Cost-Effectiveness of Echocardiography to Identify Intracardiac Thrombus among Patients with First Stroke or Transient Ischemic Attack

Cost-effectiveness analysis of transthoracic echocardiographic assessment in patients with ischemic stroke or TIA of undetermined cause

BACKGROUND

The multicenter ATTEST study recently assessed 1084 patients with ischemic stroke or transient ischemic attack (TIA) of undetermined cause and found that routine transthoracic echocardiography (TTE) detects abnormalities with treatment implications (i.e., major cardiac sources of embolism) in only 1 % of patients, of whom most (91 %) also had major electrocardiographic (ECG)-abnormalities. In this study, we performed a cost-effectiveness analysis of different TTE strategies.

METHODS

We compared the cost-effectiveness of three strategies of TTE assessment: (1) TTE in all patients; (2) TTE only in patients with major ECG-abnormalities; and (3) TTE not performed. Input data were derived from ATTEST and systematic literature reviews. A Markov model was developed that simulated recurrent ischemic stroke or TIA and intracranial and gastro-intestinal bleeding complications in patients with ischemic stroke or TIA of undetermined cause. Primary outcome was the additional costs per additional quality-adjusted life-year (QALY) from a Dutch societal perspective.

RESULTS

Performing TTE only in patients with major ECG-abnormalities led to 0.0083 additional QALYs and €108 additional costs per patient as compared with not performing TTE (€12,987/QALY). Performing TTE in all patients resulted in 0.0005 additional QALYs and €422 additional costs per patient as compared with performing TTE only in case of major ECG-abnormalities (€805,336/QALY).

CONCLUSIONS

In patients with ischemic stroke or TIA of undetermined cause, a strategy of performing TTE only in patients who also had major ECG-abnormalities resulted in the most favorable ratio of additional costs per additional QALY. This supports performing TTE only in patients, who also have major ECG-abnormalities.

Bleeding risk in patients prescribed dual antiplatelet therapy and triple therapy after coronary interventions: the ADAPTT retrospective population-based cohort studies

Background

Bleeding among populations undergoing percutaneous coronary intervention or coronary artery bypass grafting and among conservatively managed patients with acute coronary syndrome exposed to different dual antiplatelet therapy and triple therapy (i.e. dual antiplatelet therapy plus an anticoagulant) has not been previously quantified.

Objectives

The objectives were to estimate hazard ratios for bleeding for different antiplatelet and triple therapy regimens, estimate resources and the associated costs of treating bleeding events, and to extend existing economic models of the cost-effectiveness of dual antiplatelet therapy.

Design

The study was designed as three retrospective population-based cohort studies emulating target randomised controlled trials.

Setting

The study was set in primary and secondary care in England from 2010 to 2017.

Participants

Participants were patients aged ≥ 18 years undergoing coronary artery bypass grafting or emergency percutaneous coronary intervention (for acute coronary syndrome), or conservatively managed patients with acute coronary syndrome.

Data sources

Data were sourced from linked Clinical Practice Research Datalink and Hospital Episode Statistics.

Interventions

Coronary artery bypass grafting and conservatively managed acute coronary syndrome: aspirin (reference) compared with aspirin and clopidogrel. Percutaneous coronary intervention: aspirin and clopidogrel (reference) compared with aspirin and prasugrel (ST elevation myocardial infarction only) or aspirin and ticagrelor.

Main outcome measures

Primary outcome: any bleeding events up to 12 months after the index event. Secondary outcomes: major or minor bleeding, all-cause and cardiovascular mortality, mortality from bleeding, myocardial infarction, stroke, additional coronary intervention and major adverse cardiovascular events.

Results

The incidence of any bleeding was 5% among coronary artery bypass graft patients, 10% among conservatively managed acute coronary syndrome patients and 9% among emergency percutaneous coronary intervention patients, compared with 18% among patients prescribed triple therapy. Among coronary artery bypass grafting and conservatively managed acute coronary syndrome patients, dual antiplatelet therapy, compared with aspirin, increased the hazards of any bleeding (coronary artery bypass grafting: hazard ratio 1.43, 95% confidence interval 1.21 to 1.69; conservatively-managed acute coronary syndrome: hazard ratio 1.72, 95% confidence interval 1.15 to 2.57) and major adverse cardiovascular events (coronary artery bypass grafting: hazard ratio 2.06, 95% confidence interval 1.23 to 3.46; conservatively-managed acute coronary syndrome: hazard ratio 1.57, 95% confidence interval 1.38 to 1.78). Among emergency percutaneous coronary intervention patients, dual antiplatelet therapy with ticagrelor, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.47, 95% confidence interval 1.19 to 1.82), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.06, 95% confidence interval 0.89 to 1.27). Among ST elevation myocardial infarction percutaneous coronary intervention patients, dual antiplatelet therapy with prasugrel, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.48, 95% confidence interval 1.02 to 2.12), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.10, 95% confidence interval 0.80 to 1.51). Health-care costs in the first year did not differ between dual antiplatelet therapy with clopidogrel and aspirin monotherapy among either coronary artery bypass grafting patients (mean difference £94, 95% confidence interval -£155 to £763) or conservatively managed acute coronary syndrome patients (mean difference £610, 95% confidence interval -£626 to £1516), but among emergency percutaneous coronary intervention patients were higher for those receiving dual antiplatelet therapy with ticagrelor than for those receiving dual antiplatelet therapy with clopidogrel, although for only patients on concurrent proton pump inhibitors (mean difference £1145, 95% confidence interval £269 to £2195).

