Biomedical subjects

Uwe Siebert

Publications and source records attributed to Uwe Siebert.

At least 37 records · Page 2Linked to original sources

PubMed2005

Cost effectiveness of haemophilia treatment: a cross-national assessment.

The aim of this study was to assess the incremental cost effectiveness of on-demand versus prophylactic haemophilia therapy in Germany, Sweden, the United Kingdom and The Netherlands from the third-party payers' perspective. Using a decision tree model, the cost effectiveness of on-demand versus prophylactic therapy was analysed by extrapolating data from the European Haemophilia Economic Study to a 1-year analytic time horizon. Five hundred and six patients with severe haemophilia A and B, without inhibitors and at least 14 years of age, were enrolled in this study. Patients treated prophylactically had fewer bleeds than patients treated on-demand. With prophylactic treatment, the incremental cost per avoided bleeding ranged from 6,650 Euro dollars for patients 30 years of age or younger in Germany to 14,140 Euro dollars for patients over 30 years old in Sweden. If quality of life was taken into account, patients receiving prophylactic treatment had higher mean utilities than patients on on-demand therapy. The incremental effectiveness ratios in Germany were 1.2 million Euro dollars per quality-adjusted life year gained for patients 30 years or younger and HIV-positive and 2.2 million Euro dollars for patients 30 years or younger and HIV-negative. In the group aged over 30 years and HIV-positive the on-demand treatment strategy was dominant, whereas in the over 30 years/HIV-negative group the incremental cost-utility ratio was 4.7 million Euro dollars per quality-adjusted life year. Based on our decision analysis, the use of prophylactic treatment was overall more effective than on-demand therapy in young haemophiliacs, but at extremely high cost.

Adolescent↗

PubMed2005

Application, feasibility, and efficacy of a combined intravascular ultrasound and stent delivery system: results from a prospective multicenter trial.

BACKGROUND: Intravascular ultrasound (IVUS) is the reference method for in vivo assessment of vessel dimensions and coronary plaque composition, which can influence device selection as well as stent sizing. OBJECTIVES: The objective of this prospective multicenter-study was to test the application, safety, and feasibility of a new combined IVUS and stent delivery system. METHODS: A total of 32 patients with planned direct stent implantation under IVUS guidance were included in the study. Procedural as well as angiographical and IVUS characteristics of the stent implantation with the combined IVUS and stent delivery system were assessed and compared to a historical control cohort where IVUS-guided stenting was performed with a separate IVUS catheter. RESULTS: Direct stent placement was successfully performed in all patients and no malfunctions of the system were noted. A post-interventional IVUS assessment was possible in 27 (87%) of the 31 patients. The IVUS information led to a change in therapeutic strategy in 16 (50%) of the 32 patients. In the study group, both the procedural time and the amount of contrast dye were significantly lower than in the historical IVUS-guided stenting control group. A clinical 12-month follow-up revealed a 89% event-free survival and a target vessel revascularization rate of 7%. CONCLUSION: The use of a combined IVUS and stent delivery device is safe, easy to handle, and can provide helpful additional information to guide a percutaneous coronary interventions procedure. Beyond angiography, these informations had significant impact on the interventional strategy in these patients, which resulted in a low rate of major adverse cardiac events. The concept of combining IVUS information and a stent delivery system may be increasingly attractive with evolving imaging modalities like virtual histology or a combination with drug-eluting stents.

Aged↗

PubMed2005

Cost-effectiveness analysis in the assessment of diagnostic imaging technologies.

In many ways, diagnostic technologies differ from therapeutic medical technologies. Perhaps most important, diagnostic technologies do not generally directly affect long-term patient outcomes. Instead, the results of diagnostic tests can influence the care of patients; in that way, diagnostic tests may affect long-term outcomes. Because of this, the benefits associated with the use of a specific diagnostic technology will depend on the performance characteristics (eg, sensitivity and specificity) of the test, as well as other factors, such as prevalence of disease and effectiveness of available treatments for the disease in question. The fact that diagnostic tests affect short-term, or "surrogate," outcomes, rather than long-term patient outcomes makes evaluation of these tests more complicated than the evaluation of therapeutic technologies. This article will trace the history of technology assessment in medicine, address the role of cost-effectiveness and decision analysis in health technology assessment, and describe unique features and approaches to assessing diagnostic technologies. The article will then conclude with a consideration of the limits of medical technology assessment.

