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Biomedical subjects

Sigmund Silber

Publications and source records attributed to Sigmund Silber.

At least 37 records · Page 2Linked to original sources
PubMed2004

Cutting balloon versus conventional balloon angioplasty for the treatment of in-stent restenosis: results of the restenosis cutting balloon evaluation trial (RESCUT).

OBJECTIVES: The aim of this trial was to compare cutting balloon angioplasty (CBA) with conventional balloon angioplasty (i.e., percutaneous transluminal coronary angioplasty [PTCA]) for the treatment of patients with coronary in-stent restenosis (ISR). BACKGROUND: Retrospective studies suggest CBA might be superior to conventional PTCA in the treatment of ISR. METHODS: The Restenosis Cutting Balloon Evaluation Trial (RESCUT) is a multicenter, randomized, prospective European trial including 428 patients with all types of ISR (e.g., focal, multifocal, diffuse, proliferative). RESULTS: In both groups, the majority of ISR lesions were shorter than 20 mm. The length of restenotic stents was similar (CBA: 18.6 +/- 9.7 mm; PTCA: 18.3 +/- 8.7 mm). The number of balloons used to treat ISR was lower in the CBA group: only one balloon was used in 82.3% of CBA cases, compared with 75% of PTCA procedures (p = 0.03). Balloon slippage was less frequent in the CBA group (CBA 6.5%, PTCA 25%; p < 0.01). There was a trend toward a lower need for additional stenting in the CBA group (CBA 3.9%, PTCA 8.0%; p = 0.07). At seven-month angiographic follow-up, the binary restenosis rate was not different between the groups (CBA 29.8%, PTCA 31.4%; p = 0.82), with a similar pattern of recurrent restenosis. Clinical events at seven months were also similar. CONCLUSIONS: Cutting balloon angioplasty did not reduce recurrent ISR and major adverse cardiac events, as compared with conventional PTCA. However, CBA was associated with some procedural advantages, such as use of fewer balloons, less requirement for additional stenting, and a lower incidence of balloon slippage.

Angioplasty, Balloon↗
PubMed2004

Successful reduction of in-stent restenosis in long lesions using beta-radiation--subanalysis from the RENO registry.

PURPOSE: Long lesions remain a challenging task in interventional cardiology, with a high propensity of restenosis, especially within the stented segment. Although intracoronary gamma-radiation has been proved to reduce diffuse in-stent restenosis in long lesions, such an effect remains to be determined using beta-radiation. METHODS AND MATERIALS: Of 1098 consecutive patients at 46 European centers treated with localized beta-radiation ((90)Sr, Novoste Beta-Cath System), 139 patients (mean age 61.5 +/- 10.7 years, 84% male, 22% with diabetes mellitus) with lesions treated using a >40-mm source length underwent radiation using a single 60-mm source train (34%) or a stepping/pullback procedure with a 30-mm (12%) or 40-mm (87%) source length after conventional interventional procedures. The mean lesion length was 35.3 +/- 17.9 mm. RESULTS: Technical success was achieved in 96% of cases. Geographic miss was noted in 9 patients (6.5%). The reference (placebo) group was obtained from the Washington Hospital Center for In-Stent Restenosis Trial (WRIST) and the WRIST Trial for long lesions (LONG WRIST) studies by selecting the cases (94 patients) that required a dummy source length >/=13 seeds (or >51 mm in length). Statistically significant improvement was noted in late angiographic restenosis (34.7% vs. 76.5%, p <0.0001), target vessel revascularization (14.9% vs. 60.6), and major adverse cardiac events (i.e., death, myocardial infarction, or total vessel revascularization) (17.9% vs. 64.9%, p <0.0001) at 6 months in reference to the nonradiation group. CONCLUSION: This subanalysis from the Radiation in Europe with Novoste study confirms the safety and efficacy of beta-radiation combined with conventional interventional procedures in patients with diffuse, long, in-stent restenosis

Aged↗
PubMed2004

Intracoronary brachytherapy, a promising treatment option for diabetic patients: Results from a European multicenter registry (RENO).