Conclusions

This study suggests that more potent dual antiplatelet therapy may increase the risk of bleeding without reducing the incidence of major adverse cardiovascular events. These results should be carefully considered by clinicians and decision-makers alongside randomised controlled trial evidence when making recommendations about dual antiplatelet therapy.

Limitations

The estimates for bleeding and major adverse cardiovascular events may be biased from unmeasured confounding and the exclusion of an eligible subgroup of patients who could not be assigned an intervention. Because of these limitations, a formal cost-effectiveness analysis could not be conducted.

Future work

Future work should explore the feasibility of using other UK data sets of routinely collected data, less susceptible to bias, to estimate the benefit and harm of antiplatelet interventions.

Trial registration

This trial is registered as ISRCTN76607611.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 8. See the NIHR Journals Library website for further project information.

Diagnostic Yield of TEE in Patients with Cryptogenic Stroke and TIA with Normal TTE: A Systematic Review and Meta-Analysis

INTRODUCTION

The role of transesophageal echocardiography (TEE) in cryptogenic stroke and transient ischemic attack (TIA) with normal transthoracic echocardiography (TTE) remains controversial in the absence of definite guidelines. We aimed to perform a systematic review and meta-analysis to estimate an additional diagnostic yield and clinical impact of TEE in patients with cryptogenic stroke and TIA with normal TTE.

METHODS

We performed a systematic review of cohort studies on PubMed using the keywords 'cryptogenic stroke', cryptogenic TIA', 'TEE', and 'TTE' with matching MeSH terms. We included studies with patients who had cryptogenic stroke or TIA and had normal TTE findings, where the study intended to obtain TEE on all patients and reported all TEE abnormalities. The studies containing patients with atrial fibrillation were excluded. All studies were evaluated for internal and external validity. Inverse variance random effects models were used to calculate the effect size, the number needed to diagnose, and the 95% confidence interval.

RESULTS

We included 15 studies with 2054 patients and found LA/LAA/aortic thrombus, valvular vegetation, PFO-ASA, valvular abnormalities, and complex aortic plaques on TEE. Of these, 37.5% (29.7%-45.1%) of patients had additional cardiac findings on TEE. Management of 13.6% (8.1%-19.1%) of patients had changed after TEE evaluation. Based on current guidelines, it should change management in 4.1% (2.1%-6.2%) of patients and could potentially change management in 30.4% (21.9%-38.9%) of patients. Sensitivity analysis was also performed with only class II studies to increase internal validity, which showed additional cardiac findings in 38.4% (28.5%-48.3%), changed management in 20.2% (8.7%-31.8%), should change management in 4.7% (1.5%-7.9%), and could potentially change management in 30.4% (17.8%-43.0%) of patients.

CONCLUSIONS

The diagnostic yield of TEE to find any additional cardiac findings in patients with cryptogenic stroke or TIA is not only high, but it can also change management for certain cardiac abnormalities. TTE in cryptogenic stroke or TIA may mitigate future risks by tailoring the management of these patients.

Comparing the diagnostic value of Echocardiography In Stroke (CEIS) - results of a prospective observatory cohort study

BACKGROUND

Echocardiography is one of the main diagnostic tools for the diagnostic workup of stroke and is already well integrated into the clinical workup. However, the value of transthoracic vs. transesophageal echocardiography (TTE/TEE) in stroke patients is still a matter of debate. Aim of this study was to characterize relevant findings of TTE and TEE in the management of stroke patients and to correlate them with subsequent clinical decisions and therapies.

METHODS

We evaluated n = 107 patients admitted with an ischemic stroke or transient ischemic attack to our stroke unit of our university medical center. They underwent TTE and TEE examination by different blinded investigators.

RESULTS

Major cardiac risk factors were found in 8 of 98 (8.2%) patients and minor cardiac risk factors for stroke were found in 108 cases. We found a change in therapeutic regime after TTE or TEE in 22 (22.5%) cases, in 5 (5%) cases TEE leads to the change of therapeutic regime, in 4 (4%) TTE and in 13 cases (13.3%) TTE and TEE lead to the same change in therapeutic regime. The major therapy change was the indication to close a patent foramen ovale (PFO) in 9 (9.2%) patients with TTE and in 10 (10.2%) patients with TEE (p = 1.000).

CONCLUSION

Major finding with clinical impact on therapy change is the detection of PFO. But for the detection of PFO, TTE is non inferior to TEE, implicating that TTE serves as a good screening tool for detection of PFO, especially in young age patients.

TRIAL REGISTRATION

The trial was registered and approved prior to inclusion by our local ethics committee (1/3/17).

