Cost effectiveness of aspirin, clopidogrel, or both for secondary prevention of coronary heart disease

Safety of Early Surgery in Hip Fracture Patients Taking Clopidogrel and/or Aspirin: A Systematic Review and Meta-Analysis

BACKGROUND

The aim of this study was to investigate the safety of early surgery in hip fracture patients who took clopidogrel and/or aspirin.

METHODS

A systematic search was conducted using databases, including PubMed/MEDLINE, Embase, Cochrane Library, and Web of Science, for studies relating to early arthroplasty or internal fixation for femoral neck fractures, intertrochanteric fractures, and subtrochanteric fractures in patients taking clopidogrel and/or aspirin. A total of 20 observational studies involving 3,077 patients were included in this meta-analysis, and analyzed in groups of early surgery versus delayed surgery, and clopidogrel and/or aspirin versus nonantiplatelet agents.

RESULTS

Patients in the clopidogrel and/or aspirin group who underwent early surgery had significantly more intraoperative blood loss than those in the non-antiplatelet group (mean difference = 17.96, 95% confidence interval [CI] [4.37, 31.55], P = .01), and patients in the clopidogrel and/or aspirin group had a lower overall incidence of complications after early surgery than those in the delayed surgery group (odds ratio = 0.26, 95% CI [0.14, 0.29], P < .001) and a shorter length of hospital stay (odds ratio = 0.26, 95% CI [0.14, 0.29], P < .001). There was no significant difference in postoperative mortality and other related indicators.

CONCLUSIONS

Early surgery in hip fracture patients taking clopidogrel and/or aspirin appears to be safe based on the available evidence and needs to be clarified by higher quality studies. However, the increased risk of cardiovascular events associated with discontinuation of clopidogrel or clopidogrel combined with aspirin dual antiplatelet therapy requires attention in the perioperative period.

Monotherapy with P2Y12-inhibitors after dual antiplatelet therapy: Filling gaps in evidence

BACKGROUND

Whether P2Y12 inhibitor monotherapy (P2Y12-I) is superior to aspirin following DAPT discontinuation post-PCI remains to be established.

METHODS

We updated our prior network meta-analysis where P2Y12-I and aspirin had been compared with DAPT or directly with each other. The focus is specifically on the available direct evidence, now consisting of the three head-to-head comparisons of P2Y12-I and aspirin in event-free PCI patients after DAPT. We include a Trial Sequential Analysis of the direct evidence based on meta-analytical literature.

RESULTS

The main finding reveals a 39% significantly lower risk of myocardial infarction with P2Y12-I (RR 0.61, 95% CI 0.47-0.78, p = 0.0001, I2 = 0%) with no difference in bleeding. Trial Sequential Analysis demonstrates clinically meaningful evidence for a reduction in the incidence of myocardial infarction with P2Y12-I that is also supported by statistical significance.

CONCLUSIONS

Accruing data highlight that P2Y12-I following DAPT discontinuation after PCI is associated with lower risk for MI and a similar risk for bleeding as compared with ASA. In light of potential limitations to the widespread adoption of life-long P2Y12-I treatment, clinicians should consider identifying selected patients who are expected to derive the highest benefit.

Cangrelor for neurointerventional procedures: A systematic review

Thromboembolism is a complication of neurointerventional procedures that requires patients to be placed under antiplatelet therapy. Current options for antiplatelet therapies have a delayed onset of action that prevents a rapid door to puncture transition for patents presenting in acute settings. Cangrelor (Kengreal, Chiesi, USA) is an intravenous P2Y12 platelet inhibitor approved in percutaneous coronary interventions that has an immediate onset of action and half-life between 2 and 6 min. Thus, the goal of this study is to report on the safety, effectiveness, and indications for using Cangrelor in neurointerventional procedures. A systematic review of studies describing the use of Cangrelor in neurointervention was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search was conducted on PubMed, Ovid Medline, and Embase databases through June 2023. Seventeen studies with 314 patients met inclusion criteria. The most common indication for Cangrelor use was acute ischemic strokes: 70% followed by aneurysms 27.4%. The Infusion protocol varied from 5 to 30 μg/kg bolus and 1 to 4 µg/kg/min infusion with 30 μg/kg bolus and 4 µg/kg/min infusion being reported in 64.7% of studies. Intra-operative platelet reacting unit levels were below 200 in all the studies that reported it, and the percentage of hemorrhagic, thromboembolic, and deaths occurrence in this patient cohort was respectively 11.1%, 4.8%, and 8.6%. Cangrelor appears to be a promising P2Y12 platelet inhibitor for neurointerventional procedures. However, large, randomized trials are needed to determine the full range of its effects in neurointerventional procedures.

Clopidogrel vs Aspirin Monotherapy Beyond 1 Year After Percutaneous Coronary Intervention

BACKGROUND

It remains unclear whether clopidogrel is better suited than aspirin as the long-term antiplatelet monotherapy following dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI).

OBJECTIVES

This study compared clopidogrel monotherapy following 1 month of DAPT (clopidogrel group) with aspirin monotherapy following 12 months of DAPT (aspirin group) after PCI for 5 years.

METHODS

STOPDAPT-2 (Short and Optimal Duration of Dual Antiplatelet Therapy 2) is a multicenter, open-label, adjudicator-blinded, randomized clinical trial conducted in Japan. Patients who underwent PCI with cobalt-chromium everolimus-eluting stents were randomized in a 1-to-1 fashion either to clopidogrel or aspirin groups. The primary endpoint was a composite of cardiovascular outcomes (cardiovascular death, myocardial infarction, stroke, or definite stent thrombosis) or major bleeding (TIMI major or minor bleeding).

RESULTS

Among 3,005 study patients (age: 68.6 ± 10.7 years; women: 22.3%; acute coronary syndrome: 38.3%), 2,934 patients (97.6%) completed the 5-year follow-up (adherence to the study drugs at 395 days: 84.7% and 75.9%). The clopidogrel group compared with the aspirin group was noninferior but not superior for the primary endpoint (11.75% and 13.57%, respectively; HR: 0.85; 95% CI: 0.70-1.05; Pnoninferiority < 0.001; Psuperiority = 0.13), whereas it was superior for the cardiovascular outcomes (8.61% and 11.05%, respectively; HR: 0.77; 95% CI: 0.61-0.97; P = 0.03) and not superior for major bleeding (4.44% and 4.92%, respectively; HR: 0.89; 95% CI: 0.64-1.25; P = 0.51). By the 1-year landmark analysis, clopidogrel was numerically, but not significantly, superior to aspirin for cardiovascular events (6.79% and 8.68%, respectively; HR: 0.77; 95% CI: 0.59-1.01; P = 0.06) without difference in major bleeding (3.99% and 3.32%, respectively; HR: 1.23; 95% CI: 0.84-1.81; P = 0.31).

CONCLUSIONS

Clopidogrel might be an attractive alternative to aspirin with a borderline ischemic benefit beyond 1 year after PCI.

Aspirin inhibits rotavirus replication and alters rat gut microbial composition

BACKGROUND

Aspirin is widely used to treat various clinical symptoms. Evidence suggests that aspirin has antiviral properties, but little is known about its specific effect against rotavirus.

