Use of MRI and Ga-68 DOTATATE for the detection of neuroendocrine liver metastases.

PURPOSE: To compare detection rates of NET liver metastases of MRI and Ga-68-DOTATATE PET/CT to provide more clarity when selecting diagnostic imaging tests for NET staging. METHODS: In this IRB-approved single-institution retrospective study, all patients with pathology-proven NET who underwent Ga-68-DOTATATE and MRI scans within 8 weeks of each other (3/2017-2/2020) were reviewed. Number of metastases for each patient on diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) MRI, and Ga-68 DOTATATE were recorded by two blinded radiologists, followed by consensus review with two separate blinded readers for MRI and nuclear medicine. Per-lesion and -modality scoring at each lesion location were then performed in consensus. Per-patient linear regression was performed comparing MRI and Ga-68 DOTATATE detection rates for each reader and in consensus, and per-lesion-matched pair difference means were used to compare detection frequency between modalities. RESULTS: 32 patients (mean age 59 years, 59.4% male) and 90 liver metastases were analyzed. Intraclass coefficients (ICC) [95% CI] between the two readers were 0.97 [0.95, 0.99], 0.89 [0.82, 0.94], and 0.98 [0.97, 0.99] for Ga-68 DOTATATE, DWI, and DCE, respectively. Matched per-lesion mean differences were + 0.17 ± 0.07 (p = 0.01) and + 0.22 ± 0.06 (p = < 0.001) for DWI versus Ga-68 DOTATATE and DCE vs Ga-68 DOTATATE, respectively, favoring MRI. Case-based linear regressions estimate that DWI and DCE detect 1.28 [1.07, 1.49] and 1.33 [1.12, 1.54] lesions, respectively, for each one detected on Ga-68 DOTATATE. CONCLUSION: MRI detects more hepatic NET metastasis in comparison to Ga-68 DOTATATE. Liver MRI should be performed in concert with Ga-68 DOTATATE in NET staging.

Artificial intelligence to assess body composition on routine abdominal CT scans and predict mortality in pancreatic cancer- A recipe for your local application.

BACKGROUND: Body composition is associated with mortality; however its routine assessment is too time-consuming. PURPOSE: To demonstrate the value of artificial intelligence (AI) to extract body composition measures from routine studies, we aimed to develop a fully automated AI approach to measure fat and muscles masses, to validate its clinical discriminatory value, and to provide the code, training data and workflow solutions to facilitate its integration into local practice. METHODS: We developed a neural network that quantified the tissue components at the L3 vertebral body level using data from the Liver Tumor Challenge (LiTS) and a pancreatic cancer cohort. We classified sarcopenia using accepted skeletal muscle index cut-offs and visceral fat based its median value. We used Kaplan Meier curves and Cox regression analysis to assess the association between these measures and mortality. RESULTS: Applying the algorithm trained on LiTS data to the local cohort yielded good agreement [>0.8 intraclass correlation (ICC)]; when trained on both datasets, it had excellent agreement (>0.9 ICC). The pancreatic cancer cohort had 136 patients (mean age: 67 ± 11 years; 54% women); 15% had sarcopenia; mean visceral fat was 142 cm2. Concurrent with prior research, we found a significant association between sarcopenia and mortality [mean survival of 15 ± 12 vs. 22 ± 12 (p < 0.05), adjusted HR of 1.58 (95% CI: 1.03-3.33)] but no association between visceral fat and mortality. The detector analysis took 1 ± 0.5 s. CONCLUSIONS: AI body composition analysis can provide meaningful imaging biomarkers from routine exams demonstrating AI's ability to further enhance the clinical value of radiology reports.

Visceral Adiposity and Severe COVID-19 Disease: Application of an Artificial Intelligence Algorithm to Improve Clinical Risk Prediction.

