A randomized multicenter comparison of hybrid sirolimus-eluting stents with bioresorbable polymer versus everolimus-eluting stents with durable polymer in total coronary occlusion: rationale and design of the Primary Stenting of Occluded Native Coronary Arteries IV study

Difficult Wiring of a Recanalized Thrombotic Lesion in the Right Coronary Artery Analyzed with Optical Coherence Tomography

BACKGROUND Recanalized thrombi are usually unrecognized in conventional coronary angiography. However, multiple channels have been observed in recanalized thrombotic lesions. Therefore, the wire apparently crosses the lesion in some difficult cases. We analyzed the cause of difficult wiring of a recanalized thrombotic lesion using optical coherence tomography (OCT). CASE REPORT An 87-year-old man with chest pain was admitted to our hospital. Coronary angiography showed significant stenosis of the proximal right coronary artery with irregular linear filling and haziness. Crossing of the wire for the lesion was very difficult but was achieved using a parallel wire technique. OCT clearly demonstrated multiple small channels which had ambiguous findings on angiography and intravascular ultrasound. These structures showed a honeycomb-like appearance suggests the recanalized thrombi. A drug-eluting stent was subsequently deployed to fully cover the entire lesion. CONCLUSIONS OCT is useful to evaluate the accurate tissue characteristics of a recanalized thrombotic lesion. Because recanalized thrombi have multiple small channels and since there are some cases in which a part of the channel only flows into a side branch, it is necessary to carefully monitor wiring at the time of percutaneous coronary intervention.

Randomized Multicenter Trial Investigating Angiographic Outcomes of Hybrid Sirolimus-Eluting Stents With Biodegradable Polymer Compared With Everolimus-Eluting Stents With Durable Polymer in Chronic Total Occlusions: The PRISON IV Trial

OBJECTIVES

The aim of this study was to investigate the efficacy and safety of the hybrid ultrathin-strut sirolimus-eluting stent (SES) with biodegradable polymer compared with the thin-strut everolimus-eluting stent (EES) with durable polymer in successfully recanalized chronic total occlusions (CTOs).

BACKGROUND

The introduction of drug-eluting stents revolutionized the treatment of CTOs. However, limited data are available on new-generation drug-eluting stents with biodegradable polymer in CTOs.

METHODS

In this multicenter trial, patients were randomized, after successful CTO recanalization, to either SES or EES. The primary noninferiority endpoint was in-segment late lumen loss (noninferiority margin 0.2 mm). Secondary endpoints included in-stent late lumen loss and clinical endpoints.

RESULTS

Overall, 330 patients were included. At 9 months, angiography was available in 281 patients (85%). Duration of occlusion ≥3 months was 92.5%, with mean stent length of 52.4 ± 28.1 mm versus 52.3 ± 26.5 mm in the SES and EES groups. The primary noninferiority endpoint, in-segment late lumen loss, was not met for SES versus EES (0.13 ± 0.63 mm vs. 0.02 ± 0.47 mm; p = 0.08, 2-sided; difference 0.11 mm; 95% confidence interval: -0.01 to 0.25 mm; p_{noninferiority} = 0.11, 1-sided). In-stent late lumen loss was comparable between SES and EES (0.12 ± 0.59 mm vs. 0.07 ± 0.46 mm; p = 0.52). The incidence of in-stent and in-segment binary restenosis was significantly higher with SES compared with EES (8.0% vs. 2.1%; p = 0.028), with comparable rates of reocclusions (2.2% vs. 1.4%; p = 0.68). Clinically indicated target lesion and target vessel revascularization (9.2% vs. 4.0% [p = 0.08] and 9.2% vs. 6.0% [p = 0.33]), target vessel failure (9.9% vs. 6.6%; p = 0.35), and definite or probable stent thrombosis (0.7% vs. 0.7%; p = 1.00) were comparable between the SES and EES groups.

CONCLUSIONS

This randomized trial failed to show noninferiority of hybrid SES relative to EES in terms of in-segment late lumen loss in successfully recanalized CTOs. Furthermore, a statistically significantly higher rate of binary restenosis was found with SES.

Coronary intervention for chronic total occlusion: current indications and future directions

Chronic total occlusions (CTOs) are routinely encountered during coronary angiography, but subsequent revascularization rates are low. This has likely been driven by a historical belief that there is minimal clinical benefit and poor success rates with a percutaneous coronary intervention (PCI). However, in the current era, with the development of new techniques and tools, experienced operators can perform CTO-PCI successfully in the majority of patients. The current indications and benefit of CTO-PCI remain a topic of controversy and debate. There is a growing body of predominantly nonrandomized studies reporting both short-term and long-term outcomes of CTO-PCI. Recent and upcoming randomized-controlled trials in this area will also potentially expand indications in both stable and patients with acute coronary syndrome. In this review, we will discuss the current evidence for CTO-PCI and also future directions in this field.

Elevated survivin expression in peripheral blood mononuclear cells is central to collateral formation in coronary chronic total occlusion

Survivin is essential to angiogenesis and revascularization, but its role in coronary collateral formation remains unclear. The role of survivin in peripheral blood mononuclear cells (PBMCs) of coronary chronic total occlusion (CTO) patients was investigated. Coronary CTO patients (n=46; mean age 60.1±8.5, male 54.3%) (CTO group) and normal control patients (n=18; mean age 58.0±10.0, male 55.6%) underwent angiographic collateral vessel grading by Rentrop classification (C0 - C3) and provided peripheral blood between June 2006 and February 2007. Rat hind limb ischemia models were constructed using four equal groups of Sprague-Dawley rats (n=36): normal control, sham operation, operation and granulocyte macrophage colony-stimulating factor (GM-CSF). PBMC numbers and characteristics, collateral vessels, survivin, CD4, CD8, CD44, vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) expression were determined using RT-PCR, flow cytometry, immunocytochemistry and western blot analysis. PBMC survivin mRNA and protein expression levels were higher in patients with good collateral circulation (C2 + C3) than in patients with no collateral flow (C0) (all P<0.05). Survivin single-positive and survivin and CD8, VEGF and ICAM-1 double-positive percentages were elevated in patients with good collateral circulation compared to those with normal and no collateral flow (all P<0.05), consistent with the rat model results, wherein higher survivin levels produced significantly larger and more visible collateral vessels. In conclusion, elevated survivin expression in PBMCs, particularly survivin and CD8, VEGF, and ICAM-1 double-positive PBMCs, may be crucial for good collateral formation in patients with coronary CTO, as confirmed by assessment of a rat model.

Metallic implant drug/device combinations for controlled drug release in orthopaedic applications

The study of metallic drug/device combinations for controlled drug release in orthopaedic applications has gained significant momentum in the past decade, particularly for the prevention and reduction of implant associated infection. Such combinations are commonly based upon a permanent metallic implant (such as stainless steel or titanium) and are then coated with a drug-eluting polymer or ceramic system. Drug elution is also possible from the implant itself by utilising metallic foams, porous architectures and bioresorbable metals. This review will explore the current research into metallic implant drug/device combinations via a critical review of the relevant literature.