Cost-Benefit Analysis↗

PubMed2005

Cost of illness and its predictors for Parkinson's disease in Germany.

OBJECTIVE: To prospectively evaluate the health economic burden of patients with Parkinson's disease (PD) in Germany over a 6-month observation period and to identify the predictors of these costs. STUDY DESIGN AND METHODS: Direct and indirect costs were evaluated in 145 patients with PD (mean age 67.3 +/- 9.6 years). PD patients were recruited from an outpatient department for movement disorders, a specialised PD clinic, two office-based neurologists and general practitioners, all located in Germany, and were enrolled between January and June 2000. Relevant economic data were documented in a patient diary over the 6-month period. Clinical evaluations (Unified Parkinson's Disease Rating Scale [UPDRS]) were performed at baseline and at 3 and 6 months. Costs were derived from various German medical economic resources. Costs were calculated from the perspective of healthcare and transfer payment providers and the individual patient. Indirect costs for lost productivity were also calculated. Costs are presented as means +/- standard deviation (SD). Multivariate regression analyses were performed to identify independent cost predictors. Costs are in year 2000-02 values. RESULTS: We estimated average per patient direct, indirect and total costs for the 6-month observation period. The costs from the perspective of statutory health insurance (Gesetzliche Krankenkversicherung [GKV]) consisted of direct medical costs 1370 euro +/- 3240 euro, including rehabilitation (420 euro +/- 1630 euro), hospitalisation (710 euro +/-2520 euro), outpatient treatment (40 euro +/- 30 euro), ancillary treatment (190 euro +/- 280 euro) and ambulatory diagnostic procedures (10 euro +/-30 euro). In addition, parkinsonian drug costs were 1520 euro +/-euro1250. Non-medical direct costs calculated from the GKV perspective were estimated to be euro480 +/-euro1710, which included transportation (10 euro+/- 20 euro), special equipment (420 euro +/- 1640 euro), social/home-help services (10 euro +/-110 euro) and sickness benefit (40 euro +/- 540 euro). The total medical (including drug costs) and non-medical direct costs for the GKV were 3380 euro +/- 4230 euro. Univariate predictors for GKV direct costs included occurrence of motor complications and falls, disease severity, nightmares and dementia. However, multivariate analyses only suggested disease severity and health-related quality of life as significant predictors. For nursing insurance, payments of 1330 euro +/- 2890 euro were calculated. For retirement insurance, payments were 650 euro +/- 1510 euro and there were patient (or caregiver) costs of 1490 euro +/- 2730 euro. Total indirect costs amounted to 3180 euro +/-6480 euro. CONCLUSION: According to our study, PD puts a high financial burden on society and underscores the need for further economic and medical research to optimise treatment for PD.

Aged↗

PubMed2004

Comparison of acute and long-term results and underlying mechanisms from sirolimus-eluting stent implantation for the treatment of in-stent restenosis and recurrent in-stent restenosis in patients in whom intracoronary radiation failed as assessed by intravascular ultrasound.

In-stent restenosis (ISR), especially after vascular brachytherapy, is a therapeutic challenge. Sirolimus-eluting stent implantation is a promising new option for the treatment of patients with ISR. The efficacy of sirolimus-eluting stent implantation for the treatment of patients with their first episodes of ISR and with recurrent ISR due to the failure of vascular brachytherapy was compared using intravascular ultrasound imaging.

Aged↗

PubMed2004

The socioeconomic impact of narcolepsy.