BACKGROUND: Obesity has been linked to severe clinical outcomes among people who are hospitalized with coronavirus disease 2019 (COVID-19). We tested the hypothesis that visceral adipose tissue (VAT) is associated with severe outcomes in patients hospitalized with COVID-19, independent of body mass index (BMI). METHODS: We analyzed data from the Massachusetts General Hospital COVID-19 Data Registry, which included patients admitted with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 infection from March 11 to May 4, 2020. We used a validated, fully automated artificial intelligence (AI) algorithm to quantify VAT from computed tomography (CT) scans during or before the hospital admission. VAT quantification took an average of 2 ± 0.5 seconds per patient. We dichotomized VAT as high and low at a threshold of ≥100 cm2 and used Kaplan-Meier curves and Cox proportional hazards regression to assess the relationship between VAT and death or intubation over 28 days, adjusting for age, sex, race, BMI, and diabetes status. RESULTS: A total of 378 participants had CT imaging. Kaplan-Meier curves showed that participants with high VAT had a greater risk of the outcome compared with those with low VAT (P < .005), especially in those with BMI <30 kg/m2 (P < .005). In multivariable models, the adjusted hazard ratio (aHR) for high vs low VAT was unchanged (aHR, 1.97; 95% CI, 1.24-3.09), whereas BMI was no longer significant (aHR for obese vs normal BMI, 1.14; 95% CI, 0.71-1.82). CONCLUSIONS: High VAT is associated with a greater risk of severe disease or death in COVID-19 and can offer more precise information to risk-stratify individuals beyond BMI. AI offers a promising approach to routinely ascertain VAT and improve clinical risk prediction in COVID-19.

Three-Dimensional Neural Network to Automatically Assess Liver Tumor Burden Change on Consecutive Liver MRIs.

BACKGROUND: Tumor response to therapy is often assessed by measuring change in liver lesion size between consecutive MRIs. However, these evaluations are both tedious and time-consuming for clinical radiologists. PURPOSE: In this study, we sought to develop a convolutional neural network to detect liver metastases on MRI and applied this algorithm to assess change in tumor size on consecutive examinations. METHODS: We annotated a data set of 64 patients with neuroendocrine tumors who underwent at least two consecutive liver MRIs with gadoxetic acid. We then developed a 3-D neural network using a U-Net architecture with ResNet-18 building blocks that first detected the liver and then lesions within the liver. Liver lesion labels for each examination were then matched in 3-D space using an iterative closest point algorithm followed by Kuhn-Munkres algorithm. RESULTS: We developed a deep learning algorithm that detected liver metastases, co-registered the detected lesions, and then assessed the interval change in tumor burden between two multiparametric liver MRI examinations. Our deep learning algorithm was concordant in 91% with the radiologists' manual assessment about the interval change of disease burden. It had a sensitivity of 0.85 (95% confidence interval (95% CI): 0.77; 0.93) and specificity of 0.92 (95% CI: 0.87; 0.96) to classify liver segments as diseased or healthy. The mean DICE coefficient for individual lesions ranged between 0.73 and 0.81. CONCLUSIONS: Our algorithm displayed high agreement with human readers for detecting change in liver lesions on MRI, offering evidence that artificial intelligence-based detectors may perform these tasks as part of routine clinical care in the future.

Long-term health outcomes and cost-effectiveness of coronary CT angiography in patients with suspicion for acute coronary syndrome.

BACKGROUND: Randomized trials have shown favorable clinical outcomes for coronary CT angiography (CTA) in patients with suspected acute coronary syndrome (ACS). Our goal was to estimate the cost-effectiveness of coronary CTA as compared to alternative management strategies for ACP patients over lifetime. METHODS: Markov microsimulation model was developed to compare cost-effectiveness of competitive strategies for ACP patients: 1) coronary CTA, 2) standard of care (SOC), 3) AHA/ACC Guidelines, and 4) expedited emergency department (ED) discharge protocol with outpatient testing. ROMICAT-II trial was used to populate the model with low to intermediate risk of ACS patient data, whereas diagnostic test-, treatment effect-, morbidity/mortality-, quality of life- and cost data were obtained from the literature. We predicted test utilization, costs, 1-, 3-, 10-year and over lifetime cardiovascular morbidity/mortality for each strategy. We determined quality adjusted life years (QALY) and incremental cost-effectiveness ratio. Observed outcomes in ROMICAT-II were used to validate the short-term model. RESULTS: Estimated short-term outcomes accurately reflected observed outcomes in ROMICAT-II as coronary CTA was associated with higher costs ($4,490 vs. $2,513-$4,144) and revascularization rates (5.2% vs. 2.6%-3.7%) compared to alternative strategies. Over lifetime, coronary CTA dominated SOC and ACC/AHA Guidelines and was cost-effective compared to expedited ED protocol ($49,428/QALY). This was driven by lower cardiovascular mortality (coronary CTA vs. expedited discharge: 3-year: 1.04% vs. 1.10-1.17; 10-year: 5.06% vs. 5.21-5.36%; respectively). CONCLUSION: Coronary CTA in patients with suspected ACS renders affordable long-term health benefits as compared to alternative strategies.

Hypertension and diabetes control along the HIV care cascade in rural South Africa.

