Cost-effectiveness of myocardial perfusion SPECT and stress test according to coronary revascularization therapy, cardiac events and total mortality: Register of 8,496 patients. / Coste-efectividad de la SPECT de perfusión miocárdica y de la prueba de esfuerzo en relación con la revascularización coronaria, eventos cardíacos y mortalidad total. Registro de 8.496 pacientes.

OBJECTIVE: The aim was to analyze the cost-effectiveness ratio (CER) of stress electrocardiogram (ES) and stress myocardial perfusion imaging (SPECT-MPI) according to coronary revascularization (CR) therapy, cardiac events (CE) and total mortality (TM). MATERIAL AND METHODS: A total of 8,496 consecutive patients who underwent SPECT-MPI were followed-up (mean 5.3±3.5years). Cost-effectiveness for coronary bypass (CABG) or percutaneous CR (PCR) (45.6%/54.4%) according to combined electrocardiographic ischemia and scintigraphic ischemia were evaluated. Effectiveness was evaluated as TM, CE, life-year saved observed (LYSO) and CE-LYSO; costs analyses were conducted from the perspective of the health care payer. A sensitivity analysis was performed considering current CABG/PCR ratios (12%/88%). RESULTS: When electrocardiogram and SPECT approaches are combined, the cost-effectiveness values for CABG ranged between 112,589€ (electrocardiographic and scintigraphic ischemia) and 2,814,715€ (without ischemia)/event avoided, 38,664 and 2,221,559€/LYSO; for PCR ranged between 18,824€ (electrocardiographic and scintigraphic ischemia) and 46,377€ (without ischemia)/event avoided, 6,464 and 36,604€/LYSO. To CE: the cost-effectiveness values of the CABG and CPR in presence of electrocardiographic and scintigraphic ischemia were 269,904€/CE-avoided and 24,428€/CE-avoided, respectively; and the €/LYSO of the CABG and PCR were 152,488 and 13,801, respectively. The RCE was maintained for the current proportion of revascularized patients (12%/88%). CONCLUSIONS: Combined ES and SPECT-MPI results, allows differentiation between patient groups, where the PCR and CABG are more cost-effective in different economic frameworks. The major CER in relation to CR, CE and TM occurs in patients with electrocardiographic and scintigraphic ischemia. PCR is more cost-effective than CABG.

Cost-Utility of Video-Electroencephalography Monitoring Followed by Surgery in Adults with Drug-Resistant Focal Epilepsy in Thailand.

OBJECTIVES: This study assessed whether video-electroencephalography (VEEG) monitoring followed by surgery was cost-effective in adult patients with drug-resistant focal epilepsy under Thai health care context, as compared with continued medical treatment without VEEG. METHODS: The total cost (in Thai Baht, THB) and effectiveness (in quality-adjusted life years, QALYs) were estimated over a lifetime horizon, using a decision tree and a Markov model. Data on short-term surgical outcomes, direct health care costs, and utilities were collected from Thai patients in a specialized hospital. Long-term outcomes and relative effectiveness of the surgery over medical treatment were derived, using systematic reviews of published literature. RESULTS: Seizure-free rates at years 1 and 2 after surgery were 79.4% and 77.8%, respectively. Costs of VEEG and surgery plus 1-year follow-up care were 216,782 THB, of which the VEEG and other necessary investigations were the main cost drivers (42.8%). On the basis of societal perspective, the total cost over a 40-year horizon accrued to 1,168,679 THB for the VEEG option, 64,939 THB higher than that for no VEEG. The VEEG option contributed to an additional 1.50 QALYs over no VEEG, resulting in an incremental cost-effectiveness ratio of 43,251 THB (USD 1236) per 1 QALY gained. Changes in key parameters had a minimal impact on the incremental cost-effectiveness ratio. Accounting for uncertainty, there was an 84% probability that the VEEG option was cost-effective on the basis of Thailand's cost-effective threshold of 160,000 THB/QALY. CONCLUSIONS: For patients with drug-resistant epilepsy, VEEG monitoring followed by epilepsy surgery was cost-effective in Thailand. Therefore it should be recommended for health insurance coverage.

Comparison of single photon emission CT (SPECT) with SPECT/CT imaging in preoperative localization of parathyroid adenomas: A cost-effectiveness analysis.

