Percutaneous recanalization of chronic total occlusions: wherein lies the body of proof?

Although interventional technology and skills have markedly advanced, percutaneous coronary intervention (PCI) for coronary chronic total occlusion (CTO) lesions remains challenging. Indeed, CTO PCI is technically complex, carries the potential for a relatively high likelihood of failure and acute complications, and requires specifically skilled operators and a demanding use of resources. In addition, controversy persists surrounding appropriate indications for attempting CTO revascularization. Finally, there is a wide uncertainty on the actual benefits achieved with successful CTO recanalization. A growing number of studies have reported procedural results and/or assessed functional effects and long-term clinical outcomes of CTO PCI. We therefore sought to review and critically appraise the evidence base for procedural outcomes and potential clinical benefits of CTO PCI.

Epidemiology and clinical impact of different anatomical phenotypes of the left main coronary artery.

Several studies have produced estimates of the outcome of percutaneous coronary intervention (PCI) in the field of left main (LM) coronary artery disease, but no research has been found that surveyed the issue of a comprehensive knowledge of LM anatomy and assessed the impact of different anatomic phenotypes on the likelihood of developing complications after LM PCI. We sought to develop a specific investigation on the basis of the regional anatomy and quantitative analysis of a large series of angiograms performed in our institution. We reviewed the baseline selective digital coronary angiographic examinations of 1,000 patients who did not undergo LM PCI and 296 patients with significant LM stenosis who did undergo PCI. All patients in both groups underwent a comprehensive qualitative and quantitative assessment of LM anatomical features according to several parameters. Hierarchical cluster analysis (HCA) was used to identify different anatomic phenotypes of the LM coronary artery. Three different anatomical patterns were identified by HCA. The proportion of patients with LM disease increased across clusters (19% in cluster 1, 27% in cluster 2 and 44% in cluster 3, p < 0.001). No differences were observed in terms of 18-month major adverse cardiac event-free survival among patients with LM disease undergoing PCI stratified by clusters (log rank p = 0.77). In conclusion, LM phenotypes can be identified that are more likely to present with atherosclerotic disease and significant stenosis.

Bioresorbable vascular scaffold in patients with complex coronary artery disease.

The advent of fully bioresorbable stent technology is heralded as breakthrough technology in the current era of percutaneous coronary interventions (PCI). Bioresorbable scaffolds (BRS) have the potential to introduce a paradigm shift in interventional cardiology, representing an anatomical and functional "vascular restoration" therapy instead of an artificial stiff tube encased by persistent metallic foreign body. Among BRS, the everolimus-eluting scaffold (ABSORB, Abbott Vascular, Santa Clara, CA, USA) has been the most extensively investigated in clinical studies. The use of ABSORB in the treatment of relatively simple lesions appears to provide a similar degree of safety and efficacy compared with metallic drug-eluting stent (DES) treated under randomized trials conditions, but patients treated in real-world practice are far more complex than those included in randomized trials. Therefore, several ABSORB all-comers registries dealing with real world conditions are being performed. Their currently available results are summarized in the present overview.