Koronare Stent-Thrombosen: Was gibt es Neues für 2011?

Zusammenfassung: Stent-Thrombosen (ST) stellen eine schwerwiegende Komplikation der perkutanen Behandlung der koronaren Herzkrankheit dar und sind mit einer hohen Sterblichkeitsrate von bis zu 45% verbunden. Bare-Metal-Stents (BMS) und Drug-Eluting-Stents (DES) haben eine ähnliche Inzidenz für frühe (0,6-1,2%) und späte (0,3-0,4%) ST. Sehr späte ST (über 1Jahr nach Stent-Implantation) weisen einen unabhängigen pathogenetischen Mechanismus auf und werden fast ausschließlich nach der Implantation von DES der 1. Generation mit einer Rate von 0,6% Ereignissen/Jahr beobachtet. Starke Determinanten für das Auftreten früher und später ST sind eine unzureichende Thrombozytenaggregationshemmertherapie, ein akutes Koronarsyndrom, Auftreten von Komplikationen während des Eingriffs, das unmittelbare postprozedurale Resultat sowie Begleiterkrankungen des Patienten. Sehr späte ST haben eine eigenständige Pathogenese - eine direkt medikamentös bedingte Hemmung der Reendothelialisierung und eine durch das Medikament oder das Polymer des Stent verursachte chronische Entzündung der Gefäßwand mit in der Folge gestörter Reendothelialisierung, welche zu einem positivem Remodelling der Arterienwand mit sekundärer Malapposition des Stent führt. In der Prävention der ST spielt die duale Thrombozytenaggregationshemmertherapie eine zentrale Rolle. Das vorzeitige Absetzen dieser Therapie in den ersten 6Monaten nach Stent-Implantation führt zu einer erhöhten Inzidenz von ST. Zur Prävention gehört auch der Fortschritt. Erfreulicherweise haben die Verwendung von DES der 2. Generation und neue Thrombozytenaggregationshemmertherapien die Inzidenz der ST signifikant verringer

Acute coronary syndrome in patients younger than 30 years--aetiologies, baseline characteristics and long-term clinical outcome.

Coronary atherosclerosis begins early in life, but acute coronary syndromes in adults aged <30 years are exceptional. We aimed to investigate the rate of occurrence, clinical and angiographic characteristics, and long-term clinical outcome of acute coronary syndrome (ACS) in young patients who were referred to two Swiss hospitals. From 1994 to 2010, data on all patients with ACS aged <30 years were retrospectively retrieved from our database and the patients were contacted by phone or physician's visit. Baseline, lesion and procedural characteristics, and clinical outcome were compared between patients in whom an underlying atypical aetiology was found (non-ATS group; ATS: atherosclerosis) and patients in whom no such aetiology was detected (ATS group). The clinical endpoint was freedom from any major adverse cardiac event (MACE) during follow-up. A total of 27 young patients with ACS aged <30 years were admitted during the study period. They accounted for 0.05% of all coronary angiograms performed. Mean patient age was 26.8 ± 3.5 years and 22 patients (81%) were men. Current smoking (81%) and dyslipidaemia (59%) were the most frequent risk factors. Typical chest pain (n = 23; 85%) and ST-segment elevation myocardial infarction (STEMI; n = 18 [67%]) were most often found. The ATS group consisted of 17 patients (63%) and the non-ATS group of 10 patients (37%). Hereditary thrombophilia was the most frequently encountered atypical aetiology (n = 4; 15%). At 5 years, mortality and MACE rate were 7% and 19%, respectively. ACS in young patients is an uncommon condition with a variety of possible aetiologies and distinct risk factors. In-hospital and 5-year clinical outcome is satisfactory

Design and testing of hydrophobic core/hydrophilic shell nano/micro particles for drug-eluting stent coating

In this study, we designed a novel drug-eluting coating for vascular implants consisting of a core coating of the anti-proliferative drug docetaxel (DTX) and a shell coating of the platelet glycoprotein IIb/IIIa receptor monoclonal antibody SZ-21. The core/shell structure was sprayed onto the surface of 316L stainless steel stents using a coaxial electrospray process with the aim of creating a coating that exhibited a differential release of the two drugs. The prepared stents displayed a uniform coating consisting of nano/micro particles. In vitro drug release experiments were performed, and we demonstrated that a biphasic mathematical model was capable of capturing the data, indicating that the release of the two drugs conformed to a diffusion-controlled release system. We demonstrated that our coating was capable of inhibiting the adhesion and activation of platelets, as well as the proliferation and migration of smooth muscle cells (SMCs), indicating its good biocompatibility and anti-proliferation qualities. In an in vivo porcine coronary artery model, the SZ-21/DTX drug-loaded hydrophobic core/hydrophilic shell particle coating stents were observed to promote re-endothelialization and inhibit neointimal hyperplasia. This core/shell particle-coated stent may serve as part of a new strategy for the differential release of different functional drugs to sequentially target thrombosis and in-stent restenosis during the vascular repair process and ensure rapid re-endothelialization in the field of cardiovascular disease