INTRODUCTION: Participation in antiretroviral therapy (ART) programmes has been associated with greater utilization of care for hypertension and diabetes in rural South Africa. The objective of this study was to assess whether people living with HIV on ART with comorbid hypertension or diabetes also have improved chronic disease management indicators. METHODS: The Health and Aging in Africa: a longitudinal study of an INDEPTH Community in South Africa (HAALSI) is a cohort of 5059 adults >40 years old. Enrollment took place between November 2014 and November 2015. The study collected population-based data on demographics, healthcare utilization, height, weight, blood pressure (BP) and blood glucose as well as HIV infection, HIV-1 RNA viral load (VL) and ART exposure. We used regression models to determine whether HIV care cascade stage (HIV-negative, HIV+ /No ART, ART/Detected HIV VL, and ART/Undetectable VL) was associated with diagnosis or treatment of hypertension or diabetes, and systolic blood pressure and glucose among those with diagnosed hypertension or diabetes. ART use was measured from drug level testing on dried blood spots. RESULTS AND DISCUSSION: Compared to people without HIV, ART/Undetectable VL was associated with greater awareness of hypertension diagnosis (adjusted risk ratio (aRR) 1.18, 95% CI: 1.09 to 1.28) and treatment of hypertension (aRR 1.24, 95% CI: 1.10 to 1.41) among those who met hypertension diagnostic criteria. HIV care cascade stage was not significantly associated with awareness of diagnosis or treatment of diabetes. Among those with diagnosed hypertension or diabetes, ART/Undetectable VL was associated with lower mean systolic blood pressure (5.98 mm Hg, 95% CI: 9.65 to 2.32) and lower mean glucose (3.77 mmol/L, 95% CI: 6.85 to 0.69), compared to being HIV-negative. CONCLUSIONS: Participants on ART with an undetectable VL had lower systolic blood pressure and blood glucose than the HIV-negative participants. HIV treatment programmes may provide a platform for health systems strengthening for cardiometabolic disease.

Clinical Decision Support for Ordering CTA-PE Studies in the Emergency Department-A Pilot on Feasibility and Clinical Impact in a Tertiary Medical Center.

PURPOSE: To determine the feasibility and impact of Clinical Decision Support for imaging ordering. METHODS: A survey of 231 emergency providers identified Computed tomography angiography (CTA)-Pulmonary embolism (PE) as an overutilized study. We developed an algorithm that combined established risk scores to stratify patients for PE work-up (recommendations: CTA, D-dimer or no further testing); the algorithm was integrated into the Epic Radiology Information Ordering System. RESULTS: Among 872 studies requested, 479 (55%) received a recommendation to change their order: 6 (1.3%) were cancelled; 13 (2.7%) changed to a D-dimer, and 460 (96%) proceeded with CTA. Of the 853 studies conducted, 8.2% were positive for PE. The algorithm had good discriminatory power with positivity rates of 12.0% (CT), 10.0% (D-dimer), and 2.6% (no further testing). Compliance with the recommendation ranged from 12%-68% (mean 45%) with 10% correlation between compliance and positivity rates. CONCLUSION: While the CDS algorithm was accurate, it had only a minimal impact on ordering practices, in part due to heterogeneity in physician adherence.

Noninvasive Imaging of Endothelial Damage in Patients With Different HbA1c Levels: A Proof-of-Concept Study.

The aim of this study was to compare endothelial permeability, which is considered a hallmark of coronary artery disease, between patients with different HbA1c levels using an albumin-binding magnetic resonance (MR) probe. This cross-sectional study included 26 patients with clinical indication for X-ray angiography who were classified into three groups according to HbA1c level (<5.7% [<39 mmol/mol], 5.7-6.4% [39-47 mmol/mol], and ≥6.5% [48 mmol/mol]). Subjects underwent gadofosveset-enhanced coronary magnetic resonance and X-ray angiography including optical coherence within 24 h. Contrast-to-noise ratios (CNRs) were assessed to measure the probe uptake in the coronary wall by coronary segment, excluding those with culprit lesions in X-ray angiography. In the group of patients with HbA1c levels between 5.7 and 6.4%, 0.30 increased normalized CNR values were measured, compared with patients with HbA1c levels <5.7% (0.30 [95% CI 0.04, 0.57]). In patients with HbA1c levels ≥6.5%, we found 0.57 higher normalized CNR values compared with patients with normal HbA1c levels (0.57 [95% CI 0.28, 0.85]) and 0.26 higher CNR values for patients with HbA1c level ≥6.5% compared with patients with HbA1c levels between 5.7 and 6.4% (0.26 [95% CI -0.04, 0.57]). Additionally, late atherosclerotic lesions were more common in patients with high HbA1c levels (HbA1c ≥6.5%, n = 14 [74%]; HbA1c 5.7-6.4%, n = 6 [60%]; and HbA1c <5.7%, n = 10 [53%]). In conclusion, coronary MRI in combination with an albumin-binding MR probe suggests that both patients with intermediate and patients with high HbA1c levels are associated with a higher extent of endothelial damage of the coronary arteries compared with patients with HbA1c levels <5.7%.