Despite advances in the interventional treatment of coronary disease, diabetics still have double the case fatality rate as nondiabetics. The purpose of this analysis from the Radiation in Europe With Novoste (RENO) registry was to assess the clinical and angiographic 6-month outcome of diabetic patients in comparison to nondiabetic patients after localized beta-radiation. A total of 1,098 patients (83.8% with in-stent restenosis) treated with the Novoste Beta-Cath system in Europe were enrolled in the RENO registry. Diabetes was, irrespective of the type of lesion treated, no significant risk factor for major adverse cardiac events or target vessel revascularization. Individuals with diabetes (n = 256) and without diabetes (n = 833) displayed no significant differences concerning clinical or angiographic endpoints. Vascular brachytherapy appears to be the first technique to even out the increased risk of diabetic patients undergoing percutaneous coronary interventions in the routine clinical setting. Thus, intracoronary brachytherapy represents a promising treatment option for diabetic patients.

Brachytherapy↗
PubMed2004

The NUGGET study: NIR ultra gold-gilded equivalency trial.

This study should clarify whether the gold-coated NIROYAL stent is equivalent to the stainless steel NIR stent. Patients were randomized to either NIR stent (n = 298) or a NIROYAL stent (n = 305). The primary endpoint was the minimum lumen diameter of the target lesion at 6 months postprocedure. Secondary endpoints focused on clinical events. At 30 days, adverse events were similar in both groups. At 6 months, the minimal lumen diameter was 1.83/1.64 mm (P < 0.001; 95% CI = 0.08-0.30) and the angiographic restenosis rate was 20.6%/37.7% (P < 0.001; 95% CI = -24.7 to -9.3) for NIR/NIROYAL. The 6-month MACE rates were NIR 7.4% and NIROYAL 10.5% (95% CI = -7.7 to 1.4). Compared to stainless steel stent, the NIROYAL stent demonstrated a smaller minimal lumen diameter, a higher late loss (i.e., higher neointimal hyperplasia in spite of a significantly better initial gain), with higher restenosis and similar MACE rates at 6 months.

Aged↗
PubMed2004

Drug-eluting stents for in-stent restenosis and acute myocardial infarction: present data from nonrandomized studies.

In-stent restenosis (ISR) remains the "Achilles' heel" of percutaneous stent angioplasty treatment of patients with atherosclerotic disease of the coronary arteries. Recently, drug-eluting stents (DES) have ushered in a revolution in the treatment of these patients, yet, to date, their efficacy and safety have been demonstrated primarily for native de novo coronary lesions. For ISR, intracoronary brachytherapy using beta- or gamma-radiation is considered the standard of care. Nevertheless, DES are used for ISR lesions in clinical practice. This review outlines the few results currently available from small observational studies and larger registries. The designs of two ongoing randomized trials evaluating the sirolimus-eluting and the paclitaxel-eluting stent versus brachytherapy in patients with ISR lesions are also presented. Patients with acute myocardial infarction (AMI) have mostly been investigated in the context of small, uncontrolled studies and registries. The incomplete evidence to date is that implantation of sirolimus-eluting stents in patients with AMI is safe and effective.

Administration, Topical↗
PubMed2004

Direct stenting with TAXUS stents seems to be as safe and effective as with predilatation. A post hoc analysis of TAXUS II.

