Alexandre Abizaid

Two-Year Angiographic and Intravascular Ultrasound Follow-Up After Implantation of Sirolimus-Eluting Stents in Human Coronary Arteries

Background—The safety and efficacy of sirolimus-eluting stenting have been demonstrated, but the outcome of patients treated with this novel technology beyond the first year remains unknown. We sought to evaluate the angiographic, intravascular ultrasound (IVUS), and clinical outcomes of patients treated with sirolimus-eluting stents 2 years after implantation. Methods and Results—This study included 30 patients treated with sirolimus-eluting Bx Velocity stenting (slow release [SR], n=15, and fast release [FR], n=15) in São Paulo, Brazil. Twenty-eight patients underwent 2-year angiographic and IVUS follow-up. No deaths occurred during the study period. In-stent late loss was slightly greater in the FR group (0.28±0.4 mm) than in the SR group (−0.09±0.23 mm, P =0.007). No patient had in-stent restenosis. At 2-year follow-up, only 1 patient (FR group) had a 52% diameter stenosis within the lesion segment, which required repeat revascularization. The target-vessel revascularization rate for the entire cohort was 10% (3/30) at 2 years. All other patients had ≤35% diameter stenosis. Angiographic lumen loss at the stent edges was also minimal (in-lesion late loss was 0.33±0.42 mm [FR] and 0.13±0.29 mm [SR]). In-stent neointimal hyperplasia volume, as detected by IVUS, remained minimal after 2 years (FR= 9.90±9 mm3 and SR=10.35±9.3 mm3). Conclusions—This study demonstrates the safety and efficacy of sirolimus-eluting Bx Velocity stents 2 years after implantation in humans. In-stent lumen dimensions remained essentially unchanged at 2-year follow-up in the 2 groups, although angiographic lumen loss was slightly higher in the FR group. Restenosis “catch-up” was not found in our patient population.

Sustained Suppression of Neointimal Proliferation by Sirolimus-Eluting Stents

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 Sao Paulo, Brazil (n=30, 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 ≥50% diameter stenosis at 1 year by angiograp...

Stents farmacológicos no mundo real: impacto de sua disponibilidade no perfil de pacientes tratados por meio de intervenção coronária percutânea em um hospital público

INTRODUCTION: Patients submitted to percutaneous intervention in public hospitals in Brazil have no access to DES. At the beginning of 2006, we participated in an international multicenter registry which made available the routine use of these prosthesis, in a real world scenario. In this article, we intend to identify the clinical, angiographical and procedural profiles of the patients, consecutively treated in two-month subsequent periods, according to the availability of these models, with the aim of identifying eventual changes in their profiles. METHOD: Observational series of 471 patients, divided into two groups: A) 229 cases, treated during a period of availability of DES for routine use; and B) 242 patients subsequently treated as usual (no routine avalilability of DES). There were no inclusion/exclusion criteria. RESULTS: More DES were implanted in group A (44% vs. 2%; p<0.0001). Regarding baseline clinical and angiographic characteristics, a significant predominance of insulin-dependent diabetics was observed in group A (8% vs. 3%; p=0.02), as well as B2 or C lesions (73% vs. 57%; p<0.0001); lesions in bifurcations (15% vs. 9%; p=0.02), and multiarterial interventions (15% vs. 6%; p=0.003). Quantitative angiography identified the A group cases as bearers of stenosis placed in smaller vessels (2.4 mm vs. 2.6 mm; p=0.0004), also exhibiting longer lesions (14.9 mm vs. 12.7 mm; p=0.0008). CONCLUSIONS: The availability of DES changed the profile of the patients treated, being more likely situations prone to restenosis, such as insulin dependent diabetics, multiarterial disease, patients presenting complex lesions, longer lesions and smaller target vessels.

CLINICAL EXPERIENCE WITH A SIROLIMUS-ELUTING NITINOL STENT IN A BIODEGRADABLE POLYMER MATRIX USING THE CARDIOMIND® 0.014″ SPARROW® STENT SYSTEM

Background: Lower plaque trauma may result in favorable late outcomes after coronary stenting. The Sparrow® Coronary Stent System (CardioMind, Inc. Sunnyvale, CA) is a 0.014” guidewire-based stent delivery platform combining the Sirolimus drug in a fully biodegradable SynBiosys polymer matrix on CardioMind’s nitinol stent platform. Stent release is achieved with a novel release mechanism which utilizes a principle of electrochemical dissolution. Both the Bare metal (BMS) and sirolimus eluting (DES) versions are under evaluation in the CARE II randomized clinical study.