Clinical utility of echocardiography in secondary ischemic stroke prevention

Echocardiography employs ultrasound to evaluate cardiac function, structure and pathology. The clinical value in secondary ischemic stroke prevention depends on identification of associated conditions for which a change in treatment from antiplatelet agents and risk factor intervention leads to improved outcomes. Such therapeutically relevant findings include primarily intracardiac thrombus, valvular heart disease and, in highly selected patients, patent foramen ovale (PFO). Echocardiography in unselected patients with ischemic stroke has a very low yield of therapeutically relevant findings and is not cost-effective. With the exception of PFO, findings on echocardiography that are therapeutically relevant for secondary stroke prevention are almost always associated with history, signs or symptoms of cardiac or systemic disease. Choice of specific echocardiographic modalities should be based on the specific pathology or pathologies that are under consideration for the individual clinical situation. Transthoracic echocardiography (TTE) with agitated saline has comparable accuracy to transesophageal echocardiography (TEE) for PFO detection. For other therapeutically relevant pathologies, with the possible exception of left ventricular thrombus (LVT), TEE is more sensitive than TTE. Professional societies recommend TTE as the initial test but these recommendations do not take cost into account. In contrast, cost-effectiveness studies have determined that the most sensitive echocardiographic modality should be selected as the initial and only test.

Study protocol: Using peer support to aid in prevention and treatment in prediabetes (UPSTART)

BACKGROUND

There is an urgent need to develop and evaluate effective and scalable interventions to prevent or delay the onset of type 2 diabetes mellitus (T2DM).

METHODS

In this randomized controlled pragmatic trial, 296 adults with prediabetes will be randomized to either a peer support arm or enhanced usual care. Participants in the peer support arm meet face-to-face initially with a trained peer coach who also is a patient at the same health center to receive information on locally available wellness and diabetes prevention programs, discuss behavioral goals related to diabetes prevention, and develop an action plan for the next week to meet their goals. Over six months, peer coaches call their assigned participants weekly to provide support for weekly action steps. In the final 6 months, coaches call participants at least once monthly. Participants in the enhanced usual care arm receive information on local resources and periodic updates on available diabetes prevention programs and resources. Changes in A1c, weight, waist circumference and other patient-centered outcomes and mediators and moderators of intervention effects will be assessed.

RESULTS

At least 296 participants and approximately 75 peer supporters will be enrolled.

DISCUSSION

Despite evidence that healthy lifestyle interventions can improve health behaviors and reduce risk for T2DM, engagement in recommended behavior change is low. This is especially true among racial and ethnic minority and low-income adults. Regular outreach and ongoing support from a peer coach may help participants to initiate and sustain healthy behavior changes to reduce their risk of diabetes.

TRIAL REGISTRATION

The ClinicalTrials.gov registration number is NCT03689530.

Clinical Utility and Cost of Inpatient Transthoracic Echocardiography Following Acute Ischemic Stroke

Background and Purpose

It is unclear whether it is clinically necessary or cost-effective to routinely obtain a transthoracic echocardiogram (TTE) during inpatient admission for ischemic stroke.

Methods

We assessed consecutive patients presenting with acute ischemic stroke at a comprehensive stroke center from 2015 to 2017 who underwent TTE. We assessed for findings on TTE that would warrant urgent intervention including cardiac thrombus, atrial myxoma, mitral stenosis, valve vegetation, valve dysfunction requiring surgery, and low ejection fraction. Subsequent changes in management included changes in anticoagulation, antibiotics, or valve surgery. We calculated in-hospital resource utilization and associated costs for inpatient TTE using individual direct cost details within a case-costing system.

Results

Of 695 patients admitted with acute ischemic stroke, 516 (74%) had a TTE and were included in our analysis. TTE findings were potentially clinically significant in 30 patients (5.8%) and changed management in 17 patients (3.3%). Inpatient admission was prolonged to expedite TTE in 24 patients, while TTE occurred after discharge in 76 patients. After correcting for the cost of TTE, the mean difference in cost to prolong an admission for TTE was $555.52 (USD), or $16 832 per change in management.

Conclusions

Given the low clinical utility of inpatient TTE after acute ischemic stroke and the costs associated with prolonging admission, discharge from hospital should not be delayed solely to obtain TTE.

Diagnostic accuracy of acute infarcts in multiple cerebral circulations for cardioembolic stroke: Literature review and meta-analysis

OBJECTIVE

To determine the diagnostic value of acute infarcts in multiple cerebral circulations (AIMCC) on MRI diffusion-weighted imaging (DWI) for cardioembolism (CE) stroke subtype in adult patients hospitalized with acute ischemic stroke, we conducted a systematic literature review and meta-analysis.

METHODS

MEDLINE was searched via PubMed for articles reporting patients hospitalized with acute ischemic stroke with MRI DWI categorized as AIMCC vs other and use of Trial of Org 10172 in Acute Stroke Treatment (TOAST) Criteria for cardioembolism subtype. Measures of diagnostic accuracy were calculated from the retrieved studies.

RESULTS

Seven eligible articles comprised 5813 patients. Bivariate random effects models estimated sensitivity 0.19 (95% CI, 0.13 to 0.27), specificity 0.89 (0.86 to 0.91), positive predictive value 0.37 (0.30 to 0.45), negative predictive value 0.76 (0.7 to 0.82), positive likelihood ratio 1.70 (1.13 to 2.57) and negative likelihood ratio 0.91 (0.83 to 1).

INTERPRETATION

The pattern of AIMCC on DWI is of limited diagnostic value. It is not sufficiently accurate to exclude cardiac pathology by a negative test nor does a positive test indicate a major increase in the probability of identifying a potential cardioembolic source.

