Could Computed Tomography Coronary Angiography Replace Invasive Coronary Angiography as a First-Line Diagnostic Investigation in Suspected Acute Coronary Syndromes? A Decision-Analytic Model.

BACKGROUND: The implementation of high-sensitivity cardiac troponin (hs-cTn) assays into clinical practice has resulted in the identification of a novel cohort of patients with modestly increased troponin concentrations. Subsequent increases in rates of coronary angiography have been observed, without significant increases in rates of coronary revascularisation. Computed tomography coronary angiography (CTCA) is a non-invasive investigation that offers the opportunity to decouple investigation from the impetus to revascularise, and may provide an alternative, more risk-appropriate initial investigative strategy for the cohort with low to moderate hs-cTn increases. This analysis seeks to define the threshold of pre-test probability of coronary revascularisation in patients with suspected acute coronary syndrome at which a strategy of initial CTCA is safe and a more cost-effective approach than standard invasive coronary angiography (ICA). METHODS: A cost-benefit evaluation was conducted using a decision-analytic model. The primary outcome measure was the incremental cost-effectiveness ratio (ICER) of CTCA in comparison with ICA as an initial diagnostic investigation for patients with hs-cTnT levels between 5 and 100 ng/L. Secondary outcome measures of costs, patient outcomes, and quality-adjusted life years were analysed. RESULTS: Median base case ICER over 1,000 trials was $17,163 AUD but demonstrated large variability. Sensitivity analysis demonstrated that CTCA was cost-effective until the probability of requiring revascularisation was ∼60%, beyond which point CTCA was associated with higher costs and poorer outcomes than ICA. CONCLUSIONS: Computed tomography coronary angiography may be a cost-effective first-line investigation for patients with moderate hs-cTnT rises until/up to a 60% pre-test probability for receiving coronary revascularisation. To objectively assess the optimal circumstances of cost-effectiveness, prospective evaluation incorporating the estimated probability of revascularisation will be required.

Catheter ablation for supraventricular tachycardia and health resource utilization and expenditures: A propensity-matched cohort study.

BACKGROUND: Few data are available regarding temporal patterns of health resource utilization (HRU) and expenditures among patients undergoing catheter ablation for paroxysmal supraventricular tachycardia (PSVT). This study aimed to describe expenditures and HRU in patients with PSVT who underwent catheter ablation compared to a matched cohort of patients on medical therapy alone. METHODS: Using a large US administrative database, we identified adult patients (age 18 to 65 years) with a new PSVT diagnosis between 2008 and 2016. Propensity-score matching was used to assemble a PSVT cohort treated with ablation or medical therapy alone (N = 2556). Longitudinal trends in HRU and expenditures in the 3-years preceding and following PSVT diagnosis were compared. RESULTS: There were no significant differences in expenditures between groups except within the first year after PSVT diagnosis: $48,004 ablation vs. $17,560 medical therapy (p < 0.001). This difference was driven by procedural expenditures, where the mean cost of catheter ablation was $32,057 ± SD 26,737. In Years 2 and 3 post-ablation, HRU and expenditures decreased to the levels associated with the medical therapy group, although fewer ablation patients required any prescription for beta-blockers, calcium channel blockers, or anti-arrhythmic drugs (32% ablation vs. 42% medical therapy group, p < 0.001). CONCLUSION: Catheter ablation reduces medication burden in PSVT, yet health resource use and expenditures were similar beyond 2 years post-ablation when compared to PSVT patients on medical therapy alone. Additional studies are required to better understand drivers of these sustained health expenditures, and barriers to achieving cost-savings for a potentially curative procedure.

Economic Analysis of AbClo, a Novel Abdominal Fascia Closure Device, for Patients With an Open Abdomen Following Trauma or Acute Abdominal Surgery.

