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Coronary bifurcation lesions are a common challenge for interventional cardiologists, for which there is no clear consensus on optimal treatment. The side branch (SB) ostium has become the focus of new treatment strategies because it is a common site of restenosis. In comparison, restenosis and reintervention rates in the main branch are acceptably low, reflecting improved techniques and greater use of drug-eluting stents. Many different companies are evaluating dedicated bifurcation devices that are designed to offer easy access to the SB, but that differ in concept and in the degree of coverage provided to the SB ostium. Some are bare metal stents, whereas several are drug-eluting iterations based on platforms used in conventional stents. The promise of these dedicated bifurcation devices is illustrated by early results from single-arm clinical studies. [ABSTRACT FROM AUTHOR]

Objectives: Poorly defined measurement impairs interinstitutional comparison, interpretation of results, and process improvement in health care operations. We sought to develop a unifying framework that could be used by administrators, practitioners, and investigators to help define and document operational performance measures that are comparable and reproducible., Study Design: Retrospective analysis., Methods: Health care operations and clinical investigators used an iterative process consisting of (1) literature review, (2) expert assessment and collaborative design, and (3) end-user feedback. We sampled the literature from the medical, health systems research, and health care operations (business and engineering) disciplines to assemble a representative sample of studies in which outpatient health care performance metrics were used to describe the primary or secondary outcome of the research., Results: We identified 2 primary deficiencies in outpatient performance metric definitions: incompletion and inconsistency. From our review of performance metrics, we propose the FASStR framework for the Focus, Activity, Statistic, Scale type, and Reference dimensions of a performance metric. The FASStR framework is a method by which performance metrics can be developed and examined from a multidimensional perspective to evaluate their comprehensiveness and clarity. The framework was tested and revised in an iterative process with both practitioners and investigators., Conclusions: The FASStR framework can guide the design, development, and implementation of operational metrics in outpatient health care settings. Further, this framework can assist investigators in the evaluation of the metrics that they are using. Overall, the FASStR framework can result in clearer, more consistent use and evaluation of outpatient performance metrics.

Healthcare providers can benefit from adding less costly capacity to their existing resources in order to satisfy demand while maintaining the quality of patient care. The addition of mid-level service providers (MLSPs) such as physician assistants or nurse practitioners that carry out portions of patient care provides a viable alternative for adding physician capacity. This research considers the circumstances under which adding an MLSP to a single-physician outpatient office becomes the best strategy for the clinic, and determines how scheduling policies from the widely-researched single-stage environment should be adjusted for a multi-stage environment. Compared to a single-stage system where a physician completes all portions of the service, we show that adding an MLSP can reduce patient waiting time, patient flow time, and physician service time with patients. This, in turn, can enable the clinic to see more patients and/or free up physician time for other tasks. Appointment scheduling rules are developed for a multi-stage outpatient service system using a simulation optimization approach. Performance measures focus on the patient experience and clinic operation before and during each stage of service.

Although current everolimus-eluting coronary stents have shown improved event-free survival within the first year following implantation compared with bare-metal stents or earlier generation drug-eluting stents, they remain associated with an ongoing risk for adverse outcomes (thrombosis, myocardial infarction, and restenosis) beyond 1 year at rates similar to those observed following bare-metal stent deployment. This ongoing very late hazard has been attributed to the permanent presence of the metal frame and/or polymer in these stents. The Absorb everolimus-eluting bioresorbable vascular scaffold (Absorb BVS) has been developed to provide mechanical support and drug-delivery functions similar to metallic drug-eluting stents, followed by complete resorption with recovery of more normal vascular structure and function, thus avoiding the limitations associated with permanent metallic endovascular prostheses. Absorb BVS has shown safety and efficacy in the dedicated clinical trial development program of Abbott Vascular and in an array of investigator-sponsored studies involving a broad spectrum of clinical (patient) as well as coronary anatomic complexity. Longer-term evidence, largely limited to single-arm studies, appears to reflect durable safety and efficacy and suggests Absorb BVS to be an attractive therapeutic option. Interim evidence from a series of randomized-clinical trials (RCTs) comparing Absorb BVS with the Xience cobalt-chromium metallic everolimus-eluting stent has shown noninferiority of Absorb BVS with respect to target lesion failure (composite occurrence of cardiac death, target vessel-related myocardial infarction, and ischemia-driven target lesion revascularization) beyond the first year, with no statistically significant differences in other safety/efficacy measures. However, concerns do exist in terms of increased rates of scaffold thrombosis, the risk for which may be mitigated by improved patient and lesion selection, procedural technique, and device iteration. We provide an overview of the evolution of percutaneous coronary intervention, in-vivo characterization of Absorb BVS resorption, and a summary with a critical evaluation of available evidence from RCTs, pooled analyses, and meta-analyses of RCTs for the safety and efficacy of Absorb BVS obtained primarily following the treatment of noncomplex coronary lesions in patients with stable ischemic heart disease and/or stabilized acute coronary syndromes.