Useful indices of thrombogenesis in the exclusion of intra-cardiac thrombus

Background

Cardioversion in patients with atrial fibrillation (AF) can cause cardioembolic stroke, and effective clinical management is necessary to reduce morbidity and mortality. Currently, transesophageal echocardiography (TEE) is the accepted standard to diagnose cardiogenic thromboemboli; however, a negative TEE does not eliminate the possibility of left atrial thrombus. The objective of this study was to evaluate the diagnostic value of supplementing the TEE with additional noninvasive markers to ensure thrombus absence.

Methods

A prospective study was conducted on 59 patients who underwent TEE for suspected intra‐cardiac thrombi. The TEE indications included acute ischemic stroke (45.7%) and AF or flutter (59.3%). D‐dimer level and white blood cell counts were assessed.

Results

A negative D‐dimer level (<200 ng/mL) excluded the presence of intra‐cardiac thrombi. Groups with either negative (n = 14) or positive (n = 45) D‐dimer levels had comparable clinical characteristics. Comparing positive D‐dimer–level patients with thrombus (n = 7) and without thrombus (n = 33), patients with thrombus had reduced left atrial appendage (LAA) velocity (P = .0024), reduced left ventricular ejection fraction (LVEF) (P = .0263), increased neutrophil percent (P = .0261), decreased lymphocyte percent (P = .0216), and increased monocyte counts (P = .0220). The area under the receiver operating characteristic (ROC) curve for thrombus diagnostics was larger for combinations of clinical and biochemical data than for each parameter individually.

Conclusions

Supplementing the gold standard TEE with the analysis of LAA velocity, noninvasive LVEF, D‐dimer, and hemostatic markers provided additional useful diagnostic information. Larger studies are needed to further validate the efficacy of supplementing the TEE to better assess patients for intra‐cardiac thrombi.

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Universal versus platelet reactivity assay-driven use of P2Y12 inhibitors in acute coronary syndrome patients

Platelet reactivity assays (PRAs) can predict patients’ likely response to clopidogrel. As ticagrelor and prasugrel are typically considered first-line agents for acute coronary syndrome in Europe, we assessed the cost-effectiveness of universal compared to PRA-driven selection of these agents. A Markov model was used to calculate five-year costs (2013£/€), quality-adjusted life-years and incremental cost-effectiveness ratios (ICERs) for one-year of universal ticagrelor or prasugrel (given to all) compared to each agents’ corresponding PRA-driven strategy (ticagrelor/prasugrel in those with high platelet reactivity [HPR, >208 on the VerifyNow P2Y12 assay], others given generic clopidogrel). We assumed patients had their index event at 65–70 years of age and had a 42.7% incidence of HPR 24–48 hours post-revascularisation. The analysis was conducted from the perspective of six countries (France, Germany, Italy, Spain, the Netherlands and United Kingdom) and used a one-year cycle length. Event data for P2Y12 inhibitors were taken from multinational randomised trials and adjusted using country-specific epidemiologic data. Neither universal ticagrelor nor prasugrel were found to be cost-effective (all ICERs >40,250€ or £36,600/QALY) compared to their corresponding PRA-driven strategies in any of the countries evaluated. Results were sensitive to differences in P2Y12 Inhibitors costs and drug-specific relative risks of major adverse cardiac events. Monte Carlo simulation suggested universal ticagrelor or prasugrel were cost-effective in only 25–44% and 11–17% of 10,000 iterations compared to their respective PRA-driven strategies, when applying a willingness-to-pay threshold = €30,000 or £20,000/QALY. In conclusion, the universal use of newer P2Y12 inhibitors is not likely cost-effective compared to PRA-driven strategies.

The cost-effectiveness of using chronic kidney disease risk scores to screen for early-stage chronic kidney disease

BACKGROUND

Better treatment during early stages of chronic kidney disease (CKD) may slow progression to end-stage renal disease and decrease associated complications and medical costs. Achieving early treatment of CKD is challenging, however, because a large fraction of persons with CKD are unaware of having this disease. Screening for CKD is one important method for increasing awareness. We examined the cost-effectiveness of identifying persons for early-stage CKD screening (i.e., screening for moderate albuminuria) using published CKD risk scores.

METHODS

We used the CKD Health Policy Model, a micro-simulation model, to simulate the cost-effectiveness of using CKD two published risk scores by Bang et al. and Kshirsagar et al. to identify persons in the US for CKD screening with testing for albuminuria. Alternative risk score thresholds were tested (0.20, 0.15, 0.10, 0.05, and 0.02) above which persons were assigned to receive screening at alternative intervals (1-, 2-, and 5-year) for follow-up screening if the first screening was negative. We examined incremental cost-effectiveness ratios (ICERs), incremental lifetime costs divided by incremental lifetime QALYs, relative to the next higher screening threshold to assess cost-effectiveness. Cost-effective scenarios were determined as those with ICERs less than $50,000 per QALY. Among the cost-effective scenarios, the optimal scenario was determined as the one that resulted in the highest lifetime QALYs.