BACKGROUND: Open Abdomen (OA) cases represent a significant surgical and resource challenge. AbClo is a novel non-invasive abdominal fascial closure device that engages lateral components of the abdominal wall muscles to support gradual approximation of the fascia and reduce the fascial gap. The study objective was to assess the economic implications of AbClo compared to negative pressure wound therapy (NPWT) alone on OA management. METHODS: We conducted a cost-minimization analysis using a decision tree comparing the use of the AbClo device to NPWT alone among patients with midline laparotomy for trauma or acute abdominal surgery who were ineligible for primary fascial closure. The time horizon was limited to the length of the inpatient hospital stay, and costs were considered from the perspective of the US Medicare payer. Clinical effectiveness data for AbClo was obtained from a randomized clinical trial. Cost data was obtained from the published literature. Probabilistic and deterministic sensitivity analyses were performed. The primary outcome was incremental cost. RESULTS: The mean cumulative costs per patient were $76 582 for those treated with NPWT alone and $70,582 for those in the group treated with the AbClo device. Compared to NPWT alone, AbClo was associated with lower incremental costs of -$6012 (95% CI -$19 449 to +$1996). The probability that AbClo was cost-savings compared to NPWT alone was 94%. CONCLUSIONS: The use of AbClo is an economically attractive strategy for management of OA in in patients with midline laparotomy for trauma or acute abdominal surgery who were ineligible for primary fascial closure.

Physician Variation and the Impact of Payment Model in Cardiac Imaging.

BACKGROUND: The influence of fee-for-service reimbursement on cardiac imaging has not been compared with other payment models. Furthermore, variation in ordering practices is not well understood. METHODS AND RESULTS: This retrospective, population-based cohort study using linked administrative data from Alberta, Canada included adults with chronic heart disease (atrial fibrillation, coronary artery disease, and heart failure) seen by cardiac specialists for a new outpatient consultation April 2012 to December 2018. Generalized linear mixed-effects models estimated the association of payment model (including the ability to bill to interpret imaging tests) and the use of cardiac imaging and quantified variation in cardiac imaging. Among 31 685 adults seen by 308 physicians at 136 sites, patients received an observed mean of 0.67 (95% CI, 0.67-0.68) imaging tests per consultation. After adjustment, patients seeing fee-for-service physicians had 2.07 (95% CI, 1.68-2.54) and fee-for-service physicians with ability to interpret had 2.87 (95% CI, 2.16-3.81) times the rate of receiving a test than those seeing salaried physicians. Measured patient, physician, and site effects accounted for 31% of imaging variation and, following adjustment, reduced unexplained site-level variation 40% and physician-level variation 29%. CONCLUSIONS: We identified substantial variation in the use of outpatient cardiac imaging related to physician and site factors. Physician payment models have a significant association with imaging use. Our results raise concern that payment models may influence cardiac imaging practice. Similar methods could be applied to identify the source and magnitude of variation in other health care processes and outcomes.

The economic burden of cardiac implantable electronic device infections in Alberta, Canada: a population-based study using validated administrative data.

BACKGROUND: Cardiac implantable electronic devices (CIED) are being inserted with increasing frequency. Severe surgical site infections (SSI) that occur after device implantation substantially impact patient morbidity and mortality and can result in multiple hospital admissions and repeat surgeries. It is important to understand the costs associated with these infections as well as healthcare utilization. Therefore, we conducted a population-based study in the province of Alberta, Canada to understand the economic burden of these infections. METHODS: A cohort of adult patients in Alberta who had CIEDs inserted or generators replaced between January 1, 2011 and December 31, 2019 was used. A validated algorithm of International Classification of Diseases (ICD) codes to identify complex (deep/organ space) SSIs that occurred within the subsequent year was applied to the cohort. The overall mean 12-month inpatient and outpatient costs for the infection and non-infection groups were assessed. In order to control for variables that may influence costs, propensity score matching was completed and incremental costs between those with and without infection were calculated. As secondary outcomes, number of outpatient visits, hospitalizations and length of stay were assessed. RESULTS: There were 26,049 procedures performed during our study period, of which 320 (1.23%) resulted in SSIs. In both unadjusted costs and propensity score matched costs the infection group was associated with increased costs. Overall mean cost was $145,312 in the infection group versus $34,264 in the non-infection group. The incremental difference in those with infection versus those without in the propensity score match was $90,620 (Standard deviation $190,185). Approximately 70% of costs were driven by inpatient hospitalizations. Inpatients hospitalizations, length of stay and outpatient visits were all increased in the infection group. CONCLUSIONS: CIED infections are associated with increased costs and are a burden to the healthcare system. This highlights a need to recognize increasing SSI rates and implement measures to minimize infection risk. Further studies should endeavor to apply this work to full economic evaluations to better understand and identify cost-effective infection mitigation strategies.

