Biomedical subjects

Uwe Siebert

Publications and source records attributed to Uwe Siebert.

At least 19 recordsLinked to original sources

PubMed2006

Cost-effectiveness of using N-terminal pro-brain natriuretic peptide to guide the diagnostic assessment and management of dyspneic patients in the emergency department.

The cost-effectiveness of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) in dyspneic patients in emergency departments (EDs) is unknown. The objective of this study was to assess the cost-effectiveness of NT-pro-BNP testing for the evaluation and initial management of patients with dyspnea in the ED setting. A decision model was developed to evaluate the cost-effectiveness of diagnostic assessment and patient management guided by NT-pro-BNP, compared with standard clinical assessment. The model includes the diagnostic accuracy of the 2 strategies for congestive heart failure and resulting events at 60-day follow-up. Clinical data were obtained from a prospective blinded study of 599 patients presenting to the ED with dyspnea. Costs were based on the Massachusetts General Hospital cost accounting database. The model predicted serious adverse events during follow-up (i.e., urgent care visits, repeat ED presentations, rehospitalizations) and direct medical costs for echocardiograms and hospitalizations. NT-pro-BNP-guided assessment was associated with a 1.6% relative reduction of serious adverse event risk and a 9.4% reduction in costs, translating into savings of $474 per patient, compared with standard clinical assessment. In a sensitivity analysis considering mortality, NT-pro-BNP testing was associated with a 1.0% relative reduction in post-discharge mortality. The optimal use of NT-pro-BNP guidance could reduce the use of echocardiography by up to 58%, prevent 13% of initial hospitalizations, and reduce hospital days by 12%. In conclusion, on the basis of this model, the use of NT-pro-BNP in the diagnostic assessment and subsequent management of patients with dyspnea in the ED setting could lead to improved patient care while providing substantial cost savings to the health care system.

Biomarkers↗

PubMed2006

Case finding for hepatitis C in primary care: a cost utility analysis.

BACKGROUND: Hepatitis C is an important public health problem. The need for more intensified action to identify those infected with the virus has been recognized. Primary care is an important setting for case finding. OBJECTIVES: To estimate the cost utility of case finding for hepatitis C in primary care, specifically amongst former injecting drug users (IDUs). METHODS: A Markov model was developed to investigate the impact of case finding and treatment on progression of hepatitis C (HCV) in a hypothetical cohort of 1000 former IDUs. Comparison was made with a similar cohort in which no systematic case finding was implemented but spontaneous presentation for testing was allowed. Two scenarios were explored. The testing protocol utilized ELISA and PCR tests. Those eligible for treatment received combination therapy with pegylated interferon and ribavirin. Parameter estimates were obtained from literature searches and experts in the field. RESULTS: Few estimates of the uptake of HCV testing in primary care are available. Cost utility was estimated at around 16,000 pounds sterling/QALY for both scenarios. At a willingness to pay of 30,000 pounds sterling/QALY, there is approximately a 75% probability that the initiatives would be cost-effective. Choices regarding the utility data, discounting and the rates of spontaneous/re-presentation outside of a case-finding programme appear to be important areas of uncertainty in this model. CONCLUSION: Case finding for HCV in primary care is likely to be considered cost-effective but substantial uncertainties remain. Further research is needed on different approaches to case finding in primary care.

Algorithms↗

PubMed2006

Cardiac magnetic resonance perfusion imaging for the functional assessment of coronary artery disease: a comparison with coronary angiography and fractional flow reserve.

