Ontario health technology assessment series
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Ont Health Technol Assess Ser · Jan 2010
64-slice computed tomographic angiography for the diagnosis of intermediate risk coronary artery disease: an evidence-based analysis.
In July 2009, the Medical Advisory Secretariat (MAS) began work on Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease (CAD), an evidence-based review of the literature surrounding different cardiac imaging modalities to ensure that appropriate technologies are accessed by patients suspected of having CAD. This project came about when the Health Services Branch at the Ministry of Health and Long-Term Care asked MAS to provide an evidentiary platform on effectiveness and cost-effectiveness of non-invasive cardiac imaging modalities.After an initial review of the strategy and consultation with experts, MAS identified five key non-invasive cardiac imaging technologies for the diagnosis of CAD. Evidence-based analyses have been prepared for each of these five imaging modalities: cardiac magnetic resonance imaging, single photon emission computed tomography, 64-slice computed tomographic angiography, stress echocardiography, and stress echocardiography with contrast. For each technology, an economic analysis was also completed (where appropriate). A summary decision analytic model was then developed to encapsulate the data from each of these reports (available on the OHTAC and MAS website).The Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease series is made up of the following reports, which can be publicly accessed at the MAS website at: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.html ⋯ Non-English studies.Pediatric populations.Studies of patients at low or high pre-test probability of CAD.Studies of unstable patients, e.g., emergency room visits, or a prior diagnosis of CAD.Studies in patients with non-ischemic heart disease.Studies in which outcomes were not specific to those of interest in this report.Studies in which CTA was not compared to CA in a stable population. OUTCOMES OF INTEREST): CAD defined as ≥50% stenosis. COMPARATOR: Coronary angiography. MEASURES OF INTEREST: Sensitivity, specificity;Negative predictive value (NPV), positive predictive value (PPV);Area under the curve (AUC) and diagnostic odds ratios (DOR). RESULTS OF LITERATURE SEARCH AND EVIDENCE-BASED ANALYSIS: The literature search yielded two HTAs, the first published by MAS in April 2005, the other from the Belgian Health Care Knowledge Centre published in 2008, as well as three recent non-randomized clinical studies. The three most significant studies concerning the accuracy of CTA versus CA are the CORE-64 study, the ACCURACY trial, and a prospective, multicenter, multivendor study conducted in the Netherlands. Five additional non-randomized studies were extracted from the Belgian Health Technology Assessment (2008). (ABSTRACT TRUNCATED)
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Ont Health Technol Assess Ser · Jan 2010
Percutaneous vertebroplasty for treatment of painful osteoporotic vertebral compression fractures: an evidence-based analysis.
OBJECTIVE OF ANALYSIS: The objective of this analysis is to examine the safety and effectiveness of percutaneous vertebroplasty for treatment of osteoporotic vertebral compression fractures (VCFs) compared with conservative treatment. ⋯ Recently, the results of two blinded randomized placebo-controlled trials of percutaneous vertebroplasty were reported. These trials, providing the highest quality of evidence available to date, do not support the use of vertebroplasty in patients with painful osteoporotic vertebral compression fractures. Based on the results of these trials, vertebroplasty offer no additional benefit over usual care and is not risk free. In these trials the treatment allocation was blinded to the patients and outcome assessors. The control group received a sham procedure simulating vertebroplasty to minimize the effect of expectations and to reduce the potential for bias in self-reporting of outcomes. Both trials applied stringent exclusion criteria so that the results are generalizable to the patient populations that are candidates for vertebroplasty. In both trials vertebroplasty procedures were performed by highly skilled interventionists. Multiple valid outcome measures including pain, physical, mental, and social function were employed to test the between group differences in outcomes. Prior to these two trials, there were two open randomized trials in which vertebroplasty was compared with conservative medical treatment. In the first randomized trial, patients were allowed to cross over to the other arm and had to be stopped after two weeks due to the high numbers