Differentiating Renal Neoplasms From Simple Cysts on Contrast-Enhanced CT on the Basis of Attenuation and Homogeneity.

OBJECTIVE: The purpose of this study is to compare the attenuation and homogeneity of renal neoplasms with those of cysts on contrast-enhanced CT. MATERIALS AND METHODS: A total of 129 renal neoplasms and 24 simple cysts were evaluated. Two readers determined whether each mass was qualitatively heterogeneous or homogeneous. Mean, minimum, and maximum attenuation values were measured. Statistical analysis was performed. RESULTS: A total of 116 heterogeneous renal cell carcinomas (RCCs) (99 clear cell, four papillary, four oncocytic, seven chromophobe, and two unclassified RCCs), 13 homogeneous RCCs (10 papillary, two oncocytic, and one chromophobe RCC), and 24 cysts (all of which were homogeneous) were evaluated. All homogeneous RCCs had mean attenuation values of more than 42 HU, whereas renal cysts had mean attenuation values of up to 30 HU (p < 0.001). Two readers qualitatively and identically categorized all RCCs as homogeneous or heterogeneous (κ = 1.0; p < 0.001). CONCLUSION: Homogeneous simple renal cysts can have mean attenuation values of up to 30 HU, as determined by contrast-enhanced CT, whereas homogeneous RCCs have mean attenuation values as low as 42 HU, with no overlap occurring between the two groups. These data suggest that further evaluation of a homogeneous renal mass with a mean attenuation value of 30 HU or less on a contrast-enhanced CT scan likely is unwarranted.

Diabetes diagnosis and care in sub-Saharan Africa: pooled analysis of individual data from 12 countries.

BACKGROUND: Despite widespread recognition that the burden of diabetes is rapidly growing in many countries in sub-Saharan Africa, nationally representative estimates of unmet need for diabetes diagnosis and care are in short supply for the region. We use national population-based survey data to quantify diabetes prevalence and met and unmet need for diabetes diagnosis and care in 12 countries in sub-Saharan Africa. We further estimate demographic and economic gradients of met need for diabetes diagnosis and care. METHODS: We did a pooled analysis of individual-level data from nationally representative population-based surveys that met the following inclusion criteria: the data were collected during 2005-15; the data were made available at the individual level; a biomarker for diabetes was available in the dataset; and the dataset included information on use of core health services for diabetes diagnosis and care. We first quantified the population in need of diabetes diagnosis and care by estimating the prevalence of diabetes across the surveys; we also quantified the prevalence of overweight and obesity, as a major risk factor for diabetes and an indicator of need for diabetes screening. Second, we determined the level of met need for diabetes diagnosis, preventive counselling, and treatment in both the diabetic and the overweight and obese population. Finally, we did survey fixed-effects regressions to establish the demographic and economic gradients of met need for diabetes diagnosis, counselling, and treatment. FINDINGS: We pooled data from 12 nationally representative population-based surveys in sub-Saharan Africa, representing 38 311 individuals with a biomarker measurement for diabetes. Across the surveys, the median prevalence of diabetes was 5% (range 2-14) and the median prevalence of overweight or obesity was 27% (range 16-68). We estimated seven measures of met need for diabetes-related care across the 12 surveys: (1) percentage of the overweight or obese population who received a blood glucose measurement (median 22% [IQR 11-37]); and percentage of the diabetic population who reported that they (2) had ever received a blood glucose measurement (median 36% [IQR 27-63]); (3) had ever been told that they had diabetes (median 27% [IQR 22-51]); (4) had ever been counselled to lose weight (median 15% [IQR 13-23]); (5) had ever been counselled to exercise (median 15% [IQR 11-30]); (6) were using oral diabetes drugs (median 25% [IQR 18-42]); and (7) were using insulin (median 11% [IQR 6-13]). Compared with those aged 15-39 years, the adjusted odds of met need for diabetes diagnosis (measures 1-3) were 2·22 to 3·53 (40-54 years) and 3·82 to 5·01 (≥55 years) times higher. The adjusted odds of met need for diabetes diagnosis also increased consistently with educational attainment and were between 3·07 and 4·56 higher for the group with 8 years or more of education than for the group with less than 1 year of education. Finally, need for diabetes care was significantly more likely to be met (measures 4-7) in the oldest age and highest educational groups. INTERPRETATION: Diabetes has already reached high levels of prevalence in several countries in sub-Saharan Africa. Large proportions of need for diabetes diagnosis and care in the region remain unmet, but the patterns of unmet need vary widely across the countries in our sample. Novel health policies and programmes are urgently needed to increase awareness of diabetes and to expand coverage of preventive counselling, diagnosis, and linkage to diabetes care. Because the probability of met need for diabetes diagnosis and care consistently increases with age and educational attainment, policy makers should pay particular attention to improved access to diabetes services for young adults and people with low educational attainment. FUNDING: None.