For many years, coronary artery bypass graft surgery has been the gold standard for revascularization of patients with left main disease; however, increasing evidence suggests that percutaneous coronary intervention with drug-eluting stents may be an acceptable alternative or even preferred in select cases. This review will present clinical evidence examining the outcomes of drug-eluting stents compared to coronary artery bypass graft surgery for unprotected left main coronary artery disease and discuss the anatomic factors, patient variables, and clinical strategies that may dictate choice of revascularization modality for patients with left main disease. If percutaneous coronary intervention is selected to treat unprotected left main disease, meticulous technique is essential to optimize outcomes, including use of procedural physiology and imaging guidance, optimal stent and adjunct pharmacology use, and expert management of the distal bifurcation. Finally, issues of equipoise and uncertainty are identified, representing areas for future investigation., (© 2015, Wiley Periodicals, Inc.)

The Xience Side Branch Access (SBA) stent is an everolimus-eluting stent designed specifically for branching coronary geometry, providing wire access into the side branch (SB) regardless of the planned treatment strategy. The stent is delivered via a low-profile, dual-lumen, and single-tip catheter. A single inflation deploys the stent in the main branch (MB) and opens a portal into the SB. It is through this portal opening, allowing wire access into the SB, that this device differentiates itself from certain other dedicated bifurcation devices currently in various stages of development and testing. The Xience SBA stent was compared with a standard Multi-Link Vision® stent using a provisional T-stenting strategy in an ovine beating heart model. The Xience SBA stent tended to be deployed with less mean contrast usage (21.05 vs. 43.23 mL; P = 0.09), shorter fluoroscopy time (2.55 vs. 4.52 minute; P = 0.12), and lower rates of guidewire entanglement (16% vs. 100%) compared with the workhorse stent. As a result, the total procedure time with the Xience SBA stent was significantly shorter than that with the standard stent (5.46 vs. 8.65 minute; P = 0.01). The Xience SBA stent was also evaluated by four recently trained interventionalists who had no previous experience with the device. Using a perfused synthetic heart model, SB access time was reduced by 54%, average fluoroscopy time was reduced by 46%, and average contrast usage was lowered by 39% with the Xience SBA compared with the standard stent. Initial experience in the ovine model suggests that the Xience SBA stent is also amenable for use in distal left main coronary artery disease, regardless of whether it is deployed in the left ascending coronary artery or left circumflex artery and the portal opened in the opposing vessel. On the basis of these experimental results, the Xience SBA stent is an easy to use and versatile device for the purpose of SB access and potentially for the treatment of bifurcation coronary artery lesions., (©2012, Wiley Periodicals, Inc.)

