Late outcomes of drug eluting and bare metal stents in saphenous vein graft percutaneous coronary intervention

BOP1 Knockdown Attenuates Neointimal Hyperplasia by Activating p53 and Inhibiting Nascent Protein Synthesis

The rate of ribosome biogenesis plays a vital role in cell cycle progression and proliferation and is strongly connected with coronary restenosis and atherosclerosis. Blocking of proliferation 1 (BOP1) has been found as an evolutionarily conserved gene and a pivotal regulator of ribosome biogenesis and cell proliferation. However, little is known about its role in neointimal formation and its relationship with vascular smooth muscle cell (VSMC) proliferation and migration. The present study mainly explores the effect of BOP1 on VSMCs, the progression of neointimal hyperplasia, and the pathogenic mechanism. The expression of BOP1 was found to be significantly elevated during neointimal formation in human coronary samples and the rat balloon injury model. BOP1 knockdown inspires the nucleolus stress, which subsequently activates the p53-dependent stress response pathway, and inhibits the nascent protein synthesis, which subsequently inhibits the proliferation and migration of VSMCs. Knockdown ribosomal protein L11 (RPL11) by transfecting with siRNA or inhibiting p53 by pifithrin-α (PFT-α) partly reserved the biological effects induced by BOP1 knockdown. The present study revealed that BOP1 deletion attenuates VSMC proliferation and migration by activating the p53-dependent nucleolus stress response pathway and inhibits the synthesis of nascent proteins. BOP1 may become a novel biological target for neointimal hyperplasia.

Early and midterm major adverse cardiac events in patient with saphenous vein graft using direct stenting or embolic protection device stenting

Background:

The treatment of an occluded saphenous vein graft (SVG) with percutaneous coronary intervention may encounter major adverse cardiac events (MACE). MACE rates have been reduced significantly by using the embolic protection device (EPD).

Objectives:

The aim of this study was to clarify the risks and the benefits of embolic protection devices.

Patients and Methods:

In a prospective, non-randomized observational study, patients aged 33 to 85 years old who underwent elective percutaneous coronary intervention due to SVG stenosis at our tertiary care center were enrolled between 2009 and 2011. The incidence rates of adverse events, including MACE, were obtained during the patients’ hospitalization and at 30-day and 6-month follow-up. MACE included death, Q-wave and non-Q-wave myocardial infarction, in-stent thrombosis, target lesion revascularization, and target vessel revascularization.

Results:

From 150 patients enrolled to the study, 128 (85.3%) patients underwent direct stenting and the rest underwent the EPD procedure. In-hospital MACE occurred in 17.2% of the patients in the direct stenting group versus only 9.1% in the EPD group (P = 0.530). MACE incidence was gradually increased at one and 6-month follow-up periods in the direct stenting group (19.5% and 21.9%, respectively), and remained unchanged in the EPD group (9.1% at six-month follow-up). Multivariate logistic regression model showed that the stenting procedure type could not predict early and midterm MACE with the presence of baseline characteristics as cofounders.

Conclusions:

Despite the considerable lower early and midterm MACE rates, numerically following the EPD procedure compared to direct stenting, the difference in the MACE rates between the two groups was not significant.

Long term outcomes of saphaneous vein graft intervention in elderly patients with prior coronary artery bypass graft

OBJECTIVES

To investigate the procedure characteristics and long term follow-up of percutaneous coronary intervention (PCI) for saphaneous vein graft (SVG) lesions in the elderly patients.

METHODS

From December 2005 to December 2011, 84 graft lesions were treated percutaneously. Seventeen were located at proximal anastomosis, 48 were located at SVG body, 19 were located at distal anastomosis. Primary endpoint was defined as major adverse cardiovascular events (MACE, composite of cardiac death, target vessel revascularization, acute myocardial infarction).

RESULTS

The graft age was 6.7 ± 4.0 years. Most anastomosis lesions (80.0%) presented within one year post coronary artery bypass grafting (CABG). Proximal anastomosis lesion had the lowest successful rate for PCI compared with graft body and distal anastomosis lesions (70.6% vs. 91.7%, 79.0%, P < 0.05). The distal embolic protection device was used in 19.1% of patients, most frequently used in body graft PCI (29.2%, P < 0.01). The diameter of the stent was smallest in distal anastomosis group (2.9 ± 0.4 mm, P < 0.05). The highest post dilatation pressure was required in the proximal anastomosis (17.8 ± 2.7 atm, P < 0.05). The patients were followed up for 24.3 ± 16.9 months. MACE occurred in 18.57% of patients. Incidence of MACE was highest among proximal anastomosis PCI (47.1% vs. body graft PCI 16.7%, distal anastomosis PCI 21.1%; P < 0.05). Old myocardial infarction was the predictive factor for the poor clinical outcomes (P = 0.04).

CONCLUSIONS

PCI of SVG lesions is feasible with lower success rate. PCI of ostial graft anastomosis lesions had the lowest procedure success rate and highest MACE rate compared with graft body and distal anastomosis lesions. Old myocardial infarction was a predictive factor of poor outcomes.

Drug-Eluting Stents Versus Bare Metal Stents in Saphenous Vein Graft Intervention

Percutaneous coronary intervention (PCI) of saphenous vein graft (SVG) is associated with higher adverse event rates, lower procedural success, and inferior longterm patency rates compared with native vessel PCI. The ability to comply with dual antiplatelet therapy, and whether the patient will need an interruption in dual antiplatelet therapy, should be considered when deciding whether to implant a drug-eluting stent (DES) or bare metal stent (BMS) in an SVG. DES should be used for SVG PCI because they seem to reduce target vessel revascularization. This article reviews the evolution and contemporary evidence regarding use of DES versus BMS in SVG PCI.

The Role of Self-expanding Stents in Patients with Atypical Coronary Anatomy

Despite advances with new generation stents, there remains some atypical coronary anatomy where optimal stenting continues to be a challenge; such as stent sizing in large, ectatic or aneurysmal vessels; tapered vessels; and in vasoconstricted arteries such as in ST-segment elevation myocardial infarction or chronic total occlusions. Balloon-expandable stents are tubular and cannot easily accommodate vessel diameter variations; thrombotic vessels increase the risk of distal embolisation and no-reflow; positive remodelling and vasodilation often result in subsequent malapposition; and patients with bifurcation lesions have a higher risk of adverse events. The STENTYS BMS and DES^(P) stents have a self-expanding design, which enables a better anatomical fit to the vessel, even with diameter variations (up to 6.0 millimetres [mm]), and can adapt to changes in vessel size over time. The stents deploy atraumatically from distal to proximal, which could reduce distal embolisation and contain disconnectable bridges, which can be opened up at a side branch. Self-apposing technology could therefore provide a potential solution to current challenges with balloon-expandable stent technology.