Tomosynthesis in the Diagnostic Setting: Changing Rates of BI-RADS Final Assessment over Time.

Purpose To evaluate the effect of tomosynthesis in diagnostic mammography on the Breast Imaging Reporting and Data System (BI-RADS) final assessment categories over time. Materials and Methods This retrospective study was approved by the institutional review board. The authors reviewed all diagnostic mammograms obtained during a 12-month interval before (two-dimensional [2D] mammography [June 2, 2010, to June 1, 2011]) and for 3 consecutive years after (tomosynthesis year 1 [2012], tomosynthesis year 2 [2013], and tomosynthesis year 3 [2014]) the implementation of tomosynthesis. The requirement to obtain informed consent was waived. The rates of BI-RADS final assessment categories 1-5 were compared between the 2D and tomosynthesis groups. The positive predictive values after biopsy (PPV3) for BI-RADS category 4 and 5 cases were compared. The mammographic features (masses, architectural distortions, calcifications, focal asymmetries) of lesions categorized as probably benign (BI-RADS category 3) and those for which biopsy was recommended (BI-RADS category 4 or 5) were reviewed. The χ(2) test was used to compare the rates of BI-RADS final assessment categories 1-5 between the two groups, and multivariate logistic regression analysis was performed to compare all diagnostic studies categorized as BI-RADS 3-5. Results There was an increase in the percentage of cases reported as negative or benign (BI-RADS category 1 or 2) with tomosynthesis (58.7% with 2D mammography vs 75.8% with tomosynthesis at year 3, P < .0001). A reduction in the percentage of probably benign (BI-RADS category 3) final assessments also occurred (33.3% with 2D mammography vs 16.4% with tomosynthesis at year 3, P < .0001). Although the rates of BI-RADS 4 or 5 assessments did not change significantly with tomosynthesis (8.0% with 2D mammography vs 7.8% with tomosynthesis at year 3, P = .2), there was a significant increase in the PPV3 (29.6% vs 50%, respectively; P < .0001). These trends increased during the 3 years of tomosynthesis use. Conclusion Tomosynthesis in the diagnostic setting resulted in progressive shifts in the BI-RADS final assessment categories over time, with a significant increase in the proportion of studies classified as normal, a continued decrease in the rate of studies categorized as probably benign, and improved diagnostic confidence in biopsy recommendations. (©) RSNA, 2016.

Lessons Learned from a Cross-Model Validation between a Discrete Event Simulation Model and a Cohort State-Transition Model for Personalized Breast Cancer Treatment.

OBJECTIVES: Breast cancer is the most common malignancy among women in developed countries. We developed a model (the Oncotyrol breast cancer outcomes model) to evaluate the cost-effectiveness of a 21-gene assay when used in combination with Adjuvant! Online to support personalized decisions about the use of adjuvant chemotherapy. The goal of this study was to perform a cross-model validation. METHODS: The Oncotyrol model evaluates the 21-gene assay by simulating a hypothetical cohort of 50-year-old women over a lifetime horizon using discrete event simulation. Primary model outcomes were life-years, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). We followed the International Society for Pharmacoeconomics and Outcomes Research-Society for Medical Decision Making (ISPOR-SMDM) best practice recommendations for validation and compared modeling results of the Oncotyrol model with the state-transition model developed by the Toronto Health Economics and Technology Assessment (THETA) Collaborative. Both models were populated with Canadian THETA model parameters, and outputs were compared. RESULTS: The differences between the models varied among the different validation end points. The smallest relative differences were in costs, and the greatest were in QALYs. All relative differences were less than 1.2%. The cost-effectiveness plane showed that small differences in the model structure can lead to different sets of nondominated test-treatment strategies with different efficiency frontiers. We faced several challenges: distinguishing between differences in outcomes due to different modeling techniques and initial coding errors, defining meaningful differences, and selecting measures and statistics for comparison (means, distributions, multivariate outcomes). CONCLUSIONS: Cross-model validation was crucial to identify and correct coding errors and to explain differences in model outcomes. In our comparison, small differences in either QALYs or costs led to changes in ICERs because of changes in the set of dominated and nondominated strategies.

