Coronary stents and vascular response to implantation: literature review

Drug-eluting stents (DESs) have minimized the limitations of bare-metal stents (BMSs) after percutaneous coronary interventions. Nevertheless, serious concerns remain about possible late complications of stenting, such as stent thrombosis (ST) and in-stent restenosis (ISR), although the introduction of second-generation DESs seems to have softened the phenomenon, compared to the first-generation ones. ST is a potentially catastrophic event, which has been markedly reduced by optimization of stent implantation, novel stent designs, and dual antiplatelet therapy. The exact mechanism to explain its occurrence is under investigation, and, realistically, multiple factors are responsible. ISR of BMSs has been previously considered as a stable condition with an early peak (at 6 months) of intimal hyperplasia, followed by a regression period beyond 1 year. On the contrary, both clinical and histologic studies of DESs have demonstrated evidence of continuous neointimal growth during long-term follow-up, named "late catch-up" phenomenon. The acknowledgment that ISR is a relatively benign clinical condition has been recently challenged by evidences which reported that patients with ISR can experience acute coronary syndromes. Intracoronary imaging is an invasive technology that allows identifying features of atherosclerotic plaque of stent implanted and of vascular healing after stenting; it is often used to complete diagnostic coronary angiography and to drive interventional procedures. Intracoronary optical coherence tomography is currently considered a state-of-the-art imaging technique; it provides, compared to intravascular ultrasound, better resolution (at least >10 times), allowing the detailed characterization of the superficial structure of the vessel wall. Imaging studies "in vivo," in agreement with histological findings, suggest that chronic inflammation and/or endothelial dysfunction may induce late de novo "neoatherosclerosis" inside both BMSs and DESs. So, neoatherosclerosis has become the prime suspect in the pathogenesis of late stent failure

Management and long-term prognosis of spontaneous coronary artery dissection

The optimal management and short- and long-term prognoses of spontaneous coronary artery dissection (SCAD) remain not well defined. The aim of this observational multicenter study was to assess long-term clinical outcomes in patients with SCAD. In-hospital and long-term outcomes were assessed in 134 patients with documented SCAD, as well as the clinical impact and predictors of a conservative rather than a revascularization strategy of treatment. The mean age was 52 11, years and 81% of patients were female. SCAD presented as an acute coronary syndromes in 93% of patients. A conservative strategy was performed in 58% of patients and revascularization in 42%. On multivariate analysis, distal versus proximal or mid location of dissection (odds ratio 9.27) and basal Thrombolysis In Myocardial Infarction (TIMI) flow grade 2 or 3 versus 0 or 1 (odds ratio 0.20) were independent predictors of conservative versus revascularization strategy. A conservative strategy was associated with better in-hospital outcomes compared with revascularization (rates of major adverse cardiac events 3.8% and 16.1%, respectively, p = 0.028); however, no significant differences were observed in the long-term outcomes. In conclusion, in this large observational study of patients with SCAD, angiographic features significantly influenced the treatment strategy, providing an excellent short- and long-term prognosis

[Updated SICI-GISE position paper on institutional and operator requirements for transcatheter aortic valve implantation]

Transcatheter aortic valve implantation (TAVI) has revolutionized the management of patients with symptomatic severe aortic stenosis and has become the standard of care for inoperable patients and the preferred therapy for those at increased surgical risk with peculiar clinical and anatomic features. Technology advances, growing experience and accumulating data prompted the update of the 2011 Italian Society of Interventional Cardiology (SICI-GISE) position paper on institutional and operator requirements to perform TAVI. The main objective of this document is to provide a guidance to assess the potential of institutions and operators to initiate and maintain an efficient TAVI program