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Sigmund Silber

Publications and source records attributed to Sigmund Silber.

49 records · Page 3Linked to original sources
PubMed2003

Direct stent implantation using the EXPRESS Coronary Stent System: results of a multi-center feasibility study.

The aim of this prospective, multicenter, single arm study was to assess the safety and feasibility of EXPRESS Coronary Stent implantation in native coronary arteries without balloon predilatation. Forty-two patients with de novo or restenotic lesions were enrolled, of which 38 were eligible for analysis. The coronary lesions were predominantly complex, occurring in arteries with a mean reference diameter of 2.80 +/- 0.49 mm. Technical and procedural success were achieved in 89.5% and 84% of the cases respectively. The mean minimal lumen diameter increased from 1.08 +/- 0.26 mm to 2.55 +/- 0.44 mm and diameter stenosis decreased from 61 +/- 7% to 13 +/- 8%. The primary endpoint of major adverse cardiac events at 30 days was 2.6% and was limited to only one event (target vessel revascularization, nontarget lesion). No other MACE were observed during the three-month follow-up period. Based on the findings of this study, direct stenting with the EXPRESS Stent appears feasible and is well tolerated.

Aged↗
PubMed2003

Paclitaxel-eluting stents: are they all equal? An analysis of six randomized controlled trials in de novo lesions of 3,319 patients.

In Germany, four different drug eluting stents (DES) systems are currently commercially available. Whereas sirolimus has been clinically tested in only a single type of stent with a single type of coating in only a single dose, paclitaxel has been tested on various stent designs, in various dose densities, and in various release formulations with or without a polymer carrier. Therefore, the question arises: are all paclitaxel stents equally safe and effective? Six clinical randomized trials investigated the safety and efficacy of paclitaxel-eluting stents in patients with de-novo lesions: TAXUS-I (61 pats), TAXUS-II (536 pats), ASPECT (177 pats), ELUTES (190 pats), DELIVER-I (1041 pats) and TAXUS-IV (1314 pats). In the TAXUS-series, paclitaxel released from the stent was controlled by the Translute polymer. In the other studies, however, no polymer carrier was used. In TAXUS-I, II & IV, the dose density of 1 microg/mm2 significantly reduced angiographic parameters of restenosis and improved clinical outcomes. In ASPECT and ELUTES there was a dose-dependent effect on angiographic parameters of restenosis with the best results for a paclitaxel dose density of approximately 3.0 microg/mm2. Clinical outcomes at 6 and 12 months, however, were not improved in these studies without coating. The studies unanimously show that the paclitaxel-eluting stents are safe, if clopidogrel is added to ASA for 3 to 6 months. The safety of paclitaxel-eluting stents is independent of the stent design, the dose density and the presence or absence of a polymer carrier system. For paclitaxel-eluting stents using a polymer carrier, the dose density of 1 microg/mm2 is highly effective, whereas for paclitaxel-eluting stents without a polymer carrier, the minimal effective dose density is much higher (3 microg/mm2). Despite their improvement of angiographic parameters, paclitaxel-eluting stents without a polymer carrier did not demonstrate a positive effect on clinical outcome. In contrast, polymer-based paclitaxel elution produced significant clinical benefit.

Clinical Trials as Topic↗
PubMed2003

European guidelines on cardiovascular disease prevention in clinical practice: third joint task force of European and other societies on cardiovascular disease prevention in clinical practice (constituted by representatives of eight societies and by invited experts).

Guidelines aim to present all the relevant evidence on a particular issue in order to help physicians to weigh the benefits and risks of a particular diagnostic or therapeutic procedure. They should be helpful in everyday clinical decision-making. A great number of guidelines have been issued in recent years by different organisations--European Society of Cardiology (ESC), American Heart Association (AHA), American College of Cardiology (ACC), and other related societies. By means of links to web sites of National Societies several hundred guidelines are available. This profusion can put at stake the authority and validity of guidelines, which can only be guaranteed if they have been developed by an unquestionable decision-making process. This is one of the reasons why the ESC and others have issued recommendations for formulating and issuing guidelines. In spite of the fact that standards for issuing good quality guidelines are well defined, recent surveys of guidelines published in peer-reviewed journals between 1985 and 1998 have shown that methodological standards were not complied with in the vast majority of cases. It is therefore of great importance that guidelines and recommendations are presented in formats that are easily interpreted. Subsequently, their implementation programmes must also be well conducted. Attempts have been made to determine whether guidelines improve the quality of clinical practice and the utilisation of health resources. In addition, the legal implications of medical guidelines have been discussed and examined, resulting in position documents, which have been published by a specific task force. The ESC Committee for practice guidelines (CPG) supervises and coordinates the preparation of new guidelines and expert consensus documents produced by task forces, expert groups or consensus panels. The Committee is also responsible for the endorsement of these guidelines or statements.