METHODS

MA104, Caco-2, and CV-1 cells were infected with rotavirus, and aspirin was added after 12 h. Viral mRNA and titer levels were measured by qRT-PCR and immunofluorescence assays. For in vivo validation, forty specific-pathogen-free SD rats were randomly divided into oral aspirin (ASP) groups and control (NC) groups. 16 S rRNA gene sequencing was performed to identify gut microbiota. After 6 months of continuous ASP/NC administration, the rats were infected with rotavirus. Fecal samples were collected over a 30-day time course, and viral levels were quantified. Proinflammatory cytokines/chemokine levels were measured by ELISA.

RESULTS

Aspirin inhibited rotavirus infection in cell lines and in rats. The effects of aspirin on viral replication were associated with the alteration of gut microbiota composition by aspirin, including increased abundance of Firmicutes and decreased abundance of Bacteroidetes after aspirin treatment. Mechanistically, aspirin reduced IL-2 and IL-10 levels, and increased IRF-1 and COX-2 levels. Aspirin blocked rotavirus replication in vitro and in vivo, which might be related to effects on IRF-1, COX-2, chemokines, and gut microbial composition.

CONCLUSION

These results indicate that long-term oral aspirin administration reduces rotavirus infection. Intestinal virus infection may be suppressed in elderly patients who take aspirin for a long time. The change of their Gut microbiota may lead to functional disorder of the intestinal tract, which may provide some reference for clinical adjuvant probiotics treatment.

Advances in combined application of dental stem cells and small-molecule drugs in regenerative medicine

Teeth are a kind of masticatory organs of special histological origin, unique to vertebrates, playing an important role in chewing, esthetics, and auxiliary pronunciation. In the past decades, with the development of tissue engineering and regenerative medicine, the studies of mesenchymal stem cells (MSCs) gradually attracted the interest of researchers. Accordingly, several types of MSCs have been successively isolated in teeth or teeth-related tissues, including dental pulp stem cells, periodontal ligament stem cells, stem cells from human exfoliated deciduous teeth, dental follicle stem cells, stem cells from apical papilla and gingival mesenchymal stem cells. These dental stem cells (DSCs) are easily accessible, possess excellent stem cell characteristics, such as high proliferation rates and profound immunomodulatory properties. Small-molecule drugs are widely used and show great advantages in clinical practice. As research progressed, small-molecule drugs are found to have various complex effects on the characteristics of DSCs, especially the enhancement of biological characteristics of DSCs, which has gradually become a hot issue in the field of DSCs research. This review summarizes the background, current status, existing problems, future research directions, and prospects of the combination of DSCs with three common small-molecule drugs: aspirin, metformin, and berberine.

Cost-Effectiveness of Clopidogrel vs Aspirin Monotherapy After Percutaneous Coronary Intervention: Results From the HOST-EXAM Study

Background

The HOST-EXAM (Harmonizing Optimal Strategy for Treatment of Coronary Artery Disease-Extended Antiplatelet Monotherapy) trial showed superior efficacy and safety of clopidogrel monotherapy compared with aspirin monotherapy during the chronic maintenance period after percutaneous coronary intervention (PCI).

Objectives

The goal of this study was to investigate the cost-effectiveness of clopidogrel monotherapy compared with that of aspirin monotherapy.

Methods

A Markov model was developed for patients in the stable phase after PCI. From the perspectives of the South Korean, UK, and U.S. health care systems, the lifetime health care costs and quality-adjusted life-years (QALYs) of each strategy were estimated. Transition probabilities were obtained from the HOST-EXAM trial, and health care costs and health-related utilities were obtained from data and literature for each country.

Results

From the perspective of the South Korean health care system, the base-case analysis showed that clopidogrel monotherapy was $3,192 higher in lifetime health care costs and 0.139 lower in QALYs compared with aspirin. This result was greatly influenced by the numerically but insignificantly higher cardiovascular mortality of clopidogrel compared with aspirin. In the analogous UK and U.S. models, clopidogrel monotherapy was projected to decrease health care costs by £1,122 and $8,920 per patient compared with aspirin monotherapy while reducing QALYs by 0.103 and 0.175, respectively.

Conclusions

Based on empirical data from the HOST-EXAM trial, clopidogrel monotherapy was projected to lead to reduced QALYs compared with aspirin during the chronic maintenance period after PCI. These results were affected by a numerically higher rate of cardiovascular mortality in clopidogrel monotherapy reported from the HOST-EXAM trial. (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis-Extended Antiplatelet Monotherapy [HOST-EXAM]; NCT02044250).

Aspirin Resistance in Vascular Disease: A Review Highlighting the Critical Need for Improved Point-of-Care Testing and Personalized Therapy

Aspirin resistance describes a phenomenon where patients receiving aspirin therapy do not respond favorably to treatment, and is categorized by continued incidence of adverse cardiovascular events and/or the lack of reduced platelet reactivity. Studies demonstrate that one in four patients with vascular disease are resistant to aspirin therapy, placing them at an almost four-fold increased risk of major adverse limb and adverse cardiovascular events. Despite the increased cardiovascular risk incurred by aspirin resistant patients, strategies to diagnose or overcome this resistance are yet to be clinically validated and integrated. Currently, five unique laboratory assays have shown promise for aspirin resistance testing: Light transmission aggregometry, Platelet Function Analyzer-100, Thromboelastography, Verify Now, and Platelet Works. Newer antiplatelet therapies such as Plavix and Ticagrelor have been tested as an alternative to overcome aspirin resistance (used both in combination with aspirin and alone) but have not proven to be superior to aspirin alone. A recent breakthrough discovery has demonstrated that rivaroxaban, an anticoagulant which functions by inhibiting active Factor X when taken in combination with aspirin, improves outcomes in patients with vascular disease. Current studies are determining how this new regime may benefit those who are considered aspirin resistant.

Meta-analysis on aspirin combined with low-molecular-weight heparin for improving the live birth rate in patients with antiphospholipid syndrome and its correlation with d-dimer levels

BACKGROUND

Antiphospholipid antibody syndrome (APS) is a systemic, autoimmune, prothrombotic disease characterized by persistent antiphospholipid antibodies, thrombosis, recurrent abortion, complications during pregnancy, and occasionally thrombocytopenia. At present, there is no consensus on the treatment of this disease. Long-term anticoagulation is recommended in most cases in patients with thrombotic APS. This study aimed to evaluate whether aspirin combined with low-molecular-weight heparin (LMWH) can improve the live birth rate in antiphospholipid syndrome and its correlation with D-dimer.

METHODS

The data were retrieved from the WanFang Data, CBM, VIP, CNKI, the Cochrane Library, PubMed, EMBASE, OVID, and Web of Science databases. We collected data on randomized controlled trials of aspirin combined with LMWH in the treatment of pregnant women with APS. The "Risk of Bias Assessment" tool and the "Jadad Scale" provided by the Cochrane Collaboration were used to evaluate the risk of bias and quality of the collected literature. The risk ratio (RR) and its 95% confidence interval (CI) were determined using Statase-64 software.

