Differential Prognostic Effect Between First- and Second-Generation Drug-Eluting Stents in Coronary Bifurcation Lesions: Patient-Level Analysis of the Korean Bifurcation Pooled Cohorts

ObjectivesThe purpose of this study was to investigate the differential clinical outcomes after percutaneous coronary intervention (PCI) for coronary bifurcation lesions with 1- or 2-stenting techniques using first- or second-generation drug-eluting stents (DES).BackgroundThe 2-stenting technique has been regarded to have worse clinical outcomes than the 1-stenting technique after bifurcation PCI with first-generation DES. However, there has been a paucity of data comparing the 1- and 2-stenting techniques with the use of second-generation DES.MethodsPatient-level pooled analysis was performed with 3,162 patients undergoing PCI using first- or second-generation DES for bifurcation lesions from the “Korean Bifurcation Pooled Cohorts” (COBIS [Coronary Bifurcation Stenting] II, EXCELLENT [Registry to Evaluate Efficacy of Xience/Promus Versus Cypher in Reducing Late Loss After Stenting], and RESOLUTE-Korea [Registry to Evaluate the Efficacy of Zotarolimus-Eluting Stent]). The 3-year clinical outcomes were compared between 1- and 2-stenting techniques, stratified by the type of DES.ResultsWith first-generation DES, rates of target lesion failure (TLF) or patient-oriented composite outcome (POCO) (a composite of all death, any myocardial infarction, any repeat revascularization, and cerebrovascular accidents) at 3 years were significantly higher after the 2-stenting than the 1-stenting technique (TLF 8.6% vs. 17.5%; p < 0.001; POCO 18.1% vs. 28.5%, p < 0.001). With second-generation DES, however, there was no difference between 1- and 2-stenting techniques (TLF 5.4% vs. 5.8%; p = 0.768; POCO 11.2% vs. 12.9%; p = 0.995). The differential effects of 2-stenting technique on the prognosis according to the type of DES were also corroborated with similar results by the inverse probability weighted model. The 2-stenting technique was a significant independent predictor of TLF in first-generation DES (hazard ratio: 2.046; 95% confidence interval: 1.114 to 3.759; p < 0.001), but not in second-generation DES (hazard ratio: 0.667; 95% confidence interval: 0.247 to 1.802; p = 0.425).ConclusionsPatient-level pooled analysis of 3,162 patients in Korean Bifurcation Pooled Cohorts demonstrated that the 2-stenting technique showed comparable outcomes to 1-stenting technique with second-generation DES, which is different from the results of first-generation DES favoring the 1-stenting technique.     

Novel stent system for bifurcation lesions: examination by intravascular ultrasound.

Bifurcation disease represents a mechanical and biological challenge for definitive interventional treatment. This case report discusses an experience with a novel stent system designed for the treatment of bifurcation lesions.     

Anisotropic growth shapes intestinal tissues during embryogenesis

Embryogenesis offers a real laboratory for pattern formation, buckling, and postbuckling induced by growth of soft tissues. Each part of our body is structured in multiple adjacent layers: the skin, the brain, and the interior of organs. Each layer has a complex biological composition presenting different elasticity. Generated during fetal life, these layers will experience growth and remodeling in the early postfertilization stages. Here, we focus on a herringbone pattern occurring in fetal intestinal tissues. Common to many mammalians, this instability is a precursor of the villi, finger-like projections into the lumen. For avians (chicks’ and turkeys’ embryos), it has been shown that, a few days after fertilization, the mucosal epithelium of the duodenum is smooth, and then folds emerge, which present 2 d later a pronounced zigzag instability. Many debates and biological studies are devoted to this specific morphology, which regulates the cell renewal in the intestine. After reviewing experimental results about duodenum morphogenesis, we show that a model based on simplified hypothesis for the growth of the mesenchyme can explain buckling and postbuckling instabilities. Being completely analytical, it is based on biaxial compressive stresses due to differential growth between layers and it predicts quantitatively the morphological changes. The growth anisotropy increasing with time, the competition between folds and zigzags, is proved to occur as a secondary instability. The model is compared with available experimental data on chick’s duodenum and can be applied to other intestinal tissues, the zigzag being a common and spectacular microstructural pattern of intestine embryogenesis.     

Theoretical prediction of side branch compromise after main branch stenting in coronary bifurcation

One of the main problems of treatment of bifurcation lesions is side branch (SB) stenosis appearing after stent placement in the main vessel.The aim of this study was to create quantitative method for prediction of side branch compromise extent.We accepted that the main mechanism for SB ostial stenosis is flow divider (FD) displacement from stent struts after stent implantation in the main vessel.Using easily measurable parameters from coronary angiography,as SB diameter,angle α (initial angle between axes of parent vessel and SB axis) and angle α' (angle between above mentioned axes after stent placement) we can calculate percentage diameter stenosis at branch ostium (%DS):%DS = sin (α - α')/(tan α).In boundary condition of full FD displacement %DS = cos α.We tested our theoretical predictions with fluoroscopic observation of elastic wall model of bifurcation (45°distal angle between branches)permitting wall deformations with stent.There is full coincidence of values of %DS and percentage area stenosis (%AS).The regular formulas for calculations of %DS and %AS overestimate stenosis severity between 10% and 25%.Our model tests have shown full coincidence between predicted values for %DS and observed values.We demonstrate that part of the SB ostium is not visible in regular angiography and contributes to ostial lumen area.This is a method that permits quantitative prediction of side branch compromise.     

Posterior circulation aneurysms. Results of direct operations

Twenty-eight patients with aneurysms of the posterior circulation were managed by direct operations, 53.6% of these being done within 14 days of a subarachnoid hemorrhage. Transvenous cardiac pacing was used in 4 of the 13 patients with aneurysms of the basilar bifurcation in order to produce a short period of profound hypotension while final dissection and clip application was performed. There were nine patients with posterior-inferior cerebellar artery/vertebral-junction aneurysms, the only one dying having a large aneurysm. The operative technique used in the majority of the 13 patients with basilar bifurcation aneurysms involved subtotal temporal lobectomy, and the operative exposure so obtained was excellent. Five patients died, one of whom rebled from an aneurysm of the basilar artery origin that could only be wrapped, the total mortality being 17.9%. Seventeen (74%) of the 23 survivors were assessed as showing good results; 5 (22%) as showing fair results, and only 1 (4%) as showing a poor result.     

动态市场经济行为模型及其分歧、浑沌现象之分析

根据市场经济的行为特点,结合考虑人的心理因素等影响,提出了一种新的市场动态行为模型,并讨论了它的几种扩展形式,随后对其解的稳定性做了分析。通过仿真实验,发现此系统中存在着非线性动态系统所特有的分歧、浑沌现象。