STUDY OBJECTIVE: To evaluate the economic burden of patients suffering from narcolepsy. DESIGN: Cross-sectional study. PARTICIPANTS: 75 narcoleptic patients diagnosed at the Hephata Klinik, Germany, who met the International Classification of Sleep Disorders criteria for narcolepsy. MEASUREMENTS: A standardized telephone interview was used to inquire about the disease and its burden. In addition, health-related quality of life scales (SF-36 and EQ-5D) were mailed to the patients. Complete data were available for 75 patients. Direct and indirect costs were calculated from the societal perspective. All costs (mean +/- SD) were calculated in 2002 Euros (Euros). RESULTS: Total annual costs were Euros 14,790 +/- 16,180 (US-dollars 15,410) per patient. Direct costs were Euros 3,180 +/- 3,540 (US-dollars 3,310), which consisted of hospital costs (Euros 1,210 +/- 2,210; US-dollars 1,260), drug costs (narcolepsy medication: Euros 1,020 +/- 1,420; US-dollars 1,060), ambulatory care (Euros 90 +/- 90; US-dollars 40), and ambulatory diagnostics (Euros 20 +/- 30; US-dollars 20). More than 50% of the drug costs were due to the newer wake-promoting drugs. Total annual indirect costs amounted to Euros 11,390 +/- 15,740 (US-dollars 11,860) per patient and were mainly attributable to early retirement due to the disease. Narcolepsy was listed as being the cause of unemployment by 32 patients. In patients with sleep attacks, there was a significant correlation between early retirement and higher indirect costs compared to patients without these attacks. CONCLUSIONS: Narcolepsy causes a high socioeconomic burden, which is comparable to other chronic neurologic diseases, Indirect costs are considerably higher than direct costs. Measures should be taken to increase public awareness of this disease. Appropriate treatment must be provided in order to increase quality of life and to assist patients continuing in working life.

Adult↗

PubMed2004

Long-term patency of internal mammary artery bypass grafts: relationship with preoperative severity of the native coronary artery stenosis.

BACKGROUND: Internal mammary artery conduits (IMA) have an excellent long-term patency rate. Nevertheless, graft closure does occur and significantly limits future revascularization options. We sought to investigate the relationship between the long-term patency of IMA with clinical and angiographic parameters. Particularly, the preoperative degree of stenosis of the relevant bypassed coronary vessel was assessed to analyze the importance of chronic competitive flow on the arterial graft closure rate. METHODS AND RESULTS: Consecutive patients in whom occlusion of at least 1 IMA had been documented at angiography (OCC group) were compared with a group of patients with patent IMA grafts (PAT group). The degree of stenosis in the native coronary artery on which the IMA was placed was analyzed by off-line quantitative coronary angiography. Multivariate stepwise logistic regression was used to identify independent clinical and angiographic predictors of occlusion. The OCC group comprised 96 patients (67+/-10 years) with 103 native bypassed arteries analyzed. The PAT group comprised 127 patients (69+/-8 years) with 170 native bypassed arteries analyzed. Both groups were similar except for gender (42% versus 32% female; P=0.04), height (166+/-8 versus 169+/-8 cm; P=0.006), minimum lumen diameter (0.76+/-0.7 versus 0.51+/-0.5; P=0.001), and diameter stenosis of the native artery (73+/-25% versus 84+/-16%; P<0.0001) in OCC versus PAT, respectively. In the multivariate analysis, only percent diameter stenosis was an independent and statistically significant predictor for graft patency. Among IMA placed on coronary arteries with a diameter of stenosis <50% (n=28), the occlusion rate was very high (79%). CONCLUSIONS: The degree of stenosis in the native vessel is a major predictor of internal mammary artery bypass graft patency. The association between nonsignificant stenosis of the native artery and high occlusion rate of the arterial bypass conduit raises concerns about the use of IMA in the treatment of native vessels with only mild or moderate stenosis.

Aged↗

PubMed2004

Evolution of angiographic restenosis rate and late lumen loss after intracoronary beta radiation for in-stent restenotic lesions.

The aim of this study was to investigate the time course of angiographic restenosis rate and late loss after successful percutaneous coronary intervention and vascular brachytherapy with beta-irradiation using strontium-90/yttrium-90 in 98 patients who were prospectively enrolled into a quantitative angiographic and clinical follow-up protocol at 6, 12, and 24 months after the index procedure, regardless of their symptom status. Actuarial restenosis rates measured 11.2 +/- 5% at 6 months of follow-up, 24.5 +/- 5% at 12 months, and 28.5 +/- 6% at 24 months, respectively. Late loss of the stent segment during the first 6 months measured 0.38 +/- 0.40 mm (6 to 12 months: 0.25 +/- 0.38 mm; 12 to 24 months: 0.16 +/- 0.32 mm), of the injured segment 0.27 +/- 0.21 mm (6 to 12 months: 0.21 +/- 0.26 mm; 12 to 24 months: 0.13 +/- 0.24 mm), of the irradiated segment 0.18 +/- 0.29 mm (6 to 12 months: 0.19 +/- 0.31 mm; 12 to 24 months: 0.11 +/- 0.27 mm), and of the analysis segment 0.18 +/- 0.36 mm (6 to 12 months: 0.17 +/- 0.29 mm; 12 to 24 months: 0.11 +/- 0.20 mm). Restenosis after angioplasty and beta-irradiation of in-stent restenotic lesions is not complete within 6 months but is sustained with a gradual decrease over 24 months.