RESULTS

In this study, a total of 11 studies were included, comprising a total of 2101 patients. The live birth rate in pregnant women with APS was higher on administration of aspirin combined with LMWH than with aspirin alone (RR = 1.29, 95% CI = 1.22-1.35, P < .001). d-dimer concentration in plasma predicted the live birth rate, which was higher below the baseline than above it (RR = 1.16, 95% CI = 1.09-1.23, P < .001). The subgroup analysis of the live birth rate was carried out based on the course of treatment, and the results were consistent with the overall results. Begg funnel plot test revealed no publication bias. Sensitivity analysis showed that deleting any study did not affect the results.

CONCLUSION

Aspirin combined with LMWH for APS may improve live birth rate, and detection of d-dimer levels in APS pregnant women may predict pregnancy complications and guide the use of anticoagulants.

Current state-of-the-art antiplatelet and anticoagulation therapy in diabetic patients with coronary artery disease

Diabetes mellitus is a complex disease that leads to long-term damage to various organ systems. Among the numerous cardiovascular disease-related complications, thrombotic events frequently occur in patients with diabetes. Although guidelines exist for treating and preventing most diabetes-related co-morbidities, the evidence on antithrombotic therapy in primary and secondary prevention is limited due to the scarcity of randomized trials dedicated to patients with diabetes mellitus. Most of the available data are derived from studies that only included a small proportion of patients with diabetes. The present review provides an overview of the status of knowledge on antiplatelet and anticoagulation therapy in patients with diabetes, focusing on the risk-benefit balance of these therapies and future treatment strategies.

Retrospective high volume comparative study suggests that patients on aspirin could have immediate surgery for hip fractures without significant blood loss

PURPOSE

This study aimed to investigate the effects of aspirin on peri-operative hidden blood loss during hip fracture surgery by adjusting for possible factors affecting blood loss using a propensity score matching method.

METHODS

We retrospectively collected data from a cohort of isolated hip fracture patients (aged ≥ 65 years)who underwent surgery from January 2010 to December 2019. The study's primary outcome was blood loss from admission to the day after surgery in the aspirin and control groups. We estimated the hidden blood loss, calculated based on patient's blood volume, haemoglobin measurements, and blood transfusions. The secondary outcome focused on the requirement for blood transfusion. We adjusted for possible factors affecting blood loss using a propensity score matching method and statistically examined the effects of aspirin on hip fracture surgery.

RESULTS

We enrolled 806 patients of whom 271 (34%) were taking anticoagulant and antiplatelet drugs, while 114 (14%) were taking only aspirin (aspirin group). A total of 535 patients were not taking antiplatelets and anticoagulants (control group). In propensity score matching, 103 patients were matched. Aspirin was not associated with a significantly higher risk of hidden blood loss (aspirin group; median 598 mL [410-783 mL] vs control group; median 556 ml [321-741 mL], p = 0.14) and higher risk of blood transfusion requirement (aspirin group; 49 patients [48%] vs control group; 39 patients [38%], p = 0.21).

CONCLUSION

Aspirin did not affect peri-operative blood loss in hip fracture surgery. We concluded that patients taking aspirin can safely undergo hip fracture surgery without delay.

Current Status of Chemoprevention in Barrett's Esophagus

Candidates for chemoprevention in Barrett's esophagus have long been suggested and there has been observational data to support many drugs, including statins, hormone replacement therapy, metformin, proton pump inhibitor therapy, and aspirin. Proton pump inhibitor therapy and aspirin are the most promising agents. Data suggest that aspirin and proton pump inhibitor therapy can decrease the risk of neoplastic progression in Barrett's esophagus. Further, the combination of aspirin and proton pump inhibitor therapy decrease all-cause mortality by approximately 33%. Future guideline groups need to evaluate the evidence rigorously, but the combination of proton pump inhibitor therapy and aspirin is promising.

Aspirin use for cardiovascular disease prevention in the uninsured population

INTRODUCTION

Aspirin is an effective anti-inflammatory and antiplatelet agent as an irreversible inhibitor of cyclooxygenase. In 2016, the U.S. Preventive Services Task Force recommended aspirin for primary prevention of cardiovascular disease in patients aged 50-69 years with a 10% or greater 10-year cardiovascular disease risk. Current guidelines for patients with prior myocardial infarction or coronary artery disease recommend aspirin use for the secondary prevention of cardiovascular disease. Due to the lack of literature describing adherence to these recommendations in the uninsured patient population, we studied aspirin use for cardiovascular disease prevention in free medical clinics.

METHODS

We conducted a cross sectional study of uninsured patients who visited nine free medical clinics in 2016-2017. Data from the records of 8857 patients were combined into a database for analysis. 10-year Framingham risk scores for coronary artery disease were calculated for the 50-69-year-old population to evaluate which patients qualified for aspirin usage. Aspirin use was assessed for patients with prior myocardial infarction or coronary artery disease.

RESULTS

In total, 1443 patients met the criteria to take aspirin for primary prevention of cardiovascular disease, but just 17% of these patients aged 50-59 years were on the medication. About 15% of the patients aged 60-69 years were taking aspirin. Of the 297 patients who had prior myocardial infarction or coronary artery disease, 50% were taking aspirin for secondary prevention.

CONCLUSION

Among the uninsured population, there are low rates of aspirin use for risk reduction of cardiovascular disease. This study demonstrates that improvements are needed to increase adherence to current guidelines and address barriers uninsured patients may face in maintaining their cardiovascular health.

Separation-free spectrophotometric platforms for rapid assessment of combined antiplatelet therapy in complex matrices

Aim: To develop simple and rapid UV-spectrophotometric platforms for the simultaneous quantification of a binary mixture containing clopidogrel bisulphate (CPS) and aspirin (ASP) in complex matrices without prior separation. Experimental: Five mathematical models namely ratio-difference method, mean centering of the ratio spectra, dual wavelength, induced dual wavelength and H-Point Standard Addition method, were utilized for resolving spectral overlap by mathematical processing of ratio and zero-order absorption spectra. Analytes were extracted from tested matrices (whole blood, pharmaceutical formulations and dissolution media buffer) and quantified using the proposed methods. The methods were validated according to ICH guidelines. Results: The developed methods demonstrated limits of detection ranging from 0.67 to 1.09 μg/ml-1 for CPS and 0.49 to 0.71 μg.ml-1 for ASP. All proposed methods allowed for reliable determination of CPS and ASP in complex matrices within reported reference ranges, indicating their potential application for therapeutic drug monitoring and quality control testing.

Antiplatelet Effect of a Pulaimab [Anti-GPIIb/IIIa F(ab)2 Injection] Evaluated by a Population Pharmacokinetic-pharmacodynamic Model

BACKGROUND

Cardiovascular disease has one of the highest mortality rates among all the diseases. Platelets play an important role in the pathogenesis of cardiovascular diseases. Platelet membrane glycoprotein GPIIb/IIIa antagonists are the most effective antiplatelet drugs, and pulaimab is one of these. The study aims to promote individual medication of pulaimab [anti-GPIIb/IIIa F(ab)2 injection] by discovering the pharmacological relationship among the dose, concentration, and effects. The goal of this study is to establish a population pharmacokineticpharmacodynamic model to evaluate the antiplatelet effect of intravenous pulaimab injection.