Adult↗
PubMed2003

[Off-label use of clopidogrel after coronary stent implantation in Germany: optional or mandatory?].

Although the combined use of acetylsalicylic acid (ASA) and clopidogrel represents the standard in the 4-week treatment after coronary stent implantation, a discussion persists in Germany regarding clopidogrel use and the actual measures for cost containment in the healthcare system. Indeed, clopidogrel has not been approved in Germany for use after stent im-plantation. The prescription of clopidogrel in this context is thus considered off-label use. Consequently, patients with social healthcare insurance should pay for clopidogrel out of their own pockets. This regimen, however, bears the inherent risk that patients will not purchase the drug and thus not take it. This overview article describes the risk to patients when social healthcare insurance companies would not pay for clopidogrel after coronary stent implantation. Five international, prospective, randomized and control-led studies in 3,230 patients have shown that "double" antiaggregation, i.e. a combination of ASA and the thienopyridin derivative ticlopidin, compared with ASA alone clearly reduced death, myocardial infarction and the need for another PCI or CABG to a manifold extent. Due to its lower rate of side effects, clopidogrel has replaced ticlopidin since mid-1998. The clinical results of three prospective, randomized studies and seven single-center registries in approximately 14,000 patients have shown that the combination of ASA and clopidogrel results not only in a lower rate of side effects, but also in a significant rate reduction of cardiovascular events of ca. 50% (from 4.0% to 2.1%). Therefore, the combined use of ASA and clopidogrel should be prescribed to avoid (sub)acute stent thrombosis --even if this is not according to the rules of the German healthcare system. The threat of fines to physicians prescribing clopdiogrel at the expense of the social health care insurance is counterproductive and jeopardizes the life of the patients.

Aspirin↗
PubMed2003

Clinical outcome following combination of cutting balloon angioplasty and coronary beta-radiation for in-stent restenosis: a report from the RENO registry.

At present, vascular brachytherapy is the only efficient therapy for in-stent restenosis. Nevertheless, edge restenosis often related to geographical miss has been identified as a major limitation of the technique. The non-slippery cutting balloon has the potential to limit vascular barotraumas, which, together with low-dose irradiation at both ends of the radioactive source, are the prerequisite for geographical miss. This prospective study aimed to examine the efficacy of combining cutting balloon angioplasty and brachytherapy for in-stent restenosis. The Radiation in Europe NOvoste (RENO) registry prospectively tracked all patients who had been treated by coronary beta-radiation with the Beta-Cath System (Novoste Corporation, Brussels, Belgium) but were not included in a randomized radiation trial. A subgroup of patients with in-stent restenosis treated by cutting balloon angioplasty and coronary beta-radiation (group 1, n = 166) was prospectively defined, and clinical outcomes of patients at 6 months were compared with those of patients treated by conventional angioplasty and coronary beta-radiation (group 2, n = 712). At 6-month follow-up, there was a significant difference between groups 1 and 2 in target vessel revascularization (10.2% versus 16.6% respectively; p = 0.04) and in the incidence of major adverse clinical events (MACE) including death, myocardial infarction, and revascularization (10.8% versus 19.2%; p = 0.01). This observation was confirmed by a multivariate analysis indicating a lower risk for MACE at 6 months (odds ratio: 0.49; confidence intervals: 0.27 0.88; p = 0.02). Compared to conventional angioplasty, cutting balloon angioplasty prior to coronary beta-radiation with the Beta-Cath System seems to improve the 6-month clinical outcome in patients with in-stent restenosis.

Aged↗
PubMed2002

Randomized comparison of success and adverse event rates and cost effectiveness of one long versus two short stents for treatment of long coronary narrowings.