RESULTS

ICERs ranged from $8,823 per QALY to $124,626 per QALY for the Bang et al. risk score and $6,342 per QALY to $405,861 per QALY for the Kshirsagar et al. risk score. The Bang et al. risk score with a threshold of 0.02 and 2-year follow-up screening was found to be optimal because it had an ICER less than $50,000 per QALY and resulted in the highest lifetime QALYs.

CONCLUSIONS

This study indicates that using these CKD risk scores may allow clinicians to cost-effectively identify a broader population for CKD screening with testing for albuminuria and potentially detect people with CKD at earlier stages of the disease than current approaches of screening only persons with diabetes or hypertension.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

The Cost-Effectiveness of Anemia Treatment for Persons with Chronic Kidney Disease

BACKGROUND

Although major guidelines uniformly recommend iron supplementation and erythropoietin stimulating agents (ESAs) for managing chronic anemia in persons with chronic kidney disease (CKD), there are differences in the recommended hemoglobin (Hb) treatment target and no guidelines consider the costs or cost-effectiveness of treatment. In this study, we explored the most cost-effective Hb target for anemia treatment in persons with CKD stages 3-4.

METHODS AND FINDINGS

The CKD Health Policy Model was populated with a synthetic cohort of persons over age 30 with prevalent CKD stages 3-4 (i.e., not on dialysis) and anemia created from the 1999-2010 National Health and Nutrition Examination Survey. Incremental cost-effectiveness ratios (ICERs), computed as incremental cost divided by incremental quality adjusted life years (QALYs), were assessed for Hb targets of 10 g/dl to 13 g/dl at 0.5 g/dl increments. Targeting a Hb of 10 g/dl resulted in an ICER of $32,111 compared with no treatment and targeting a Hb of 10.5 g/dl resulted in an ICER of $32,475 compared with a Hb target of 10 g/dl. QALYs increased to 4.63 for a Hb target of 10 g/dl and to 4.75 for a target of 10.5 g/dl or 11 g/dl. Any treatment target above 11 g/dl increased medical costs and decreased QALYs.

CONCLUSIONS

In persons over age 30 with CKD stages 3-4, anemia treatment is most cost-effective when targeting a Hb level of 10.5 g/dl. This study provides important information for framing guidelines related to treatment of anemia in persons with CKD.

Embolic Stroke Diagnosed by Elevated D-Dimer in a Patient With Negative TEE for Cardioembolic Source

We report a case of cerebrovascular accident with thromboembolic stroke etiology in a patient who had atrial flutter and negative transesophageal echocardiography (TEE) results. The increased D-dimer levels (1877 ng/mL) initiated referral for magnetic resonance imaging and magnetic resonance angiography of the brain that showed classic recanalization of an embolic thrombus in the angular branch of the left middle cerebral distribution. The D-dimer level of this patient was normalized after 3 months of anticoagulation therapy. Although TEE is considered the gold standard for evaluation of cardiac source of embolism, exclusion of intracardiac thrombus with TEE alone does not eliminate the risk of thromboembolic events. This case highlights the utility of D-dimer as a potential adjunct in the decision-making process to guide investigation of thromboembolism, determine subsequent therapy, and hence reduce the risk of embolic stroke recurrence.

Net clinical benefit of oral anticoagulants: a multiple criteria decision analysis

BACKGROUND

This study quantitatively evaluated the comparative efficacy and safety of new oral anticoagulants (dabigatran, rivaroxaban, and apizaban) and warfarin for treatment of nonvalvular atrial fibrillation. We also compared these agents under different scenarios, including population with high risk of stroke and for primary vs. secondary stroke prevention.

METHODS

We used multiple criteria decision analysis (MCDA) to assess the benefit-risk of these medications. Our MCDA models contained criteria for benefits (prevention of ischemic stroke and systemic embolism) and risks (intracranial and extracranial bleeding). We calculated a performance score for each drug accounting for benefits and risks in comparison to treatment alternatives.

RESULTS

Overall, new agents had higher performance scores than warfarin; in order of performance scores: dabigatran 150 mg (0.529), rivaroxaban (0.462), apixaban (0.426), and warfarin (0.191). For patients at a higher risk of stroke (CHADS2 score≥3), apixaban had the highest performance score (0.686); performance scores for other drugs were 0.462 for dabigatran 150 mg, 0.392 for dabigatran 110 mg, 0.271 for rivaroxaban, and 0.116 for warfarin. Dabigatran 150 mg had the highest performance score for primary stroke prevention, while dabigatran 110 mg had the highest performance score for secondary prevention.

CONCLUSIONS

Our results suggest that new oral anticoagulants might be preferred over warfarin. Selecting appropriate medicines according to the patient's condition based on information from an integrated benefit-risk assessment of treatment options is crucial to achieve optimal clinical outcomes.

Transesophageal echocardiography in patients with cryptogenic ischemic stroke: a systematic review

BACKGROUND

The clinical utility of routine transesophageal echocardiography (TEE) for patients with unexplained ischemic stroke is controversial. We performed a systematic review to determine the frequency of detection of new cardiac findings in patients with cryptogenic ischemic stroke (IS) undergoing transesophageal echocardiography (TEE).

METHODS

Systematic review and meta-analysis of cohort studies of consecutive patients with "cryptogenic" IS undergoing TEE after routine etiologic workup. Patients were categorized into 2 groups: A (< 55 years) and B (≥ 55 years). Outcomes included proportion of patients with new TEE-detected cardiac findings and proportion of patients commenced on oral anticoagulation after TEE.