Within labeled indications, drug-eluting stents (DES) are as safe as bare-metal stents (BMS). Data from key randomized, controlled trials comparing paclitaxel-eluting stents with BMS or sirolimus-eluting stents with BMS show no difference in risk of death/myocardial infarction or stent thrombosis using uniform definitions of stent thrombosis. However, these trials and other analyses indicate a difference in time distribution of stent thrombosis, with more cases of stent thrombosis occurring later (ie, after 1 year) in patients with DES--a problem to which the lack of adequate antiplatelet therapy appears to be a main contributor. A consistent finding from randomized, controlled trials of DES versus BMS is the significantly reduced need for reintervention associated with DES use. In the absence of any other differences in safety between DES and BMS, this reduced need for reintervention constitutes a significant advantage for DES in clinical practice.

The treatment of bifurcation coronary artery disease is a common challenge facing the interventional cardiologist. There have been major advances in techniques as well as more widespread use of drug-eluting stents; both appear to have contributed to the realization of single-digit target lesion revascularization rates as well as improvement in short-term complications such as stent thrombosis. Adequate treatment of the side branch ostium, the site most frequently described as being susceptible to restenosis, has become the focus of newer bifurcation techniques as well as dedicated devices for the treatment of this complex lesion subset. Since main branch reintervention rates are sufficiently low and silent restenosis of the side branch ostium is an all-too-common finding, there is no clear consensus on the optimal treatment strategy for bifurcation coronary disease. The following is a comprehensive review of those commonly used techniques as well as dedicated devices currently under development for the treatment of bifurcation coronary artery disease.

Remarkable advances in our ability to achieve early and sustained culprit vessel patency in acute myocardial infarction have been satisfying, but our enthusiasm must be tempered by the knowledge that the overall treatment strategy often leaves an inadequate long term clinical result. Early success of percutaneous therapy as judged at angiography does not ensure recovery of normal left ventricular function, the most important determinant of survival in acute myocardial infarction. That congestive heart failure and death still complicate apparently successful percutaneous procedures underscores the need to develop novel therapies which salvage jeopardized myocardium, limit infarct size and preserve left ventricular function. An ever-increasing body of data demonstrates a multifactorial mechanism of myocyte injury and microvascular collapse and also demonstrates that these injuries seem to have a profound impact on long-term outcomes. Given these findings, microvascular protection during the acute event has become the focus of a variety of emerging technologies. The goal of these mechanical and pharmacologic therapies is the restoration of normal metabolic function at the myocyte level. The acute pathologic mechanisms which contribute to sustained left ventricular dysfunction despite angiographically successful revascularization will be reviewed as will be several strategies being developed to counter these pathologic mechanisms.

Objective: The purpose of this study was to evaluate the long-term outcomes of bifurcation coronary lesions treated with a novel technique called "balloon alignment T-stenting"., Background: The optimal technique for the treatment of bifurcation coronary disease has not yet been established., Methods: Twenty-six patients with bifurcation coronary lesions were treated with currently available drug-eluting stent (DES) platforms. This was a pilot study to determine the long-term efficacy of a novel technique, "balloon alignment T-stenting". Based on this technique we performed 6-month anniversary angiography to determine restenosis rates for both main and side branch lesions treated., Results: Twenty-six main branches and 27 side branches were treated with this novel technique. Angiographic 6-month follow up was available for all 26 patients treated. There were no postprocedural mortalities and no cases of postprocedural stent thrombosis during the follow-up period. At 6-month anniversary angiography, no evidence of main branch restenosis was seen. However, there were 2 cases of side branch restenosis for a total side branch restenosis rate of 7.4%. Target lesion revascularization for the 26 patients in the study was 7.6%. The total major adverse cardiac event rate for the group as a whole was 15.4%, with 2 periprocedural non-Q-wave myocardial infarctions and 2 target lesions requiring revascularization at 6 months., Conclusion: Using currently available DES platforms, the data compiled from this small, single-center pilot study suggest that balloon alignment T-stenting may represent a reasonable approach for the treatment of bifurcation coronary artery disease. However, more comprehensive, larger-scale trials will be required to validate these preliminary findings.