BACKGROUND: Controversy exists regarding the superiority of single photon emission CT (SPECT)/CT over SPECT for preoperative localization of parathyroid adenomas in primary hyperparathyroidism (PHPT), as well as the cost-effectiveness. METHODS: A retrospective review was undertaken of patients undergoing surgery for PHPT from January 2009 to August 2014. Ultrasound and SPECT (ultrasound-SPECT) or SPECT/CT (ultrasound-SPECT/CT) were performed for each patient. Sensitivity and positive predictive value (PPV) of each modality were calculated. Cost-effectiveness was determined by an incremental cost-effectiveness ratio (ICER) analysis. RESULTS: Two hundred fifty-nine patients with 266 parathyroid adenomas were included in the study. Lateralization sensitivity and PPV of ultrasound-SPECT were 85.1% and 98.2%, respectively. The lateralization sensitivity and PPV of ultrasound-SPECT/CT were 86.9% and 99.4%, respectively. A cost of $2499.22 (CAD) per additional parathyroid adenoma detection by ultrasound-SPECT/CT was determined from the ICER analysis. CONCLUSION: Similar sensitivities and PPVs were observed between ultrasound-SPECT and ultrasound-SPECT/CT in preoperatively lateralizing parathyroid adenomas, with relatively equivalent cost-effectiveness. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2062-E2065, 2016.

Streamlining the imaging of clinically suspected pheochromocytoma: using urine metanephrines to decrease imaging costs.

PURPOSE: To improve the cost efficiency of the imaging evaluation of clinically suspected pheochromocytoma by using 24-hour fractionated urine metanephrine (FUM) results. METHODS: A retrospective review of I-123 meta-iodo-benzyl-guanidine single photon emission tomography (SPECT) computed tomography (CT) studies performed at our institution between January 2007 and February 2011 for clinically suspected pheochromocytoma was performed. SPECT-CT results from 70 patients were compared with results from 24-hour FUM analysis (within 2 months of SPECT-CT) and with relevant CT or magnetic resonance imaging studies (within 6 months of SPECT-CT). An imaging algorithm was developed to maximize cost efficiency without altering the final imaging interpretation. Actual imaging costs for the studied cohort were compared with the expected costs if this algorithm had been applied. RESULTS: If the 24-hour FUMs were normal, then all the SPECT-CT studies were negative (16/70). Eighty-seven percent of patients with abnormal total metanephrine had a positive SPECT-CT. If the total metanephrine was normal but 1 or more of the metanephrine fractions were abnormal, then 39%-58% of the SPECT-CT studies were positive. Within this subgroup, none had a positive SPECT-CT if a CT or magnetic resonance image was negative or benign. The actual imaging costs averaged CAD$2833.19 per patient for this cohort. Applying a streamlined imaging algorithm guided by 24-hour FUM analysis would result in an average imaging cost of CAD$1225.97 per patient without an expected change in the final imaging impression. CONCLUSION: By using 24-hour FUM results to streamline imaging, considerable cost savings per patient (56.7%) can be attained without a change in the final overall imaging interpretation.

Quantificação da área de infarto usando-se SPECT de perfusão miocárdica de alta resolução em ratos / Myocardial infarction area quantification using high-resolution SPECT images in rats

FUNDAMENTO: Técnicas de imageamento in vivo permitem avaliar sequencialmente a morfologia e a função dos órgãos em diversos modelos experimentais. Desenvolvemos um dispositivo de adaptação de uma gama-câmara clínica para obter imagens tomográficas por emissão de fótons singulares (SPECT) de alta resolução, baseado em colimador pinhole. OBJETIVO: Determinar a acurácia desse sistema na quantificação da área de infarto miocárdico em ratos. MÉTODOS: Treze ratos Wistar machos (250 g) foram submetidos a infarto do miocárdio por oclusão da artéria coronária esquerda. Após 4 semanas, foram adquiridas imagens tomográficas com o sistema desenvolvido, 1,5 hora após a injeção endovenosa de 555MBq de 99mTc-Sestamibi. Na reconstrução tomográfica, utilizamos software especialmente desenvolvido baseado no algoritmo de Máxima Verossimilhança. Comparamos as médias e analisamos a correlação entre a extensão dos defeitos perfusionais detectados pela cintilografia e a extensão da fibrose miocárdica avaliada pela histologia. RESULTADOS: As imagens apresentaram ótima relação órgão-alvo/fundo, com apropriada visualização das paredes e da cavidade do ventrículo esquerdo. Todos os animais exibindo áreas de infarto foram corretamente identificados pelas imagens de perfusão. Não houve diferença entre a área do infarto medida pelo SPECT (21,1 ± 21,2%) e pela histologia (21,7 ± 22,0%; p = 0,45), obtendo forte correlação entre os valores da área de infarto mensurada pelos dois métodos (r = 0,99; p < 0,0001). CONCLUSÃO: O sistema desenvolvido apresentou resolução espacial adequada e elevada acurácia para detecção e quantificação das áreas de infarto miocárdico, sendo uma opção de baixo custo e grande versatilidade na obtenção de imagens em SPECT de alta resolução de órgãos de pequenos roedores.