Cost-effectiveness and cost-utility of a structured collaborative disease management in the Interdisciplinary Network for Heart Failure (INH) study.

BACKGROUND: Non-pharmacological treatment programmes are being developed, in which specialised nurses take care of heart failure (HF) patients. Such disease management programmes might increase survival and quality of life in HF patients, but evidence on their cost-effectiveness remains limited. METHODS AND RESULTS: A prospective economic evaluation piggy-backed onto the randomised controlled Interdisciplinary Network for Heart Failure (INH) Study weighted costs of the intervention HeartNetCare -HF™ (HNC) regarding effectiveness, mortality and quality-adjusted life years (QALYs). To consider uncertainty sensitivity analyses were performed. Compared to usual care (UC), HNC revealed 8,284 per death avoided within the 6 month study follow-up period. The cost-utility analysis showed additional costs of 49,335 per QALY. CONCLUSION: Although HNC did not reduce short-term re-admission rates of HF patients hospitalised for cardiac decompensation within the first 180 days after discharge, HNC might reduce mortality and increase quality of life in these patients at reasonable costs. Therefore, long-term HNC-effects deserve further evaluation.

Examining the use of comparative and cost-effectiveness analyses in radiology.

OBJECTIVE: This article explores key principles of comparative effectiveness analysis--in particular, how radiologic comparative and cost-effectiveness studies differ from other clinical trials. Exemplary studies are reviewed to show how comparative effectiveness has been implemented in radiology and how future studies might be conducted. Finally, the article closes with a discussion of several additional key themes relevant to quality and value in clinical radiology going forward. CONCLUSION: Comparative effectiveness is likely to require a paradigm shift in thinking within the discipline. For new radiologic applications to be accepted, we will need to show at least a significant change in treatment planning and at best a meaningful change in patient outcomes. This shift will require a forward-thinking approach to robust evidence generation for new imaging modalities or indications and the inclusion of other modes of value demonstration such as clinical decision support and intelligent data mining.

Cost-effectiveness of follow-up of pulmonary nodules incidentally detected on cardiac computed tomographic angiography in patients with suspected coronary artery disease.

BACKGROUND: Pulmonary nodules (PNs) are often detected incidentally during coronary computed tomographic (CT) angiography, which is increasingly being used to evaluate patients with chest pain symptoms. However, the efficiency of following up on incidentally detected PN is unknown. METHODS AND RESULTS: We determined demographic and clinical characteristics of stable symptomatic patients referred for coronary CT angiography in whom incidentally detected PNs warranted follow-up. A validated lung cancer simulation model was populated with data from these patients, and clinical and economic consequences of follow-up per Fleischner guidelines versus no follow-up were simulated. Of the 3665 patients referred for coronary CT angiography, 591 (16%) had PNs requiring follow-up. The mean age of patients with PNs was 59±10 years; 66% were male; 67% had ever smoked; and 21% had obstructive coronary artery disease. The projected overall lung cancer incidence was 5.8% in these patients, but the majority died of coronary artery disease (38%) and other causes (57%). Follow-up of PNs was associated with a 4.6% relative reduction in cumulative lung cancer mortality (absolute mortality: follow-up, 4.33% versus non-follow-up, 4.54%), more downstream testing (follow-up, 2.34 CTs per patient versus non-follow-up, 1.01 CTs per patient), and an average increase in quality-adjusted life of 7 days. Costs per quality-adjusted life-year gained were $154 700 to follow up the entire cohort and $129 800 per quality-adjusted life-year when only smokers were included. CONCLUSIONS: Follow-up of PNs incidentally detected in patients undergoing coronary CT angiography for chest pain evaluation is associated with a small reduction in lung cancer mortality. However, significant downstream testing contributes to limited efficiency, as demonstrated by a high cost per quality-adjusted life-year, especially in nonsmokers.

Cost-effectiveness analysis of coronary artery disease screening in HIV-infected men.