BACKGROUND AND METHOD: Although direct coronary stenting does not improve angiographic outcome, it makes sense by reducing procedure times, radiation exposure and costs. Other potential advantages of direct stenting may be a reduction of myocardial ischemia time, which could be clinically relevant in high-risk patients. With the introduction of drug-eluting stents, however, concern arose that direct stenting would possibly damage the polymer coating and change or diminish the efficacy of the programmed drug release. Also, concerns about safety by preventing optimal apposition of single stent struts developed. It is the purpose of this paper to retrospectively analyze the data from the TAXUS-II Trial (536 patients) regarding patients with and without direct stenting. While predilatation was recommended per protocol, direct stenting was not forbidden: thus, direct stenting was performed in 49 patients (TAXUS n = 23, control n = 26). RESULTS: In the TAXUS groups, there was no significant difference regarding major adverse cardiac events (MACE; 7.5% vs. 4.3%), angiographic restenosis in the analysis segment (4.8% vs. 4.3%), late loss (0.28 +/- 0.36 vs. 0.33 +/- 0.30 mm) or intravascular ultrasound-(IVUS-)measured volume obstruction (7.95 +/- 9.84% vs. 5.61 +/- 7.91%) at six months between the predilated and directly stented patients. The same was true for the patients receiving the control stent. Compared with the directly stented control group, the statistically significant positive effects of TAXUS direct stenting were maintained, regarding angiographic restenosis in the analysis segment (4.3% vs. 30.8%), late loss (0.33 +/- 0.30 vs. 0.80 +/- 0.62 mm) or IVUS-measured volume obstruction (5.61 +/- 7.91% vs. 22.50 +/- 21.62%) at six months. MACE was reduced from 19.2% to 4.3%; due to the small number of patients this trend did not reach statistical significance. After predilatation, all parameters were significantly improved by the TAXUS stent. CONCLUSION: Comparison of patients receiving TAXUS stents with or without predilatation revealed no differences in clinical, angiographic or IVUS parameters at six months. This suggests that direct stenting with the polymer-based paclitaxel-eluting TAXUS stent is feasible, safe and equally effective. Randomized trials comparing stenting after predilatation versus direct stenting with drug-eluting stents are warranted.

Angioplasty, Balloon, Coronary↗
PubMed2004

Which parameter should be chosen as primary endpoint for randomized drug-eluting stent studies?

In Europe, 1,108 percutaneous coronary interventions (PCIs) per one Mio inhabitants are currently annually performed, most of them with stent implantation. Drug-eluting stents have been the focus of attention of interventional coronary therapy since the RAVEL study was first presented in September 2001 at the European Society of Cardiology Meeting. Ever since, numerous studies have assessed the effects of various antiproliferative and anti-inflammatory substances and a variety of different stents was used as platform, either covered with polymer carriers of different chemical and physical properties or without a polymer carrier. CE- or FDA-certified drug-eluting stents are increasingly replacing the use of bare metal stents to reduce in-stent restenosis. Today, physicians have a choice of several approved drug-eluting stents and, therefore, need some evidence-based guidance through the "jungle of information" to make the right decisions. Even when focusing on randomized trials, differences between the studies regarding primary endpoints and sample sizes exist, making it difficult to compare the various drug-eluting stent studies. Randomized studies use either nonclinical (i.e., angiographic diameter stenosis, in-stent MLD, or in-stent late lumen loss) or clinical (i.e., TVF, TVR, and MACE) parameters as primary endpoints. Choosing an angiographic parameter as primary endpoint results in two major limitations: first, a significant improvement of an angiographic "surrogate" parameter does not necessarily translate into a better clinical outcome (DELIVER-I); second, conclusions regarding possible improvements of clinical outcome are underpowered, because the sample size calculation is based on the primary endpoint. Usually the number of patients needed is lower for angiographic than for clinical endpoints. Until today, only three trials with a primary clinical endpoint have shown a significantly positive impact on patients' outcome: the SIRIUS trial (Cypher stent) with its reduction of primary endpoint TVF (21.0% vs 8.6%), the TAXUS-IV trial (Taxus stent) with its reduction of primary endpoint TVR (12.0% vs 4.7%) and TAXUS-VI in long lesions with its reduction of primary endpoint TVR (19.4% vs 9.1%). Although the angiographic results of other drug-eluting stents are encouraging, they will have to prove their clinical impact based on adequately powered randomized trials with a primary clinical endpoint at an adequate time interval.