Actuarial Analysis↗

PubMed2004

Are high doses of intracoronary adenosine an alternative to standard intravenous adenosine for the assessment of fractional flow reserve?

BACKGROUND: Achievement of maximal hyperemia of the coronary microcirculation is a prerequisite for the measurement of fractional flow reserve (FFR). Intravenous adenosine is considered the standard method, but its use in the catheterization laboratory is time consuming and expensive compared with intracoronary adenosine. Therefore, this study compared different high, intracoronary doses of adenosine for the potential to achieve a maximal hyperemia equivalent to the standard intravenous route. METHODS: FFR was assessed in 50 patients with 50 intermediate lesions during cardiac catheterization. FFR was calculated as the ratio of the distal coronary pressure to the aortic pressure at hyperemia. Different incremental doses of intracoronary adenosine (60, 90, 120, and 150 microg as boli) and a standard intravenous infusion of 140 microg/kg/min were administered in a randomized fashion. RESULTS: Different incremental doses of intracoronary adenosine were well tolerated, with fewer systemic adverse effects than intravenous adenosine. At baseline, there were no significant differences for mean aortic and distal coronary pressure or heart rate in the different adenosine doses and routes. FFR decreased with increasing adenosine doses, with the lowest values observed with the 150-microg intracoronary bolus and 140-microg/kg/min dose of intravenous adenosine. All intracoronary doses, except the 150-microg bolus, resulted in mean FFR values that were significantly (P <.05) higher than FFR after the administration intravenous adenosine. Furthermore, 5 patients (10%) with a FFR value >0.75 and 3 subjects (6%) with a FFR value >0.80 who received a 60-microg intracoronary bolus reached a value below the cutoff point of 0.75 with the intravenous administration. CONCLUSIONS: This study suggests a dose-response relationship on hyperemia for intracoronary adenosine doses >60 microg. The administration of very high intracoronary adenosine boli is safe and associated with fewer systemic adverse effects than standard intravenous adenosine. However, intravenous adenosine administration with 140 microg/kg/min produced a more pronounced hyperemia than intracoronary adenosine in most patients and should be the preferred mode of application for the assessment of FFR.

Adenosine↗

PubMed2004

Reduction of cyclosporine after introduction of mycophenolate mofetil improves chronic renal dysfunction in heart transplant recipients--the IMPROVED multi-centre study.

AIMS: This comparative prospective multi-centre study evaluated efficacy and safety of cyclosporine A downtitration in heart transplant recipients with chronic renal dysfunction potentially attributable to cyclosporine (n=161). METHODS: In the intervention arm (n=109, recruited from 9 centres), mycophenolate mofetil was introduced de novo or substituting azathioprine, followed by cyclosporine reduction (target trough levels 2-4 microg/ml and 50 ng/ml, respectively). In controls (n=52, recruited from 1 centre), immunosuppression remained unchanged. Renal function was recorded twelve, six, and three months before, and throughout the eight-month study period. RESULTS: At study entry, cyclosporine trough levels and renal function parameters were comparable. At study end, mean+/-SD cyclosporine in the intervention arm was 57+/-24 vs. 116+/-36 ng/ml in controls. During the study, creatinine decreased by 23.3+/-50.7 micromol/l (P<0.0001) in the intervention arm but increased by 7.3+/-46.9 micromol/l (P=0.992) in controls (P=0.0001 for comparison between groups). A creatinine reduction of at least 20% was found in 35% of subjects of the intervention arm but only in 4% in the control arm (P<0.0001 for comparison between groups). Improvement in renal function was not weakened after adjustment for baseline characteristics in multiple regression analysis. Renal function improved in strata of creatinine entry values from 150 to 310 micromol/l, regardless of the presence of diabetes. Myocardial biopsies at target levels for cyclosporine and mycophenolate mofetil showed three reversible subclinical rejection episodes. CONCLUSIONS: Cyclosporine downtitration improved renal dysfunction in diabetic and non-diabetic heart transplant recipients across a wide range of creatinine levels. The long-term benefit of this strategy deserves further study.