METHODS

Data were collected from 59 healthy subjects who participated in a Phase-I clinical trial. Plasma concentration was used as the pharmacokinetic index, and platelet aggregation inhibition rate was used as the pharmacodynamic index. The basic pharmacokinetics model was a two-compartment model, whereas the basic pharmacodynamics model was a sigmoid-EMAX model with a direct effect. The covariable model was established by a stepwise method. The final model was verified by a goodness-of-fit method, and predictive performance was assessed by a Bootstrap (BS) method.

RESULTS

In the final model, typical population values of the parameters were as follows: central distribution Volume (V1), 183 L; peripheral distribution Volume (V2), 349 L; Central Clearance (CL), 31 L/h; peripheral clearance(Q), 204 L/h; effect compartment concentration reaching half of the maximum effect (EC50), 0.252 mg/L; maximum effect value (EMAX), 54.0%; and shape factor (γ), 0.42. In the covariable model, thrombin time had significant effects on CL and EMAX. Verification by the goodness-of-fit and BS methods showed that the final model was stable and reliable.

CONCLUSION

A model was successfully established to evaluate the antiplatelet effect of intravenous pulaimab injection that could provide support for the clinical therapeutic regimen.

Cost-Effectiveness of Aspirin Adherence for Secondary Prevention of Cardiovascular Events

BACKGROUND

Suboptimal adherence to aspirin therapy for secondary prevention of cardiovascular (CV) events is an important public health problem. Prior studies have demonstrated non-adherent patients are at higher risk of experiencing CV events.

OBJECTIVES

This study aimed to estimate the clinical and economic outcomes of aspirin non-adherence in patients with a prior primary CV event.

METHODS

We developed a Markov model to estimate the cost-effectiveness of aspirin adherence from a generic US managed care payer perspective over a 5-year time horizon. Costs, utilities and rates of aspirin adherence, CV events and adverse events were gathered from published literature to populate the model. Outcomes were quality-adjusted life years (QALYs), costs (US$) and incremental cost-effectiveness ratios (ICERs). We applied the model separately to a population without type II diabetes as a comorbidity (non-diabetic model) and a population with type II diabetes (type II diabetes model). A one-way sensitivity analysis was performed to assess the model uncertainty.

RESULTS

The base case showed adherent patients lived 0.25 and 0.36 QALYs longer than non-adherent patients in the non-diabetic model and type II diabetes model, respectively. Adherence to aspirin had an ICER of US$25/QALY in the non-diabetic population, while it saved US$297 per patient over a 5-year period in the type II diabetes population. One-way sensitivity analysis showed the models were most sensitive to rates of non-fatal events in non-adherent patients.

CONCLUSION

This study suggests aspirin adherence may improve QALYs for patients with a prior primary CV event. Further, it may decrease costs in patients with type II diabetes. While additional research is needed to validate these results, payers may wish to increase strategies to promote adherence in order to improve population health.

TRIAL REGISTRATION

Not applicable.

Aspirin resistance predicts unfavorable functional outcome in acute ischemic stroke patients

OBJECTIVE

To investigate the prognostic value of aspirin reaction units (ARU) in a 3-month follow-up study in a cohort of Chinese patients with first-ever ischemic stroke.

METHODS

Prospective single-center survey of acute ischemic stroke patients receiving aspirin therapy. Two hundred and seventy-five Chinese patients with first-ever ischemic stroke who previously received aspirin therapy were enrolled. ARU was measured using the VerifyNow system. A cutoff of 550 ARU was used to determine the presence of aspirin resistance (AR).

RESULTS

Median age at study entry was 67 years (IQR: 59-75) and 142(51.6%) were male. A total of 52 of 275 enrolled patients (18.9%) were AR. Median regression estimated a statistically significant increase in NIHSS score of 0.033 point for every 1-point increase in ARU (95% CI, 0.024 to 0.068; P < 0.001). The unfavorable outcomes distribution across the ARU quartiles ranged between 11.8% (first quartile) to 64.8% (fourth quartile). After adjusting for other established risk factors, in multivariate models comparing the third and fourth quartiles against the first quartile of the ARU, levels of ARU were associated with unfavorable outcome, and the adjusted risk of unfavorable outcome increased by 145% (OR = 2.45 [95% CI 1.46-3.87], P = 0.011) and 317% (4.17[2.76-6.15], P < 0.001), respectively. Similarly, the adjusted risk of mortality increased by 215% (OR = 3.15 [95% CI 1.98-4.73], P = 0.008) and 429% (5.29[4.02-8.17], P < 0.001), respectively.

CONCLUSIONS

The results suggest that AR is a meaningful and independent marker to predict short-term functional outcome in patients with ischemic stroke.

Clopidogrel plus aspirin versus aspirin alone for preventing cardiovascular events

BACKGROUND

Aspirin is the prophylactic antiplatelet drug of choice for people with cardiovascular disease. Adding a second antiplatelet drug to aspirin may produce additional benefit for people at high risk and people with established cardiovascular disease. This is an update to a previously published review from 2011.

OBJECTIVES

To review the benefit and harm of adding clopidogrel to aspirin therapy for preventing cardiovascular events in people who have coronary disease, ischaemic cerebrovascular disease, peripheral arterial disease, or were at high risk of atherothrombotic disease, but did not have a coronary stent.

SEARCH METHODS

We updated the searches of CENTRAL (2017, Issue 6), MEDLINE (Ovid, 1946 to 4 July 2017) and Embase (Ovid, 1947 to 3 July 2017) on 4 July 2017. We also searched ClinicalTrials.gov and the WHO ICTRP portal, and handsearched reference lists. We applied no language restrictions.

SELECTION CRITERIA

We included all randomised controlled trials comparing over 30 days use of aspirin plus clopidogrel with aspirin plus placebo or aspirin alone in people with coronary disease, ischaemic cerebrovascular disease, peripheral arterial disease, or at high risk of atherothrombotic disease. We excluded studies including only people with coronary drug-eluting stent (DES) or non-DES, or both.

DATA COLLECTION AND ANALYSIS

We collected data on mortality from cardiovascular causes, all-cause mortality, fatal and non-fatal myocardial infarction, fatal and non-fatal ischaemic stroke, major and minor bleeding. The overall treatment effect was estimated by the pooled risk ratio (RR) with 95% confidence interval (CI), using a fixed-effect model (Mantel-Haenszel); we used a random-effects model in cases of moderate or severe heterogeneity (I2 ≥ 30%). We assessed the quality of the evidence using the GRADE approach. We used GRADE profiler (GRADE Pro) to import data from Review Manager to create a 'Summary of findings' table.