of patients crossing over. The other study did not allow cross over and recently published the results of 12 months follow-up. The following is the summary of the results of these 4 trials: Two blinded RCTs on vertebroplasty provide the highest level of evidence available to date. Results of these two trials are supported by findings of an open randomized trial with 12 months follow-up. Blinded RCTs showed: No significant differences in pain scores of patients who received vertebroplasty and patients who received a sham procedure as measured at 3 days, 2 weeks and 1 month in one study and at 1 week, 1 month, 3 months, and 6 months in the other.The observed differences in pain scores between the two groups were neither statistically significant nor clinically important at any time points.The above findings were consistent with the findings of an open RCT in which patients were followed for 12 months. This study showed that improvement in pain was similar between the two groups at 3 months and were sustained to 12 months.In the blinded RCTs, physical, mental, and social functioning were measured at the above time points using 4-5 of the following 7 instruments: RDQ, EQ-5D, SF-36 PCS, SF-36 MCS, AQoL, QUALEFFO, SOF-ADLThere were no significant differences in any of these measures between patients who received vertebroplasty and patients who received a sham procedure at any of the above time points (with a few exceptions in favour of control intervention).These findings were also consistent with the findings of an open RCT which demonstrated no significant between group differences in scores of ED-5Q, SF-36 PCS, SF 36 MCS, DPQ, Barthel, and MMSE which measure physical, mental, and social functioning (with a few exceptions in favour of control intervention).One small (n=34) open RCT with a two week follow-up detected a significantly higher improvement in pain scores at 1 day after the intervention in vertebroplasty group compared with conservative treatment group. However, at 2 weeks follow-up, this difference was smaller and was not statistically significant.Conservative treatment was associated with fewer clinically important complicationsRisk of new VCFs following vertebroplasty was higher than those in conservative treatment but it requires further investigation.
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Ont Health Technol Assess Ser · Jan 2010
Extracorporeal lung support technologies - bridge to recovery and bridge to lung transplantation in adult patients: an evidence-based analysis.
For cases of acute respiratory distress syndrome (ARDS) and progressive chronic respiratory failure, the first choice or treatment is mechanical ventilation. For decades, this method has been used to support critically ill patients in respiratory failure. Despite its life-saving potential, however, several experimental and clinical studies have suggested that ventilator-induced lung injury can adversely affect the lungs and patient outcomes. Current opinion is that by reducing the pressure and volume of gas delivered to the lungs during mechanical ventilation, the stress applied to the lungs is eased, enabling them to rest and recover. In addition, mechanical ventilation may fail to provide adequate gas exchange, thus patients may suffer from severe hypoxia and hypercapnea. For these reasons, extracorporeal lung support technologies may play an important role in the clinical management of patients with lung failure, allowing not only the transfer of oxygen and carbon dioxide (CO(2)) but also buying the lungs the time needed to rest and heal. ⋯ TRIALS ON ILA: Of the seven studies identified, six involved patients with ARDS caused by a range of underlying conditions; the seventh included only patients awaiting LTx. All studies reported the rate of gas exchange and respiratory mechanics before ILA and for up to 7 days of ILA therapy. Four studies reported the means and standard deviations of blood gas transfer and arterial blood pH, which were used for meta-analysis. Fischer et al. reported their first experience on the use of ILA as a bridge to LTx. In their study, 12 patients at high urgency status for LTx, who also had severe ventilation refractory hypercapnea and respiratory acidosis, were connected to ILA prior to LTx. Seven patients had a systemic infection or sepsis prior to ILA insertion. Six hours after initiation of ILA, the partial pressure of CO(2) in arterial blood significantly decreased (P < .05) and arterial blood pH significantly improved (P < .05) and remained stable for one week (last time point reported). (ABSTRACT TRUNCATED)
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Ont Health Technol Assess Ser · Jan 2010
Endovascular laser therapy for varicose veins: an evidence-based analysis.
