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Currently percutaneous aortic valve replacement (PAVR) is indicated for patients at high surgical risk or for inoperable patients. Preprocedural evaluation is crucial to select the patients who will benefit the most and have the procedure done safely. This review will focus on risk assessment and the value of the available risk score systems, and on the screening process, which is the key for success in PAVR. Because of the large delivery system, careful evaluation of iliofemoral vessels is crucial. It is important to know the amount of atherosclerosis and plaque in the aortic arch and ascending aorta for potential risk for neurological events. Accurate measurement of aortic annulus diameter and coronary arteries origin before the procedure is important. Specific coexistent conditions can influence the procedure, such as left ventricular function or left ventricular hypertrophy with narrow outflow tract. Assessment of all these components is necessary for procedural planning of access approach, valve sizing, and deployment. [ABSTRACT FROM AUTHOR]

Objective: To examine the effects of intracoronary PhotoPoint photodynamic therapy (PDT) with a new photosensitiser, MV0611, in the overstretch balloon and stent porcine models of restenosis. Methods: 28 pigs were injected with 3 mg/kg of MV0611 systemically 4 h before the procedure. Animals were divided into either the balloon overstretch injury (BI) group (n = 19) or the stented group (n = 9). After 81, a centred delivery catheter was positioned in the artery to cover the injured area, and light (532 nm, 125 J/cm²) was applied to activate the drug (n = 10). Control arteries (n = 9) were not activated by light. In the stented group, the drug was light activated before stent deployment. Serial sections of vessels were processed 14 days after treatment in the BI group and 30 days after treatment in the stented group for histomorphometric or immunohistochemical analysis. Results: Intracoronary PDT significantly reduced intimal thickness in both BI and stented arteries (about 65%: 0.22 (SEM 0.05) mm v 0.62 (0.05) mm, p < 0.01; and about 26%: 0.40 (0.04) mm v 0.54 (0.04) mm, p < 0.01, respectively). PDT increased luminal area by ⩽ 60% and 50% within BI and stented arteries (3.43 (0.27) mm² v 5.51 (0.52) mm², p < 0.05; 4.0 (0.02) mm² v 6.0 (0.16) mm², p < 0.01), respectively. Complete re-endothelialisation was observed by immunohistochemical and gross histological analyses in all PDT and control arteries. There were no cases of aneurysm formation or thrombosis. Conclusion: Intracoronary PhotoPoint PDT with MV0611 reduces intimal proliferation without suppressing re-endothelialisatiori in a porcine model of restenosis. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to establish safety and feasibility of oral Rapamycin at two doses-2 mg and 5 mg-in achieving low rates of repeat target lesion revascularization (TLR) in de novo native coronary artery lesions. Background: Drug-eluting stents have shown the ability to limit restenosis. Oral Rapamycin is an alternative strategy that can target multiple coronary lesions suitable for treatment with any approved metal stent and at potentially lower cost. Methods: The Oral Rapamune to Inhibit Restenosis (ORBIT) study is an open-label study of 60 patients with de novo lesions treated with bare metal stents in up to two vessels. After a loading dose of 5 mg, patients received a daily dose of 2 mg (n = 30) and 5 mg (n = 30) for 30 days. Six-month angiographic, intravascular ultrasound (IVUS), and clinical follow-up were conducted. Results: Baseline clinical and procedural characteristics were similar: 10% of patients in the 2-mg group and 30% in the 5-mg group did not complete the course; 43% in the 2-mg group and 66% in the 5-mg group had side effects. At six-month follow-up, late loss (0.6 +/- 0.5 mm vs. 0.7 +/- 0.5 mm; p = NS), in-stent binary restenosis (7.1% vs. 6.9%; p = NS), in-stent percent volume obstruction by IVUS (29% vs. 24%; p = NS), and clinically driven TLR (14.3% vs. 6.9%; p = NS) were similar in 2-mg and 5-mg groups. Conclusions: Oral Rapamycin for the prevention of restenosis is safe, feasible, and associated with low rates of repeat revascularization. Although associated with certain side effects, it may be considered for patients undergoing multivessel stents if proven in larger randomized studies. [ABSTRACT FROM AUTHOR]

Intracoronary gamma radiation is effective in reducing recurrent in-stent restenosis (ISR) involving native coronary arteries. This study compares the effectiveness and safety of intracoronary gamma radiation for the treatment of ISR in saphenous vein grafts (SVGs) versus native coronary arteries. In the Washington Radiation for In-Stent restenosis Trial (WRIST) series of gamma radiation trials, 1,142 patients with ISR (230 in SVG and 912 in native coronary arteries) completed 6-month clinical follow-up. All patients underwent balloon angioplasty, atherectomy, and/or restenting. Different ribbon lengths containing 6 to 23 seeds of iridium-192 were used to cover lesion lengths <80 mm. The prescribed radiation doses were 14 or 15 Gy at 2-mm radial distance from the center of the source. Baseline demographics showed that patients with SVGs were older (65 +/- 13 vs 61 +/- 11 years, p <0.001), more likely male (79% vs 64%, p <0.001), had more multivessel coronary disease (81% vs 50%, p <0.001), and less diffuse lesions (17 +/- 10 vs 24 +/- 12 mm, p <0.001). At 6 months, event-free survival was similar for patients with SVG ISR and native coronary ISR (82% vs 84%, p = 0.35). The SVG ISR population had a low rate of late total occlusion (4.6%) and late thrombosis (3.5%). Thus, treatment of ISR with gamma radiation in SVGs had similar outcome to native coronary arteries. The use of gamma radiation for the treatment of ISR should expand to SVGs. [ABSTRACT FROM AUTHOR]

Endovascular radiation therapy has proved to be safe and effective in preventing restenosis after coronary intervention both in animal studies and in pilot feasibility studies in humans. The rationale for such therapy is that radiation prevents neointimal proliferation and vessel constriction after vascular injury. Two forms of endovascular radiation therapy are available: catheter-based systems and radioactive stenting. However, several practical issues related to this technique still need to be addressed, such as questions about dosimetry, shielding, expense, handling and disposal of radioisotopes, certification for potential users, and-above all-safety and efficacy. In their pivotal studies, investigators and industry need to focus on prioritizing the clinical applications of this form of treatment. The clinical trials must attempt to determine the cost-effectiveness of this therapy as well as its risk versus benefit. For example, brachytherapy may prove to be of great benefit to patients with in-stent restenosis, and favorable results of studies examining this application should expedite the approval of endovascular radiation therapy for clinical use. [ABSTRACT FROM AUTHOR]