MAIN RESULTS

The search identified 13 studies in addition to the two studies in the previous version of our systematic review. Overall, we included data from 15 trials with 33,970 people. We completed a 'Risk of bias' assessment for all studies. The risk of bias was low in four trials because they were at low risk of bias for all key domains (random sequence generation, allocation concealment, blinding, selective outcome reporting and incomplete outcome data), even if some of them were funded by the pharmaceutical industry.Analysis showed no difference in the effectiveness of aspirin plus clopidogrel in preventing cardiovascular mortality (RR 0.98, 95% CI 0.88 to 1.10; participants = 31,903; studies = 7; moderate quality evidence), and no evidence of a difference in all-cause mortality (RR 1.05, 95% CI 0.87 to 1.25; participants = 32,908; studies = 9; low quality evidence).There was a lower risk of fatal and non-fatal myocardial infarction with clopidogrel plus aspirin compared with aspirin plus placebo or aspirin alone (RR 0.78, 95% CI 0.69 to 0.90; participants = 16,175; studies = 6; moderate quality evidence). There was a reduction in the risk of fatal and non-fatal ischaemic stroke (RR 0.73, 95% CI 0.59 to 0.91; participants = 4006; studies = 5; moderate quality evidence).However, there was a higher risk of major bleeding with clopidogrel plus aspirin compared with aspirin plus placebo or aspirin alone (RR 1.44, 95% CI 1.25 to 1.64; participants = 33,300; studies = 10; moderate quality evidence) and of minor bleeding (RR 2.03, 95% CI 1.75 to 2.36; participants = 14,731; studies = 8; moderate quality evidence).Overall, we would expect 13 myocardial infarctions and 23 ischaemic strokes be prevented for every 1000 patients treated with the combination in a median follow-up period of 12 months, but 9 major bleeds and 33 minor bleeds would be caused during a median follow-up period of 10.5 and 6 months, respectively.

AUTHORS' CONCLUSIONS

The available evidence demonstrates that the use of clopidogrel plus aspirin in people at high risk of cardiovascular disease and people with established cardiovascular disease without a coronary stent is associated with a reduction in the risk of myocardial infarction and ischaemic stroke, and an increased risk of major and minor bleeding compared with aspirin alone. According to GRADE criteria, the quality of evidence was moderate for all outcomes except all-cause mortality (low quality evidence) and adverse events (very low quality evidence).

Aspirin for Prevention of Preeclampsia

Aspirin is currently the most widely prescribed treatment in the prevention of cardiovascular complications. The indications for the use of aspirin during pregnancy are, however, the subject of much controversy. Since the first evidence of the obstetric efficacy of aspirin in 1985, numerous studies have tried to determine the effect of low-dose aspirin on the incidence of preeclampsia, with very controversial results. Large meta-analyses including individual patient data have demonstrated that aspirin is effective in preventing preeclampsia in high-risk patients, mainly those with a history of preeclampsia. However, guidelines regarding the usage of aspirin to prevent preeclampsia differ considerably from one country to another. Screening modalities, target population, and aspirin dosage are still a matter of debate. In this review, we report the pharmacodynamics of aspirin, its main effects according to dosage and gestational age, and the evidence-based indications for primary and secondary prevention of preeclampsia.

The budget impact of using enteric-coated aspirin 325 mg + immediate-release omeprazole 40 mg to prevent recurrent cardiovascular events

OBJECTIVE

Aspirin (acetylsalicylic acid; ASA) is commonly used for secondary prevention of cardiovascular (CV) events, but may be associated with gastrointestinal (GI) adverse events, which can reduce adherence. Use of ASA co-therapy with proton pump inhibitors in patients at risk may be suboptimal. PA32540 (Yosprala™) is a coordinated-delivery tablet combining EC-ASA 325 mg and immediate-release omeprazole 40 mg. The objective of this flexible budget impact model was to project the financial consequences of introducing PA32540 325 mg/40 mg to prevent recurrent CV events, while reducing ASA-associated GI events in US adults.

METHODS

A Markov Model was employed to estimate health state transitions associated with ASA 75-325 mg, ASA 75-325 mg + generic delayed-release omeprazole 40 mg, PA32540, or clopidogrel 75 mg to prevent recurrent CV events. Health states included ulcers, GI bleeding, CV events, and death. Model inputs included demographics, treatment dosages, treatment costs, adverse GI and CV events, and premature death. Data from peer-reviewed literature and censuses enabled appropriate allocation of CV and GI disease prevalence and mortality. The PA32540 non-adherence rate was conservatively set at 20%. PA32540 market share was set to 50%.

RESULTS

The model projected annual savings of $81.0 million to $190.9 million within 1-5 years after PA32540 introduction to the plan, which included 134,558 members at risk for recurrent CV events. These values translate into savings of $602 (year 5) to $1,419 (year 1) per patient per year, and $81 (year 5) to $191 (year 1) per member per year. These values were robust to variations in parameters under a deterministic sensitivity analysis.

CONCLUSION

PA32540 use to prevent recurrent CV events was associated with cost reductions in each year examined with the model. From a health plan perspective, PA32540 is likely to have a net overall effect, resulting in significant cost savings.

Recognition and treatment of sleep-disordered breathing: an important component of chronic disease management

Sleep-disordered breathing (SDB) is a highly prevalent condition, and is associated with many debilitating chronic diseases. The role of untreated obstructive sleep apnea (OSA) in arterial hypertension has been recognized in international guidelines. Treatment with continuous positive airway pressure (CPAP) is associated with clinically-relevant reductions in blood pressure. In heart failure (HF), SDB is associated with worse prognosis and increased mortality. Major HF guidelines recommend that patients should be treated for sleep apnea to improve their HF status. Severe OSA increases the risk of arrhythmias, including atrial fibrillation, influences risk management in stroke, and is highly prevalent in patients with type 2 diabetes. Effective treatment with CPAP improves the success of antiarrhythmic interventions, improves outcomes in stroke and reduces hyperglycemia in diabetes. Patients with coronary artery disease also have a high prevalence of SDB, which is independently associated with worse outcomes. The role of CPAP for secondary cardiovascular prevention remains to be determined. Data from large, well-conducted clinical trials have shown that noninvasive ventilation, targeted to markedly reduce hypercapnia, significantly improves survival and reduces readmission in stable hypercapnic chronic obstructive pulmonary disease. The association of SDB with chronic diseases contributes to the high healthcare costs incurred by SDB patients. SDB also has an important negative impact on quality of life, which is reversed by CPAP treatment. The high prevalence of SDB, and its association with diseases that cause significant morbidity and mortality, suggest that the diagnosis and management of SDB is an important therapeutic goal. First, adherent CPAP treatment significantly improves the quality of life of all patients with SDB; second, it eliminates the negative impact of untreated SDB on any associated chronic diseases; and third, it significantly reduces the increased costs of all hospital and medical services directly associated with untreated SDB. In short, the recognition and treatment of SDB is vital for the continued health and wellbeing of individual patients with SDB.

Clopidogrel Versus Aspirin as an Antiplatelet Monotherapy After 12-Month Dual-Antiplatelet Therapy in the Era of Drug-Eluting Stents

BACKGROUND

The use of dual-antiplatelet therapy (DAPT) exceeding 12 months may increase a bleeding risk despite a lower risk of ischemic events. There is no study to compare clinical outcomes in patients treated with a single-antiplatelet drug after DAPT in the era of drug-eluting stents (DES). We sought to investigate the efficacy and safety of clopidogrel versus aspirin monotherapy after 12-month DAPT after DES implantation using an institutional registry.

