Background-We have previously reported a virtual absence of neointimal hyperplasia 4 months after implantation of sirolimus-eluting stents. The aim of the present investigation was to determine whether these results are sustained over a period of 1 year. Methods and Results-Forty-five patients with de novo coronary disease were successfully treated with the implantation of a single sirolimus-eluting Bx VELOCITY stent in São Paulo, Brazil (nϭ30, 15 fast release [group I, GI] and 15 slow release [GII]) and Rotterdam, The Netherlands (15 slow release, GIII). Angiographic and volumetric intravascular ultrasound (IVUS) follow-up was obtained at 4 and 12 months (GI and GII) and 6 months (GIII). In-stent minimal lumen diameter and percent diameter stenosis remained essentially unchanged in all groups (at 12 months, GI and GII; at 6 months, GIII). Follow-up in-lesion minimal lumen diameter was 2.28 mm (GIII), 2.32 mm (GI), and 2.48 mm (GII). No patient approached the Ն50% diameter stenosis at 1 year by angiography or IVUS assessment, and no edge restenosis was observed. Neointimal hyperplasia, as detected by IVUS, was virtually absent at 6 months (2Ϯ5% obstruction volume, GIII) and at 12 months (GIϭ2Ϯ5% and GIIϭ2Ϯ3%). Key Words: angiography Ⅲ drugs Ⅲ stents Ⅲ restenosis Ⅲ ultrasonics D espite major technological advances in the past decades, of which the coronary stent is one of the most important, the percutaneous treatment of coronary artery disease is still hampered by a 20% to 30% incidence of restenosis. The list of candidate therapies and devices for prevention of restenosis after angioplasty is long and ever expanding. However, few if any have substantially improved the result of stenting for the treatment of de novo lesions. Intracoronary radiation has so far proven to be effective for the treatment of in-stent restenosis but not for the treatment of de novo lesions. 1 As a result of their ability to deliver prolonged and sufficient intramural drug concentrations to the target coronary segment, drug-eluting stents have emerged as a potential solution for restenosis. Our group has recently reported an almost complete absence of neointimal hyperplasia 4 months after implantation of sirolimus-eluting Bx VELOCITY stents. 2 The local release of sirolimus (rapamycin, Rapamune), a natural macrocyclic lactone with potent immunosuppressive action, 3 resulted in elimination of restenosis in this first series of patients. Comparable results have only been observed after the implantation of high-activity ␤-emitting stents (9 mm 3 of neointimal hyperplasia at 6-month follow-up). 4 However, a worrying late progression of in-stent neointimal hyperplasia was observed between 6 months and 1 year after implantation of radioactive stents. 5 Conclusions-This See p 1996The aim of the present investigation was to determine whether sirolimus-eluting stents produce a sustained suppression of the neointimal proliferation over a period of 1 year or merely delay the restenosis process. Methods Study PopulationForty-five patients with nati...

In this secondary post-hoc analysis, BMS were associated with lower long-term mortality than SES for SVG disease. Also, the 6-month reduction in repeated revascularization procedures with SES was lost at longer-term follow-up. (RRISC Study: Reduction of Restenosis In Saphenous Vein Grafts With Cypher Sirolimus-Eluting Stent; http://clinicaltrials.gov/ct/show/NCT00263263?order=1; NCT00263263).

Background-Temperature heterogeneity of atherosclerotic plaques has been associated with macrophage accumulation in ex vivo studies. We investigated in vivo whether modifying the cell composition of rabbit atherosclerotic plaques by dietary cholesterol lowering can influence temperature heterogeneity. Methods and Results-Twenty New Zealand rabbits were randomized to either a normal (nϭ10) or cholesterol-rich (0.3%) diet (nϭ10) for 6 months. Thereafter, intravascular ultrasound and intravascular catheter-based thermography of the surface of aortic arch and descending aorta were performed in all animals. Ten control and 5 hypercholesterolemic rabbits were euthanized, and their aortas were analyzed histologically. The 5 remaining rabbits received a normal diet for 3 months and underwent repeat ultrasound and thermography before euthanasia followed by histology. Ex vivo temperature was measured in 3 additional rabbits at 6 months to correlate local temperature with local plaque composition. In control animals, plaque formation and temperature heterogeneity were absent. In hypercholesterolemic rabbits, plaque formation was prominent in the thoracic aorta. Plaques were composed of fibromuscular tissue and contained, underneath endothelial cells, an accumulation of foam cells of macrophage origin. Temperature heterogeneity was markedly elevated and increased with plaque thickness. Importantly, after 3 months of cholesterol lowering, plaque thickness remained unchanged, but temperature heterogeneity was significantly decreased. This paralleled plaque histology, which showed a marked loss of macrophages. The ex vivo experiments demonstrated the relation between local temperature and local total macrophage mass. Conclusions-In vivo temperature heterogeneity of rabbit atherosclerotic plaques is determined by plaque composition. In vivo thermography may have important clinical implications in the assessment of plaque composition.

Sirolimus-eluting stents significantly reduce late loss in SVG as opposed to BMS. This is associated with a reduction in restenosis rate and repeated target lesion and vessel revascularization procedures. (The RRISC Study; http://clinicaltrials.gov/ct/show; NCT00263263).