Cardiac Catheterization↗
PubMed2004

[European study of ambulatory management of heart failure by cardiologists].

INTRODUCTION AND OBJECTIVES: This cross-sectional study examined the overall clinical characteristics and management of 1252 outpatients with heart failure in 3 countries (Spain, France and Germany). MATERIAL AND METHOD: A standardized questionnaire was used to record demographic, diagnostic, clinical and treatment data for all patients seen on one day (26 April 2001) by 465 outpatient cardiologists. RESULTS: Men accounted for 62.1% of the patients in the population, and mean age of the patients was 68.3 years. In the twelve months prior to the study 78% of the patients consulted their physician at least once because of heart failure, and 36.2% had hospital admissions. Differences between the three countries were observed in reported causes of heart failure (alone or in combination) such as ischemic heart disease (France 40.7%, Germany 41.3%, Spain 26%, P<.0001) and hypertension (France 10.7%, Germany 16.7%, Spain 43.6%, P<.0001). How-ever the proportion of patients with prior myocardial infarction was very similar (France 63.7%, Germany 69.5%, Spain 65%, P=NS). Diuretics were not prescribed in 19.7% of the patients, ACE inhibitors were not prescribed in 27.9%, and beta blockers were not prescribed in 52.3%. CONCLUSIONS: The study provides further information on the consumption of large amounts of medical resources because of heart failure. The reported etiologies differed between countries. However, the proportion of patients with prior myocardial infarction was very similar. Treatment with ACE inhibitors and beta blockers was slightly more common than previously reported, although beta blockers continue to be underused.

Aged↗
PubMed2003

Vascular brachytherapy using a beta emitter source in diabetic patients with in-stent restenosis: angiographic and clinical outcomes.

PURPOSE: The management of diabetic patients with restenosis after percutaneous coronary intervention remains a significant challenge. Diabetic patients remain at significant risk of restenosis despite stent implantation. This retrospective analysis was performed to determine the extent to which vascular brachytherapy improves late clinical and angiographic outcomes in diabetic patients compared to conventional therapy and compared to patients' nondiabetic counterparts. METHODS: Pooled data from two studies (START [Stents and Radiation Trial] and START-40 trials) of patients (204 diabetic, 477 nondiabetic) receiving vascular brachytherapy (VBT) with a (90)Sr/(90)Y source after conventional percutaneous coronary intervention for in-stent restenosis comprise the study population. The radiation delivery system used in both studies was the Beta-Cath system. The prescribed dose at 2 mm from the centerline of the source axis was 18.4 Gy or 23 Gy, depending on vessel diameter. The reference vessel diameter, minimal lumen diameter, and percent diameter stenosis were measured before the intervention, at the conclusion of the procedure, and at the 8-month follow-up examination. The Breslow-Day test was used to formally assess the similarity of treatment effect between diabetic and nondiabetic patients. RESULTS: Target lesion and target vessel revascularization rates and angiographic restenosis rates in diabetic and nondiabetic patients treated with beta radiation or placebo were analyzed. Diabetic patients were more likely to have longer and more complex coronary lesions. In-hospital outcomes in diabetic and nondiabetic patients were similar, irrespective of treatment status. At 8 months, patients treated with beta radiation exhibited less target lesion revascularization (diabetic: 10.9% vs. 22.7%, p = 0.02; nondiabetic: 12.8% vs. 22.3%, p = 0.007) and less target vessel revascularization (diabetic: 14.7% vs. 25.3%, p = 0.06; nondiabetic: 16.6% vs. 23.6%, p = 0.06) compared to placebo. In-stent binary angiographic restenosis was lower in irradiated patients (diabetic: 19.4% vs. 37.3% for placebo, p = 0.01; nondiabetic: 12.9% vs. 43% for placebo, p < 0.001). However, restenosis beyond the stent site reduced the impact of VBT, regardless of diabetic status. The magnitude of the treatment effect for target lesion and target vessel revascularization rates was similar between diabetic and nondiabetic patients. CONCLUSIONS: Previously published institutional experiences have suggested that diabetic patients benefit from the use of VBT in the management of in-stent restenosis. This analysis now provides direct evidence to support the role of beta radiation VBT in this patient population. Diabetic patients undergoing this therapy are just as likely to benefit from it as their nondiabetic counterparts.