Cost-Effectiveness of Vericiguat in Patients With Heart Failure With Reduced Ejection Fraction: The VICTORIA Randomized Clinical Trial.

BACKGROUND: The VICTORIA trial (Vericiguat Global Study in Subjects With Heart Failure With Reduced Ejection Fraction) demonstrated that, in patients with high-risk heart failure, vericiguat reduced the primary composite outcome of cardiovascular death or heart failure hospitalization relative to placebo. The hazard ratio for all-cause mortality was 0.95 (95% CI, 0.84-1.07). In a prespecified analysis, treatment effects varied substantially as a function of baseline NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels, with survival benefit for vericiguat in the lower NT-proBNP quartiles (hazard ratio, 0.82 [95% CI, 0.69-0.97]) and no benefit in the highest NT-proBNP quartile (hazard ratio, 1.14 [95% CI, 0.95-1.38]). An economic analysis was a major secondary objective of the VICTORIA research program. METHODS: Medical resource use data were collected for all VICTORIA patients (N=5050). Costs were estimated by applying externally derived US cost weights to resource use counts. Life expectancy was projected from patient-level empirical trial survival results with the use of age-based survival modeling methods. Quality-of-life adjustments were based on prospectively collected EQ-5D-based utilities. The primary outcome was the incremental cost-effectiveness ratio, comparing vericiguat with placebo, assessed from the US health care sector perspective over a lifetime horizon. Cost-effectiveness was estimated using the total VICTORIA cohort, both with and without interaction between treatment and baseline NT-proBNP. RESULTS: Life expectancy modeling results varied according to whether the observed heterogeneity of treatment effect by baseline NT-proBNP values was incorporated into the modeling. Including the interaction term, the vericiguat arm had an estimated quality-adjusted life expectancy of 4.56 quality-adjusted life-years (QALYs) compared with 4.13 QALYs for placebo (incremental discounted QALY, 0.43). Without the treatment heterogeneity/interaction term, vericiguat had 4.50 QALYs compared with 4.33 QALYs for placebo (incremental discounted QALY, 0.17). Incremental discounted costs (vericiguat minus placebo) were $28 546 with the treatment interaction and $20 948 without it. Corresponding incremental cost-effectiveness ratios were $66 509 per QALY allowing for treatment heterogeneity and $124 512 without heterogeneity. CONCLUSIONS: Vericiguat use in the VICTORIA trial met criteria for intermediate value, but the incremental cost-effectiveness ratio estimates were sensitive to whether the analysis accounted for observed NT-proBNP treatment effect heterogeneity. The cost-effectiveness of vericiguat was driven by the projected incremental life expectancy among patients in the lowest 3 quartiles of NT-proBNP. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02861534.

Economic evaluation in cardiac electrophysiology: Determining the value of emerging technologies.