METHODS AND RESULTS

This observational study was conducted on consecutive patients receiving DES between January 2003 and December 2010. A total of 3243 patients receiving 12-month DAPT after DES implantation without adverse clinical outcomes were divided into 2 groups based on prescribed antiplatelet status: aspirin (n=2472) and clopidogrel (n=771). Clinical, angiographic, and procedural characteristics revealed more comorbidities and more complex lesions in the clopidogrel group than in the aspirin group. At 36 months after initiation of antiplatelet monotherapy, clopidogrel was associated with a reduction in risk for a composite of cardiac death, myocardial infarction, or stroke (aspirin versus clopidogrel; 3.8% versus 2.6%; hazard ratio, 0.54; 95% confidence interval, 0.32-0.92; P=0.02). The risk of cardiac death was lower with clopidogrel monotherapy than with aspirin monotherapy (1.4% versus 0.5%; hazard ratio, 0.31; 95% confidence interval, 0.11-0.93; P=0.04). Thrombolysis in myocardial infarction major bleeding occurred similarly between both groups (0.9% versus 1.3%; hazard ratio, 1.03; 95% confidence interval, 0.46-2.32; P=0.95).

CONCLUSIONS

After 12-month DAPT, clopidogrel monotherapy, when compared with aspirin monotherapy, might be associated with a reduced risk of recurrent ischemic events in patients receiving DES.

A Critique and Impact Analysis of Decision Modeling Assumptions

Background . Numerous guidelines have been published defining good practice for the conduct of economic evaluations in general and model-based evaluations in particular. The extent to which guidelines are accepted is unknown, and the impact of deviations from good practice is not generally recorded. The authors identified 4 specific issues in applied studies that may affect the accuracy and comparability of different evaluations. Methods . A descriptive analysis of 4 modeling issues (inclusion of incident cases over a model time horizon, appropriate time horizon, parsimonious model structure, and the handling of age-specific subgroups) is presented. A case study model is analyzed to illustrate the quantitative impact of 3 of the issues. Results . In the case study model, alternative specifications of the modeling framework are shown to alter the estimated cost-effectiveness by large percentages. The combined effect of including incident cases and reduced follow-up yielded the highest divergence from the reference case results, by between 20% and 40%, depending on the age group. Reference case results of an age-weighted population were almost 14% different from the middle single age cohort. Discussion . The identified issues are all generalizable to a wide range of treatment areas and are, or should be, addressed by evaluative guidelines. The authors call for the continued development, dissemination, and application of guidelines for the conduct of economic evaluation in general and model-based economic evaluations in particular.

Masterclass series in peripheral arterial disease

Peripheral arterial disease (PAD) of the lower extremities is a common and potentially life-threatening manifestation of systemic atherosclerosis. Significant PAD is identified by an ankle brachial index (ABI) <0.90; its presence is strongly associated with the major modifiable cardiac risk factors. Early detection and treatment of asymptomatic PAD is a current focus of numerous cardiovascular guideline organizations as less than a third of patients report typical claudication symptoms. This has created an ever-increasing treatment gap, whereby millions of eligible patients are inadequately treated. Risk factor management including exercise, smoking cessation, and aggressive treatment of lipids and blood pressure are essential in PAD patients. However, life-long antiplatelet therapy provides additional reductions in vascular events beyond aggressive risk factor management. The use of aspirin as well as more potent antiplatelet therapies such as thienopyridines holds promise for reducing atherothrombosis in this very high-risk population.

Multimorbidity in chronic disease: impact on health care resources and costs

Effective and resource-efficient long-term management of multimorbidity is one of the greatest health-related challenges facing patients, health professionals, and society more broadly. The purpose of this review was to provide a synthesis of literature examining multimorbidity and resource utilization, including implications for cost-effectiveness estimates and resource allocation decision making. In summary, previous literature has reported substantially greater, near exponential, increases in health care costs and resource utilization when additional chronic comorbid conditions are present. Increased health care costs have been linked to elevated rates of primary care and specialist physician occasions of service, medication use, emergency department presentations, and hospital admissions (both frequency of admissions and bed days occupied). There is currently a paucity of cost-effectiveness information for chronic disease interventions originating from patient samples with multimorbidity. The scarcity of robust economic evaluations in the field represents a considerable challenge for resource allocation decision making intended to reduce the burden of multimorbidity in resource-constrained health care systems. Nonetheless, the few cost-effectiveness studies that are available provide valuable insight into the potential positive and cost-effective impact that interventions may have among patients with multiple comorbidities. These studies also highlight some of the pragmatic and methodological challenges underlying the conduct of economic evaluations among people who may have advanced age, frailty, and disadvantageous socioeconomic circumstances, and where long-term follow-up may be required to directly observe sustained and measurable health and quality of life benefits. Research in the field has indicated that the impact of multimorbidity on health care costs and resources will likely differ across health systems, regions, disease combinations, and person-specific factors (including social disadvantage and age), which represent important considerations for health service planning. Important priorities for research include economic evaluations of interventions, services, or health system approaches that can remediate the burden of multimorbidity in safe and cost-effective ways.

Aspirin-Exacerbated Diseases: Advances in Asthma with Nasal Polyposis, Urticaria, Angioedema, and Anaphylaxis

Aspirin-exacerbated diseases are important examples of drug hypersensitivities and include aspirin-exacerbated respiratory disease (AERD), aspirin- or non-steroidal anti-inflammatory drug (NSAID)-induced urticaria/angioedema, and aspirin- or NSAID-induced anaphylaxis. While each disease subtype may be distinguished by unique clinical features, the underlying mechanisms that contribute to these phenotypes are not fully understood. However, the inhibition of the cyclooxygenase-1 enzyme is thought to play a significant role. Additionally, eosinophils, mast cells, and their products, prostaglandins and leukotrienes, have been identified in the pathogenesis of AERD. Current diagnostic and treatment strategies for aspirin-exacerbated diseases remain limited, and continued research focusing on each of the unique hypersensitivity reactions to aspirin is essential. This will not only advance the understanding of these disease processes, but also lead to the subsequent development of novel therapeutics that patients who suffer from aspirin-induced reactions desperately need.

Trends in early aspirin use among patients with acute myocardial infarction in China, 2001-2011: the China PEACE-Retrospective AMI study

Background

Aspirin is an effective, safe, and inexpensive early treatment of acute myocardial infarction (AMI) with few barriers to administration, even in countries with limited healthcare resources. However, the rates and recent trends of aspirin use for the early treatment of AMI in China are unknown.

Methods and Results

Using data from the China Patient‐centered Evaluative Assessment of Cardiac Events Retrospective Study of Acute Myocardial Infarction (China PEACE‐Retrospective AMI Study), we identified a cohort of 14 041 patients with AMI eligible for early aspirin therapy. Early use of aspirin for AMI increased over time (78.4% in 2001, 86.5% in 2006, and 90.0% in 2011). However, about 15% of hospitals had a rate of use of <80% in 2011. Treatment was less likely in patients who were older, presented with cardiogenic shock at admission, presented without chest discomfort, had a final diagnosis of non‐ST‐segment elevation acute myocardial infarction, or did not receive reperfusion therapy. Hospitalization in rural regions was also associated with aspirin underuse.

