Cost-effectiveness of diagnostic evaluation strategies for individuals with stable chest pain syndrome and suspected coronary artery disease

Advanced Heart Block and Asystole After Regadenoson Infusion: When Cautionary Tales Become Reality

Regadenoson (brand name Lexiscan) is a specific adenosine receptor agonist commonly used in pharmacologic stress testing due to its coronary vasodilatory effects. Despite it being generally well-tolerated, the American Society of Nuclear Cardiology established absolute and relative contraindications to the use of regadenoson in patients with certain co-morbidities such as uncontrolled hyper/hypotension, sinus node disease, and second-degree heart blocks. While cases of advanced heart block after the administration of regadenoson have been reported, they remain incidental. We report the case of an 84-year-old male sustaining second-degree type II heart block, followed by pulseless electrical activity and asystole after the administration of regadenoson.

Challenges and Burdens in the Coronary Artery Disease Care Pathway for Patients Undergoing Percutaneous Coronary Intervention: A Contemporary Narrative Review

Clinical and economic burdens exist within the coronary artery disease (CAD) care pathway despite advances in diagnosis and treatment and the increasing utilization of percutaneous coronary intervention (PCI). However, research presenting a comprehensive assessment of the challenges across this pathway is scarce. This contemporary review identifies relevant studies related to inefficiencies in the diagnosis, treatment, and management of CAD, including clinician, patient, and economic burdens. Studies demonstrating the benefits of integration and automation within the catheterization laboratory and across the CAD care pathway were also included. Most studies were published in the last 5-10 years and focused on North America and Europe. The review demonstrated multiple potentially avoidable inefficiencies, with a focus on access, appropriate use, conduct, and follow-up related to PCI. Inefficiencies included misdiagnosis, delays in emergency care, suboptimal testing, longer procedure times, risk of recurrent cardiac events, incomplete treatment, and challenges accessing and adhering to post-acute care. Across the CAD pathway, this review revealed that high clinician burnout, complex technologies, radiation, and contrast media exposure, amongst others, negatively impact workflow and patient care. Potential solutions include greater integration and interoperability between technologies and systems, improved standardization, and increased automation to reduce burdens in CAD and improve patient outcomes.

The financial implications of cardiac stress testing prior to abdominal aortic aneurysm repair

BACKGROUND

The utilization and cost-effectiveness of stress testing before abdominal aortic aneurysm (AAA) repair remains insufficiently studied. We examined the variation and financial implications of stress testing, and their association with major adverse cardiovascular events (MACE).

METHODS

We studied patients who underwent elective endovascular (EVAR) or open AAA repair (OAR) at Vascular Quality Initiative centers from 2015 to 2019. We grouped centers into quintiles of preoperative stress testing frequency. We calculated the risk of postoperative MACE, a composite of in-hospital myocardial infarction, heart failure, or death, for each center-quintile. We obtained charges for stress tests locally and applied these to the cohort to estimate charges per 1000 patients.

RESULTS

We studied 32,459 patients (EVAR: 27,978; OAR: 4481; 283 centers). Stress test utilization varied across quintiles from 13.0% to 68.6% (median: 36.8%) before EVAR and 15.9% to 85.0% (median: 59.4%) before OAR. The risk of MACE was 1.4% after EVAR and 10.2% after OAR. There was a trend towards more common MACE after EVAR among centers with higher utilization of stress testing: 0.9% among centers in the lowest quintile, versus 1.7% in the highest quintile (p-trend = 0.068). There was no association between MACE and stress testing frequency for OAR (p-trend = 0.223). The estimated financial charges for stress testing before EVAR ranged from $125,806 per 1000 patients at 1^st-quintile centers, to $665,975 at 5^th-quintile centers. Charges before OAR ranged from $153,861 at 1^st-quintile centers, to $825,473 at 5^th-quintile centers.

CONCLUSION

Stress test use before AAA repair is highly variable and associated with substantial cost, with an unclear association with postoperative MACE. This highlights the need for improved stress testing paradigms prior to surgery.

Economic Analysis of the CADScor System for Ruling Out Coronary Artery Disease in England

BACKGROUND

Coronary artery disease (CAD) is the most common type of heart and circulatory disease and is the leading cause of death worldwide. The current diagnostic pathway can lead to patient complications and is also extremely costly. A new medical device, the CADScor System (Acarix AB), was developed for the acoustic detection of CAD before patients undergo invasive diagnostic procedures.