Cardiac electrophysiology is a constantly evolving speciality that has benefited from technological innovation and refinements over the past several decades. Despite the potential of these technologies to reshape patient care, their upfront costs pose a challenge to health policymakers who are responsible for the assessment of the novel technology in the context of increasingly limited resources. In this context, it is critical for new therapies or technologies to demonstrate that the measured improvement in patients' outcomes for the cost of achieving that improvement is within conventional benchmarks for acceptable health care value. The field of Health Economics, specifically economic evaluation methods, facilitates this assessment of value in health care. In this review, we provide an overview of the basic principles of economic evaluation and provide historical applications within the field of cardiac electrophysiology. Specifically, the cost-effectiveness of catheter ablation for both atrial fibrillation (AF) and ventricular tachycardia, novel oral anticoagulants for stroke prevention in AF, left atrial appendage occlusion devices, implantable cardioverter defibrillators, and cardiac resynchronization therapy will be reviewed.

Cost-effectiveness of immediate initiation of dapagliflozin in patients with a history of heart failure.

AIMS: To compare the cost-effectiveness of immediate and 12-month delayed initiation of dapagliflozin treatment in patients with a history of hospitalization for heart failure (HHF) from the UK, Canadian, German, and Spanish healthcare perspectives. METHODS AND RESULTS: A cost-utility analysis was conducted using a decision-analytic Markov model with health states defined by Kansas City Cardiomyopathy Questionnaire scores, type 2 diabetes mellitus status and incidence of heart failure (HF) events. Patient-level data for patients with prior HHF from the Dapagliflozin And Prevention of Adverse-outcomes in Heart Failure (DAPA-HF) trial were used to inform the model inputs on clinical events and utility values. Healthcare costs were sourced from the relevant national reference databases and the published literature. Compared to standard therapy, immediate initiation of dapagliflozin decreased HHF (187 events), urgent HF visits (32 events) and cardiovascular mortality (18 events). Standard therapy was associated with lifetime costs of £13 224 and 4.02 quality-adjusted life years (QALYs). Twelve-month delayed initiation of dapagliflozin was associated with total discounted lifetime costs and QALYs of £16 660 and 4.61, respectively, compared to £16 912 and 4.66, respectively, for immediate initiation. Compared to standard therapy, immediate and 12-month delayed initiation of dapagliflozin yielded an incremental cost-effectiveness ratio (ICER) of £5779 and £5821, respectively. Compared to 12-month delayed initiation, immediate initiation of dapagliflozin had an ICER of £5263. Results were similar from the Canadian, German, and Spanish healthcare perspectives. CONCLUSION: Both immediate and 12-month delayed initiation of dapagliflozin are cost-effective. However, immediate initiation provides greater clinical benefits, with almost 10% additional QALYs gain, compared to 12-month delayed initiation of dapagliflozin and should be considered standard of care.

Chest Pain Management Using Prehospital Point-of-Care Troponin and Paramedic Risk Assessment.

