy for tomorrow, continued follow up and analysis of all datasets is imperative to define the role of BioResorbable (BRS) technology for the future. In this issue of the Journal Baquet et al. present their retrospective analysis of patterns and predictors of in-BVS restenosis [1]. It is less than a perfect study for many reasons. It is a retrospective analysis of a small subgroup of patients (of a much larger cohort studied in the Ghost-EU Registry) [2] who underwent non protocol driven angiography for a variety of reasons at a variable time interval upto 1-year from the index procedure. Yet, it is the first of its kind to analyze the pattern of in-BVS restenosis and is therefore scientifically important. The study demonstrates low rates of restenosis despite the fact that no BVS specific implantation technique was used and intracoronary imaging guidance was used in only 30% of the patients. Seventy five percent of the restenosis was focal (in body or at edges) and treatment of small vessels was the strongest predictor of in scaffold restenosis. Furthermore, most of the patients could be treated by implantation of metallic DES. These data are relevant and encouraging for many reasons. First, pivotal randomized trials have demonstrated the effectiveness of BVS with low rates of Target Vessel Failure, Target Lesion Revascularization, and clinical or angiographic restenosis comparable to current generation of DES [3]. That the patterns and predictors of in-BVS restenosis, in a broader “real world” use, are also “DES like” further reaffirms its effectiveness. Second, while the present generation of permanent metallic DES are safe, they are still less than perfect solutions for many subsets of patients with long and diffuse disease who get treated by “full metal jackets” or bifurcation lesions which get treated by “coulloted and crushed” metal stents. Focal restenosis in BVS is not an unfavorable outcome. Long lesions, diffuse disease, complex and multiple lesions could be treated with BVS; if focal restenosis were to occur, this could be further treated by PCI using Drug Eluting Balloons, another BVS or DES, thus restoring diseased arteries to their physiological state and avoiding a permanent “full metal jackets” or “metallic stent sandwiches” and their lifelong adverse sequalae. Third, in the presence of DES like clinical effectiveness, if the safety of BVS could be improved by decreasing scaffold thrombosis, then the device may again hold true to its promise as a “fourth revolution” in interventional cardiology. Despite unexpected setbacks and adverse publicity, BRS technology is by no means on the “backburner.” Concerted efforts are being made to improve the safety of BRS. While acute and early scaffold thrombosis may be due to suboptimal technique and inappropriate lesion and vessel selection, very late scaffold thrombosis is multifactorial due to scaffold malapposition, scaffold resorbtion and dismantling, discontinuation of dual antiplatelet therapy prior to full resorption and others. Meticulous and dedicated implantation technique preferably under image guidance [4] are essential in mitigating the risk of acute and early scaffold thrombosis and possibly very late scaffold thrombosis also. Next gen thinner strut (80–100 micron) scaffolds with faster resorption times, which are less thrombogenic in vitro, have already completed first-in-human studies with DES like outcomes and are moving into pivotal randomized studies [5]. Design, deployment and delivery characteristics are being improved to be more DES like. Four BRS are already available for commercial use in Europe and at the last count, more than 20 BRS are in various stages of development or Received: 15 June 2018 | Accepted: 15 June 2018 DOI: 10.1002/ccd.27781