OBJECTIVES

Our objective was to assess the cost utility of the CADScor System for the diagnosis of CAD at an early stage in the diagnostic testing pathway in England.

METHODS

A two-part economic model, consisting of a decision tree and Markov model, was developed to consider the cost utility (cost per quality-adjusted life-year [QALY] gained) of introducing the CADScor System for the diagnosis of CAD. The decision tree component explored the short-term costs and diagnostic outcomes associated with introduction of the test compared with the existing testing pathway. A Markov model was developed to explore the longer-term health and economic implications of the condition and original diagnosis, with costs and health effects estimated over different time horizons. Parameter uncertainty was explored in deterministic and probabilistic sensitivity analyses.

RESULTS

Base-case results indicated that the CADScor System would result in cost savings (- £131 per patient) and a marginal increase in QALYs (0.00001) over a 1-year time horizon. Probabilistic results indicated that the intervention had a > 99% probability of being cost effective at a willingness-to-pay threshold of £20,000 per QALY gained and 100% probability of being cost saving. Results from the deterministic sensitivity analyses indicated that variations in parameters related to the accuracy and cost of the CADScor System, and the prevalence of CAD, had the greatest impact on the overall results. The overall cost saving was estimated to be over £12.3 million per 100,000 eligible patient population.

CONCLUSIONS

The CADScor System is a potentially cost-saving test for the diagnosis of CAD. When initiated before the use of non-invasive cardiac imaging tests such as computed tomography coronary angiography, the test reduced costs to the healthcare service over various time horizons.

Non-invasive imaging software to assess the functional significance of coronary stenoses: a systematic review and economic evaluation

BACKGROUND

QAngio^® XA 3D/QFR^® (three-dimensional/quantitative flow ratio) imaging software (Medis Medical Imaging Systems BV, Leiden, the Netherlands) and CAAS^® vFFR^® (vessel fractional flow reserve) imaging software (Pie Medical Imaging BV, Maastricht, the Netherlands) are non-invasive technologies to assess the functional significance of coronary stenoses, which can be alternatives to invasive fractional flow reserve assessment.

OBJECTIVES

The objectives were to determine the clinical effectiveness and cost-effectiveness of QAngio XA 3D/QFR and CAAS vFFR.

METHODS

We performed a systematic review of all evidence on QAngio XA 3D/QFR and CAAS vFFR, including diagnostic accuracy, clinical effectiveness, implementation and economic analyses. We searched MEDLINE and other databases to January 2020 for studies where either technology was used and compared with fractional flow reserve in patients with intermediate stenosis. The risk of bias was assessed with quality assessment of diagnostic accuracy studies. Meta-analyses of diagnostic accuracy were performed. Clinical and implementation outcomes were synthesised narratively. A simulation study investigated the clinical impact of using QAngio XA 3D/QFR. We developed a de novo decision-analytic model to estimate the cost-effectiveness of QAngio XA 3D/QFR and CAAS vFFR relative to invasive fractional flow reserve or invasive coronary angiography alone. Scenario analyses were undertaken to explore the robustness of the results to variation in the sources of data used to populate the model and alternative assumptions.

RESULTS

Thirty-nine studies (5440 patients) of QAngio XA 3D/QFR and three studies (500 patients) of CAAS vFFR were included. QAngio XA 3D/QFR had good diagnostic accuracy to predict functionally significant fractional flow reserve (≤ 0.80 cut-off point); contrast-flow quantitative flow ratio had a sensitivity of 85% (95% confidence interval 78% to 90%) and a specificity of 91% (95% confidence interval 85% to 95%). A total of 95% of quantitative flow ratio measurements were within 0.14 of the fractional flow reserve. Data on the diagnostic accuracy of CAAS vFFR were limited and a full meta-analysis was not feasible. There were very few data on clinical and implementation outcomes. The simulation found that quantitative flow ratio slightly increased the revascularisation rate when compared with fractional flow reserve, from 40.2% to 42.0%. Quantitative flow ratio and fractional flow reserve resulted in similar numbers of subsequent coronary events. The base-case cost-effectiveness results showed that the test strategy with the highest net benefit was invasive coronary angiography with confirmatory fractional flow reserve. The next best strategies were QAngio XA 3D/QFR and CAAS vFFR (without fractional flow reserve). However, the difference in net benefit between this best strategy and the next best was small, ranging from 0.007 to 0.012 quality-adjusted life-years (or equivalently £140-240) per patient diagnosed at a cost-effectiveness threshold of £20,000 per quality-adjusted life-year.