Importance: Prehospital point-of-care troponin testing and paramedic risk stratification might improve the efficiency of chest pain care pathways compared with existing processes with equivalent health outcomes, but the association with health care costs is unclear. Objective: To analyze whether prehospital point-of-care troponin testing and paramedic risk stratification could result in cost savings compared with existing chest pain care pathways. Design, Setting, and Participants: In this economic evaluation of adults with acute chest pain without ST-segment elevation, cost-minimization analysis was used to assess linked ambulance, emergency, and hospital attendance in the state of Victoria, Australia, between January 1, 2015, and June 30, 2019. Interventions: Paramedic risk stratification and point-of-care troponin testing. Main Outcomes and Measures: The outcome was estimated mean annualized statewide costs for acute chest pain. Between May 17 and June 25, 2022, decision tree models were developed to estimate costs under 3 pathways: (1) existing care, (2) paramedic risk stratification and point-of-care troponin testing without prehospital discharge, or (3) prehospital discharge and referral to a virtual emergency department (ED) for low-risk patients. Probabilities for the prehospital pathways were derived from a review of the literature. Multivariable probabilistic sensitivity analysis with 50 000 Monte Carlo iterations was used to estimate mean costs and cost differences among pathways. Results: A total of 188 551 patients attended by ambulance for chest pain (mean [SD] age, 61.9 [18.3] years; 50.5% female; 49.5% male; Indigenous Australian, 2.0%) were included in the model. Estimated annualized infrastructure and staffing costs for the point-of-care troponin pathways, assuming a 5-year device life span, was $2.27 million for the pathway without prehospital discharge and $4.60 million for the pathway with prehospital discharge (incorporating virtual ED costs). In the decision tree model, total annual cost using prehospital point-of-care troponin and paramedic risk stratification was lower compared with existing care both without prehospital discharge (cost savings, $6.45 million; 95% uncertainty interval [UI], $0.59-$16.52 million; lower in 94.1% of iterations) and with prehospital discharge (cost savings, $42.84 million; 95% UI, $19.35-$72.26 million; lower in 100% of iterations). Conclusions and Relevance: Prehospital point-of-care troponin and paramedic risk stratification for patients with acute chest pain could result in substantial cost savings. These findings should be considered by policy makers in decisions surrounding the potential utility of prehospital chest pain risk stratification and point-of-care troponin models provided that safety is confirmed in prospective studies.

Alert-driven vs scheduled remote monitoring of implantable cardiac defibrillators: A cost-consequence analysis from the TRUST trial.

BACKGROUND: Alert-driven remote patient monitoring (RPM) or fully virtual care without routine evaluations may reduce clinic workload and promote more efficient resource allocation, principally by diminishing nonactionable patient encounters. OBJECTIVE: The purpose of this study was to conduct a cost-consequence analysis to compare 3 postimplant implantable cardioverter-defibrillator (ICD) follow-up strategies: (1) in-person evaluation (IPE) only; (2) RPM-conventional (hybrid of IPE and RPM); and (3) RPM-alert (alert-based ICD follow-up). METHODS: We constructed a decision-analytic Markov model to estimate the costs and benefits of the 3 strategies over a 2-year time horizon from the perspective of the US Medicare payer. Aggregate and patient-level data from the TRUST (Lumos-T Safely RedUceS RouTine Office Device Follow-up) randomized clinical trial informed clinical effectiveness model inputs. TRUST randomized 1339 patients 2:1 to conventional RPM or IPE alone, and found that RPM was safe and reduced the number of nonactionable encounters. Cost data were obtained from the published literature. The primary outcome was incremental cost. RESULTS: Mean cumulative follow-up costs per patient were $12,688 in the IPE group, $12,001 in the RPM-conventional group, and $11,011 in the RPM-alert group. Compared to the IPE group, both the RPM-conventional and RPM-alert groups were associated with lower incremental costs of -$687 (95% confidence interval [CI] -$2138 to +$638) and -$1,677 (95% CI -$3134 to -$304), respectively. Therefore, the RPM-alert strategy was most cost-effective, with an estimated cost-savings in 99% of simulations. CONCLUSIONS: Alert-driven RPM was economically attractive and, if patient outcomes and safety are comparable to those of conventional RPM, may be the preferred strategy for ICD follow-up.

Left Atrial Appendage Occlusion Versus Oral Anticoagulation in Atrial Fibrillation : A Decision Analysis.