BACKGROUND: Imaging techniques enable in vivo sequential assessment of the morphology and function of animal organs in experimental models. We developed a device for high-resolution single photon emission computed tomography (SPECT) imaging based on an adapted pinhole collimator. OBJECTIVE: To determine the accuracy of this system for quantification of myocardial infarct area in rats. METHODS: Thirteen male Wistar rats (250 g) underwent experimental myocardial infarction by occlusion of the left coronary artery. After 4 weeks, SPECT images were acquired 1.5 hours after intravenous injection of 555 MBq o f 99mTc-Sestamibi. The tomographic reconstruction was performed by using specially developed software based on the Maximum Likelihood algorithm. The analysis of the data included the correlation between the area of perfusion defects detected by scintigraphy and extent of myocardial fibrosis assessed by histology. RESULTS: The images showed a high target organ/background ratio with adequate visualization of the left ventricular walls and cavity. All animals presenting infarction areas were correctly identified by the perfusion images. There was no difference of the infarct area as measured by SPECT (21.1 ± 21.2%) and by histology (21.7 ± 22.0%; p=0.45). There was a strong correlation between individual values of the area of infarction measured by these two methods. CONCLUSION: The developed system presented adequate spatial resolution and high accuracy for the detection and quantification of myocardial infarction areas, consisting in a low cost and versatile option for high-resolution SPECT imaging of small rodents.

Dopamine transporter imaging in clinically unclear cases of parkinsonism and the importance of Scans Without Evidence of Dopaminergic Deficit (SWEDDs) / Neuroimagem do transportador de dopamina em casos de parkinsonismo clinicamente indefinidos e a importância dos SWEDDs (exames sem evidência de déficit dopaminérgico)

The clinical diagnosis of Parkinson's disease (PD) is susceptible to misdiagnosis, especially in the earlier stages of the disease. Recently, in vivo imaging techniques assessing the presynaptic dopamine transporter (DAT) have emerged as a useful tool in PD diagnosis, improving its accuracy. OBJECTIVE: It was to illustrate the clinical usefulness of a brain single-photon emission computed tomography (SPECT) DAT ligand, and highlight relevant aspects of scans without evidence of dopaminergic deficit (SWEDDs) in this context. CASES: We described four representative patients with clinically unclear parkinsonian syndromes who underwent [99mTc]-TRODAT-1 SPECT and reviewed the clinical implications. CONCLUSION: DAT-SPECT is an important, cost-effective, technique for the differential diagnosis of parkinsonian syndromes. Additionally, SWEDD cases present clinical and paraclinical peculiarities that may retrospectively identify them as essential/dystonic tremor. The lack of histopathological data limits further conclusions.

O diagnóstico clínico da doença de Parkinson (DP) pode estar sujeito a erros especialmente nas fases iniciais da doença. Recentemente, técnicas de imagem in vivo que avaliam o transportador de dopamina pré-sináptico (DAT) surgiram como uma ferramenta empregada no diagnóstico da DP, melhorando sua acurácia. OBJETIVO: Foi demonstrar a utilização clínica de um traçador de tomografia computadorizada por emissão de fóton único (SPECT) e destacar importantes aspectos dos casos de SWEDDs (exames sem evidência de déficit dopaminérgico) neste contexto. CASOS: Descrevemos quatro pacientes representativos de síndromes parkinsonianas clinicamente incertas submetidos a [99mTc]-TRODAT-1 SPECT e revisamos suas implicações. CONCLUSÃO: O DAT-SPECT é uma técnica importante e eficiente para o diagnóstico diferencial das síndromes parkinsonianas. Além disso, os casos de SWEDDs apresentam peculiaridades clínicas e paraclínicas que podem retrospectivamente identificá-los como tremor essencial ou tremor distônico. As conclusões têm alcance limitado pela falta de dados histopatológicos.