AIMS: Cardiac magnetic resonance perfusion imaging (CMRI) is a promising technique for non-invasive measurement of myocardial perfusion reserve. Fractional flow reserve (FFR) is an established invasive method for functional assessment of coronary artery disease (CAD). To prospectively assess the diagnostic value of CMRI for the detection of haemodynamically significant coronary lesions, compared with coronary angiography (CA) and FFR. METHODS AND RESULTS: Forty-three patients with suspected or known CAD underwent CA, CMRI, and FFR measurement. First pass magnetic resonance perfusion examination was performed during hyperaemia (140 microg/kg/min adenosine over 6 min) and at rest. One hundred and twenty-nine perfusion territories were assessed by semi-quantitative evaluation of signal intensity-time curves using the myocardial perfusion reserve index (MPRI) [upslope(stress(corrected))/upslope(rest(corrected))]. Perfusion territories were categorized as normal (coronary stenosis < or = 50%), intermediate (stenosis > 50% and FFR > 0.75), or severe (stenosis > 50% and FFR < or = 0.75 or total occlusion). MPRI values (+/-SD) were significantly different between the three categories [normal, 2.2 +/- 0.5 vs. intermediate, 1.8 +/- 0.5 (P = 0.005) and intermediate vs. severe, 1.2 +/- 0.3 (P < 0.001)]. An MPRI cut-off value of 1.5 (derived from receiver operating characteristics analysis) distinguished haemodynamically relevant (severe) from non-relevant (normal and intermediate) stenoses with a sensitivity of 88% (CI 74-100%) and a specificity of 90% (CI 84-96%). CONCLUSION: In contrast to earlier studies that compared CMRI with morphological examination (CA) alone, the present study compared CMRI with CA plus a standard invasive functional assessment (FFR) and demonstrated that CMRI is able to distinguish haemodynamically relevant from non-relevant coronary lesions with a high sensitivity and specificity and may therefore contribute to clinical decision-making.

Aged↗

PubMed2006

The German cervical cancer screening model: development and validation of a decision-analytic model for cervical cancer screening in Germany.

BACKGROUND: We sought to develop and validate a decision-analytic model for the natural history of cervical cancer for the German health care context and to apply it to cervical cancer screening. METHODS: We developed a Markov model for the natural history of cervical cancer and cervical cancer screening in the German health care context. The model reflects current German practice standards for screening, diagnostic follow-up and treatment regarding cervical cancer and its precursors. Data for disease progression and cervical cancer survival were obtained from the literature and German cancer registries. Accuracy of Papanicolaou (Pap) testing was based on meta-analyses. We performed internal and external model validation using observed epidemiological data for unscreened women from different German cancer registries. The model predicts life expectancy, incidence of detected cervical cancer cases, lifetime cervical cancer risks and mortality. RESULTS: The model predicted a lifetime cervical cancer risk of 3.0% and a lifetime cervical cancer mortality of 1.0%, with a peak cancer incidence of 84/100,000 at age 51 years. These results were similar to observed data from German cancer registries, German literature data and results from other international models. Based on our model, annual Pap screening could prevent 98.7% of diagnosed cancer cases and 99.6% of deaths due to cervical cancer in women completely adherent to screening and compliant to treatment. Extending the screening interval from 1 year to 2, 3 or 5 years resulted in reduced screening effectiveness. CONCLUSIONS: This model provides a tool for evaluating the long-term effectiveness of different cervical cancer screening tests and strategies.

Adolescent↗

PubMed2006

Evidence for lower variability of coronary artery calcium mineral mass measurements by multi-detector computed tomography in a community-based cohort--consequences for progression studies.