LIMITATIONS

Diagnostic accuracy evidence on CAAS vFFR, and evidence on the clinical impact of QAngio XA 3D/QFR, were limited.

CONCLUSIONS

Quantitative flow ratio as measured by QAngio XA 3D/QFR has good agreement and diagnostic accuracy compared with fractional flow reserve and is preferable to standard invasive coronary angiography alone. It appears to have very similar cost-effectiveness to fractional flow reserve and, therefore, pending further evidence on general clinical benefits and specific subgroups, could be a reasonable alternative. The clinical effectiveness and cost-effectiveness of CAAS vFFR are uncertain. Randomised controlled trial evidence evaluating the effect of quantitative flow ratio on clinical and patient-centred outcomes is needed.

FUTURE WORK

Studies are required to assess the diagnostic accuracy and clinical feasibility of CAAS vFFR. Large ongoing randomised trials will hopefully inform the clinical value of QAngio XA 3D/QFR.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42019154575.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 56. See the NIHR Journals Library website for further project information.

Cost-utility analysis of an integrated genetic/epigenetic test for assessing risk for coronary heart disease

Aim: New epigenetically based methods for assessing risk for coronary heart disease may be more sensitive but are generally more costly than current methods. To understand their potential impact on healthcare spending, we conducted a cost-utility analysis. Methods: We compared costs using the new Epi + Gen CHD™ test with those of existing tests using a cohort Markov simulation model. Results: We found that use of the new test was associated with both better survival and highly competitive negative incremental cost-effectiveness ratios ranging from -$42,000 to -$8000 per quality-adjusted life year for models with and without a secondary test. Conclusion: The new integrated genetic/epigenetic test will save money and lives under most real-world scenarios. Similar advantages may be seen for other epigenetic tests.

Prospective validation of an acoustic-based system for the detection of obstructive coronary artery disease in a high-prevalence population

Recent guidelines recommend a risk-adjusted, non-invasive work-up in patients presenting with chest discomfort to exclude coronary artery disease (CAD). However, a risk-adjusted diagnostic approach remains challenging in clinical practice. An acoustic detection device for analyzing micro-bruits induced by stenosis-generated turbulence in the coronary circulation has shown potential for ruling out CAD in patients with low-to-intermediate likelihood. We examined the diagnostic value of this acoustic detection system in a high-prevalence cohort. In total, 226 patients scheduled for clinically indicated invasive coronary angiography (ICA) were prospectively enrolled at two centers and examined using a portable, acoustic detection system. The acoustic analysis was performed in double-blinded fashion prior to quantitative ICA and following percutaneous coronary intervention (PCI). An acoustic detection result (CAD score) was obtained in 94% of all patients. The mean baseline CAD score was 41.2 ± 11.9 in patients with obstructive CAD and 33.8 ± 13.4 in patients without obstructive CAD (p < 0.001). ROC analysis revealed an AUC of 0.661 (95% CI 0.584-0.737). Sensitivity was 97.6% (95% confidence interval (CI) 91.5-99.7%), specificity was 14.5% (CI 9.0-21.7%), negative predictive value was 90.5% (CI 69.6-98.8%), and positive predictive value was 41.7% (CI 34.6-49.0%). Following PCI, the mean CAD score decreased from 40.5 ± 11.2 to 38.3 ± 13.7 (p = 0.039). Using an acoustic detection device identified individuals with CAD in a high-prevalence cohort with high sensitivity but relatively low specificity. The negative predictive value was within the predicted range and may be of value for a fast rule-out of obstructive CAD even in a high-prevalence population.

The optimal diagnostic strategies for patient with coronary artery diseases and stable chest pain syndrome: a cost-effectiveness analysis

Background

Numerous invasive and noninvasive diagnostic tests with different cost and effectiveness exist for detection of coronary artery disease. This diversity leads to unnecessary utilization of health services. For this reason, this study focused on the cost-effectiveness analysis of diagnostic strategies for coronary artery disease from the perspective of the health care system with 1-year time horizon.