Cyclosporine↗

PubMed2004

Postoperative troponin-T predicts prolonged intensive care unit length of stay following cardiac surgery.

OBJECTIVE: To evaluate the use of postoperative cardiac troponin T (cTnT) for the prediction of prolonged intensive care unit length of stay following cardiac surgery. DESIGN: Prospective, single-center, observational cohort study of patients following cardiac surgical procedures. The enrollment period was from October through December 2000. Patients were enrolled on admission to the intensive care unit and followed until hospital discharge. SETTING: The cardiac surgical intensive care unit of the Massachusetts General Hospital. PATIENTS: A total of 222 consecutive patients were enrolled. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Perioperative clinical factors and serum concentrations of cTnT measured every 8 hrs after surgery were recorded. These clinical factors and the results of serum cTnT measurement were correlated with the need for prolonged intensive care unit length of stay (defined as >24 hrs). Univariable analysis identified factors predictive of prolonged intensive care unit length of stay. Stepwise logistic regression identified independent predictors of prolonged intensive care unit length of stay. Multiple linear regression was used to explore the direct relationship between cTnT concentrations at several postoperative time points and intensive care unit length of stay. At each time point assessed, cTnT concentrations from patients requiring a prolonged intensive care unit length of stay were significantly higher (all p <.001) than in those individuals with normal length of stay. In contrast, creatine kinase isoenzymes were not significantly different between patients with normal or prolonged intensive care unit length of stay. Multivariable analysis demonstrated that an immediate postoperative cTnT concentration > or =1.58 ng/mL was the strongest predictor of a prolonged intensive care unit length of stay (odds ratio, 5.6; 95% confidence interval, 2.9-10.8). Multiple linear regression analysis revealed that intensive care unit length of stay increased by 0.32 days with each incremental 1.0 ng/mL increase in cTnT measured at 18-24 hrs postprocedure. CONCLUSIONS: Elevated postoperative cTnT concentrations can prospectively identify patients requiring prolonged intensive care unit length of stay after cardiac surgery.

Aged↗

PubMed2004

Magnetic resonance angiography in the follow-up of distal lower-extremity bypass surgery: comparison with duplex ultrasound and digital subtraction angiography.

PURPOSE: The danger of limb loss as a consequence of acute occlusion of infrapopliteal bypasses underscores the requirement for careful patient follow-up. The objective of this study was to determine the agreement and accuracy of contrast material-enhanced moving-table magnetic resonance (MR) angiography and duplex ultrasonography (US) in the assessment of failing bypass grafts. In cases of discrepancy, digital subtraction angiography (DSA) served as the reference standard. MATERIALS AND METHODS: MR angiography was performed in 24 consecutive patients with 26 femorotibial or femoropedal bypass grafts. Each revascularized limb was divided into five segments--(i) native arteries proximal to the graft; (ii) proximal anastomosis; (iii) graft course; (iv) distal anastomosis; and (v) native arteries distal to the graft-resulting in 130 vascular segments. Three readers evaluated all MR angiograms for image quality and the presence of failing grafts. The degree of stenosis was compared to the findings of duplex US, and in case of discrepancy, to DSA findings. Two separate analyses were performed with use of DSA only and a combined diagnostic endpoint as the reference standard. RESULTS: Image quality was rated excellent or intermediate in 119 of 130 vascular segments (92%). Venous overlay was encountered in 26 of 130 segments (20%). In only two segments was evaluation of the outflow region not feasible. One hundred seventeen of 130 vascular segments were available for quantitative analysis. In 109 of 117 segments (93%), MR angiography and duplex US showed concordant findings. In the eight discordant segments in seven patients, duplex US overlooked four high-grade stenoses that were correctly identified by MR angiography and confirmed by DSA. Percutaneous transluminal angioplasty was performed in these cases. In no case did MR angiography miss an area of stenosis of sufficient severity to require treatment. Total accuracy for duplex US ranged from 0.90 to 0.97 depending on the reference standard used, whereas MR angiography was completely accurate (1.00) regardless of the standard definition. CONCLUSION: Our data strongly suggest that the accuracy of MR angiography for identifying failing grafts in the infrapopliteal circulation is equal to that of duplex US and superior to that of duplex US in cases of complex revascularization. MR angiography should be included in routine follow-up of patients undergoing infrapopliteal bypass surgery.

