ACC/AHA/ASE/ASNC/HRS/IAC/Mended Hearts/NASCI/RSNA/SAIP/SCAI/SCCT/SCMR/SNMMI 2014 health policy statement on use of noninvasive cardiovascular imaging: a report of the American College of Cardiology Clinical Quality Committee

Inter-observer agreement and image quality of model-based algorithm applied to the Coronary Artery Disease-Reporting and Data System score

Purpose

To evaluate the inter-observer agreement of the CAD-RADS reporting system and compare image quality between model-based iterative reconstruction algorithm (MBIR) and standard iterative reconstruction algorithm (IR) of low-dose cardiac computed tomography angiography (CCTA).

Methods

One-hundred-sixty patients undergone a 256-slice MDCT scanner using low-dose CCTA combined with prospective ECG-gated techniques were enrolled. CCTA protocols were reconstructed with both MBIR and IR. Each study was evaluated by two readers using the CAD-RADS lexicon. Vessels enhancement, image noise, signal-to-noise (SNR), and contrast-to-noise (CNR) were computed in the axial native images, and inter-observer agreement was assessed. Radiation dose exposure as dose–length product (DLP) and effective dose were finally reported.

Results

The reliability analysis between the two readers was almost perfect for all CAD-RADS standard categories. Moreover, a significantly higher value of subjective qualitative analysis, SNR, and CNR in MBIR images compared to IR were found, due to a lower noise level (all p < 0.05). The mean DLP measured was 63.9 mGy*cm, and the mean effective dose was 0.9 mSv.

Conclusion

Inter-observer agreement of CAD-RADS was excellent confirming the importance, the feasibility, and the reproducibility of the CAD-RADS scoring system for CCTA. Moreover, lower noise and higher image quality with MBIR compared to IR were found.

Implications for practice

MBIR, by reducing noise and improving image quality, can help a better assessment of CAD-RADS, in comparison with standard IR algorithm.

Patient Symptoms and Stress Testing After Elective Percutaneous Coronary Intervention in the Veterans Affairs Health Care System

IMPORTANCE

Up to 60% of patients in the US receive a stress test within 2 years of percutaneous coronary intervention (PCI), prompting concerns about the possible overuse of stress testing.

OBJECTIVE

To examine the proportion of patients who underwent stress testing within 2 years of elective PCI, proportion of patients who had symptoms that were consistent with coronary artery disease (CAD), timing of stress testing, and site-level variation in stress testing among symptomatic and asymptomatic patients.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used administrative claims data and clinical records from the US Department of Veterans Affairs (VA) Clinical Assessment, Reporting, and Tracking program. Patients who underwent stress testing within 2 years of elective PCI for stable CAD between November 1, 2013, and October 31, 2015, at 64 VA facilities were included in the analysis. Patients who received stress testing for staging purposes, cardiac rehabilitation evaluation, or preoperative testing before high-risk surgery were excluded. Data were analyzed from June to December 2020.

MAIN OUTCOMES AND MEASURES

The main outcome was the proportion of patients who underwent stress testing and had symptoms that were consistent with obstructive CAD, using definitions from the 2013 clinical practice guideline (Multimodality Appropriate Use Criteria for the Detection and Risk Assessment of Stable Ischemic Heart Disease). Secondary outcomes were the timing of stress testing (assessed using a cumulative incidence curve) and site-level variation in stress testing (assessed using multilevel logistic regression models).

RESULTS

A total of 3705 consecutive patients (mean [SD] age 66.3 [7.6] years; 3656 men [98.7%]; 437 Black individuals [11.8%], 3175 White individuals [85.7%], and 93 individuals [2.5%] of other races and ethnicities [Asian, Hispanic or Latinx, or unknown]) had elective PCI. Of these patients, 916 (24.7%) received a stress test within 2 years, among whom 730 (79.7%) had symptoms that were consistent with obstructive CAD at the time of stress testing. Visual inspection of a cumulative incidence curve for stress testing showed no rapid increases in stress testing at 6 months or 1 year after PCI, which might coincide with routine clinical visits. The proportion of symptomatic patients who underwent stress testing at each VA site ranged from 67.7% to 100%, with no significant site-level variation in stress testing.