BACKGROUND: Left atrial appendage occlusion (LAAO) is a potential alternative to oral anticoagulants in selected patients with atrial fibrillation (AF). Compared with anticoagulants, LAAO decreases major bleeding risk, but there is uncertainty regarding the risk for ischemic stroke compared with anticoagulation. OBJECTIVE: To determine the optimal strategy for stroke prevention conditional on a patient's individual risks for ischemic stroke and bleeding. DESIGN: Decision analysis with a Markov model. DATA SOURCES: Evidence from the published literature informed model inputs. TARGET POPULATION: Women and men with nonvalvular AF and without prior stroke. TIME HORIZON: Lifetime. PERSPECTIVE: Clinical. INTERVENTION: LAAO versus warfarin or direct oral anticoagulants (DOACs). OUTCOME MEASURES: The primary end point was clinical benefit measured in quality-adjusted life-years. RESULTS OF BASE-CASE ANALYSIS: The baseline risks for stroke and bleeding determined whether LAAO was preferred over anticoagulants in patients with AF. The combined risks favored LAAO for higher bleeding risk, but that benefit became less certain at higher stroke risks. For example, at a HAS-BLED score of 5, LAAO was favored in more than 80% of model simulations for CHA2DS2-VASc scores between 2 and 5. The probability of LAAO benefit in QALYs (>80%) at lower bleeding risks (HAS-BLED score of 0 to 1) was limited to patients with lower stroke risks (CHA2DS2-VASc score of 2). Because DOACs carry lower bleeding risks than warfarin, the net benefit of LAAO is less certain than that of DOACs. RESULTS OF SENSITIVITY ANALYSIS: Results were consistent using the ORBIT bleeding score instead of the HAS-BLED score, as well as alternative sources for LAAO clinical effectiveness data. LIMITATION: Clinical effectiveness data were drawn primarily from studies on the Watchman device. CONCLUSION: Although LAAO could be an alternative to anticoagulants for stroke prevention in patients with AF and high bleeding risk, the overall benefit from LAAO depends on the combination of stroke and bleeding risks in individual patients. These results suggest the need for a sufficiently low stroke risk for LAAO to be beneficial. The authors believe that these results could improve shared decision making when selecting patients for LAAO. PRIMARY FUNDING SOURCE: None.

Cost-Effectiveness of Catheter Ablation Versus Antiarrhythmic Drug Therapy in Atrial Fibrillation: The CABANA Randomized Clinical Trial.

BACKGROUND: In the CABANA trial (Catheter Ablation vs Antiarrhythmic Drug Therapy for Atrial Fibrillation), catheter ablation did not significantly reduce the primary end point of death, disabling stroke, serious bleeding, or cardiac arrest compared with drug therapy by intention-to-treat, but did improve the quality of life and freedom from atrial fibrillation recurrence. In the heart failure subgroup, ablation improved both survival and quality of life. Cost-effectiveness was a prespecified CABANA secondary end point. METHODS: Medical resource use data were collected for all CABANA patients (N=2204). Costs for hospital-based care were assigned using prospectively collected bills from US patients (n=1171); physician and medication costs were assigned using the Medicare Fee Schedule and National Average Drug Acquisition Costs, respectively. Extrapolated life expectancies were estimated using age-based survival models. Quality-of-life adjustments were based on EQ-5D-based utilities measured during the trial. The primary outcome was the incremental cost-effectiveness ratio, comparing ablation with drug therapy on the basis of intention-to-treat, and assessed from the US health care sector perspective. RESULTS: Costs in the first 3 months averaged $20 794±SD 1069 higher with ablation compared with drug therapy. The cumulative within-trial 5-year cost difference was $19 245 (95% CI, $11 360-$27 170) and the lifetime mean cost difference was $15 516 (95% CI, -$2963 to $35,512) higher with ablation than with drug therapy. The drug therapy arm accrued an average of 12.5 life-years (LYs) and 10.7 quality-adjusted life-years (QALYs). For the ablation arm, the corresponding estimates were 12.6 LYs and 11.0 QALYs. The incremental cost-effectiveness ratio was $57 893 per QALY gained, with 75% of bootstrap replications yielding an incremental cost-effectiveness ratio <$100 000 per QALY gained. With no quality-of-life/utility adjustments, the incremental cost-effectiveness ratio was $183 318 per LY gained. CONCLUSIONS: Catheter ablation of atrial fibrillation was economically attractive compared with drug therapy in the CABANA Trial overall at present benchmarks for health care value in the United States on the basis of projected incremental QALYs but not LYs alone.