Health-care consumers continue to be frustrated with long waits, especially when an appointment has been made. However, providers who book appointments are under increasing pressure to maximize utilization so that revenues will be increased and costs reduced. Thus, scheduling appointments involves opposing forces that are difficult to manage. This challenge is addressed in a rolling-horizon environment with fluctuating demand loads. These two issues have not been explored previously in the appointment-scheduling research. Two management policies are considered: overload rules (OLR) and rule delay (RD). The former considers different scheduling methods (overtime, double booking) when demand loads are high, and the rule delay policy considers when to implement the overload rules. These methods are explored for six different demand patterns/loads and evaluated with a variety of client and server-oriented measures. The results show that managers of appointment scheduling systems must carefully consider which measures are most important to them since the best choices of OLR and RD vary substantially by measure. Good choices also depend on the general type of client demand pattern. Thus, to consider the various tradeoffs between client and server measures a matrix is developed that outlines good choices for each scenario.

Because of the frequent occurrence of premature cardiovascular disease in patients with non-insulin-dependent, type II diabetes mellitus (NIDDM), the attenuated fibrinolytic activity of plasma from type II diabetic patients with increased concentrations of plasminogen activator inhibitor type-1 (PAI-1), and the fact that insulin stimulates synthesis of PAI-1 by human hepatic cells in vitro, we and others have hypothesized that accelerated vascular disease in type II diabetes may result in part from impaired fibrinolysis secondary to excessive elaboration of PAI-1 stimulated by insulin. Alternatively, the hyperglycemia associated with type II diabetes could influence the synthesis and secretion of PAI-1 directly. The present study was performed to determine whether PAI-1 secretion is or is not sensitive to the prevailing concentration of glucose in the conditioned medium of endothelial and liver cells, which are thought to be the major sources of circulating PAI-1 in vivo. Confluent cells were exposed to 0, 2.8, 5.6, 11.1, or 22.2 mmol/L (0, 50, 100, 200, or 400 mg/dL) glucose in medium without serum and subsequently to media with or without insulin (7.3 nmol/L). Secretion of PAI-1 by highly differentiated human hepatoma (Hep G2) cells did not increase as a function of increasing concentrations of glucose, whether or not insulin was present. In contrast, with pig aortic endothelial cells, the secretion of PAI-1 increased significantly with extracellular glucose with or without insulin. The increases in PAI-1 were specific (as shown by metabolic labeling experiments) and not attributable to osmotic effects (as shown by replacement of glucose by sorbitol).(ABSTRACT TRUNCATED AT 250 WORDS)

Background: Both tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) are synthesized by vascular endothelium, whereas hepatocytes synthesize PAI-1 but not t-PA. Non-insulin-dependent diabetes mellitus (NIDDM) is associated with decreased fibrinolytic activity in blood secondary to increased PAI-1 activity, and the increase in PAI-1 activity is correlated with the magnitude of elevation of plasma immunoreactive insulin. To determine whether the increased PAI-1, known to be associated with accelerated coronary artery disease in non-diabetic subjects, is a consequence of direct effects of insulin on endothelial cells, we performed the present study with primary cultures of human aortic endothelial cells., Methods: Endothelial cells isolated from human aortas from donor hearts for transplantation were grown to confluence and exposed to selected concentrations of agonists. Accumulation of t-PA and PAI-1 in conditioned media was quantified, as was PAI-1 activity., Results: Insulin at pharmacologic concentrations did not alter either PAI-1 or t-PA production by the human aortic endothelial cells, although insulin stimulated PAI-1 synthesis in human hepatoma (Hep G2) cells as expected. Transforming growth factor-beta (TGF-beta) stimulated endothelial cell PAI-1 production markedly, indicating that the cells could respond positively to stimulation in vitro. PAI-1 activity in the conditioned media was zero under all conditions, which was indicative of the rapid inactivation and degradation of PAI-1 known to occur in media devoid of vitronectin., Conclusions: The decreased fibrinolytic activity in blood seen in patients with NIDDM appears to reflect direct effects of insulin or its precursor on hepatocytes rather than on endothelial cells.