Results

Incremental cost effectiveness ratios of all strategies were less than the threshold except for the electrocardiography-computed tomography angiography-coronary angiography strategy, and cost of the cardiac magnetic resonance imaging-based strategy was higher than the cost of other strategies. Also, the number of correct diagnosis in the electrocardiography-coronary angiography strategy was higher than the other strategies, and its ICER was 15.197 dollars per additional correct diagnosis. Moreover, the sensitivity analysis found that the probability of doing MRI and sensitivity of the exercise electrocardiography had impact on the results.

Conclusion

The most cost-effective strategy for acute patient is ECG-CA strategy, and for chronic patient, the most cost-effective strategies are electrocardiography-single photon emission computed tomography-coronary angiography and electrocardiography-exercise electrocardiography-coronary angiography. Applying these strategies in the same clinical settings may lead to a better utilization of resources.

Comparison Between Anatomical and Functional Imaging Modalities for Evaluation of Chest Pain in the Emergency Department

Evaluation of chest pain in the emergency department (ED) frequently employs a noninvasive strategy, including coronary computed tomography angiography (CCTA), stress echocardiography (SE), or myocardial perfusion imaging (MPI). We sought to report the real-world experience of utilizing CCTA compared with SE and MPI at an urban hospital ED. We conducted a retrospective cohort study of consecutively enrolled patients presenting with chest pain who had normal or nondiagnostic electrocardiogram (ECG), negative initial troponin-T, at least intermediate risk based on modified Diamond-Forrester criteria, and who underwent CCTA, SE, or MPI based on their individual test eligibility criteria. The primary outcome was ED discharge time. Secondary outcomes included test utilization and 30-days rehospitalization rates. The 2,143 patients who were included (mean age was 56 ± 12 years; 55% women) utilization rate (test performed/eligible) was lower for CCTA (n = 354/1,329) and MPI (n = 530/1,435) compared with SE (n = 1,259/1,650), p <0.001. Mean ED discharge times for both CCTA and SE were 12.5 ± 7.4 versus 16 ± 7.3 hours for MPI (p <0.0001). Patients with SE and CCTA were less likely to undergo coronary angiography (29%, 25%, vs 52% for MPI). There was a 1% cardiac-related 30-days rehospitalization rate in the CCTA group versus 1% in SE and 3% in the MPI group (p <0.01). In conclusion, CCTA and SE were associated with faster ED discharge and lower frequency of diagnostic coronary angiography. Notwithstanding its clinical utility, CCTA was underutilized at our large urban ED setting.

Cost-effectiveness for imaging stable ischemic disease

Stable ischemic heart disease remains a major cause of morbidity and mortality. Although there are multiple imaging modalities to diagnose and/or assist in the clinical management, the most cost-effective approach remains unclear. We reviewed the relevant and recent evidence-based clinical studies and trials to suggest the most cost-effective approach to stable ischemic heart disease. The limitations of these studies are discussed. Incorporating the results of recent multicenter trials, we suggest that for appropriate patients with coronary artery disease with any degree of stenosis or presence of coronary calcium, optimal medical therapy may be most cost-effective. Invasive coronary angiography and/or coronary revascularization would be primarily for non-responders or >/=50% left main stenosis. Stress cardiac magnetic imaging would be performed for those patients with non-diagnostic coronary CT angiography from motion and non-responders from optimal medical therapy in non-diagnostic coronary CT angiography group from high coronary calcium. These paths seem to be safe and cost-effective but requires modeling for confirmation.

Letter by Garcia A, et al. regarding article: Coronary artery disease risk reclassification by a new acoustic-based score

The best cost-effective non-invasive test for the diagnosis of coronary artery disease (CAD) in patients with intermediate pre-test probability (PTP) is unknown. Nevertheless one of the most common non invasive test used is the exercise treadmill testing (ETT) that is the less expensive non-invasive test but with the lowest sensitivity for the diagnosis of CAD, therefore many patients with intermediate PTP will required another non-invasive test with a higher cost and some of them require exposure to radiation. Despite all these measures, an estimated $108.9 billion is spent annually on CAD treatment. Some studies had showed that diastolic dysfunction is associated to CAD. A novel signal-processed surface ECG (MyoVista hsECG) can detection the abnormal myocardial relaxation and therefore identified CAD. The non-invasive acoustic device CADScore V3 algorithm had lower cost compared with any noninvasive test, with a high negative predictive value but not good enough specificity to diagnose CAD, hence should be the first approach in patients with a low and intermediate probability of CAD, and if to this evaluation will added the Myovista hs ECG to detection of CAD, therefore some patients with intermediate PTP could be reclassified into high risk and a better cost-effective decisions could be taken as referring directly to coronary angiography.