High-cost imaging in elderly patients with stage IV cancer.

BACKGROUND: Medicare expenditures for high-cost diagnostic imaging have risen faster than those for total cancer care and have been targeted for potential cost reduction. We sought to determine recent and long-term patterns in high-cost diagnostic imaging use among elderly (aged ≥65 years) patients with stage IV cancer. METHODS: We identified claims within the Surveillance, Epidemiology, and End Results (SEER)-Medicare database with computed tomography, magnetic resonance imaging, positron emission tomography, and nuclear medicine scans between January 1994 and December 2009 for patients diagnosed with stage IV breast, colorectal, lung, or prostate cancer between January 1995 and December 2006 (N = 100,594 patients). The proportion of these patients imaged and rate of imaging per-patient per-month of survival were calculated for each phase of care in patients diagnosed between January 2002 and December 2006 (N = 55,253 patients). Logistic regression was used to estimate trends in imaging use in stage IV patients diagnosed between January 1995 and December 2006, which were compared with trends in imaging use in early-stage (stages I and II) patients with the same tumor types during the same period (N = 192,429 patients). RESULTS: Among the stage IV patients diagnosed between January 2002 and December 2006, 95.9% underwent a high-cost diagnostic imaging procedure, with a mean number of 9.79 (SD = 9.77) scans per patient and 1.38 (SD = 1.24) scans per-patient per-month of survival. After the diagnostic phase, 75.3% were scanned again; 34.3% of patients were scanned in the last month of life. Between January 1995 and December 2006, the proportion of stage IV cancer patients imaged increased (relative increase = 4.6%, 95% confidence interval [CI] = 3.7% to 5.6%), and the proportion of early-stage cancer patients imaged decreased (relative decrease = -2.5%, 95% CI = -3.2% to -1.9%). CONCLUSIONS: Diagnostic imaging is used frequently in patients with stage IV disease, and its use increased more rapidly over the decade of study than that in patients with early-stage disease.

Is there still a place for SPET in the era of PET brain imaging?

Although positron emission tomography (PET) may be credited with providing the impetus for the new clinical interest in functional neuroimaging and currently is an increasingly important imaging tool for noninvasive assessment of brain tumors, single-photon emission tomography (SPET) has offered an alternative technique with the relative advantages of lower price and wide availability. Brain SPET has been proven useful in the differentiation of tumor recurrence from radiation necrosis, in the non-invasive assessment of gliomas and meningiomas aggressiveness, in differentiating neoplastic from non neoplastic intracerebral haemorrhage, in monitoring treatment response and estimating patients' prognosis. Thus, SPET may still have a role in the diagnosis and characterization of brain tumors. Future comparative studies between SPET and PET or latest magnetic resonance based neuroimaging techniques are warranted.

Would scan, but which scan? A cost-utility analysis to optimize preoperative imaging for primary hyperparathyroidism.

BACKGROUND: Minimally invasive parathyroidectomy for primary hyperparathyroidism depends on accurate preoperative localization. This study examines the cost-utility of sestamibi in combination with single photon emission computed tomography (sestamibi-SPECT); ultrasound; and 4-dimensional computed tomography (4D-CT). METHODS: A decision tree was constructed for patients undergoing initial parathyroidectomy. Patients were randomized to 1 of 5 preoperative localization protocols: (1) ultrasound; (2) sestamibi-SPECT; (3) 4D-CT; (4) sestamibi-SPECT and ultrasound; and (5) sestamibi-SPECT and ultrasound and 4D-CT, if discordant (sestamibi-SPECT and ultrasound ± 4D-CT). From a societal perspective, all relevant costs were included. Input data were obtained from literature and Medicare. The incremental cost-utility ratio was determined in dollars per quality-adjusted life years ($/QALY). Sensitivity analyses were performed. RESULTS: In the base-case, ultrasound was least expensive, with a cost of $6666, compared to $6773 (4-D CT); $7214 (sestamibi-SPECT and ultrasound ± 4D-CT); $7330 (sestamibi-SPECT); and $7371(sestamibi-SPECT and ultrasound). Sestamibi-SPECT and ultrasound ± 4D-CT were most cost-effective because improved localization resulted in fewer bilateral explorations. QALY were comparable across modalities. Compared to sestamibi-SPECT, ultrasound, 4D- CT, and sestamibi-SPECT and ultrasound ± 4D-CT resulted a win-win situation-costing less and accruing more utility. Sensitivity analyses demonstrated that the model was sensitive to surgery cost and diagnostic accuracy of imaging. CONCLUSION: In our model, sestamibi-SPECT and ultrasound ± 4D-CT were the most cost-effective methods, followed by 4D-CT and ultrasound. Sestamibi-SPECT alone was least cost-effective. Cost-utilities were dependent on the sensitivities of ultrasound and 4D-CT and may vary by institution.