Beta Particles↗
PubMed2003

Randomized study to assess the effectiveness of slow- and moderate-release polymer-based paclitaxel-eluting stents for coronary artery lesions.

BACKGROUND: Early clinical studies demonstrated the feasibility of local paclitaxel delivery in reducing restenosis after treatment of de novo coronary lesions in small patient populations. METHODS AND RESULTS: We conducted a randomized, double-blind trial of 536 patients at 38 medical centers evaluating slow-release (SR) and moderate-release (MR) formulations of a polymer-based paclitaxel-eluting stent (TAXUS) for revascularization of single, primary lesions in native coronary arteries. Cohort I compared TAXUS-SR with control stents, and Cohort II compared TAXUS-MR with a second control group. The primary end point was 6-month percent in-stent net volume obstruction measured by intravascular ultrasound. Secondary end points were 6-month angiographic restenosis and 6- and 12-month incidence of major adverse cardiac events, a composite of cardiac death, myocardial infarction, and repeat revascularization. At 6 months, percent net volume obstruction within the stent was significantly lower for TAXUS stents (7.9% SR and 7.8% MR) than for respective controls (23.2% and 20.5%; P<0.0001 for both). This corresponded with a reduction in angiographic restenosis from 17.9% to 2.3% in the SR cohort (P<0.0001) and from 20.2% to 4.7% in the MR cohort (P=0.0002). The incidence of major adverse cardiac events at 12 months was significantly lower (P=0.0192) in the TAXUS-SR (10.9%) and TAXUS-MR (9.9%) groups than in controls (22.0% and 21.4%, respectively), predominantly because of a significant reduction in repeat revascularization of the target lesion in TAXUS-treated patients. CONCLUSIONS: Compared with a bare metal stent, paclitaxel-eluting stents reduced in-stent neointimal formation and restenosis and improved 12-month clinical outcome of patients with single de novo coronary lesions.

Coated Materials, Biocompatible↗
PubMed2003

TAXUS I: six- and twelve-month results from a randomized, double-blind trial on a slow-release paclitaxel-eluting stent for de novo coronary lesions.

BACKGROUND: The TAXUS NIRx stent (Boston Scientific Corp) provides local delivery of paclitaxel via a slow-release polymer coating. The TAXUS I trial was the first in-human experience evaluating safety and feasibility of the TAXUS NIRx stent system compared with bare NIR stents (control) (Boston Scientific Corp) for treatment of coronary lesions. METHODS AND RESULTS METHODS AND RESULTS: The TAXUS I trial was a prospective, double-blind, three-center study randomizing 61 patients with de novo or restenotic lesions (< or =12 mm) to receive a TAXUS (n=31) versus control (n=30) stent (diameter 3.0 or 3.5 mm). Demographics, lesion characteristics, clinical outcomes were comparable between the groups. The 30-day major adverse cardiac event (MACE) rate was 0% in both groups (P=NS). No stent thromboses were reported at 1, 6, 9, or 12 months. At 12 months, the MACE rate was 3% (1 event) in the TAXUS group and 10% (4 events in 3 patients) in the control group (P=NS). Six-month angiographic restenosis rates were 0% for TAXUS versus 10% for control (P=NS) patients. There were significant improvements in minimal lumen diameter (2.60+/-0.49 versus 2.19+/-0.65 mm), diameter stenosis (13.56+/-11.77 versus 27.23+/-16.69), and late lumen loss (0.36+/-0.48 versus 0.71+/-0.48 mm) in the TAXUS group (all P<0.01). No evidence of edge restenosis was seen in either group. Intravascular ultrasound analysis showed significant improvements in normalized neointimal hyperplasia in the TAXUS (14.8 mm3) group compared with the control group (21.6 mm3) (P<0.05). CONCLUSIONS: In this feasibility trial, the TAXUS slow-release stent was well tolerated and showed promise for treatment of coronary lesions, with significant reductions in angiographic and intravascular ultrasound measures of restenosis.