RESULTS

Twenty-seven studies were included (n = 5,653). We identified significant heterogeneity among studies and report a range of prevalence rates and I2 statistic as our primary analysis. Prevalence of individual cardiac findings on TEE varied significantly among studies; patent foramen ovale (A: 12.0%-57.8%, I2 = 89.9%; B: 3.9%-43.5%, I2 = 86.7%), atrial septal aneurysm (A: 0-48.9%, I2 = 91.9%; B: 3.5%-25.0%, I2 = 84.5%), left atrial thrombus (A: 0-10.9%, I2 = 61.1%; B: 0-21.2%, I2 = 91.7%), spontaneous echo contrast (A: 0-11.9%, I2 = 57.2%; B: 0-21.3%, I2 = 89.8%), and aortic atheroma (A: 0-9.6%, I2 = 53.8%; B: 2.8%-44.4%, I2 = 89.7%). Definitions of common findings were not provided for many studies. Five studies (n = 591) reported on the proportion of patients who were commenced on anticoagulant therapy after TEE (range 0-30.7%).

CONCLUSIONS

Routine TEE in patients with cryptogenic IS identifies cardiac findings in a large proportion. However, there is marked interstudy variation in the definition and prevalence of common findings. Transesophageal echocardiography-detected findings prompted the introduction of anticoagulant therapy in up to one-third of patients. However, these were mostly not for established guideline-based indications based on randomized controlled trial evidence. It is unclear if routine use of TEE in patients with cryptogenic IS is indicated.

[Usefulness of transesophageal echocardiography to optimize treatment after ischemic stroke]

AIM OF THE STUDY

In the setting of ischemic stroke, the place of transesophageal echocardiography (TEE) is still matter of debate. The aim of the study is to evaluate the therapeutic impact provided by TEE and to characterize patients in whom TEE is warranted.

PATIENTS AND METHOD

Three hundred and fifty-nine consecutive patients were included in the study. "Decisive TEE" (DTEE) was defined by echographic findings resulting in a change of treatment, whereas "informative TEE" (ITEE) was defined by TEE revealing a potential cardiac or aortic source of embolism.

RESULTS

Three hundred and forty-one patients underwent TEE. Twenty-eight patients (8.2%) had DTEE and 184 (53.9%) had ITEE. DTEE were as follows: thrombus in the left atrial appendage in 6 patients, complex aortic plaques in 10 patients, patent foramen ovale (PFO) associated with atrial septal aneurism (ASA) and an important right to left shunt (3 patients), FOP associated with ASA and lower limb phlebitis (1 patient), 4 cases of endocarditis and 4 patients with intense spontaneous echo contrast in the left atrium. In most cases of DTEE (67.8%), the patient was given anticoagulation drugs. Left atrial dilatation (P=0.005) and multivessel territory stroke (P=0.018) were statistically predictive of DTEE.

CONCLUSIONS

In the setting of ischemic stroke, TEE provides important additional informations, but modifies therapeutic strategy in less than 10% of cases. Multivessel territory stroke, and left atrial dilatation were predictive of DTEE.

Economic evaluation of using a genetic test to direct breast cancer chemoprevention in white women with a previous breast biopsy

BACKGROUND

Tamoxifen therapy reduces the risk of breast cancer but increases the risk of serious adverse events including endometrial cancer and thromboembolic events.

OBJECTIVES

The cost effectiveness of using a commercially available breast cancer risk assessment test (BREVAGen™) to inform the decision of which women should undergo chemoprevention by tamoxifen was modeled in a simulated population of women who had undergone biopsies but had no diagnosis of cancer.

METHODS

A continuous time, discrete event, mathematical model was used to simulate a population of white women aged 40-69 years, who were at elevated risk for breast cancer because of a history of benign breast biopsy. Women were assessed for clinical risk of breast cancer using the Gail model and for genetic risk using a panel of seven common single nucleotide polymorphisms. We evaluated the cost effectiveness of using genetic risk together with clinical risk, instead of clinical risk alone, to determine eligibility for 5 years of tamoxifen therapy. In addition to breast cancer, the simulation included health states of endometrial cancer, pulmonary embolism, deep-vein thrombosis, stroke, and cataract. Estimates of costs in 2012 US dollars were based on Medicare reimbursement rates reported in the literature and utilities for modeled health states were calculated as an average of utilities reported in the literature. A 50-year time horizon was used to observe lifetime effects including survival benefits.

RESULTS

For those women at intermediate risk of developing breast cancer (1.2-1.66 % 5-year risk), the incremental cost-effectiveness ratio for the combined genetic and clinical risk assessment strategy over the clinical risk assessment-only strategy was US$47,000, US$44,000, and US$65,000 per quality-adjusted life-year gained, for women aged 40-49, 50-59, and 60-69 years, respectively (assuming a price of US$945 for genetic testing). Results were sensitive to assumptions about patient adherence, utility of life while taking tamoxifen, and cost of genetic testing.

CONCLUSIONS

From the US payer's perspective, the combined genetic and clinical risk assessment strategy may be a moderately cost-effective alternative to using clinical risk alone to guide chemoprevention recommendations for women at intermediate risk of developing breast cancer.