Targeted multi-pinhole SPECT.

PURPOSE: Small-animal single photon emission computed tomography (SPECT) with focused multi-pinhole collimation geometries allows scanning modes in which large amounts of photons can be collected from specific volumes of interest. Here we present new tools that improve targeted imaging of specific organs and tumours, and validate the effects of improved targeting of the pinhole focus. METHODS: A SPECT system with 75 pinholes and stationary detectors was used (U-SPECT-II). An XYZ stage automatically translates the animal bed with a specific sequence in order to scan a selected volume of interest. Prior to stepping the animal through the collimator, integrated webcams acquire images of the animal. Using sliders, the user designates the desired volume to be scanned (e.g. a xenograft or specific organ) on these optical images. Optionally projections of an atlas are overlaid semiautomatically to locate specific organs. In order to assess the effects of more targeted imaging, scans of a resolution phantom and a mouse myocardial phantom, as well as in vivo mouse cardiac and tumour scans, were acquired with increased levels of targeting. Differences were evaluated in terms of count yield, hot rod visibility and contrast-to-noise ratio. RESULTS: By restricting focused SPECT scans to a 1.13-ml resolution phantom, count yield was increased by a factor 3.6, and visibility of small structures was significantly enhanced. At equal noise levels, the small-lesion contrast measured in the myocardial phantom was increased by 42%. Noise in in vivo images of a tumour and the mouse heart was significantly reduced. CONCLUSION: Targeted pinhole SPECT improves images and can be used to shorten scan times. Scan planning with optical cameras provides an effective tool to exploit this principle without the necessity for additional X-ray CT imaging.

Cost-effective utilization of single photon emission computed tomography (SPECT) in decision making for epilepsy surgery.

PURPOSE: To investigate the utility of single photon emission computed tomography (SPECT) without subtraction and MRI co-registration in decision making for epilepsy surgery. METHODS: Patients with refractory epilepsy and nonlocalizing or discordant non-invasive data (clinical, long-term VEEG, and MRI) were subjected to interictal and ictal SPECT studies before planning invasive or surgical strategy. Final localization was based upon the preoperative information and seizure freedom after surgery. SPECT was considered to be useful for decision-making if it obviated the need for intracranial monitoring or influenced its planning. RESULTS: 61 patients (mean age, 25.1±8.3 years) underwent SPECT studies between January 2004 and December 2008. Twenty-two patients had mesial temporal lobe epilepsy (MTLE), 13 had neocortical temporal lobe epilepsy (NTLE), and 26 had extratemporal lobe epilepsy (ETLE). As compared to ETLE, SPECT provided more localizing information (77.3% vs 46.2%, p=0.006) and influenced the final decision-making (45.4% vs 11.53%, p=0.005) in a significantly higher number of patients with MTLE. SPECT was particularly useful in patients with lesional TLE and nonlocalizing ictal data and in those with dual pathologies. SPECT did not provide any additional information in patients having either TLE or ETLE with normal MRI. CONCLUSIONS: SPECT is useful in a selected group of patients and unlikely to provide additional information in others. By restricting its use in patients who are likely to be benefited, a cost-effective utilization strategy can be employed in countries with limited resources. Due to the small number, these findings need to be validated in a larger group of patients.

Computed tomography and scintigraphy vs. cardiac catheterization for coronary disease screening prior to noncardiac surgery.