Economic Burden of Surgical Management of Prosthetic Joint Infections Following Hip and Knee Replacements in Alberta, Canada: An analysis and comparison of two major urban centers.

BACKGROUND: Complex surgical site infections (SSIs) and revisions for these infectious complications following total knee and hip arthroplasties are associated with significant economic costs. AIM: To evaluate the cost of one-stage and two-stage revisions; debridement, antibiotic, and implant retention (DAIR) and DAIR with liner exchange for complex hip or knee SSIs in Alberta, Canada. METHODS: We used the Alberta Health Services Infection Prevention and Control database to identify individuals >18 years old from the two major urban centers in Alberta, Calgary, and Edmonton zone, with complex hip or knee SSIs who underwent surgical intervention between April 1, 2012, and March 31, 2019. Micro-costing and gross-costing methods were used to estimate 12 and 24-month costs following the initial hospital admission for arthroplasty. Subgroup, inverse gaussian and gamma regression analysis were used to evaluate the associations of the revision procedure, age, sex, and comorbidities on cost. FINDINGS: A total of 382 patients with complex SSIs were identified with a mean age of 66.1 years. DAIR and DAIR with liner exchange resulted in the lowest 12- and 24-month costs at $53,197 (95% CI, $38,006 - $68,388) and $57,340 (95% CI, $48,576 - $66,105), respectively; two-stage revision was the costliest procedure. Most of the incurred costs (>98%) were accrued within the first 12 months following the initial procedure. CONCLUSIONS: Medical costs are highest 12 months following initial arthroplasty and for two-stage revisions in hip and knee complex SSI.

Objective risk assessment vs standard care for acute coronary syndromes-The Australian GRACE Risk tool Implementation Study (AGRIS): a process evaluation.

BACKGROUND: Structured risk-stratification to guide clinician assessment and engagement with evidence-based therapies may reduce care variance and improve patient outcomes for Acute Coronary Syndrome (ACS). The Australian Grace Risk score Intervention Study (AGRIS) explored the impact of the GRACE Risk Tool for stratification of ischaemic and bleeding risk in ACS. While hospitals in the active arm had a higher overall rate of invasive ACS management, there was neutral impact on important secondary prevention prescriptions/referrals, hospital performance measures, myocardial infarction and 12-month mortality leading to early trial cessation. Given the Grace Risk Tool is under investigation internationally, this process evaluation study provides important insights into the possible contribution of implementation fidelity on the AGRIS study findings. METHODS: Using maximum variation sampling, five hospitals were selected from the 12 centres enrolled in the active arm of AGRIS. From these facilities, 16 local implementation stakeholders (Cardiology advanced practice nurses, junior and senior doctors, study coordinators) consented to a semi-structured interview guided by the Theoretical Domains Framework. Directed Content Analysis of qualitative data was structured using the Capability/Opportunity/Motivation-Behaviour (COM-B) model. RESULTS: Physical capability was enhanced by tool usability. While local stakeholders supported educating frontline clinicians, non-cardiology clinicians struggled with specialist terminology. Physical opportunity was enhanced by the paper-based format but was hampered when busy clinicians viewed risk-stratification as one more thing to do, or when form visibility was neglected. Social opportunity was supported by a culture of research/evidence yet challenged by clinical workflow and rotating medical officers. Automatic motivation was strengthened by positive reinforcement. Reflective motivation revealed the GRACE Risk Tool as supporting but potentially overriding clinical judgment. Divergent professional roles and identity were a major barrier to integration of risk-stratification into routine Emergency Department practice. The cumulative result revealed poor form completion behaviors and a failure to embed risk-stratification into routine patient assessment, communication, documentation, and clinical practice behaviors. CONCLUSIONS: Numerous factors negatively influenced AGRIS implementation fidelity. Given the prominence of risk assessment recommendations in United States, European and Australian guidelines, strategies that strengthen collaboration with Emergency Departments and integrate automated processes for risk-stratification may improve future translation internationally.