The objective of the MAS evidence review was to conduct a systematic review of the available evidence on the safety, effectiveness, durability and cost-effectiveness of endovascular laser therapy (ELT) for the treatment of primary symptomatic varicose veins (VV). ⋯ The MAS evidence search identified 14 systematic reviews, 29 cohort studies on safety and effectiveness, four cost studies and 12 randomized controlled trials involving ELT, six of these comparing endovascular laser with surgical ligation and saphenous vein stripping. Since 2007, 22 cohort studies involving 10,883 patients undergoing ELT of the great saphenous vein (GSV) have been published. Imaging defined treatment effectiveness of mean vein closure rates were reported to be greater than 90% (range 93%- 99%) at short term follow-up. Longer than one year follow-up was reported in five studies with life table analysis performed in four but the follow up was still limited at three and four years. The overall pooled major adverse event rate, including DVT, PE, skin burns or nerve damage events extracted from these studies, was 0.63% (69/10,883). The overall level of evidence of randomized trials comparing ELT with surgical ligation and vein stripping (n= 6) was graded as moderate to high. Recovery after treatment was significantly quicker after ELT (return to work median number of days, 4 vs. 17; p= .005). Major adverse events occurring after surgery were higher [(1.8% (n=4) vs. 0.4% (n = 1) 1 but not significantly. Treatment effectiveness as measured by imaging vein absence or closure, symptom relief or quality of life similar in the two treatment groups and both treatments resulted in statistically significantly improvements in these outcomes. Recurrence was low after both treatments at follow up but neovascularization (growth of new vessels, a key predictor of long term recurrence was significantly more common (18% vs. 1%; p = .001) after surgery. Although patient satisfaction was reported to be high (>80%) with both treatments, patient preferences evaluated through recruitment process, physician reports and consumer groups were strongly in favour of ELT. For patients minimal complications, quick recovery and dependability of outpatient scheduling were key considerations. As clinical effectiveness of the two treatments was similar, a cost-analysis was performed to compare differences in resources and costs between the two procedures. A budget impact analysis for introducing ELT as an insured service was also performed. The average case cost (based on Ontario hospital costs and medical resources) for surgical vein stripping was estimated to be $1,799. Because of the uncertainties with resources associated with ELT, in addition to the device related costs, hospital costs were varied and assumed to be the same as or less than (40%) those for surgery resulting in an average ELT case cost of $2,025 or $1,602. (ABSTRACT TRUNCATED)
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Ont Health Technol Assess Ser · Jan 2010
Stress echocardiography with contrast for the diagnosis of coronary artery disease: an evidence-based analysis.
In July 2009, the Medical Advisory Secretariat (MAS) began work on Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease (CAD), an evidence-based review of the literature surrounding different cardiac imaging modalities to ensure that appropriate technologies are accessed by patients suspected of having CAD. This project came about when the Health Services Branch at the Ministry of Health and Long-Term Care asked MAS to provide an evidentiary platform on effectiveness and cost-effectiveness of non-invasive cardiac imaging modalities.After an initial review of the strategy and consultation with experts, MAS identified five key non-invasive cardiac imaging technologies for the diagnosis of CAD. Evidence-based analyses have been prepared for each of these five imaging modalities: cardiac magnetic resonance imaging, single photon emission computed tomography, 64-slice computed tomographic angiography, stress echocardiography, and stress echocardiography with contrast. For each technology, an economic analysis was also completed (where appropriate). A summary decision analytic model was then developed to encapsulate the data from each of these reports (available on the OHTAC and MAS website).The Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease series is made up of the following reports, which can be publicly accessed at the MAS website at: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.htmlSINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY FOR THE DIAGNOSIS OF CORONARY ARTERY DISEASE: An Evidence-Based AnalysisSTRESS ECHOCARDIOGRAPHY FOR THE DIAGNOSIS OF CORONARY ARTERY DISEASE: An Evidence-Based AnalysisSTRESS ECHOCARDIOGRAPHY WITH CONTRAST FOR THE DIAGNOSIS OF CORONARY ARTERY DISEASE: An Evidence-Based Analysis64-Slice Computed Tomographic Angiography for the Diagnosis of Coronary