CONCLUSIONS AND RELEVANCE

Results of this study suggest that most veterans who underwent stress testing within 2 years after elective PCI had symptoms that were consistent with obstructive CAD. Therefore, measuring low-value stress testing using only administrative claims data may overestimate its prevalence, and concerns about overuse of post-PCI stress testing may be overstated.

Evidence-based cardiovascular magnetic resonance cost-effectiveness calculator for the detection of significant coronary artery disease

BACKGROUND

Although prior reports have evaluated the clinical and cost impacts of cardiovascular magnetic resonance (CMR) for low-to-intermediate-risk patients with suspected significant coronary artery disease (CAD), the cost-effectiveness of CMR compared to relevant comparators remains poorly understood. We aimed to summarize the cost-effectiveness literature on CMR for CAD and create a cost-effectiveness calculator, useable worldwide, to approximate the cost-per-quality-adjusted-life-year (QALY) of CMR and relevant comparators with context-specific patient-level and system-level inputs.

METHODS

We searched the Tufts Cost-Effectiveness Analysis Registry and PubMed for cost-per-QALY or cost-per-life-year-saved studies of CMR to detect significant CAD. We also developed a linear regression meta-model (CMR Cost-Effectiveness Calculator) based on a larger CMR cost-effectiveness simulation model that can approximate CMR lifetime discount cost, QALY, and cost effectiveness compared to relevant comparators [such as single-photon emission computed tomography (SPECT), coronary computed tomography angiography (CCTA)] or invasive coronary angiography.

RESULTS

CMR was cost-effective for evaluation of significant CAD (either health-improving and cost saving or having a cost-per-QALY or cost-per-life-year result lower than the cost-effectiveness threshold) versus its relevant comparator in 10 out of 15 studies, with 3 studies reporting uncertain cost effectiveness, and 2 studies showing CCTA was optimal. Our cost-effectiveness calculator showed that CCTA was not cost-effective in the US compared to CMR when the most recent publications on imaging performance were included in the model.

CONCLUSIONS

Based on current world-wide evidence in the literature, CMR usually represents a cost-effective option compared to relevant comparators to assess for significant CAD.

Differences in High- and Low-Value Cardiovascular Testing by Health Insurance Provider

Background

Quality of care incentives and reimbursements for cardiovascular testing differ between insurance providers. We hypothesized that there are differences in the use of guideline‐concordant testing between Medicaid versus commercial insurance patients <65 years, and between Medicare Advantage versus Medicare fee‐for‐service patients ≥65 years.

Methods and Results

Using data from the Colorado All‐Payer Claims Database from 2015 to 2018, we identified patients eligible to receive a high‐value test recommended by guidelines: assessment of left ventricular function among patients hospitalized with acute myocardial infarction or incident heart failure, or a low‐value test that provides minimal patient benefit: stress testing prior to low‐risk surgery or routine stress testing within 2 years of percutaneous coronary intervention or coronary artery bypass graft surgery. Among 145 616 eligible patients, 37% had fee‐for‐service Medicare, 18% Medicare Advantage, 22% Medicaid, and 23% commercial insurance. Using multilevel logistic regression models adjusted for patient characteristics, Medicaid patients were less likely to receive high‐value testing for acute myocardial infarction (odds ratio [OR], 0.84 [0.73–0.98]; P=0.03) and heart failure (OR, 0.59 [0.51–0.70]; P<0.01) compared with commercially insured patients. Medicare Advantage patients were more likely to receive high‐value testing for acute myocardial infarction (OR, 1.35 [1.15–1.59]; P<0.01) and less likely to receive low‐value testing after percutaneous coronary intervention/ coronary artery bypass graft (OR, 0.63 [0.55–0.72]; P<0.01) compared with Medicare fee‐for‐service patients.

Conclusions

Guideline‐concordant testing was less likely to occur among patients with Medicaid compared with commercial insurance, and more likely to occur among patients with Medicare Advantage compared with fee‐for‐service Medicare. Insurance plan features may provide valuable targets to improve guideline‐concordant testing.

