Publications

The traditional metallic stents have significant limitations as they predispose to late thrombosis, may preclude surgical revascularization and distort vessel physiology. Bioresorbable scaffolds (BRSs) are a relatively new technology introduced to overcome these drawbacks. The potential of these devices as well as the reported results from their clinical applications attracted interest and drove research and industry towards the development of new BRSs and the improvement of the existing devices. Thus, over the last years considerable progress has been made and today numerous BRSs are available. The aim of this review article is to highlight the potentialities of these devices, describe the evidence from the recent clinical trials and discuss the advantages, limitations and concerns that were aroused during the first implementation of BRSs in clinical arena.

No abstract is provided for this article.

An influx of eosinophils into the lungs occurs in several pulmonary disorders. However, the mechanisms involved remain unknown. Lung epithelial cell release of eosinophil chemotactic factors such as RANTES or macrophage inflammatory protein-1 alpha (MIP-1 alpha) could account for the influx of eosinophils into the lungs. In order to demonstrate the potential role for lung epithelial cells to release RANTES and/or MIP-1 alpha, we investigated the mRNA expression and protein release in cultured A549 cells. Tumor necrosis factor-alpha (TNF alpha) and interleukin-1 beta (IL-1 beta) induced a time- and dose-dependent increase in RANTES mRNA expression and protein release. In contrast, MIP-alpha protein release was not detectable in these cells. As corticosteroids decrease the influx of eosinophils into the lungs in vivo, we also investigated the capacity of dexamethasone to decrease the TNF alpha-induced RANTES release and mRNA expression; both were decreased in a time- and concentration-dependent manner. Dexamethasone did not affect the TNF alpha-induced RANTES mRNA half-life and did not require protein synthesis to manifest an inhibitory effect. Supernatant from cells stimulated with TNF alpha and IL-1 beta increased eosinophil chemotaxis and this was also inhibited by dexamethasone. These findings suggest a role for RANTES release by lung epithelial cells in the recruitment of eosinophils into the lungs in pulmonary disorders such as interstitial lung diseases, idiopathic pulmonary fibrosis, or asthma and suggest that one beneficial effect of corticosteroids may be inhibition of lung epithelial cell RANTES mRNA expression and protein release.

Background Coronary microvascular dysfunction (CMD) subsequent to ST-elevation myocardial infarction (STEMI) is increasingly recognized as a determinant of adverse clinical prognoses. Despite its significance, CMD diagnosis is rare in clinical settings, mainly due to its complexity and technical challenges. Considering these challenges, this study endeavors to explore the diagnostic potential of Trimethylamine N-oxide (TMAO), a metabolite derived from gut microbiota. TMAO has been implicated in the pathogenesis of endothelial dysfunction and atherosclerosis, suggesting its utility as a novel biomarker for CMD and determining prognosis. Purpose To investigate the association between TMAO levels and CMD in STEMI patients, evaluating TMAO's utility as a biomarker for CMD and prognosis predictor. Methods In this prospective, observational study, 210 STEMI patients were enrolled. At the 3-month follow-up, these patients were subjected to comprehensive coronary physiology assessments, including measurements of coronary flow reserve (CFR), fractional flow reserve (FFR), and the index of microcirculatory resistance (IMR) via utilization of pressure-temperature sensor-tipped wires. CMD was diagnosed in patients presenting with an IMR ≥ 25 or a CFR < 2.0, alongside an FFR > 0.80. Levels of TMAO, C-reactive protein (CRP), and brain natriuretic peptide (BNP), along with other traditional biomarkers were measured at baseline, 3 and 12-month follow-up. Using the Delong test and Youden index to find optimal TMAO cutoffs for CMD detection, due to no predefined TMAO threshold. The primary endpoint was the incidence of CMD at 3 months, with the secondary endpoint being major adverse cardiovascular and cerebrovascular events (MACCE) at 12 months. Results Among enrolled patients, 85 (40.5%) were female, with a median age of 65 (IQR: 58-76). TMAO's baseline receiver operating characteristic (ROC) curve area was 0.55 (95% CI: 0.46-0.64; p=0.426), improving to 0.80 (95% CI: 0.73-0.87; P<0.001) at 3-month follow-up. An optimal TMAO cutoff of 3.91 μM achieved 75% sensitivity (95% CI: 0.63-0.86) and 82% specificity (95% CI: 0.76-0.88), outperforming BNP and CRP with ROC areas of 0.62 and 0.67, respectively. Patients were divided into low (n=140) and high (n=70) TMAO groups at the 3.91 μM threshold. A higher percentage of females was noted in the high TMAO group (55.7% vs. 32.9%; p<0.001). Clinical characteristics and risk factors like stroke and CAD history showed no significant differences across TMAO groups. Multivariable logistic regression revealed TMAO levels at 3 months as an independent predictor for CMD. A cubic spline curve indicated a marked increase in CMD odds with TMAO between 3 and 6 μM.The Incidence of MACCE was significantly higher in patients with a TMAO≥3.91 (41.4% vs 10.7%; p < 0.001). Conclusion Elevated TMAO levels 3 months post-STEMI are significantly associated with increased CMD risk, and significantly predict MACCE.TMAO as a Biomarker for CMD and MACCETMAO Cubic Spline Analysis for CMD Odds

With the thrombogenic tendency and permanent implant nature of metallic stents, synthetic polymers have been proposed as candidate materials for stents and local drug delivery designs. We investigated the biocompatibility of several synthetic polymers after experimental placement in the coronary artery.Five different biodegradable polymers (polyglycolic acid/polylactic acid [PGLA], polycaprolactone [PCL], polyhydroxybutyrate valerate [PHBV], polyorthoester [POE], and polyethyleneoxide/polybutylene terephthalate [PEO/ PBTP]) and three nonbiodegradable polymers (polyurethane [PUR], silicone [SIL], and polyethylene terephthalate [PETP]) were tested as strips deployed longitudinally across 90 degrees of the circumferential surface of coil wire stents. Appropriately sized polymer-loaded stents were implanted in porcine coronary arteries of 2.5- to 3.0-mm diameter. Four weeks after implantation, stent patency was assessed by angiography followed by microscopic examination of the coronary arteries. The biodegradable PCL, PHBV, and POE and the nonbiodegradable PUR and SIL evoked extensive inflammatory responses and fibrocellular proliferation (thickness of tissue response: 0.79 +/- 0.22, 1.12 +/- 0.01, 2.36 +/- 0.60, 1.24 +/- 0.36, and 1.43 +/- 0.15 mm, respectively). Less but still severe responses were observed for the biodegradable PGLA and PEO/PBTP (0.46 +/- 0.18 and 0.61 +/- 0.23 mm, respectively) and for the nonbiodegradable PETP (0.46 +/- 0.11 mm).An array of both biodegradable and nonbiodegradable polymers has been demonstrated to induce a marked inflammatory reaction within the coronary artery with subsequent neointimal thickening, which was not expected on the basis of in vitro tests. The observed tissue response may be attributable to a combination of parent polymer compound, biodegradation products, and possibly implant geometry.

No abstract is provided for this article.