OBJECTIVE: The goal of this study was to investigate the utility of multidetector-row computed tomography (MDCT) and adenosine triphosphate stress cardiac single photon emission computed tomography (ATP-SPECT) in evaluating coronary artery disease (CAD) in patients scheduled for non-cardiac surgery. PATIENTS AND METHODS: We routinely performed echocardiography and exercise stress electrocardiography as preoperative cardiac screening examinations for patients scheduled for non-cardiac surgery under general anesthesia. Of 848 consecutive preoperative patients (Non-invasive Group), 49 patients with abnormalities of these screening examinations had MDCT and ATP-SPECT. Of 809 consecutive preoperative patients studied at an earlier time (Invasive Group), 58 patients with abnormalities of these screening examinations had cardiac catheterization as an additional cardiac examination. RESULTS: The number of patients in the non-invasive and invasive subgroups having additional screening examinations was comparable, and there was no significant difference in perioperative cardiac events between the two subgroups. Based on results of the additional tests in the two subgroups, preoperative prophylactic invasive treatment for CAD was carried out in a small number of patients, again with no significant differences between the groups. However, total medical expenses for the additional cardiac examinations were significantly reduced in the non-invasive subgroup compared with the invasive subgroup (140,030+/-34,800 vs. 187,170+/-26,120 yen, respectively, p=0.0002). CONCLUSION: Non-invasive examination prior to noncardiac surgery using MDCT and ATP-SPECT in a subgroup of patients suspected of having CAD appears to be a useful screening procedure. Compared with invasive cardiac catheterization, CT testing has comparable diagnostic utility without an increase in perioperative cardiac events, and in addition, it has an improved cost-benefit profile.

[Metabolic imaging--PET, PET/CT--in oncologic surgery]. / A metabolikus képalkotás - PET, PET/CT - onkosebészeti vonatkozásai.

The availability of PET/CT examinations in Hungary has significantly improved in the past few years. In the three Hungarian centres approximately 10,000 examinations can be performed yearly, which are financed by the national healthcare system. The PET/CT technique using FDG has become an efficient tumour diagnostic method due to its outstanding sensitivity and specificity. Similarly to other medical imaging techniques, PET/CT is a useful and cost-beneficial diagnostic modality in the hand of those clinicians, who clearly know its advantages and limitations. In the present paper the most frequent indications of PET/CT examinations are reviewed, with special attention to cases relevant to the everyday surgical practice. The applicability of this technique is also considered.

Economic analysis including long-term risks and costs of alternative diagnostic strategies to evaluate patients with chest pain.

BACKGROUND: Diagnosis costs for cardiovascular disease waste a large amount of healthcare resources. The aim of the study is to evaluate the clinical and economic outcomes of alternative diagnostic strategies in low risk chest pain patients. METHODS: We evaluated direct and indirect downstream costs of 6 strategies: coronary angiography (CA) after positive troponin I or T (cTn-I or cTnT) (strategy 1); after positive exercise electrocardiography (ex-ECG) (strategy 2); after positive exercise echocardiography (ex-Echo) (strategy 3); after positive pharmacologic stress echocardiography (PhSE) (strategy 4); after positive myocardial exercise stress single-photon emission computed tomography with technetium Tc 99m sestamibi (ex-SPECT-Tc) (strategy 5) and direct CA (strategy 6). RESULTS: The predictive accuracy in correctly identifying the patients was 83,1% for cTn-I, 87% for cTn-T, 85,1% for ex-ECG, 93,4% for ex-Echo, 98,5% for PhSE, 89,4% for ex-SPECT-Tc and 18,7% for CA. The cost per patient correctly identified results $2.051 for cTn-I, $2.086 for cTn-T, $1.890 for ex-ECG, $803 for ex-Echo, $533 for PhSE, $1.521 for ex-SPECT-Tc ($1.634 including cost of extra risk of cancer) and $29.673 for CA ($29.999 including cost of extra risk of cancer). The average relative cost-effectiveness of cardiac imaging compared with the PhSE equal to 1 (as a cost comparator), the relative cost of ex-Echo is 1.5x, of a ex-SPECT-Tc is 3.1x, of a ex-ECG is 3.5x, of cTnI is x3.8, of cTnT is x3.9 and of a CA is 56.3x. CONCLUSION: Stress echocardiography based strategies are cost-effective versus alternative imaging strategies and the risk and cost of radiation exposure is void.

Cost-effectiveness of coronary artery disease screening in asymptomatic patients with type 2 diabetes and other atherogenic risk factors in Japan: factors influencing on international application of evidence-based guidelines.