PURPOSE: To compare the measurement variability for coronary artery calcium (CAC) measurements using mineral mass compared with a modified Agatston score (AS) or volume score (VS) with multi-detector CT (MDCT) scanning, and to estimate the potential impact of these methods on the design of CAC progression studies. MATERIALS AND METHODS: We studied 162 consecutive subjects (83 women, 79 men, mean age 51 +/- 11 years) from a general Caucasian community-based cohort (Framingham Heart Study) with duplicate runs of prospective electrocardiographically-triggered MDCT scanning. Each scan was independently evaluated for the presence of CAC by four experienced observers who determined a "modified" AS, VS and mineral mass. RESULTS: Of the 162 subjects, CAC was detected in both scans in 69 (42%) and no CAC was detected in either scan in 72 (45%). Calcium scores were low in the 21/162 subjects (12%) for whom CAC was present in one but not the other scan (modified AS < 20 in 20/21 subjects, mean AS 4.6 +/- 1.9). For all three quantification algorithms, the inter- and intraobserver correlation were excellent (r > 0.96). However, the mean interscan variability was significantly different between mineral mass, modified AS, and VS (coefficient of variation 26 +/- 19%, 41 +/- 28% and 34 +/- 25%, respectively; p < 0.04), with significantly smaller mean differences in pair-wise comparisons for mineral mass compared with modified AS (p < 0.002) or with VS (p < 0.03). The amount of CAC but not heart rate was an independent predictor of interscan variability (r = -0.638, -0.614 and -0.577 for AS, VS, and mineral mass, respectively; all p < 0.0001). The decreased interscan variability of mineral mass would allow a sample size reduction of 5.5% compared with modified AS for observational studies of CAC progression and for randomized clinical trials. CONCLUSION: There is significantly reduced interscan variability of CAC measurements with mineral mass compared with the modified AS or VS. However, the measurement variability of all quantification methods is predicted by the amount of CAC and is inversely correlated to the extent of partial volume artifacts. Moreover, the improvement of measurement reproducibility leads to a modest reduction in sample size for observational epidemiological studies or randomized clinical trials to assess the progression of CAC.

Adult↗

PubMed2006

A validated clinical and biochemical score for the diagnosis of acute heart failure: the ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) Acute Heart Failure Score.

BACKGROUND: No method integrating amino-terminal pro-brain natriuretic peptide (NT-proBNP) testing with clinical assessment for the evaluation of patients with suspected acute heart failure (HF) has been described. METHODS: Amino-terminal pro-brain natriuretic peptide results and clinical factors from 599 patients with dyspnea were analyzed. The beta coefficients of the 8 independent predictors of HF were used to assign a weighted integeric score for predictor. The sum of these integers provided a diagnostic HF "score" for each patient. Receiver operating characteristic curve analysis determined the optimal cut point for the diagnosis of acute HF. The performance of the score was evaluated in the development cohort and subsequently in a patient population from a separate clinical trial of patients with dyspnea conducted in Christchurch, New Zealand. RESULTS: Eight factors comprised the score: elevated NT-proBNP (4 points), interstitial edema on chest x-ray (2 points), orthopnea (2 points), absence of fever (2 points), loop diuretic use, age > 75 years, rales, and absence of cough (all 1 point). Median scores in patients with acute HF were higher than those without acute HF (9 vs 3 points, P < .001). At a cut point of > or = 6 points, the score had a sensitivity of 96% and a specificity of 84% for the diagnosis of acute HF (P < .001). The score improved diagnostic accuracy over NT-proBNP testing alone and retained discriminative capacity in patients in whom clinical uncertainty was present. Lastly, the accuracy of the score was validated in the external data set of patients with suspected acute HF. CONCLUSION: We report a simple and accurate scoring system combining NT-proBNP testing and clinical assessment for the diagnosis or exclusion of acute HF in patients with dyspnea.

Acute Disease↗

PubMed2006

A systematic meta-analysis of the efficacy and heterogeneity of disease management programs in congestive heart failure.

BACKGROUND: We sought to systematically combine the evidence on efficacy of disease management programs (DMPs) in the treatment of congestive heart failure (CHF), to identify and explain heterogeneity of results from prior studies of DMPs, and to assess potential publication bias from these studies. METHODS AND RESULTS: We conducted a systematic literature search on randomized clinical trials investigating the effect of DMPs on CHF outcomes and performed meta-analyses and meta-regressions comparing DMPs and standard care for mortality and rehospitalization. We included 36 studies from 13 different countries (with data from 8341 patients). Our meta-analysis yielded a pooled risk difference of 3% (95% confidence interval [CI] 1-6%, P < .01) for mortality and of 8% (95% CI 5-11%, P < .0001) for rehospitalization, both favoring DMP. Factors explaining heterogeneity between studies included severity of disease, proportion of beta-blocker at baseline, country, duration of follow-up, and mode of postdischarge contact. No statistically significant publication bias was detected. CONCLUSION: DMPs have the potential to reduce morbidity and mortality for patients with CHF. The benefit of the intervention depends on age, severity of disease, guideline-based treatment at baseline, and DMP modalities. Future studies should directly compare the effect of different aspects of disease management programs for different populations.