Conclusions

Despite improvements in early use of aspirin for AMI in China, there remains marked variation in practice and opportunities for improvement that are concentrated in some hospitals and patient groups.

Clinical Trial Registration

URL: ClinicalTrials.gov Unique identifier: NCT01624883.

Evaluation of Aspirin Use in Patients With Diabetes Receiving Care in Community Health

Background: The American Diabetes Association (ADA) recommends low-dose aspirin therapy as a primary prevention strategy in patients with type 1 or type 2 diabetes mellitus (DM) at increased cardiovascular risk. However, not all patients who are indicated are taking aspirin therapy, and it is not routinely documented in the electronic health record (EHR). Objective: To determine frequencies of appropriate aspirin use and documentation in the EHR in adult patients with DM. Methods: Adult patients with DM were randomized and contacted for participation in a telephonic survey between January and October 2013. Patients who consented were administered a standardized oral telephone survey regarding aspirin use. Patient demographics, current medications, allergies, past medical history, and pertinent laboratory values were collected. Patients were then stratified by the ADA-defined indication for aspirin. The primary outcomes were rates of appropriate aspirin use and documentation of aspirin therapy in the EHR. Results: Investigators contacted 276 patients for inclusion. Of the 81 patients surveyed, 74% were indicated for aspirin therapy. Nearly all (92.3%) patients reporting aspirin use were indicated for aspirin therapy compared with only 57.1% of patients who did not report aspirin but were indicated ( P = 0.0003). Alternatively, 96.7% of patients with aspirin use documented in their EHR were indicated for aspirin therapy compared with only 60.8% of patients who did not have aspirin use documented in the EHR but had an indication ( P = 0.0002). Approximately 20% of the patients indicated for and reporting aspirin use did not have aspirin documented in their EHR. Conclusions: Aspirin use in patients with DM who are indicated for therapy is significantly underutilized and underdocumented.

Pharmacologic regimens for knee osteoarthritis prevention: can they be cost-effective?

OBJECTIVE

We sought to determine the target populations and drug efficacy, toxicity, cost, and initiation age thresholds under which a pharmacologic regimen for knee osteoarthritis (OA) prevention could be cost-effective.

DESIGN

We used the Osteoarthritis Policy (OAPol) Model, a validated state-transition simulation model of knee OA, to evaluate the cost-effectiveness of using disease-modifying OA drugs (DMOADs) as prophylaxis for the disease. We assessed four cohorts at varying risk for developing OA: (1) no risk factors, (2) obese, (3) history of knee injury, and (4) high-risk (obese with history of knee injury). The base case DMOAD was initiated at age 50 with 40% efficacy in the first year, 5% failure per subsequent year, 0.22% major toxicity, and annual cost of $1,000. Outcomes included costs, quality-adjusted life expectancy (QALE), and incremental cost-effectiveness ratios (ICERs). Key parameters were varied in sensitivity analyses.

RESULTS

For the high-risk cohort, base case prophylaxis increased quality-adjusted life-years (QALYs) by 0.04 and lifetime costs by $4,600, and produced an ICER of $118,000 per QALY gained. ICERs >$150,000/QALY were observed when comparing the base case DMOAD to the standard of care in the knee injury only cohort; for the obese only and no risk factors cohorts, the base case DMOAD was less cost-effective than the standard of care. Regimens priced at $3,000 per year and higher demonstrated ICERs above cost-effectiveness thresholds consistent with current US standards.

CONCLUSIONS

The cost-effectiveness of DMOADs for OA prevention for persons at high risk for incident OA may be comparable to other accepted preventive therapies.

Cost-effectiveness of treatment of diabetic macular edema

BACKGROUND

Macular edema is the most common cause of vision loss among patients with diabetes.

OBJECTIVE

To determine the cost-effectiveness of different treatments of diabetic macular edema (DME).

DESIGN

Markov model.

DATA SOURCES

Published literature and expert opinion.

TARGET POPULATION

Patients with clinically significant DME.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

Laser treatment, intraocular injections of triamcinolone or a vascular endothelial growth factor (VEGF) inhibitor, or a combination of both.

OUTCOME MEASURES

Discounted costs, gains in quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs).

RESULTS OF BASE-CASE ANALYSIS

All treatments except laser monotherapy substantially reduced costs, and all treatments except triamcinolone monotherapy increased QALYs. Laser treatment plus a VEGF inhibitor achieved the greatest benefit, gaining 0.56 QALYs at a cost of $6975 for an ICER of $12 410 per QALY compared with laser treatment plus triamcinolone. Monotherapy with a VEGF inhibitor achieved similar outcomes to combination therapy with laser treatment plus a VEGF inhibitor. Laser monotherapy and triamcinolone monotherapy were less effective and more costly than combination therapy.

RESULTS OF SENSITIVITY ANALYSIS

VEGF inhibitor monotherapy was sometimes preferred over laser treatment plus a VEGF inhibitor, depending on the reduction in quality of life with loss of visual acuity. When the VEGF inhibitor bevacizumab was as effective as ranibizumab, it was preferable because of its lower cost.

LIMITATION

Long-term outcome data for treated and untreated diseases are limited.

CONCLUSION

The most effective treatment of DME is VEGF inhibitor injections with or without laser treatment. This therapy compares favorably with cost-effective interventions for other conditions.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Antiplatelet therapy in patients undergoing percutaneous coronary intervention: economic considerations

Percutaneous coronary intervention (PCI) is one of the most common medical procedures performed for treatment of coronary artery disease. Antiplatelet medications as adjunctive therapy for PCI are used routinely, with indications for specific agents or their combinations varying depending on the clinical scenario. While the cost-effectiveness of well-established agents has been extensively studied, newer drugs have not been evaluated as thoroughly. In addition, the clinical application of some antiplatelet drugs has recently changed, thus making older studies of cost effectiveness less applicable to the current landscape of clinical practice. This article reviews cost-effectiveness considerations of antiplatelet therapies in the treatment of coronary artery disease in patients undergoing PCI. Aspirin, P2Y12 inhibitors including clopidogrel and the newer agents prasugrel and ticagrelor, as well as glycoprotein (GP) IIb/IIIa inhibitors, are discussed. Overall, the use of dual antiplatelet therapy with aspirin and a P2Y12 inhibitor in patients undergoing PCI improves ischaemic outcomes and appears to be cost effective. The few available studies suggest that the recently approved medications prasugrel and ticagrelor are cost-effective alternatives to clopidogrel. However, no direct comparison between these two newer agents is available. The indications for GP IIb/IIIa inhibitors have changed in the current PCI era, and there is a paucity of cost-effectiveness data for their use in contemporary care.

Estimating the payoffs from cardiovascular disease research in Canada: an economic analysis

BACKGROUND

Investments in medical research can result in health improvements, reductions in health expenditures and secondary economic benefits. These "returns" have not been quantified in Canada. Our objective was to estimate the return on cardiovascular disease research funded by public or charitable organizations.

METHODS

Our primary outcome was the internal rate of return on cardiovascular disease research funded by public or charitable sources. The internal rate of return is the annual monetary benefit to the economy for each dollar invested in cardiovascular disease research. Calculation of the internal rate of return involved the following: measuring expenditures on cardiovascular disease research, estimating the health gains accrued from new treatments for cardiovascular disease, determining the proportion of health gains attributable to cardiovascular disease research and the time lag between research expenditures and health gains, and estimating the spillovers from public- or charitable-sector investments to other sectors of the economy.