Long stents of high flexibility and low profile have become widely available. Treatment of long coronary lesions by 1 long stent may require less interventional efforts and reduce the rate of restenosis due to a lack of overlapping stent segments. This study sought to evaluate the use of 1 long stent compared with 2 short stents for treatment of long coronary lesions. One-hundred twenty-four patients with a coronary lesion 20 to 40 mm in length, in a vessel 2.5 to 4.0 mm in diameter, were randomly assigned to treatment with 1 long stent (GFX II stents or S670 of 24, 30, or 40 mm lengths; n = 62) or 2 stents (GFX II or S670 stents, n = 62) of equal length. Procedural success, interventional costs, as well as long-term clinical and angiographic outcomes were evaluated. Lesion characteristics were similar for the 2 treatment groups. Stent placement was possible as assigned by randomization in 61 of 62 cases (98%) in the 1-long-stent group and 100% of cases in the 2-short-stents group. There was crossover to successful short-stent placement in 1 case. The in-hospital success rate was 97% for the 1-long-stent group and 98% for the 2-short-stents group. Acute angiographic results were similar for both groups after intervention. The angiographic restenosis rate at 6 months was 38.5% in the 1-long-stent group and 37.5% in the 2-short-stents group (p = 0.919). Intervention time was less, and the need for a contrast agent had a tendency to be lower in the long-stent group. Procedural costs were significantly less in the long-stent group. In conclusion, 1 long stent can be used with identical procedural success and adverse event rates as 2 short stents in long, atherosclerotic coronary lesions. The restenosis rate is not reduced by the use of 1 long stent compared with 2 stents. However, long stent placement is highly cost effective.

Aged↗
PubMed2002

Randomized trial of 90Sr/90Y beta-radiation versus placebo control for treatment of in-stent restenosis.

BACKGROUND: After conventional treatment of in-stent restenosis, the incidence of recurrent clinical restenosis may approach 40%. We report the first multicenter, blinded, and randomized trial of intracoronary radiation with the use of a 90Sr/90Y beta-source for the treatment of in-stent restenosis. METHODS AND RESULTS: After successful catheter-based treatment of in-stent restenosis, 476 patients were randomly assigned to receive an intracoronary catheter containing either 90Sr/90Y (n=244) or placebo (n=232) sources. The prescribed dose 2 mm from the center of the source was 18.4 Gy for vessels between 2.70 and 3.35 mm in diameter and 23.0 Gy for vessels between 3.36 and 4.0 mm. The primary end point, ie, clinically driven target-vessel revascularization by 8 months, was observed in 56 (26.8%) of the patients assigned to placebo and 39 (17.0%) of the patients assigned to radiation (P=0.015). The incidence of the composite including death, myocardial infarction, and target-vessel revascularization was observed in 60 (28.7%) of the patients assigned to placebo and 44 (19.1%) of the patients assigned to radiation (P=0.024). Binary 8-month angiographic restenosis (> or =50% diameter stenosis) within the entire segment treated with radiation was reduced from 45.2% in the placebo-treated patients to 28.8% in the 90Sr/90Y-treated patients (P=0.001). Stent thromboses occurred in 1 patient assigned to placebo <24 hours after the procedure and in 1 patient assigned to 90Sr/90Y at day 244. CONCLUSIONS: The results of this study demonstrated that beta-radiation using 90Sr/90Y is both safe and effective for preventing recurrence in patients with in-stent restenosis.

Beta Particles↗
PubMed2002

Rotational atherectomy does not reduce recurrent in-stent restenosis: results of the angioplasty versus rotational atherectomy for treatment of diffuse in-stent restenosis trial (ARTIST).