Age Factors↗

PubMed2006

Intravascular optical coherence tomography: comparison with histopathology in atherosclerotic peripheral artery specimens.

PURPOSE: Intravascular optical coherence tomography (OCT) is a new imaging modality that provides microstructural information on atherosclerotic plaques and has an axial resolution of 10-20 microm. OCT of coronary arteries characterizes different atherosclerotic plaque components by their distinctive signal patterns. Peripheral human arteries were examined ex vivo by means of OCT, and attempts to distinguish among fibrous, lipid-rich, and calcified atherosclerotic plaques were made based on imaging criteria previously established for coronary arteries. MATERIALS AND METHODS: One hundred fifty-one atherosclerotic arterial segments were obtained from 15 below-knee amputations. OCT imaging criteria for different plaque types (fibrous, lipid-rich, calcified) were established in a subset of 30 arterial segments. The remaining 121 OCT images were analyzed by two independent readers. Each segment was divided into four quadrants. Agreement between histopathology and OCT was quantified by the kappa test of concordance, as were interobserver, intraobserver, and inter-method variability. RESULTS: Four hundred sixty-nine of 484 quadrants (97%) were available for comparison. Sensitivity and specificity for OCT criteria (consensus readers 1 and 2) were 86% and 86% for fibrous plaques, 78% and 93% for lipid-rich plaques, and 84% and 95% for calcified plaques, respectively (overall agreement, 84%). The interobserver and intraobserver reliabilities of OCT assessment were high (kappa values of 0.84 and 0.87, respectively). The inter-method agreement was 0.74 for consensus OCT versus consensus histology. CONCLUSIONS: OCT of peripheral human arteries ex vivo characterized different atherosclerotic plaque types with a high degree of agreement with histopathologic findings. Findings were comparable to those reported for coronary arteries. OCT promises to improve understanding of the progression or regression of peripheral atherosclerosis in vivo.

Adult↗

PubMed2006

Diagnostic performance of stress perfusion and delayed-enhancement MR imaging in patients with coronary artery disease.

PURPOSE: To prospectively determine the accuracy of a combined magnetic resonance (MR) imaging approach (stress first-pass perfusion imaging followed by delayed-enhancement imaging) for depicting clinically significant coronary artery stenosis (> or = 70% stenosis) in patients suspected of having or known to have coronary artery disease (CAD), with coronary angiography serving as the reference standard. MATERIALS AND METHODS: The committee on human research approved the study protocol, and all participants gave written informed consent. This study was HIPAA compliant. Forty-seven patients (38 men and nine women; mean age, 63 years +/- 5.3 [standard deviation]) scheduled for coronary angiography were prospectively enrolled: 33 were suspected of having CAD (group A) and 14 had experienced a previous myocardial infarction and were suspected of having new lesions (group B). The MR imaging protocol included cine function, gadolinium-enhanced stress and rest first-pass perfusion MR imaging, and delayed-enhancement MR imaging. Myocardial ischemia was defined as a segment with perfusion deficit at stress first-pass perfusion MR imaging and no hyperenhancement at delayed-enhancement imaging. Myocardial infarction was defined as an area with hyperenhancement at delayed-enhancement imaging. RESULTS: One patient was excluded from analysis because of poor-quality MR images. Coronary angiography depicted significant stenosis in 30 of 46 patients (65%). In a per-vessel analysis (n = 138), stress first-pass perfusion MR imaging and delayed-enhancement imaging yielded sensitivity of 0.87, specificity of 0.89, and accuracy of 0.88, when compared with coronary angiography. The diagnostic accuracy of stress first-pass perfusion MR imaging and delayed-enhancement imaging was slightly better than that of stress and rest first-pass perfusion MR imaging in the entire population (0.88 vs 0.85), in group A (0.86 vs 0.82), and in group B (0.93 vs 0.90). CONCLUSION: Stress first-pass perfusion MR imaging followed by delayed-enhancement imaging is an accurate method to depict significant coronary stenosis in patients suspected of having or known to have CAD.