Adult↗

PubMed2004

Cost effectiveness of combination therapy with pioglitazone for type 2 diabetes mellitus from a german statutory healthcare perspective.

BACKGROUND: Pioglitazone has been approved in Europe for oral combination therapy for type 2 diabetes mellitus. Along with other agents of the thiazolidinedione class, it has a novel intracellular mechanism of action. Clinical trials with pioglitazone have confirmed a strong product profile in terms of control of blood glucose and lipids. However, the drug acquisition cost for pioglitazone is greater than standard medications for type 2 diabetes. Long-term data regarding the cost effectiveness of pioglitazone-based combination therapy are not available. OBJECTIVE: To evaluate, using a decision analysis model, the cost effectiveness of pioglitazone-based combination therapy compared with relevant alternative medications for the treatment of type 2 diabetes in Germany. METHODS: This study compared the clinical effects and costs of pioglitazone 30 mg added to metformin in patients who failed metformin monotherapy and pioglitazone added to a sulphonylurea in patients who failed sulphonylurea monotherapy, with the most relevant treatment alternatives. A published and validated Markov model was adapted to reflect the management of type 2 diabetes. This simulated the number of severe complications occurring and the mean life expectancy of a diabetic cohort, which was based on the overweight group of the UK Prospective Diabetes Study at year 6 of follow-up. Drug treatment costs, other costs for general management of type 2 diabetes and the costs of complications were combined to compute overall lifetime treatment costs from the perspective of the German statutory healthcare system in 2002. RESULTS: Combination therapy with pioglitazone/metformin was associated with a higher life expectancy (15.2 years) relative to sulphonylurea/metformin (14.9 years) or acarbose/metformin (14.7 years). Likewise, pioglitazone/sulphonylurea (15.5 years) was superior to metformin/sulphonylurea (14.9 years) and acarbose/sulphonylurea (14.8 years). Undiscounted incremental cost-effectiveness ratios in comparison to the next best strategy were euro20,002 per life-year gained (LYG) for pioglitazone/metformin versus sulphonylurea/metformin, and euro8707 per LYG for pioglitazone/sulphonylurea versus metformin/sulphonylurea. After discounting costs and life expectancy at 5% per year, the incremental cost-effectiveness ratio was euro47 636 per LYG for pioglitazone/metformin versus sulphonylurea/metformin, and euro19 745 per LYG for pioglitazone/sulphonylurea versus metformin/sulphonylurea. CONCLUSIONS: In this model, with its underlying assumptions and data, combination therapy with pioglitazone increased life expectancy in overweight type 2 diabetes patients at acceptable cost compared with other well established medications in Germany. These findings should be re-evaluated as soon as additional evidence becomes available from the currently ongoing long-term clinical and economic studies.

Cost-Benefit Analysis↗

PubMed2004

Impact of barotrauma on acute and late angiographic and clinical outcomes following angioplasty and beta-irradiation of coronary in-stent restenotic lesions.

