Percutaneous coronary intervention (PCI) has evolved significantly over the past four decades. Since its inception, in-stent restenosis (ISR)—the progressive reduction in vessel lumen diameter after PCI—has emerged as the main complication of the procedure. Although the incidence of ISR has reduced from 30% at 6 months with bare-metal stents to 7% at 4 years with drug-eluting stents (DESs), its occurrence is relevant in absolute terms because of the dimensions of the population treated with PCI. The aim of this review is to summarize the emerging understanding of the biological pathways that underlie ISR. In-stent restenosis is associated with several factors, including patient-related, genetic, anatomic, stent, lesion, and procedural characteristics. Regardless of associated factors, there are common pathophysiological pathways involving molecular phenomena triggered by the mechanical trauma caused by PCI. Such biological pathways are responses to the denudation of the intima during balloon angioplasty and involve inflammation, hypersensitivity reactions, and stem cell mobilization particularly of endothelial progenitor cells (EPCs). The results of these processes are either vessel wall healing or neointimal hyperplasia and/or neo-atherosclerosis. Unravelling the key molecular and signal pathways involved in ISR is crucial to identify appropriate therapeutic strategies aimed at abolishing the ‘Achille’s heel’ of PCI. In this regard, we discuss novel approaches to prevent DES restenosis. Indeed, available evidence suggests that EPC-capturing stents promote rapid stent re-endothelization, which, in turn, has the potential to decrease the risk of stent thrombosis and allow the use of a shorter-duration dual antiplatelet therapy.

Contemporary evidence supports device-based transcatheter interventions for the management of patients with structural heart disease. These procedures, which include aortic valve implantation, mitral or tricuspid valve repair/implantation, left atrial appendage occlusion, and patent foramen ovale closure, profoundly differ with respect to clinical indications and procedural aspects. Yet, patients undergoing transcatheter cardiac interventions require antithrombotic therapy before, during, or after the procedure to prevent thromboembolic events. However, these therapies are associated with an increased risk of bleeding complications. To date, challenges and controversies exist regarding balancing the risk of thrombotic and bleeding complications in these patients such that the optimal antithrombotic regimens to adopt in each specific procedure is still unclear. In this review, we summarize current evidence on antithrombotic therapies for device-based transcatheter interventions targeting structural heart disease and emphasize the importance of a tailored approach in these patients.

Background: The best management of stable coronary artery disease (CAD) in patients undergoing transcatheter aortic valve implantation (TAVI) is still unclear due to the marked inconsistency of the available evidence. Methods: The REVASC-TAVI registry (Management of Myocardial Revascularization in Patients Undergoing Transcatheter Aortic Valve Implantation With Coronary Artery Disease) collected data from 30 centers worldwide on patients undergoing TAVI who had significant, stable CAD at preprocedural work-up. For the purposes of this analysis, patients with either complete or incomplete myocardial revascularization were compared in a propensity score matched analysis, to take into account of baseline confounders. The primary and co-primary outcomes were all-cause death and the composite of all-cause death, stroke, myocardial infarction, and rehospitalization for heart failure, respectively, at 2 years. Results: Among 2407 patients enrolled, 675 pairs of patients achieving complete or incomplete myocardial revascularization were matched. The primary (21.6% versus 18.2%, hazard ratio‚ 0.88 [95% CI, 0.66–1.18]; P =0.38) and co-primary composite (29.0% versus 27.1%, hazard ratio‚ 0.97 [95% CI, 0.76–1.24]; P =0.83) outcome did not differ between patients achieving complete or incomplete myocardial revascularization, respectively. These results were consistent across different prespecified subgroups of patients (< or >75 years of age, Society of Thoracic Surgeons score > or or 0.10). Conclusions: The present analysis of the REVASC-TAVI registry showed that, among TAVI patients with significant stable CAD found during the TAVI work-up, completeness of myocardial revascularization achieved either staged or concomitantly with TAVI was similar to a strategy of incomplete revascularization in reducing the risk of all cause death, as well as the risk of death, stroke, myocardial infarction, and rehospitalization for heart failure at 2 years, regardless of the clinical and anatomical situations.