Aminophylline↗

PubMed2005

Long-term outcome after stroke: evaluating health-related quality of life using utility measurements.

BACKGROUND AND PURPOSE: As stroke mortality rates decline, individuals are increasingly likely to live with their residual impairments and disabilities. Therefore, the quality of poststroke life is 1 of the pivotal topics that have to be considered beneath the functional outcome. However, data on health-related quality of life (HRQoL) have been infrequently used in stroke trials. The purpose of this study was to examine the long-term outcome (4 years after stroke) of HRQoL and to identify the determinants of HRQoL in stroke survivors. METHODS: Seventy-seven patients were included who were admitted to the Department of Neurology, Philipps-University Marburg, after experiencing an ischemic stroke, a transient ischemic attack, or a hemorrhagic stroke. All patients were examined by a physician, and assessment was performed using a standardized questionnaire. HRQoL was assessed using the German version of the EuroQoL Index (EQ-5D) and the Health Utility Index 2 and 3 (HUI2/3). RESULTS: Four years after stroke, besides physical functioning, neuropsychological sequelae such as depression and cognitive impairment contributed to a reduced HRQoL. In addition, the incidence of incontinence proved to be an important factor for HRQoL. Explained variances in regression analysis models were high (R2=0.802 for HUI and 0.633 for EQ-5D--visual analogue scale) and were based on a few important determinants, including physical state, depression, cognitive impairment, and incontinence. CONCLUSIONS: Our results underscore the importance of nonmotor symptoms on HRQoL in patients with stroke.

Activities of Daily Living↗

PubMed2005

Three-year clinical follow-up after strontium-90/yttrium-90 beta-irradiation for the treatment of in-stent coronary restenosis.

Because late vessel failure has been speculated as a possible limitation of vascular brachytherapy, we conducted a prospective clinical evaluation at 6, 12, 24, and 36 months of follow-up after irradiation with strontium-90/yttrium-90 for in-stent restenosis, regardless of the patient's symptomatic status. We report complete 3-year follow-up data for 106 consecutive patients. The cumulative rate of death at 6, 12, 24, and 36 months was 0.9%, 0.9%, 0.9%, and 1.9% respectively. The corresponding rates for acute ST-elevation myocardial infarction were 2.8%, 4.7%, 4.7%, and 4.7%, respectively. The cumulative rate of late thrombotic occlusion at 6, 12, 24, and 36 months was 3.8%, 4.7%, 4.7%, and 4.7%, respectively. The corresponding rates of target lesion revascularization and target vessel revascularization were 8.5% and 12.3% (p = 0.046), 14.2% (p = 0.157) and 18.0% (p = 0.046), 12.3% and 18.9% (p = 0.008), and 21.7% (p = 0.083) and 29.2% (p = 0.005), respectively. The cumulative rate of all major adverse cardiovascular events at 6, 12, 24, and 36 months was 16.1%, 24.5% (p = 0.003), 27.4% (p = 0.083), and 35.8% (p = 0.003), respectively. In conclusion, these results indicate a delayed and, even in the third year after the index procedure, continued restenotic process after beta irradiation of in-stent restenotic lesions.

Aged↗

PubMed2005

Critical limb ischemia: hybrid MR angiography compared with DSA.