Cost-effectiveness analysis of stand-alone or combined non-invasive imaging tests for the diagnosis of stable coronary artery disease: results from the EVINCI study

AIM

This study aimed at evaluating the cost-effectiveness of different non-invasive imaging-guided strategies for the diagnosis of obstructive coronary artery disease (CAD) in a European population of patients from the Evaluation of Integrated Cardiac Imaging in Ischemic Heart Disease (EVINCI) study.

METHODS AND RESULTS

Cost-effectiveness analysis was performed in 350 patients (209 males, mean age 59 ± 9 years) with symptoms of suspected stable CAD undergoing computed tomography coronary angiography (CTCA) and at least one cardiac imaging stress-test prior to invasive coronary angiography (ICA) and in whom imaging exams were analysed at dedicated core laboratories. Stand-alone stress-tests or combined non-invasive strategies, when the first exam was uncertain, were compared. The diagnostic end-point was obstructive CAD defined as > 50% stenosis at quantitative ICA in the left main or at least one major coronary vessel. Effectiveness was defined as the percentage of correct diagnosis (cd) and costs were calculated using country-specific reimbursements. Incremental cost-effectiveness ratios (ICERs) were obtained using per-patient data and considering "no-imaging" as reference. The overall prevalence of obstructive CAD was 28%. Strategies combining CTCA followed by stress ECHO, SPECT, PET, or stress CMR followed by CTCA, were all cost-effective. ICERs values indicated cost saving from - 969€/cd for CMR-CTCA to - 1490€/cd for CTCA-PET, - 3092€/cd for CTCA-SPECT and - 3776€/cd for CTCA-ECHO. Similarly when considering early revascularization as effectiveness measure.

CONCLUSION

In patients with suspected stable CAD and low prevalence of disease, combined non-invasive strategies with CTCA and stress-imaging are cost-effective as gatekeepers to ICA and to select candidates for early revascularization.

Self-reported functional status predicts post-operative outcomes in non-cardiac surgery patients with pulmonary hypertension

Background

Pulmonary hypertension (PHTN) is associated with increased post-procedure morbidity and mortality. Pre-procedure echocardiography (ECHO) is a widely used tool for evaluation of these patients, but its accuracy in predicting post-procedure outcomes is unproven. Self-reported exercise tolerance has not been evaluated for operative risk stratification of PHTN patients.

Objective

We analyzed whether self-reported exercise tolerance predicts outcomes (hospital length-of-stay [LOS], mortality and morbidity) in PHTN patients (WHO Class I–V) undergoing anesthesia and surgery.

Methods and findings

We reviewed 550 non-cardiac, non-obstetric procedures performed on 370 PHTN patients at a single institution between 2007 and 2013. All patients had cardiac ECHO documented within 1 year prior to the procedure. Pre-procedure comorbidities and ECHO data were collected. Functional status (< or ≥ 4 metabolic equivalents of task [METs]) was assigned based on responses to standard patient interview questions during the pre-anesthesia clinic visit. Multiple logistic regression was used to develop a risk score model (Pulmonary Hypertension Outcome Risk Score; PHORS) and determine its value in predicting post-procedure outcomes. In an adjusted model, functional status <4 METs was independently associated with a LOS >7 days (p < .003), as were higher ASA class (p < .002), open surgical approach (p < .002), procedure duration > 2 hours (p < .001), and the absence of systemic hypertension (p = .012). PHORS Score ≥2 was associated with an increased 30-day major complication rate (28.7% vs. 19.2%; p < 0.001) and ICU admission rate (8.6% s 2.8%; p = .007), but no statistical difference in hospital readmissions rate (17.6% vs. 14.0%; p = .29), or mortality (3.5% vs. 1.4%; p = .75). Similar ECHO findings did not further improve outcome prediction.

Conclusions

Poor functional status is associated with severe PHTN and predicts increased LOS and post-procedure complications in patients with moderate to severe pulmonary hypertension with different etiologies. A risk assessment model predicts increased LOS with fair accuracy. A thorough evaluation of underlying etiologies of PHTN should be undertaken in every patient.