Clinical and angiographic follow-up after coronary drug-eluting and bare metal stent implantation. Do drug-eluting stents hold the promise?

Promoting Vascular Regeneration as an Alternative to Conventional Angioplasty-Based Intervention

Technologies in interventional Cardiology have evolved from balloon to mechanical ablation, atherectomy, stenting, and brachytherapy to current drug eluting interventional strategies. New challenges are to develop techniques that not only prevent restenosis, but also promote vascular and endothelial healing after (balloon) injury. Endothelial healing approaches range from preventing endothelial injury to restoring endothelial function and reendothelialization by pharmacotherapy and cell therapy. These novel healing strategies warrant further exploration as they may represent an alternative to drug-eluting stent approaches.

[Acute coronary syndrome - a challenge for the cooperation between outpatient and inpatient care]

Acute coronary syndrome (ACS) summarizes all phases of coronary heart disease, which are imminently life-threatening. In clinical practice, these are unstable angina pectoris, acute myocardial infarction, and sudden cardiac death. As the transitions between these clinical entities are smooth, it has been established during the last years to distinguish patients based on ECG findings in groups with (STEMI) and without ST segment elevation (NSTEMI/unstable angina pectoris). Because of the life-threatening character of this disease, continuous monitoring and immediate diagnostic evaluation are mandatory in all patients with suspected ACS. Regularly, this has to be done in the emergency department of a hospital. As the diagnostic and therapeutic management of ACS necessitates rapid decision-making, an optimal cooperation between outpatient and inpatient departments is essential for maximal therapeutic performance. However, it has been shown that only 20-30% of patients admitted to an emergency department with acute chest pain have ACS and only 10-15% have acute myocardial infarction. About 50% of patients presenting with acute chest pain are part of a low-risk group and do not need hospital admission. On the other hand, 2-8% of patients with acute myocardial infarction are misdiagnosed in interdisciplinary emergency departments and discharged too early in spite of an ongoing life-threatening risk. Therefore, chest pain units (CPUs) were founded in many hospitals to optimize the diagnosis and treatment of ACS and the related consumption of financial resources. A task force of the German Society of Cardiology is presently preparing a consensus paper on the basic requirements for CPUs in Germany. The positioning of CPUs at the gateway between outpatient and inpatient care and the additional need for short-term outpatient exercise testing (stress ECG, stress echocardiography, scintigraphy, stress MRI) after ruling out ACS and myocardial infarction, predestine these facilities for new models of managed care including cardiologists in private practice.

Immobilized DNA aptamers used as potent attractors for porcine endothelial precursor cells

Because of their insufficient biocompatibility and high thrombogenicity, small diameter artificial vascular prostheses still do not show a satisfactory patency rate. In vitro endothelialization of artificial grafts before implantation has been established experimentally years ago, but, this procedure is extremely time consuming and expensive. This study deals with the coating of graft surfaces with capture molecules (aptamers) for circulating endothelial progenitor cells (EPCs), mimicking a prohoming substrate to fish out EPCs from the bloodstream after implantation and to create an autologous functional endothelium. Using the SELEX technology, aptamers with a high affinity to EPCs were identified, isolated, and grafted onto polymeric discs using a blood compatible star-PEG coating. A porcine in vitro model that demonstrates the specific adhesion of EPCs and their differentiation into vital endothelial-like cells within 10 days in cell culture is presented. We suggest that the rapid adhesion of EPCs to aptamer-coated implants could be useful to promote endothelial wound healing and to prevent increased neointimal hyperplasia. We hypothesize that future in vivo self-endothelialization of blood contacting implants by homing factor mimetic capture molecules for EPCs may bring revolutionary new perspectives towards clinical applications of stem cell and tissue engineering strategies.

Thiazolidinediones and risk of repeat target vessel revascularization following percutaneous coronary intervention: a meta-analysis

OBJECTIVE

Thiazolidinediones (TZDs) (rosiglitazone and pioglitazone) are a class of antidiabetes agents that have a high affinity for peroxisome proliferator-activated receptor-gamma. TZDs initiate a multitude of physiologic processes that may elicit benefits as systemic agents for the prevention of restenosis requiring revascularization following percutaneous coronary intervention (PCI). Numerous trials have evaluated the impact of TZDs on repeat target vessel revascularization (TVR) in patients following PCI; however, several limitations (small sample size, inconclusive results, and risk factor stratification) complicate definitive conclusions. A meta-analysis was performed to evaluate the impact of TZDs on repeat TVR following PCI.

RESEARCH DESIGN AND METHODS

Included trials met the following criteria: 1) prospective, randomized controlled trials evaluating available TZDs versus standards of care; 2) well-described protocol; 3) minimum of 6 months of follow-up; and 4) data provided on repeat TVR. Data are presented as relative risks (RRs) with 95% CIs.

RESULTS

Seven clinical trials (n = 608) met the inclusion criteria. Upon meta-analysis, the risk of repeat TVR was significantly reduced in patients who received TZD therapy compared with standards of care (RR 0.35 [95% CI 0.22-0.57]). In studies using rosiglitazone (0.45 [0.25-0.83]) and pioglitazone (0.24 [0.11-0.51]), risk of repeat TVR was significantly reduced. Risk of repeat TVR was also significantly reduced among patients with (0.34 [0.19-0.63]) and without (0.37 [0.18-0.77]) diabetes.

CONCLUSIONS

Results from this meta-analysis suggest that TZDs effectively reduce the risk of repeat TVR following PCI.