BACKGROUND: Aim of this trial was to compare rotational atherectomy followed by balloon angioplasty (rotablation [ROTA] group) with balloon angioplasty (percutaneous transluminal coronary angioplasty [PTCA] group) alone in patients with diffuse in-stent restenosis. METHODS AND RESULTS: The ARTIST study is a multicenter, randomized, prospective European trial with 298 patients with in-stent restenosis>70% (mean lesion length, 14 +/- 8 mm) in stents, implanted in coronary arteries for >/= 3 months. In the PTCA group, angioplasty was performed at the discretion of the local investigator, and rotablation was performed by using a stepped-burr approach followed by adjunctive PTCA with low (</= 6 atm) inflation pressure. Intravascular ultrasound during the intervention and at follow-up was used in a substudy in 86 patients (45 PTCA, 41 ROTA). Angiography demonstrated no difference regarding the short-term outcome, with equivalent procedural success rates defined as remaining stenosis <30% (89% PTCA, 88% ROTA). However, the results showed that, in the long term, PTCA was a significantly better strategy than ROTA. Mean net gain in minimal lumen diameter was 0.67 mm and 0.45 mm for PTCA and ROTA, respectively (P=0.0019). Mean gain in diameter stenosis was 25% and 17% (P=0.002), resulting in restenosis (>/= 50%) rates of 51% (PTCA) and 65% (ROTA) (P=0.039). By intravascular ultrasound, the major difference was the missing stent over-expansion during PTCA after ROTA. Six-month event-free survival was significantly higher after PTCA (91.3%) compared with ROTA (79.6%, P=0.0052). CONCLUSIONS: In terms of the primary objective of the study, PTCA produced a significantly better long-term outcome than ROTA followed by adjunctive low-pressure PTCA.

Angioplasty, Balloon, Coronary↗
PubMed2002

[Intracoronary radiation therapy in controlled and open clinical trials with afterloading systems and "hot" balloon catheters. Analysis of 6,692 patients].

The prevention and treatment of a restenosis, which occurs in ca. 30% of the cases following balloon dilatation of coronary stenoses, using intravascular radiation relies on the inhibition of proliferation that is inherent in every radiation therapy. The analysis is based on 6,692 patients assigned to either a control group (1,717 patients) or to radiation therapy (4,975 patients) in 41 studies. A total of 14 placebo-controlled, randomized and 27 open trials have been completed: 22 regarding in-stent restenosis, ten regarding de-novo stenosis (or restenosis without a stent) as strict inclusion criteria, and nine with all types of stenoses. For in-stent restenoses, vessel size as defined for inclusion was between 2.0 mm and 5.5 mm, stenosis length between 10 mm and 80 mm. In all trials with in-stent restenosis, the primary endpoints were reached; the restenosis rate in the longest coronary segment analyzed was between 45% and 100% in the control groups and between 7.7% and 53.5% in the brachytherapy groups. The respective values for the TVR were between 24.1% and 80% in the control groups and between 2.0% and 41.7% in the brachytherapy groups. In the control groups, MACE was between 25.9% and 80%; it was between 2.0% and 41.7% in the brachytherapy groups. Attaining results for de-novo stenoses was problematic due to "geographic miss" apparently playing a larger role in these cases; but when taking this into consideration, good results were also attained. The known limitations due to late stent thromboses (4-15% in older trials) were to the most part eliminated by administration of clopidogrel for 1 year and the limitations due to the "edge effect" by the application of longer radiation sources. With antiproliferative coated stents as treatment for de-novo stenoses, we can count on intracoronary brachytherapy losing significance in this area. But for in-stent restenoses, intracoronary brachytherapy is the only evidence-based interventional form of therapy.

Aged↗
PubMed2002

The IST registry.

Intracoronary brachytherapy has been established in Europe and the US as an evidence-based treatment of in-stent restenoses. The objective of the IST Registry is to register all patients treated in Germany with intracoronary radiation and to observe the clinical outcome for a duration of 5 years. The required set of data for each patient is kept to a minimum to encourage participation. All data are entered online. In the internet, each participating site can, at any time, check their most important parameters and compare them with those of other sites. Presently, the Novoste System is used in 58 catheter labs and the Guidant System in 16, while several sites use both. The requirements regarding radiation safety in intracoronary application of gamma radiation are very strict in Germany, so the Cordis-Gamma System is used in only one German lab. In a first analysis of 332 radiated stenoses, it was observed that late vessel occlusion could occur even after 6-month administration of clopidogrel (in addition to ASA)--without new stents being implanted within the brachytherapy session. Clopidogrel should thus be administered in addition to aspirin for at least a year. Ca. 270 patients per month receive intracoronary radiation in Germany, so the IST Registry will provide important data regarding long-term observation and a foundation for future negotiations with insurance companies potentially bearing the costs. At present, neither the physician's service nor the material costs are reimbursed. The IST Registry can furthermore be used as a comparative database regarding long-term outcome following implantation of antiproliferative-coated stents.

Angioplasty, Balloon, Coronary↗