Stents and the Endothelium

Abstract The endothelium has a central role in vascular response after percutaneous coronary intervention (PCI) with stents. Cellular and molecular mechanisms control the healing response after PCI, and the degree of this response is related to development of untoward events such as restenosis and device thrombosis. In this chapter, we briefly describe the cascade of events, which will ultimately result in stent endothelialization and different responses according to the device deployed: bare-metal vs. drug-eluting stents. Dysfunctional endothelial response, represented by pathologic vessel remodeling and delayed healing, is also addressed, as well as the potential inflammatory mechanism related to these devices. Finally, we briefly discuss the novel bioresorbable vascular scaffolds (BRS or bioabsorbable stent), and potential advantages to endothelium function that might arise from this new technology.

When calcium helps: percutaneous coronary intervention without contrast medium in an elderly female patient with renal insufficiency and unstable angina

RESUMO O uso de contraste iodado durante a realizacao de procedimentos coronarianos pode levar ao desenvolvimento de nefropatia induzida por contraste, principalmente em idosos, diabeticos e pacientes com lesao renal previa, aumentando a morbimortalidade. Nao existe tratamento especifico para esta condicao, e a prevencao por meio do uso de baixo volume de contraste e hidratacao previa ao procedimento continua como a melhor estrategia. Apresentamos um caso de intervencao coronaria percutânea em paciente idosa, com insuficiencia renal cronica e angina instavel, [...]

Clinical Data of Eluting Stents

Stents were introduced into clinical practice in the late 1980s. Subsequently, the Belgian Netherlands STENT and the Stent Restenosis Study trials established the “stent era” in coronary revascularization (1,2), despite an subacute thrombosis (SAT) rate of 3.7%, and more vascular bleeding complications with stents vs balloon angioplasty. Major advances in stent technologies have occurred in the past decades. Stent design has been altered to afford more flexibility, higher radial strength, lower profile, and minimal metallic coverage. Efforts are now directed at coating a stent with single or multiple bioactive antirestenosis agents, which is delivered uniformly to the underlying tissue, namely drug-eluting stents (DES). Recent clinical data (Table 1), which will be discussed in this chapter, have demonstrated the potential of these new stent technologies to become the predominant revascularization strategy in the near future. The list of promising DES technologies is long. Many of these devices were supported by sound basic science data, but only a few have proven clinical feasibility (Table 1). Based on the mechanism of action of the biological compound and its target in the restenotic process, DES were grouped as immunosuppressive, antiproliferative, anti-inflammatory, antithrombotic, and prohealing. Some agents, such as sirolimus, may affect multiple targets in the restenotic process but will be discussed under a single category.

Braquiterapia intracoronariana. Tratamento da reestenose intra-stent com o sistema Beta-Cath: experiência inicial na América Latina

OBJECTIVE: To assess the safety and efficacy of intracoronary brachytherapy using the Beta-Cath systemTM for preventing recurrence of in-stent restenosis (ISR), by analyzing clinical, angiographic, and intracoronary ultrasound (ICUS) results. METHODS: This study assessed 30 patients with ISR in native coronary arteries who underwent balloon catheter angioplasty followed by intracoronary beta radiation with the Beta-Cath systemTM (90Sr/Y). RESULTS: The study comprised complex, extensive (18.66±4.15 mm) restenotic lesions, 77% of which were of the diffuse-proliferative type. Brachytherapy was successful in 100% of the cases. The mean radiation dose used was 20.7±2.3 Gy, released for a mean period of 3.8±2.1 minutes. On late follow-up, the in-stent minimum luminal diameter (MLD) slightly decreased (from 1.98±0.30 mm to 1.84±0.39 mm at 6 months; P=0.13), with a late loss of 0.14±0.18 mm. The intrasegmentary MLD was significantly smaller than the in-stent diameter (1.55±0.40 mm vs 1.84±0.39 mm; P=0.008), and was associated with a more significant late loss (0.40±0.29 mm vs 0.14±0.18 mm; P=0.0001). On ICUS, a mild increase of 6.8±14.3 mm3 in the neointimal tissue was observed at 6 months (P=0.19), and the percentage of volumetric obstruction increased by 4.7±7.5%. Binary restenosis and revascularization of the target vessel recurred in 17% of the cases; late occlusion associated with myocardial infarction occurred in 1 case (3%). Event-free survival was 80%. CONCLUSION: The management of in-stent restenosis with intracoronary beta radiation proved to be a safe and effective procedure, with a high rate of immediate success, representing a therapeutic option for inhibiting neointimal hyperplasia.