Coronary artery calcium data and reporting system: Strengths and limitations

Coronary artery calcium data and reporting system (CAC-DRS) is a recently introduced standardized reporting system for calcium scoring on computed tomography. CAC-DRS provides four risk categories (0, 1, 2 and 3) along with treatment recommendations for each category. As with any other new reporting platform, CAC-DRS has both advantages and disadvantages. Improved communication, better clarity of details, organized management recommendations and utility in future research and education are the major strengths of CAC-DRS. It has many limitations such as questionable need for a new system, few missing components, use of a less accurate visual method and treatment suggestions based on expert opinion instead of clinical trials. In this contemporary review, we discuss the new reporting system CAC-DRS, its application, strengths and limitations and conclude with some remarks for the future.

Trends in High- and Low-Value Cardiovascular Diagnostic Testing in Fee-for-Service Medicare, 2000-2016

IMPORTANCE

Owing to a rapid increase in rates of diagnostic cardiovascular testing in the 1990s and early 2000s, the Centers for Medicare & Medicaid Services implemented a series of payment changes intended to reduce overall spending on fee-for-service testing. Whether guideline-concordant testing has been subsequently affected is unknown to date.

OBJECTIVE

To determine whether changes in overall rates of use of diagnostic cardiovascular tests were associated with changes in high-value testing recommended by guidelines and low-value testing that is expected to provide minimal benefits.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study assessed a national 5% random sample of Medicare fee-for-service beneficiaries aged 65 to 95 years from January 1, 1999, through December 31, 2016. Data were analyzed from February 15, 2018, through August 15, 2019.

EXPOSURES

Eligibility to receive high-value testing (assessment of left ventricular systolic function among patients hospitalized with acute myocardial infarction or heart failure) and low-value testing (stress testing before low-risk noncardiac surgery and routine stress testing within 2 years of coronary revascularization not associated with acute care visits).

MAIN OUTCOMES AND MEASURES

Age- and sex-adjusted annual rates of overall, high-value, and low-value diagnostic cardiovascular testing.

RESULTS

Mean (SD) age was similar over time (75.57 [7.32] years in 2000-2003; 74.82 [7.79] years in 2012-2016); the proportion of women slightly declined over time (63.23% in 2000 to 2003; 57.27% in 2012 to 2016). The rate of overall diagnostic cardiovascular testing per 1000 patient-years among the 5% sample of Medicare beneficiaries increased from 275 in 2000 to 359 in 2008 (P < .001) and then declined to 316 in 2016 (P < .001). High-value testing increased steadily over the entire study period for patients with acute myocardial infarction (85.7% to 89.5%; P < .001) and heart failure (72.6% to 80.1%; P < .001). Low-value testing among patients undergoing low-risk surgery increased from 2.4% in 2000 to 3.8% in 2008 (P < .001) but then declined to 2.5% in 2016 (P < .001). Low-value testing within 2 years of coronary revascularization slightly increased from 47.4% in 2000 to 49.2% in 2003 (P = .03) but then declined to 30.8% in 2014 (P < .001).

CONCLUSIONS AND RELEVANCE

Rates of overall and low-value diagnostic cardiovascular testing appear to have declined considerably and rates of high-value testing have increased slightly. Payment changes intended to reduce spending on overall testing may not have adversely affected testing recommended by guidelines.

10-Year Resource Utilization and Costs for Cardiovascular Care

BACKGROUND

Cardiovascular disease (CVD) imparts a heavy economic burden on the U.S. health care system. Evidence regarding the long-term costs after comprehensive CVD screening is limited.

OBJECTIVES

This study calculated 10-year health care costs for 6,814 asymptomatic participants enrolled in MESA (Multi-Ethnic Study of Atherosclerosis), a registry sponsored by the National Heart, Lung, and Blood Institute, National Institutes of Health.

METHODS

Cumulative 10-year costs for CVD medications, office visits, diagnostic procedures, coronary revascularization, and hospitalizations were calculated from detailed follow-up data. Costs were derived by using Medicare nationwide and zip code-specific costs, inflation corrected, discounted at 3% per year, and presented in 2014 U.S. dollars.