BACKGROUND: HIV-infected patients are at increased risk of coronary artery disease (CAD). We evaluated the cost-effectiveness of cardiac screening for HIV-positive men at intermediate or greater CAD risk. DESIGN: We developed a lifetime microsimulation model of CAD incidence and progression in HIV-infected men. METHODS: Input parameters were derived from two HIV cohort studies and the literature. We compared no CAD screening with stress testing and coronary computed tomography angiography (CCTA)-based strategies. Patients with test results indicating 3-vessel/left main CAD underwent invasive coronary angiography (ICA) and received coronary artery bypass graft surgery. In the stress testing + medication and CCTA + medication strategies, patients with 1-2-vessel CAD results received lifetime medical treatment without further diagnostics whereas in the stress testing + intervention and CCTA + intervention strategies, patients with these results underwent ICA and received percutaneous coronary intervention. RESULTS: Compared to no screening, the stress testing + medication, stress testing + intervention, CCTA + medication, and CCTA + intervention strategies resulted in 14, 11, 19, and 14 quality-adjusted life days per patient and incremental cost-effectiveness ratios of 49,261, 57,817, 34,887 and 56,518 Euros per quality-adjusted life year (QALY), respectively. Screening only at higher CAD risk thresholds was more cost-effective. Repeated screening was clinically beneficial compared to one-time screening, but only stress testing + medication every 5 years remained cost-effective. At a willingness-to-pay threshold of 83,000 €/QALY (∼ 100,000 US$/QALY), implementing any CAD screening was cost-effective with a probability of 75-95%. CONCLUSIONS: Screening HIV-positive men for CAD would be clinically beneficial and comes at a cost-effectiveness ratio comparable to other accepted interventions in HIV care.

Cost and resource utilization associated with use of computed tomography to evaluate chest pain in the emergency department: the Rule Out Myocardial Infarction using Computer Assisted Tomography (ROMICAT) study.

BACKGROUND: Coronary computed tomographic angiography (cCTA) allows rapid, noninvasive exclusion of obstructive coronary artery disease (CAD). However, concern exists whether implementation of cCTA in the assessment of patients presenting to the emergency department with acute chest pain will lead to increased downstream testing and costs compared with alternative strategies. Our aim was to compare observed actual costs of usual care (UC) with projected costs of a strategy including early cCTA in the evaluation of patients with acute chest pain in the Rule Out Myocardial Infarction Using Computer Assisted Tomography I (ROMICAT I) study. METHODS AND RESULTS: We compared cost and hospital length of stay of UC observed among 368 patients enrolled in the ROMICAT I study with projected costs of management based on cCTA. Costs of UC were determined by an electronic cost accounting system. Notably, UC was not influenced by cCTA results because patients and caregivers were blinded to the cCTA results. Costs after early implementation of cCTA were estimated assuming changes in management based on cCTA findings of the presence and severity of CAD. Sensitivity analysis was used to test the influence of key variables on both outcomes and costs. We determined that in comparison with UC, cCTA-guided triage, whereby patients with no CAD are discharged, could reduce total hospital costs by 23% (P<0.001). However, when the prevalence of obstructive CAD increases, index hospitalization cost increases such that when the prevalence of ≥ 50% stenosis is >28% to 33%, the use of cCTA becomes more costly than UC. CONCLUSIONS: cCTA may be a cost-saving tool in acute chest pain populations that have a prevalence of potentially obstructive CAD <30%. However, increased cost would be anticipated in populations with higher prevalence of disease.

Cost-effectiveness of 7-day-Holter monitoring alone or in combination with transthoracic echocardiography in patients with cerebral ischemia.

BACKGROUND AND PURPOSE: Prolonged Holter monitoring of patients with cerebral ischemia increases the detection rate of paroxysmal atrial fibrillation (PAF); this leads to improved antithrombotic regimens aimed at preventing recurrent ischemic strokes. The aim of this study was to compare a 7-day-Holter monitoring (7-d-Holter) alone or in combination with prior selection via transthoracic echocardiography (TTE) to a standard 24-h-Holter using a cost-utility analysis. METHODS: Lifetime cost, quality-adjusted life years (QALY), and incremental cost-effectiveness ratios (ICER) were estimated for a cohort of patients with acute cerebral ischemia and no contraindication to oral anticoagulation. A Markov model was developed to simulate the long-term course and progression of cerebral ischemia considering the different diagnostic algorithms (24-h-Holter, 7-d-Holter, 7-d-Holter after preselection by TTE). Clinical data for these algorithms were derived from the prospective observational Find-AF study (ISRCTN 46104198). RESULTS: Predicted lifelong discounted costs were 33,837 for patients diagnosed by the 7-d-Holter and 33,852 by the standard 24-h-Holter. Cumulated QALYs were 3.868 for the 7-d-Holter compared to 3.844 for the 24-h-Holter. The 7-d-Holter dominated the 24-h-Holter in the base-case scenario and remained cost-effective in extensive sensitivity analysis of key input parameter with a maximum of 8,354 /QALY gained. Preselecting patients for the 7-d-Holter had no positive effect on the cost-effectiveness. CONCLUSIONS: A 7-d-Holter to detect PAF in patients with cerebral ischemia is cost-effective. It increases the detection which leads to improved antithrombotic regimens; therefore, it avoids recurrent strokes, saves future costs, and decreases quality of life impairment. Preselecting patients by TTE does not improve cost-effectiveness.