Implementation and prospective evaluation of the Country Heart Attack Prevention model of care to improve attendance and completion of cardiac rehabilitation for patients with cardiovascular diseases living in rural Australia: a study protocol.

INTRODUCTION: Despite extensive evidence of its benefits and recommendation by guidelines, cardiac rehabilitation (CR) remains highly underused with only 20%-50% of eligible patients participating. We aim to implement and evaluate the Country Heart Attack Prevention (CHAP) model of care to improve CR attendance and completion for rural and remote participants. METHODS AND ANALYSIS: CHAP will apply the model for large-scale knowledge translation to develop and implement a model of care to CR in rural Australia. Partnering with patients, clinicians and health service managers, we will codevelop new approaches and refine/expand existing ones to address known barriers to CR attendance. CHAP will codesign a web-based CR programme with patients expanding their choices to CR attendance. To increase referral rates, CHAP will promote endorsement of CR among clinicians and develop an electronic system that automatises referrals of in-hospital eligible patients to CR. A business model that includes reimbursement of CR delivered in primary care by Medicare will enable sustainable access to CR. To promote CR quality improvement, professional development interventions and an accreditation programme of CR services and programmes will be developed. To evaluate 12-month CR attendance/completion (primary outcome), clinical and cost-effectiveness (secondary outcomes) between patients exposed (n=1223) and not exposed (n=3669) to CHAP, we will apply a multidesign approach that encompasses a prospective cohort study, a pre-post study and a comprehensive economic evaluation. ETHICS AND DISSEMINATION: This study was approved by the Southern Adelaide Clinical Human Research Ethics Committee (HREC/20/SAC/78) and by the Department for Health and Wellbeing Human Research Ethics Committee (2021/HRE00270), which approved a waiver of informed consent. Findings and dissemination to patients and clinicians will be through a public website, online educational sessions and scientific publications. Deidentified data will be available from the corresponding author on reasonable request. TRIAL REGISTRATION NUMBER: ACTRN12621000222842.

Cost-Effectiveness of Coronary Artery Bypass Surgery Versus Medicine in Ischemic Cardiomyopathy: The STICH Randomized Clinical Trial.

BACKGROUND: The STICH Randomized Clinical Trial (Surgical Treatment for Ischemic Heart Failure) demonstrated that coronary artery bypass grafting (CABG) reduced all-cause mortality rates out to 10 years compared with medical therapy alone (MED) in patients with ischemic cardiomyopathy and reduced left ventricular function (ejection fraction ≤35%). We examined the economic implications of these results. METHODS: We used a decision-analytic patient-level simulation model to estimate the lifetime costs and benefits of CABG and MED using patient-level resource use and clinical data collected in the STICH trial. Patient-level costs were calculated by applying externally derived US cost weights to resource use counts during trial follow-up. A 3% discount rate was applied to both future costs and benefits. The primary outcome was the incremental cost-effectiveness ratio assessed from the US health care sector perspective. RESULTS: For the CABG arm, we estimated 6.53 quality-adjusted life-years (95% CI, 5.70-7.53) and a lifetime cost of $140 059 (95% CI, $106 401 to $180 992). For the MED arm, the corresponding estimates were 5.52 (95% CI, 5.06-6.09) quality-adjusted life-years and $74 894 lifetime cost (95% CI, $58 372 to $93 541). The incremental cost-effectiveness ratio for CABG compared with MED was $63 989 per quality-adjusted life-year gained. At a societal willingness-to-pay threshold of $100 000 per quality-adjusted life-year gained, CABG was found to be economically favorable compared with MED in 87% of microsimulations. CONCLUSIONS: In the STICH trial, in patients with ischemic cardiomyopathy and reduced left ventricular function, CABG was economically attractive relative to MED at current benchmarks for value in the United States. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT00023595.