Cost-effectiveness of universal and platelet reactivity assay-driven antiplatelet therapy in acute coronary syndrome

Assays monitoring P2Y12 platelet reactivity can accurately predict which patients will have a poor response to clopidogrel. We sought to determine the cost-effectiveness of using platelet reactivity assays (PRAs) to select a dual-antiplatelet regimen for patients with acute coronary syndrome. A hybrid decision tree Markov model was developed to determine the cost-effectiveness of universal clopidogrel, ticagrelor, or prasugrel (given to all patients) or PRA-driven ticagrelor or prasugrel (given to patients with high platelet reactivity, defined as >230 on the VerifyNow P2Y12 assay; the others received generic clopidogrel). We assumed a cohort of 65-year-old patients with acute coronary syndrome and an incidence of high platelet reactivity of 32% and 13% at ~24 to 48 hours after revascularization and 1 month, respectively. The 5-year costs, quality-adjusted life-years, and incremental cost-effectiveness ratios were calculated for PRA-driven ticagrelor and prasugrel compared with universal clopidogrel, ticagrelor, or prasugrel. PRA-driven ticagrelor and prasugrel were cost-effective compared with universal clopidogrel (incremental cost-effectiveness ratio $40,100 and $49,143/quality-adjusted life-year, respectively); however, universal ticagrelor and prasugrel were not (incremental cost-effectiveness ratio $61,651 and $96,261/quality-adjusted life-year, respectively). Monte Carlo simulation suggested PRA-driven ticagrelor, PRA-driven prasugrel, universal ticagrelor, and universal prasugrel would have an incremental cost-effectiveness ratio <$50,000/quality-adjusted life-year in 52%, 40%, 23%, and 2% of the iterations compared with universal clopidogrel, respectively. Universal ticagrelor and prasugrel were not cost-effective compared with their respective PRA-driven regimens (incremental cost-effectiveness ratio $68,182; $116,875/quality-adjusted life-year, respectively). Monte Carlo simulation suggested universal ticagrelor and prasugrel would have an incremental cost-effectiveness ratio <$50,000/quality-adjusted life-year in 26% and 4% of iterations compared with their respective PRA-driven regimens. The results were most sensitive to differences in agent costs and drug-specific relative risks of death. In conclusion, even with generic clopidogrel, PRA-driven selection of antiplatelet therapy appeared to be a cost-effective strategy with the potential to decrease the overall acute coronary syndrome-associated healthcare costs.

The cost of materials for intra-arterial thrombectomy

This paper reports the cost of endovascular materials used for the treatment of large-vessel ischemic stroke in the anterior circulation according to the angiographic score and clinical results at three months. From November 2009 to July 2011, 57 ischemic patients (mean age, 64.6 ±13.8 years) with anterior large vessel occlusion were included. Mean National Institutes of Health Stroke Scale (NIHSS) on admission was 18.4 ± 4.9. Mean duration of symptoms until the arterial puncture was 207±67 minutes. Recanalization was assessed using the Thrombolysis In Myocardial Infarction (TIMI) score. Patient selection was performed on a non-enhanced CT scanner. According to the TIMI final angiographic score and the modified Rankin score (mRS) at three months, we determined the cost of the material used. Complete (n=12, TIMI grade 3) or partial perfusion (n=35, TIMI grade 2) was achieved in 47 (82.5%) lesions. At three months, 33.3% (n=19) had a mRS score ≤ 2. The mean cost of the material used in the operative room was 5018±2402 euro. Intra-arterial thrombolysis presents a substantial initial cost and the long-term economic impact has to be evaluated. Our health system has to take the price of these new technologies into account for future medical choices and urgently evaluate them in randomized controlled trials.

Ticagrelor versus genotype-driven antiplatelet therapy for secondary prevention after acute coronary syndrome: a cost-effectiveness analysis

BACKGROUND

Clopidogrel's effectiveness is likely reduced significantly for prevention of thrombotic events after acute coronary syndrome (ACS) in patients exhibiting a decreased ability to metabolize clopidogrel into its active form. A genetic mutation responsible for this reduced effectiveness is detectable by genotyping. Ticagrelor is not dependent on gene-based metabolic activation and demonstrated greater clinical efficacy than clopidogrel in a recent secondary prevention trial. In 2011, clopidogrel will lose its patent protection and likely will be substantially less expensive than ticagrelor.

OBJECTIVE

To determine the cost-effectiveness of ticagrelor compared with a genotype-driven selection of antiplatelet agents.

METHODS

A hybrid decision tree/Markov model was used to estimate the 5-year medical costs (in 2009 US$) and outcomes for a cohort of ACS patients enrolled in Medicare receiving either genotype-driven or ticagrelor-only treatment. Outcomes included life years and quality-adjusted life years (QALYs) gained. Data comparing the clinical performance of ticagrelor and clopidogrel were derived from the Platelet Inhibition and Patient Outcomes trial.

RESULTS

The incremental cost-effectiveness ratio (ICER) for universal ticagrelor was $10,059 per QALY compared to genotype-driven treatment, and was most sensitive to the price of ticagrelor and the hazard ratio for death for ticagrelor compared with clopidogrel. The ICER remained below $50,000 per QALY until a monthly ticagrelor price of $693 or a 0.93 hazard ratio for death for ticagrelor relative to clopidogrel. In probabilistic analyses, universal ticagrelor was below $50,000 per QALY in 97.7% of simulations.