RESULTS

Expenditures by public or charitable organizations on cardiovascular disease research from 1981 to 1992 amounted to $392 million (2005 dollars). Health gains associated with new treatments from 1994 to 2005 (13-yr lag) amounted to 2.2 million quality-adjusted life-years. We calculated an internal rate of return of 20.6%.

CONCLUSION

Canadians obtain relatively high health and economic gains from investments in cardiovascular disease research. Every $1 invested in cardiovascular disease research by public or charitable sources yields a stream of benefits of roughly $0.21 to the Canadian economy per year, in perpetuity.

Model performance evaluation (validation and calibration) in model-based studies of therapeutic interventions for cardiovascular diseases : a review and suggested reporting framework

Decision analytic models play an increasingly important role in the economic evaluation of health technologies. Given uncertainties around the assumptions used to develop such models, several guidelines have been published to identify and assess 'best practice' in the model development process, including general modelling approach (e.g., time horizon), model structure, input data and model performance evaluation. This paper focuses on model performance evaluation. In the absence of a sufficient level of detail around model performance evaluation, concerns regarding the accuracy of model outputs, and hence the credibility of such models, are frequently raised. Following presentation of its components, a review of the application and reporting of model performance evaluation is presented. Taking cardiovascular disease as an illustrative example, the review investigates the use of face validity, internal validity, external validity, and cross model validity. As a part of the performance evaluation process, model calibration is also discussed and its use in applied studies investigated. The review found that the application and reporting of model performance evaluation across 81 studies of treatment for cardiovascular disease was variable. Cross-model validation was reported in 55 % of the reviewed studies, though the level of detail provided varied considerably. We found that very few studies documented other types of validity, and only 6 % of the reviewed articles reported a calibration process. Considering the above findings, we propose a comprehensive model performance evaluation framework (checklist), informed by a review of best-practice guidelines. This framework provides a basis for more accurate and consistent documentation of model performance evaluation. This will improve the peer review process and the comparability of modelling studies. Recognising the fundamental role of decision analytic models in informing public funding decisions, the proposed framework should usefully inform guidelines for preparing submissions to reimbursement bodies.

Cardiovascular prophylaxis and aspirin "allergy"

Aspirin is an important antiplatelet agent in the treatment of cardiovascular disease. Aspirin "allergy" often directs the physician away from this potentially life-saving modality. The majority of patients with a history of "reactions to aspirin" have aspirin/nonsteroidal anti-inflammatory drug (NSAID)-induced gastritis, easy bruisability, or other side effects. The minority of these patients has a "true allergy," referred to as a hypersensitivity reaction. The former group can be started on aspirin without the need for special challenge. Adding a proton-pump inhibitor can often mitigate the gastrointestinal side effects. Patients with aspirin hypersensitivity can be safely challenged with aspirin.

Evaluating child welfare policies with decision-analytic simulation models

The objective was to demonstrate decision-analytic modeling in support of Child Welfare policymakers considering implementing evidence-based interventions. Outcomes included permanency (e.g., adoptions) and stability (e.g., foster placement changes). Analyses of a randomized trial of KEEP-a foster parenting intervention-and NSCAW-1 estimated placement change rates and KEEP's effects. A microsimulation model generalized these findings to other Child Welfare systems. The model projected that KEEP could increase permanency and stability, identifying strategies targeting higher-risk children and geographical regions that achieve benefits efficiently. Decision-analytic models enable planners to gauge the value of potential implementations.

Clopidogrel versus aspirin in patients with atherothrombosis: a CAPRIE-based cost-effectiveness model for Greece

BACKGROUND

Atherothrombosis represents a leading cause of morbidity and mortality worldwide. Given the prominent role of platelet aggregation in atherothrombosis, antiplatelet therapy forms the cornerstone of treatment, with proven efficacy in the secondary prevention of atherothrombotic events. Although clopidogrel seems to be superior to aspirin in terms of risk reduction for an atherothrombotic event, whether this clinical advantage is cost effective in Greece is unknown.

OBJECTIVE

The aim of this study was to conduct a cost-effectiveness analysis comparing clopidogrel with aspirin in the secondary prevention of atherothrombotic events in patients with peripheral artery disease, a recent stroke or a recent myocardial infarction, from the third-party-payer perspective in Greece.

METHODS

A Markov model with a 6-month cycle length was developed. Transition probabilities used in the model were obtained from the event rates reported in the CAPRIE trial. The effect of clopidogrel was applied only during the first 2 years of the model. Utility data were used to estimate quality-adjusted life-years (QALYs). Costs (for the year 2012) assigned to each health state included antiplatelet treatment cost, cost for the management of adverse events related to antiplatelet therapy and the direct healthcare cost of patients (i.e. concomitant medication, hospitalization, outpatient visits, rehabilitation, laboratory and imaging diagnostic examinations as well as interventions) in the acute and follow-up phase, separately. The incremental cost-effectiveness ratio (ICER) was calculated for life-years (LYs) and QALYs, separately. A probabilistic sensitivity analysis was conducted in order to evaluate the impact of the variation that characterizes the majority of model parameters to the cost-effectiveness results.

RESULTS

The Markov analysis revealed that the discounted survival was 11.83 (95% CI 11.40, 12.22) years and 12.17 (95% CI 11.75, 12.55) years in the aspirin and clopidogrel treatment groups, respectively, a difference of 0.34 (95% CI 0.09, 0.618) LYs. The corresponding discounted QALYs were 8.63 (95% CI 8.34, 8.90) and 8.84 (95% CI 8.54, 9.10), respectively, a difference of 0.21 (95% CI 0.05, 0.37) QALYs. The cumulated lifetime costs per patient were €20 678 (95% CI 19 675, 21 724) and €21 688 (95% CI 20 649, 22 773), for aspirin and clopidogrel treatment arm, respectively. The ICER for clopidogrel was calculated to be €4038 (95% CI 2743, 7837) for each LY saved and €5518 (95% CI 3358, 12 921) for each QALY saved.

CONCLUSION

The analysis indicates that clopidogrel is cost effective for the secondary prevention of atherothrombotic events in the Greek setting. These findings are in line with those reported in other European countries.

A penny-per-ounce tax on sugar-sweetened beverages would cut health and cost burdens of diabetes

Sugar-sweetened beverages are a major contributor to the US obesity and diabetes epidemics. Using the Coronary Heart Disease Policy Model, we examined the potential impact on health and health spending of a nationwide penny-per-ounce excise tax on these beverages. We found that the tax would reduce consumption of these beverages by 15 percent among adults ages 25-64. Over the period 2010-20, the tax was estimated to prevent 2.4 million diabetes person-years, 95,000 coronary heart events, 8,000 strokes, and 26,000 premature deaths, while avoiding more than $17 billion in medical costs. In addition to generating approximately $13 billion in annual tax revenue, a modest tax on sugar-sweetened beverages could reduce the adverse health and cost burdens of obesity, diabetes, and cardiovascular diseases.