Prevalence of cardiovascular diseases in HIV-infected outpatients: results from a prospective, multicenter cohort study.

BACKGROUND: Recent studies suggest a rising rate of cardiovascular disease (CVD) in HIV-infected subjects. Although most countries have an aging HIV-infected population, there remains a lack of knowledge about associated cardiovascular diseases. METHODS: This ongoing prospective multicentre observational cohort study aims to elucidate CVD prevalence in HIV-infected outpatients by standardized non-invasive cardiovascular screening. Cardiovascular and coronary risk was calculated using Framingham risk scores. RESULTS: 803 HIV-infected subjects (mean age 44.2 years, female 16.6 %) were included. The prevalence of CVD in HIV-infected subjects was 10.1 % (95 % CI 8.0-12.2 %). Aging HIV-infected patients (≥45 years, N = 348) exhibited significantly increased rates of CVD, including an elevated frequency of coronary artery disease (7.5 vs. 1.8 %, p < 0.001), myocardial infarction (6.0 vs. 1.8 %, p = 0.002) and peripheral arterial diseases (4.6 vs. 1.5 %, p < 0.017). Furthermore, aging patients exhibited a higher rate of chronic heart failure (5.2 vs. 1.5 %, p < 0.001), predominantly of ischemic etiology. In multivariate analyses, age (OR 2.05 per decade, 95 % CI 1.64-2.56), smoking (OR 5.96 per decade, 95 % CI 2.31-15.38) and advanced symptomatic HIV infection (OR 2.60 per decade, 95 % CI 1.31-5.15), were significantly associated with the prevalence of CVD. Based on the 10-year cardiovascular risk estimation, a disproportionate increase in cardiac events has to be expected in aging HIV-infected subjects in the next decades (≥45 years/<45 years 16.4 vs. 4.2 %, p < 0.001). CONCLUSION: CVD in aging HIV-infected population is an increasing medical challenge. In the era of antiretroviral therapy, prevention and diagnostic strategies are essential to reduce the prevalence of CVD in HIV-infected patients.

Coronary CT angiography versus standard evaluation in acute chest pain.

BACKGROUND: It is unclear whether an evaluation incorporating coronary computed tomographic angiography (CCTA) is more effective than standard evaluation in the emergency department in patients with symptoms suggestive of acute coronary syndromes. METHODS: In this multicenter trial, we randomly assigned patients 40 to 74 years of age with symptoms suggestive of acute coronary syndromes but without ischemic electrocardiographic changes or an initial positive troponin test to early CCTA or to standard evaluation in the emergency department on weekdays during daylight hours between April 2010 and January 2012. The primary end point was length of stay in the hospital. Secondary end points included rates of discharge from the emergency department, major adverse cardiovascular events at 28 days, and cumulative costs. Safety end points were undetected acute coronary syndromes. RESULTS: The rate of acute coronary syndromes among 1000 patients with a mean (±SD) age of 54±8 years (47% women) was 8%. After early CCTA, as compared with standard evaluation, the mean length of stay in the hospital was reduced by 7.6 hours (P<0.001) and more patients were discharged directly from the emergency department (47% vs. 12%, P<0.001). There were no undetected acute coronary syndromes and no significant differences in major adverse cardiovascular events at 28 days. After CCTA, there was more downstream testing and higher radiation exposure. The cumulative mean cost of care was similar in the CCTA group and the standard-evaluation group ($4,289 and $4,060, respectively; P=0.65). CONCLUSIONS: In patients in the emergency department with symptoms suggestive of acute coronary syndromes, incorporating CCTA into a triage strategy improved the efficiency of clinical decision making, as compared with a standard evaluation in the emergency department, but it resulted in an increase in downstream testing and radiation exposure with no decrease in the overall costs of care. (Funded by the National Heart, Lung, and Blood Institute; ROMICAT-II ClinicalTrials.gov number, NCT01084239.).