Aged↗
PubMed2003

[Noninvasive angiography of coronary bypass grafts with cardio-CT in a cardiology practice].

BACKGROUND: The role of coronary artery bypass surgery as a key foundation in the therapy of coronary artery disease remains unchanged: in Germany in 2001, 75,537 coronary bypass procedures were performed. However, the endurance of coronary bypass grafts is limited: after 3 years, 20-30% of the bypass grafts have occluded. The myocardial infarct rate significantly increases 8 years after bypass surgery. Since the clinical outcome of the patients is closely related to the patency rate of their bypass grafts, it would be important for the patients to have the patency rate of their bypass grafts assessed on time to detect any occluded bypass grafts before the majority of the grafts become occluded. Recently, multi-slice computed tomography (MSCT) offers an attractive tool for this purpose. This paper describes our first experiences with MSCT in our cardiology practice and regards whether this new method provides relevant information for a cardiology practice. PATIENTS AND METHODS: Studies were performed at the Heart Diagnostic Center in Munich with an Mx 8000 four-row spiral CT with an effective slice thickness of 1.3 mm, 120 kV at 300 mA and approximately 120 ml of contrast medium in double bolus technique. Image reconstruction was performed for 5 heart phases between 50% and 70% of the RR intervals. Thus, a total of over 1,500 slices were reconstructed. 74 patients without angina or proof of myocardial ischemia had noninvasive bypass angiography at a mean of 5 years after surgery. RESULTS: Of the total of 220 investigated bypass grafts, 132 were venous and 88 were arterial. 177 bypass grafts were classified as open, 42 as occluded; and one venous bypass graft was highly narrowed. Compared with cardiac catheterization, the sensitivity of the cardio-CT regarding the occlusion of a bypass graft was 100% with a specificity of 96%. The only "false positive" occlusion was a LIMA with a small lumen. CONCLUSIONS: Our results show that noninvasive bypass angiography with the ultrafast multi-slice CT (MSCT) provides relevant information for the practicing cardiologist. Noninvasive bypass angiography with a cardio-CT predominantly aims at asymptomatic patients without proof of myocardial ischemia ("bypass check") for the detection of asymptomatic occluded bypass grafts as early as possible. In patients with asymptomatic bypass occlusion, considering a coronary or bypass intervention for prognostic reasons is an option. It is important to note that in our study in a mean of 5 years after bypass surgery almost every third patient had an unexpected bypass graft occlusion.

Adult↗
PubMed2003

[4th report of German Association of Cardiologists in private practice (BNK) on quality assurance in cardiac catheterization and coronary intervention 1999-2002].

The Society of German Cardiologists in private practice (BNK) reports about its project on quality assurance in invasive cardiology (QuIK). Results of a computerized data collection and analysis of cardiac catheterizations and interventions in the years 1999-2002 are presented. These results are compared with other registries. The QuIK-project is done voluntarily by 70% of the society's cardiologists who perform invasive methods. A total of 225,562 diagnostic and 64,895 interventional procedures are documented over the 4 years. Patient characteristics and procedural data kept unchanged. Complication rates were low (< 2%), MACE < 0.5%. There was a rising number of patients referred with acute myocardial infarction. Less time was used to complete procedures from 1 year to another. Two out of three of the centers underwent a monitoring/auditing process in 2002. The desirable post-interventional follow-up after discharge in all cases appears to be impossible to fulfill under the given economical circumstances.

Adult↗