Artery Disease: An Evidence-Based AnalysisCARDIAC MAGNETIC RESONANCE IMAGING FOR THE DIAGNOSIS OF CORONARY ARTERY DISEASE: An Evidence-Based AnalysisPease note that two related evidence-based analyses of non-invasive cardiac imaging technologies for the assessment of myocardial viability are also available on the MAS website:POSITRON EMISSION TOMOGRAPHY FOR THE ASSESSMENT OF MYOCARDIAL VIABILITY: An Evidence-Based AnalysisMAGNETIC RESONANCE IMAGING FOR THE ASSESSMENT OF MYOCARDIAL VIABILITY: an Evidence-Based AnalysisThe Toronto Health Economics and Technology Assessment Collaborative has also produced an associated economic report entitled:The Relative Cost-effectiveness of Five Non-invasive Cardiac Imaging Technologies for Diagnosing Coronary Artery Disease in Ontario [Internet]. Available from: http://theta.utoronto.ca/reports/?id=7 OBJECTIVE: The objective of this report is to compare echocardiography (ECHO) performed with microsphere contrast agents (contrast echocardiography) to ECHO performed without contrast and to single photon emission computed tomography (SPECT). CONTRAST ECHO: Contrast agents for ECHO have been available since the technology was first introduced in the 1990s. Composed of tiny 'microbubbles' of an inert gas encapsulated within a lipid, protein, or polymer coat, these agents act to scatter incident ultrasound waves at the gas/liquid interface to increase the strength of a returning ECHO signal. When injected into a patient's arm, they are transported throughout even the smallest capillaries to greatly enhance the blood pool signal, which would otherwise appear black on conventional two dimensional ECHO. The enhanced signal then helps cardiologists to determine what parts of the patient's heart muscle are poorly perfused. The first commercially available microsphere contrast agent was Albunex, which received approval by the Food and Drug Administration in the United States in 1994. This original microsphere agent was limited by its rapid gas volume loss which caused a decline in the ultrasound signal. It worked well in the right chambers of the heart, but dissolved when passing through the pulmonary capillaries and so was unable to provide contrast in the left side. Second generation agents employed different gases that prolonged the life of the microbubbles within the circulation and increased the reproducibility of results. Today, the most common use for contrast ECHO is to enhance the definition of the left ventricular (LV) endocardial border for cases of LV opacification. The aim of contrast ECHO is to provide better quantification of LV volume and assessment of LV wall motion than ECHO alone. The newest area of development in the research of contrast ECHO is myocardial perfusion assessment, also known as myocardial contrast ECHO. Theoretically, since myocardial ischemia and infarction affect both perfusion and contractility (wall motion), contrast ECHO could be an ideal non-invasive imaging test as it could assess both perfusion and contractility, simultaneously and in real time. Notably, critically ill patients on ventilators and those with lung problems are more likely to generate poor or 'suboptimal' echocardiograms than other patients, as are obese patients and those who've undergone recent chest operations. Contrast agents can potentially be used in 10% to 15% of all studies and in approximately 33% of stress tests due to from such suboptimal echocardiograms. Stress can be induced either pharmaceutically (e.g., through dobutamine, dipyrimidamole, adenosine) or with exercise. Generally, contrast agents are used more in pharmaceutical stress echocardiograms than in exercise stress echocardiograms. EVIDENCE-BASED ANALYSIS: This MAS analysis sought to address the following research questions: Is contrast ECHO more effective than 99-technetium SPECT in terms its ability to detect CAD?What is the effectiveness of contrast ECHO in assessing patients with suboptimal echocardiograms?Is contrast ECHO safe compared to other cardiac imaging modalities?Is contrast ECHO cost-effective compared to other cardiac imaging modalities? ⋯ Twenty-three observational studies were identified that assessed the diagnostic accuracy of contrast ECHO for the diagnosis of CAD. All of these studies used stress ECHO with contrast. In addition, nine retrospective chart reviews were identified, which assessed the safety of contrast ECHO at rest or stress. Based on the results of these studies the following conclusions were made: Stress ECHO with contrast has a higher diagnostic accuracy in the diagnosis of CAD than stress ECHO (without contrast).Stress ECHO with contrast seems to have a similar diagnostic accuracy to 99 technetium SPECT.The addition of contrast to ECHO in patients with suboptimal ECHO results significantly improves interpretability of the results.There is not a statistically significantly higher mortality rate in patients who receive contrast compared to those who do not.