BACKGROUND: Screening for coronary artery disease (CAD) in asymptomatic diabetic patients with atherogenic risk factors is recommended by the American College of Cardiology/American Diabetes Association. It is not clear whether these guidelines apply to the Japanese population with a different epidemiology of CAD. This study evaluates the applicability of the U.S. guidelines to Japan, taking account of cost-effectiveness. DESIGN: A cost-effectiveness analysis using a Markov model was performed to measure the clinical benefit and cost of CAD screening in asymptomatic patients with diabetes and additional atherogenic risk factors. We evaluated cohorts of patients stratified by age, gender, and atherogenic risks. The incremental cost-effectiveness of not screening, exercise electrocardiography, exercise echocardiography, and exercise single-photon emission-tomography (SPECT) was calculated. The data used were obtained from the literature. Outcomes are expressed as US dollars per quality-adjusted life year (QALY). RESULTS: Compared with not screening, the incremental cost-effectiveness ratio (ICER) of exercise electrocardiography was $31,400/QALY for 60-year-old asymptomatic diabetic men, and 46,600 for 65-year-old women with hypertension and smoking. The ICER of exercise echocardiography was $31,500/QALY and of SPECT was $326,000/QALY, compared with the next dominant strategy. Sensitivity analyses found that these results varied according to age, gender, the combination of additional atherogenic risk factors, and the frequency of screening. CONCLUSION: From a societal perspective the U.S. guidelines on screening for CAD in high risk diabetic patients are applicable to the Japanese population. However, the population subjected to screening should be carefully selected to obtain greatest benefit from screening.

Screening asymptomatic diabetic patients for coronary artery disease: why not?

Given the elevated risk of cardiovascular events and the higher prevalence of silent coronary artery disease (CAD) in diabetic versus non-diabetic patients, screening asymptomatic diabetic patients for CAD is an appealing concept. However, many factors argue against implementing a broad-based screening program at the present time. Foremost is the lack of any published data demonstrating that a prospectively applied screening program improves outcome in asymptomatic diabetic patients. The true prevalence of CAD, and in particular prognostically important CAD, in this population is uncertain. Consensus documents recommend more aggressive treatment of hypertension and hyperlipidemia solely on the basis of diabetes status, without differentiation based on the presence or absence of identifiable CAD. There is no evidence that use of anti-ischemic medication can alter the natural history of CAD in these patients. Retrospectively performed studies using stress single-photon emission computed tomography (SPECT) imaging have reported that approximately 50% and 20% of patients have abnormal and high-risk images, respectively. However, the only prospectively designed study, the DIAD (Detection of Ischemia in Asymptomatic Diabetics) study, reported a much lower percentage of abnormal SPECT images (16%) and images with a very large (>/=10% of the left ventricle) defect (1%). The financial implications of screening all asymptomatic diabetic patients determined to be at intermediate and high risk by clinical scoring systems is enormous. Clearly more data are needed to address this issue. Future studies should consider possible methods to enrich the patient subset that might benefit from screening and should include carefully performed cost-effective analyses.

The cost-effectiveness of additional preoperative ultrasonography or sestamibi-SPECT in patients with primary hyperparathyroidism and negative findings on sestamibi scans.

OBJECTIVE: To determine whether the use of additional preoperative imaging was cost-effective compared with bilateral neck exploration (BNE) for the treatment of primary hyperparathyroidism in patients with negative findings on scans with technetium Tc 99m sestamibi. DESIGN: We performed a cost-effectiveness analysis. The decision whether to proceed to BNE or obtain additional preoperative imaging using ultrasonography (US) or single-photon emission computed tomography with technetium Tc 99m sestamibi (SPECT) was modeled using decision analysis. We obtained probabilities of cure, detection of pathologic glands, and the correct side of the neck from recent literature. MAIN OUTCOME MEASURES: Expected cost, cure rate, and the incremental cost per cured case using the preoperative imaging strategies compared with BNE. RESULTS: The US strategy dominated the SPECT and BNE strategies, with a lower expected cost (USD $6030 vs USD $7131 and $8384, respectively) and a greater expected cure rate (99.42% vs 99.26% and 97.69%, respectively). Threshold analysis suggests that the preoperative imaging strategies continued to dominate unless the cost of BNE was less than USD $5400 or the cost of unilateral neck exploration exceeded USD $6500. The US strategy dominated SPECT as a preoperative imaging strategy if the cost of SPECT exceeded $12 or the cost of a US test was less than $1300. CONCLUSIONS: For the treatment of primary hyerparathyroidism in the patient with negative findings on technetium Tc 99m sestamibi scans, a strategy that uses additional preoperative US imaging appears to be cost-effective compared with SPECT or BNE.