INTRODUCTION: The aim of this study was to prospectively evaluate the impact of different degrees of vessel barotrauma on the acute and 1-year clinical and angiographic outcomes of percutaneous coronary intervention (PCI) and adjunctive vascular brachytherapy (VBT) with 90Sr/90Y for in-stent restenotic lesions (ISR) in 118 patients. METHODS AND RESULTS: Sixty consecutive patients were treated according to an aggressive PCI strategy (group 1); fifty-eight were treated non-aggressively (group 2). Irradiation was performed with a manual afterloader. Clinical and angiographic baseline characteristics did not differ between groups. Group 1 yielded a higher acute lumen gain (2.3 +/- 1.2 mm versus 1.7 +/- 1.3 mm; p=0.005) and a higher prevalence of additional stent implantation (48.3% versus 22.4%; p=0.003). At follow-up, net gain (1.8 +/- 0.7 mm versus 1.4 +/- 0.8 mm; p=0.102) was equalized by a higher late loss in group 1 (0.6 +/- 0.8 mm versus 0.3 +/- 0.7 mm; p=0.036). Remaining target vessel late loss, due to edge effects, was considerably higher in group 1 than in group 2 (0.5 +/- 0.8 mm versus 0.2 +/- 0.5 mm; p<0.001), leading to a higher rate of binary angiographic restenosis (23.3% versus 6.9%; p=0.013) and target vessel revascularization (16.7% versus 5.2%; p=0.046). After excluding patients who received additional stents, the angiographic differences between groups were attenuated. CONCLUSION: Our study does not support the use of oversized balloons and high inflation pressures for the treatment of ISR when combined with VBT. Additional stent implantation combined with VBT carries a high risk of repeat revascularization in the setting of ISR and should be avoided.

Adult↗

PubMed2004

Cost effectiveness analysis of routine use of genotypic antiretroviral resistance testing after failure of antiretroviral treatment for HIV.

OBJECTIVES: Single use of genotypic antiretroviral resistance testing (GART) after first failure of highly active antiretroviral therapy (HAART) was reported to be cost effective; its use prior HAART initiation is unknown. Guidelines recommend GART after each treatment failure. We assessed the cost effectiveness of GART used routinely after first and subsequent treatment failures. Furthermore, we determined the minimum effectiveness required for GART prior to the first HAART to be as cost effective as after treatment failure. DESIGN AND METHODS: We developed a decision-analytic Markov model to estimate lifetime clinical and economic outcomes in a cohort of HIV patients starting HAART. Rates of treatment failure, estimates of GART effectiveness and data on disease progression were derived from published trials and observational studies. A cost effectiveness analysis was performed from the perspective of the healthcare system using cost data from a Central European healthcare setting. Deterministic and probabilistic sensitivity analyses using Monte Carlo technique were performed. RESULTS: GART after treatment failures increased life expectancy by 9 months and undiscounted life-time costs per case by 16,406 euros. The discounted incremental cost effectiveness ratio was 22,510 euros per life-year gained (euros/LY). Best- and worst-case scenarios yielded 16,512 euros/LY and 42,900 euros/LY, respectively. GART prior to the initiation of HAART would be equally cost effective if it could reduce the probability of first HAART failure by at least 36%. CONCLUSION: Routine use of GART after treatment failures is cost effective. GART prior to the first HAART would be equally cost effective if it could lower the probability of first HAART failure by approximately a third.

Acquired Immunodeficiency Syndrome↗

PubMed2003

Superiority of age and weight as variables in predicting osteoporosis in postmenopausal white women.

UNLABELLED: Identification of women at risk for osteoporosis is of great importance for the prevention of osteoporotic fractures. Routine BMD measurement of all women is not feasible for most populations, hence identification of a high-risk subset of women is an important element of effective preventive strategies. METHODS: We identified 959 postmenopausal non-Hispanic women aged 51 years and above from the NHANES III study to assess the relative contribution of risk predictors for low BMD at the whole proximal femur and the femoral neck regions. Based on recognized risk factors for osteoporosis identified by a systematic literature search, we ran several multiple linear regression models based on the results of preceding bivariate analyses. We show several models based on their explanatory ability assessed by adjusted r(2), ROC, and C-value analyses rather than on the coefficients and P values. We furthermore examined the sensitivity, specificity, and predictive values of our preferred models for various cutoff T-scores-the choice of which will vary depending on different study goals and population characteristics. RESULTS: Age and weight were by far the most informative predictors for low bone mineral density out of a list of 20 candidate risk predictors. Our preferred prediction models for the two regions hence contained only two variables: i.e., age and measured weight. The resulting parsimonious model to predict BMD at whole proximal femur had an adjusted r(2) of 0.43, an area under the ROC curve of 0.85, and a C-value of 0.70. Similarly, prediction for BMD at the femoral neck had adjusted r(2), area under the curve, and C-value of 0.39, 0.83, and 0.66, respectively. CONCLUSIONS: The model equations, predicted T-score = -1.332-0.0404 x (age) + 0.0386 x (measured weight) and predicted T-score = -1.318-0.0360 x (age) + 0.0314 x (measured weight) for whole proximal femur and femoral neck, respectively, can be used in field conditions for screening purposes. More complex prediction equations add little explanatory power. Based on the study goals and the population characteristics, specific cutoff T-scores have to be decided before using these equations.