PURPOSE: To compare a hybrid magnetic resonance (MR) angiography protocol with selective digital subtraction angiography (DSA) in patients with critical limb ischemia. MATERIALS AND METHODS: The study was approved by the institutional review board, and written consent was obtained from all patients. Pretreatment DSA and hybrid MR angiography were performed in 19 consecutive patients (15 men, four women; mean age, 69.8 years; range, 44-86 years). Hybrid MR angiography included submillimeter dual-phase three-dimensional gadolinium-enhanced MR angiography in lower calf and foot, and four-station bolus-chase MR angiography in pelvis, thigh, and upper calf. Three readers identified the target lesion and inflow and outflow segments and determined treatment (bypass graft placement, percutaneous transluminal angioplasty, conservative management, amputation). Results of interobserver and intermethod comparisons were expressed as percentage of agreement and 95% confidence interval (CI). RESULTS: On hybrid MR angiograms, no substantial venous overlay was present and image quality was excellent or adequate in 18 (95%) of 19 limbs. Readers 1, 2, and 3 selected the identical target lesion on the DSA image and the MR angiogram in 18, 17, and 18 of 18 comparable limbs, respectively. Mean percentage of agreement for readers 1 and 3 was 100% (95% CI: 81%, 100%) and for reader 2 was 94% (95% CI: 73%, 100%). Agreement of all three readers was superior with use of MR angiography for determination of inflow segments (13 [72%] of 18 limbs) and outflow segments (17 [94%] of 18 limbs), compared with agreement with use of DSA (13 [68%] of 19 inflow segments, 10 [53%] of 19 outflow segments). Agreement in therapy decisions was higher with DSA (15 [79%] of 19) than with MR angiography (11 [61%] of 18). CONCLUSION: Preliminary data strongly support the combination of submillimeter dual-phase MR angiography in lower calf and foot with four-station bolus-chase MR angiography to extend the utility of MR angiography to patients with critical limb ischemia.

Adult↗

PubMed2005

Comparing the clinical effectiveness of different new-born hearing screening strategies. A decision analysis.

BACKGROUND: Children with congenital hearing impairment benefit from early detection and treatment. At present, no model exists which explicitly quantifies the effectiveness of universal newborn hearing screening (UNHS) versus other programme alternatives in terms of early diagnosis. It has yet to be considered whether early diagnosis (within the first few months) of hearing impairment is of importance with regard to the further development of the child compared with effects resulting from a later diagnosis. The objective was to systematically compare two screening strategies for the early detection of new-born hearing disorders, UNHS and risk factor screening, with no systematic screening regarding their influence on early diagnosis. METHODS DESIGN: Clinical effectiveness analysis using a Markov Model. DATA SOURCES: Systematic literature review, empirical data survey, and expert opinion. TARGET POPULATION: All newborn babies. TIME SCALE: 6, 12 and 120 months. PERSPECTIVE: Health care system. COMPARED STRATEGIES: UNHS, Risk factor screening (RS), no systematic screening (NS). OUTCOME MEASURES: Quality weighted detected child months (QCM). RESULTS: UNHS detected 644 QCM up until the age of 6 months (72,2%). RS detected 393 child months (44,1%) and no systematic screening 152 child months (17,0%). UNHS detected 74,3% and 86,7% weighted child months at 12 and 120 months, RS 48,4% and 73,3%, NS 23,7% and 60,6%. At the age of 6 months UNHS identified approximately 75% of all children born with hearing impairment, RS 50% and NS 25%. At the time of screening UNHS marked 10% of screened healthy children for further testing (false positives), RS 2%. UNHS demonstrated higher effectiveness even under a wide range of relevant parameters. The model was insensitive to test parameters within the assumed range but results varied along the prevalence of hearing impairment. CONCLUSION: We have shown that UNHS is able to detect hearing impairment at an earlier age and more accurately than selective RS. Further research should be carried out to establish the effects of hearing loss on the quality of life of an individual, its influence on school performance and career achievement and the differences made by early fitting of a hearing aid on these factors.

Cost-Benefit Analysis↗

PubMed2005

Using competence network collaboration and decision-analytic modeling to assess the cost-effectiveness of interferon alpha-2b plus ribavirin as initial treatment of chronic hepatitis C in Germany.