CONCLUSION

Prescribing ticagrelor universally increases quality-adjusted life years for ACS patients at a cost below a typically accepted threshold.

Cost-effectiveness of recombinant tissue plasminogen activator in the management of acute ischemic stroke: a systematic review

BACKGROUND AND PURPOSE

This work was undertaken to review the current cost-effectiveness analysis data on thrombolysis by intravenous (IV) therapy with recombinant tissue plasminogen activator (rtPA) for acute ischemic stroke.

METHODS

PubMed was searched for articles published between 1995 and 2008. The cost-effectiveness analysis data from eight eligible studies were reviewed, paying particular attention to their modeling assumptions and the quality of the source data.

RESULTS

THE REVIEWED STUDIES WERE FROM SIX COUNTRIES: USA (n=2), UK (n=2), Canada (n=1), Australia (n=1), Spain (n=1), and Denmark (n=1); most were performed from the healthcare-system and/or societal perspectives. IV rtPA was associated with an acceptable increase in short-term cost [range: US$ 36-236/patient; US$ 29,148-55,591/quality-adjusted life-years (QALYs)], and a net long-term cost saving that was higher from a societal perspective (range: -US$ 12,043 to -US$ 630/patient; -US$ 207,253 to -US$ 21,938/QALYs) than from a healthcare-system perspective (range: -US$ 5,811 to -US$ 5,415/patient; -US$ 41,137 to -US$ 4,662/QALYs).

CONCLUSIONS

IV rtPA seems to be a cost-effective strategy for the management of acute ischemic stroke, and might reduce the associated healthcare costs as well as patients' disabilities. Further cost-effectiveness research and the development of a public health strategy are warranted to optimize the use of rtPA in Korea.

Cost-effective diagnostic cardiovascular imaging: when does it provide good value for the money?

To summarize the results of all original cost-utility analyses (CUAs) in diagnostic cardiovascular imaging (CVI) and characterize those technologies by estimates of their cost-effectiveness. We systematically searched the literature for original CVI CUAs published between 2000 and 2008. Studies were classified according to several variables including anatomy of interest (e.g. cerebrovascular, aorta, peripheral) and imaging modality under study (e.g. angiography, ultrasound). The results of each study, expressed as cost of the intervention to number of quality-adjusted life years saved ratio (cost/QALY) were additionally classified as favorable or not using $20,000, $50,000, and $100,000 per QALY thresholds. The distribution of results was assessed with Chi Square or Fisher exact test, as indicated. Sixty-nine percent of all cardiovascular imaging CUAs were published between 2000 and 2008. Thirty-two studies reporting 82 cost/QALY ratios were included in the final sample. The most common vascular areas studied were cerebrovascular (n = 9) and cardiac (n = 8). Sixty-six percent (21/32) of studies focused on sonography, followed by conventional angiography and CT (25%, n = 8, each). Twenty-nine (35.4%), 42 (51.2%), and 53 (64.6%) ratios were favorable at WTP $20,000/QALY, $50,000/QALY, and $100,000/QALY, respectively. Thirty (36.6%) ratios compared one imaging test versus medical or surgical interventions; 26 (31.7%) ratios compared imaging to a different imaging test and another 26 (31.7%) to no intervention. Imaging interventions were more likely (P < 0.01) to be favorable when compared to observation, medical treatment or non-intervention than when compared to a different imaging test at WTP $100,000/QALY. The diagnostic cardiovascular imaging literature has growth substantially. The studies available have, in general, favorable cost-effectiveness profiles with major determinants relating to being compared against observation, medical or no intervention instead of other imaging tests.

Implications of an economic model of health states worse than dead

We introduce a formal definition of health equivalent to dead into a standard model to develop previously unrecognized insights. We find that the health state viewed as equivalent to dead will depend on an individual's health prognosis, probability of survival, and rate of time preference. Our work on maximum endurable time shows that using QALY scores based on long-run preferences to value health states that last for shorter periods can alter cardinal and ordinal valuations. Simulations show that errors of substantial magnitude in QALY scores can consequently result. We describe situations where biases are likely and identify possible corrections.

Cardiac workup of ischemic stroke: can we improve our diagnostic yield?

BACKGROUND AND PURPOSE

Discovering potential cardiac sources of stroke is an important part of the urgent evaluation of the ischemic stroke patient as it often impacts treatment decisions that are essential for determining secondary stroke prevention strategies, yet the optimal approach to the cardiac workup of an ischemic stroke patient is not known.

METHODS

A review of the literature concerning the utility of cardiac rhythm monitoring (ECG, telemetry, Holter monitors, and event recorders) and structural imaging (transthoracic and transesophageal echocardiography) was performed.

RESULTS

Data supporting a definitive, optimal, and cost-effective approach are lacking, though some data suggest that appropriate patient selection can improve the diagnostic and therapeutic yield of rhythm monitoring and echocardiography in the evaluation of stroke etiology.

CONCLUSIONS

Based on available data, an algorithmic approach for the evaluation of patients with acute ischemic cerebrovascular events that takes into account therapeutic and diagnostic yield as well as cost-efficiency is proposed.