Age Factors↗

PubMed2003

Response to highly active antiretroviral therapy strongly predicts outcome in patients with AIDS-related lymphoma.

BACKGROUND: AIDS-related lymphoma (ARL) remains a frequent complication of HIV infection. We analyzed the outcome of patients with ARL with respect to the use and efficacy of highly active antiretroviral therapy (HAART) and to potential prognostic factors. METHODS: This multicenter cohort study included patients with systemic ARL diagnosed between 1990-2001. We evaluated overall survival and the effects of several variables on overall survival using the Kaplan-Meier method and the extended Cox proportional hazards model. Response to HAART was used as a time-dependent variable and was defined as a CD4 cell count increase of >/= 100 x 106 cells/l and/or at least one viral load < 500 copies/ml during the first 2 years following diagnosis of ARL. RESULTS: Among 203 patients with ARL, median overall survival was 9.0 months [95% confidence interval (CI), 7.6-12.4 months]. In the univariate analyses, age < 60 years, no previous AIDS, CD4 cell counts >/= 200 x 106 cells/l, hemoglobin > 11 g/dl, Ann Arbor stages I-II and A, no extranodal lesion, response to HAART, and complete remission showed statistically significant association with prolonged overall survival. In the multivariate Cox model, the only factors independently associated with overall survival were response to HAART [relative hazard (RH), 0.32; 95% CI, 0.16-0.62], complete remission (RH, 0.24; 95% CI, 0.15-0.36), previous AIDS (RH, 1.92; 95%CI, 1.23-3.01) and extranodal involvement (RH, 2.85; 95% CI, 1.47-5.51). CONCLUSIONS: Efficacy of HAART was independently associated with prolonged survival in this large cohort of patients with ARL. Information on patient's response to HAART is crucial for the evaluation of future treatment strategies.

Acquired Immunodeficiency Syndrome↗

PubMed2003

Impact of intravascular ultrasound-guided stenting on long-term clinical outcome: a meta-analysis of available studies comparing intravascular ultrasound-guided and angiographically guided stenting.

To date, only a few studies have compared the clinical efficacy of intracoronary ultrasound (IVUS)-guided to angiographically guided stenting. Furthermore, it is not yet known whether the lower restenosis rate shown with the former strategy would translate into a substantial clinical advantage. Therefore, the aim of the present investigation was to improve the level of evidence of these studies by means of a formal meta-analysis. Nine studies were considered suitable for analysis. Odds ratios (ORs) were calculated for 6-month clinical follow-up. Primary endpoint was a composite of death and nonfatal myocardial infarction (MI), as considered in every single study. Secondary endpoints were major adverse cardiac events (MACEs), according to single study definition, the individual cardiac events, as well as several pre- and postprocedure and follow-up angiographic parameters. Overall, 2,972 patients were included. At 6 months, the OR for death and nonfatal MI was 1.13 (95% CI = 0.79-1.61; P = 0.5) for patients with IVUS-guided stenting. However, patients with IVUS-guided stenting had less target vessel revascularizations (OR = 0.62; 95% CI = 0.49-0.78; P = 0.00003) and MACEs (OR = 0.79; 95% CI = 0.64-0.98; P = 0.03) compared to angiographically guided stenting. In addition, subjects treated with IVUS-guided stenting had significantly less binary restenosis (OR = 0.75; 95% CI = 0.60-0.94; P = 0.01). The present meta-analysis demonstrates that IVUS-guided stenting implantation has a neutral effect on long-term death and nonfatal MI compared to an angiographic optimization. However, IVUS-guided stenting significantly lowers 6-month angiographic restenosis and target vessel revascularizations. Whether these benefits could be very helpful when dealing with lesions at high risk for restenosis is still an issue.

Angioplasty, Balloon, Coronary↗