The objective of this study was to translate and apply a decision-analytic model for chronic hepatitis C (CHC) to the German health care context using competence network collaboration. The German Hepatitis C Model (GEHMO) competence network used a systematic multistep approach to identify and transfer a high quality Markov model for CHC to the German health care context. GEHMO was used to project lifetime clinical and economic outcomes and to determine the cost-effectiveness of initial antiviral therapy with interferon a-2b plus ribavirin from a societal perspective. In 40-year-old patients combination therapy for 24 and 48 weeks increased life expectancy by 1.6 and 2.3 years, respectively, compared with interferon alone for 48 weeks. The discounted incremental cost-utility ratios (ICUR) for combination therapy were euro 5,500 per quality-adjusted life-year gained (QALY) for 24 weeks and euro 6,800/QALY for 48 weeks of treatment. ICUR was euro 9,800/QALY for moving from 24 to 48 weeks of treatment. Combination therapy remained cost-effective in sensitivity analyses. In conclusion, combination therapy with interferon alpha-2b and ribavirin is effective and cost-effective compared with other well-accepted medical treatments. Competence network collaboration and decision modeling provide a useful and efficient approach to combine evidence from international studies with country-specific parameters.

Adult↗

PubMed2005

Sirolimus-eluting stent implantation and beta-irradiation for the treatment of in-stent restenotic lesions: comparison of underlying mechanisms of acute gain and late loss as assessed by volumetric intravascular ultrasound.

BACKGROUND: The aim of the study was to compare the angioplasty mechanisms of drug (sirolimus)-eluting stent (DES) implantation and vascular brachytherapy (VBT) for the treatment of in-stent restenosis (ISR) as assessed by intravascular ultrasound (IVUS). METHODS: We performed IVUS in 53 patients (28 DES, 25 VBT) before and after angioplasty of ISR and at 6-month follow-up. Cross-sectional areas of the external elastic membrane, the stent, and the lumen were measured. Plaque + media, peristent plaque, and intimal hyperplasia areas were calculated, respectively. RESULTS: Clinical and IVUS baseline characteristics did not differ between groups at baseline. After the index procedure, the lumen at the stent site was smaller in the DES group (DES 6.7 +/- 2.0 mm2 vs VBT 7.5 +/- 2.2 mm2, P = .042). Because of less intimal hyperplasia (DES 0.2 +/- 0.5 mm2 vs VBT 0.7 +/- 0.7 mm2, P = .043), the lumen dimensions revealed no difference between groups at follow-up (DES 6.5 +/- 2.3 mm2 vs VBT 6.8 +/- 2.2 mm2, P = .374). At the reference site, the index procedure led to a similar increase of plaque + media (DES 0.9 +/- 0.9 mm2 vs VBT 0.6 +/- 1.2 mm2, P = .150). At follow-up, the plaque + media was significantly smaller in the DES group (DES 8.0 +/- 6.6 mm2 vs VBT 9.9 +/- 7.8 mm2, P = .013). CONCLUSIONS: Drug-eluting stent for the treatment of ISR more effectively inhibits neointima formation when compared with VBT. Yet insufficient stent expansion might be a reason for device failure and should be avoided. At the reference site, lumen loss by an increased plaque burden, as has been well recognized following VBT, is not present with DES.

Aged↗

PubMed2005

Prevalence and incidence of Parkinson's disease in Europe.

OBJECTIVE: To provide an overview on the prevalence and incidence of Parkinson's disease (PD) in selected European countries. BACKGROUND: PD is a common disease of unknown etiology. Accurate information on the epidemiology of PD is critical to inform health policy. An aging population will lead to more patients with PD; thus, the high financial burden PD places on society will increase. MATERIAL AND METHODS: A systematic literature search was performed to identify studies on the prevalence and incidence of PD in the following European countries: Austria, the Czech Republic, France, Germany, Italy, The Netherlands, Portugal, Spain, Sweden and United Kingdom. Only published studies were included. Abstracts, reviews, meta-analyses and letters to the editor were excluded. There were no language restrictions. Data were extracted using a standardized assessment form, and evidence tables were used to systematically report and compare the data. RESULTS: Of 39 identified studies, most (87%) reported estimates of PD prevalence rates, while only a few (13%) reported estimates of PD annual incidence rates. Crude prevalence rate estimates ranged from 65.6 per 100,000 to 12,500 per 100,000 and annual incidence estimates ranged from 5 per 100,000 to 346 per 100,000. No publications could be identified for Austria or the Czech Republic. DISCUSSION AND CONCLUSION: The observed variations in prevalence and incidence rates may result from environmental or genetic factors, but might also be a consequence of differences in methodologies for case ascertainment, diagnostic criteria, or age distributions of the study populations. The comparability of existing studies is limited.

Age Distribution↗

PubMed2005

Effectiveness and cost-effectiveness of initial combination therapy with interferon/peginterferon plus ribavirin in patients with chronic hepatitis C in Germany: a health technology assessment commissioned by the German Federal Ministry of Health and Social Security.

OBJECTIVES: The purpose of this health technology assessment (HTA), commissioned by the German Federal Ministry of Health and Social Security, was to systematically review the evidence for the effectiveness and cost-effectiveness of antiviral treatment (AVT) with interferon (INF) or peginterferon (PegIFN) in combination with ribavirin (RBV) in treatment-naïve patients with chronic hepatitis C (CHC) and to apply these data in the context of the German health-care system. METHODS: We performed a systematic literature search on effectiveness and cost-effectiveness of AVT and summarized results using meta-analysis and evidence tables. We applied the German Hepatitis C Model (GEHMO), a decision-analytic Markov model, to determine long-term clinical effectiveness, costs, and incremental cost-effectiveness ratios (ICER) of the examined treatment strategies. Model parameters were derived from German databases, published international randomized clinical trials (RCT), and a Cochrane Review. RESULTS: Overall, nine RCTs, two HTA reports, one Cochrane review, two meta-analyses, and seven economic evaluations met the inclusion criteria. These studies indicate that PegIFN + RBV achieved the highest sustained virological response rates (SVR) (54-61 percent), followed by IFN + RBV (38-54 percent) and IFN monotherapy (11-21 percent). Based on our meta-analysis, PegIFN + RBV reduced cases without SVR by 17 percent compared with INF + RBV. International cost-effectiveness studies indicate that INF+ RBV is cost-effective when compared with INF monotherapy. For PegIFN + RBV, our decision analysis yielded an ICER of 9,800 Euros per quality-adjusted life-year gained. CONCLUSIONS: This HTA suggests that initial combination therapy prolongs life, improves quality of life, and is cost-effective in patients with CHC. Peginterferon plus ribavirin is the most effective and efficient treatment among the examined options. However, because not all chronic hepatitis C patients will develop progressive liver disease, a thorough assessment of the eligibility and appropriateness of treatment with combination therapy must be performed in each individual patient.

Antiviral Agents↗

PubMed2005

Discrepancy between morphologic and functional criteria of optimal stent deployment using intravascular ultrasound and pressure derived myocardial fractional flow reserve.

BACKGROUND: Pressure derived myocardial FFR, a functional index of epicardial stenosis has been proposed for the assessment of optimal stent deployment. The following study evaluated the potential of serial fractional flow reserve (FFR) measurements in comparison to the 'gold standard' intravascular ultrasound (IVUS) for optimal stent deployment and its long-term outcome. METHODS: 35 patients with a single de novo lesion underwent PTCA followed by stent implantation with an initial inflation pressure of 12 atm. If optimal stent expansion using IVUS-criteria were not fulfilled, re-dilatation at 16 atm as well as additional inflations with larger balloon sizes were performed to reach the procedural end-point. IVUS and FFR were performed after each dilatation (n = 136). Angiography was repeated after 6 months. RESULTS: In 30 pts who fulfilled IVUS criteria, mean lumen area (2.9+/-1.3 mm2) increased after PTCA and stent implantation to 10.0+/-3.0 mm2. In six pts, optimum stent deployment according to a value of FFR0.94 was not reached. Four of six pts reached the IVUS criteria at 12 atm and two pts at 16 atm, respectively. Positive and negative predictive values of FFR were 26 and 64%. Three of the 30 pts (10%) revealed a restenosis at three months follow-up. One of these restenosis was seen in a patient with a post-procedural FFR<0.94. CONCLUSIONS: FFR was not valid to predict optimal stent expansion according to IVUS criteria but could delineate under-expanded stents despite a reasonable angiographic appearance. Morphologic (IVUS) and functional criteria (FFR) for optimal stent deployment revealed a comparably low restenosis rate.

Aged↗