RESULTS

Risk factor prevalence increased dramatically and, by 10 years, diabetes, hypertension, and dyslipidemia was reported in 19%, 57%, and 53%, respectively. Self-reported symptoms (i.e., chest pain or shortness of breath) were common (approximately 40% of enrollees). At 10 years, approximately one-third of enrollees reported having an echocardiogram or exercise test, whereas 7% underwent invasive coronary angiography. These utilization patterns resulted in 10-year health care costs of $23,142. The largest proportion of costs was associated with CVD medication use (78%). Approximately $2 of every $10 were spent for outpatient visits and diagnostic testing among the elderly, obese, those with a high-sensitivity C-reactive protein level >3 mg/l, or coronary artery calcium score (CACS) ≥400. Costs varied widely from <$7,700 for low-risk (Framingham risk score <6%, 0 CACS, and normal glucose measurements at baseline) to >$35,800 for high-risk (persons with diabetes, Framingham risk score ≥20%, or CACS ≥400) subgroups. Among high-risk enrollees, CVD costs accounted for $74 million of the $155 million consumed by MESA participants.

CONCLUSIONS

Longitudinal patterns of health care resource use after screening revealed new evidence on the economic burden of treatment and testing patterns not previously reported. Maintenance of a healthy population has the potential to markedly reduce the economic burden of CVD among asymptomatic individuals.

Accreditation, Credentialing, and Quality Improvement in Diagnostic Medical Sonography: A Literature Review

There are few regulations regarding facility accreditation and individual credentialing in diagnostic medical sonography (DMS), although it is known that the quality of examinations in the field can vary based by the operator. This literature review summarizes the findings from 19 research studies on accreditation, credentialing, and quality improvement and includes illustrative quotes from 23 position papers and 42 editorials. The review uncovered large differences in facility accreditation status based on sonography specialty and geographical area. The findings included many examples of positive correlations between accreditation and improved quality and also a positive correlation between credentialing and improved image quality. The survey studies revealed overwhelming support for accreditation and credentialing. Many articles raised concerns about the unknown quality of sonograms performed in nonaccredited facilities or by uncredentialed sonographers. If facility accreditation and/or individual credentialing could be implemented nationwide in DMS, it may lead to increased quality within the field.

Hands-on Gross Anatomy Instruction Improves Clinical Imaging Skills Among Cardiovascular Fellows

INTRODUCTION

Multi-modality imaging is a crucial component of cardiovascular (CV) fellowship training and requires knowledge of CV anatomy for interpretation. We hypothesized that hands-on anatomy education would improve the imaging interpretation skills of CV fellows.

METHODS

The first-year CV fellowship class completed a hands-on cadaveric anatomy session correlated with clinical imaging. Fellows' ability to identify CV structures on cardiac imaging was assessed using a 30-question assessment tool administered at baseline and 1 week and 6 months post intervention. Advanced CV fellows (second or third year) who had not attended the session were also tested. Scores were expressed as median [interquartile range].

RESULTS

Among 9 first-year fellows, the majority reported no formal anatomy training since medical school (N = 7) and rated their knowledge of CV anatomy as fair or poor (N = 7) prior to the intervention. The median assessment score was higher 1 week after intervention vs baseline (24 [23-25] vs 19 [17-21]; P = .013) and remained higher than baseline at 6 months (26 [26-28] vs 19 [17-21]; P = .009). The 6-month post-intervention score for first-year fellows was not significantly different than that of senior fellows (n = 10) not exposed to the intervention (26 [26-28] vs 26 [23-27]; P = .434).

CONCLUSIONS

Gross anatomy instruction improved first-year CV fellows' interpretation of CV imaging. Anatomic instruction may be a useful adjunct to multi-modality imaging education.

Crowdsourcing consensus: proposal of a novel method for assessing accuracy in echocardiography interpretation

Quality in stress echocardiography interpretation is often gauged against coronary angiography (CA) data but anatomic obstructive coronary disease on CA is an imperfect gold standard for a stress induced wall motion abnormality. We examined the utility of crowd-sourcing a "majority-vote" consensus as an alternative 'gold standard' against which to evaluate the accuracy of an individual echocardiographer's interpretation of stress echocardiography studies. Participants independently interpreted baseline and post-exercise stress echocardiographic images of cases that had undergone follow up CA within 3 months of the stress echo in two surveys, 2 years apart. We examined the agreement of consensus on survey (survey participant response (> 60%) for one decision) with the stress echocardiography clinical read and with CA results. In the first survey, 29 participants reviewed and independently interpreted 14 stress echo cases. Consensus was reached in all 14 cases. There was good agreement between clinical and consensus (kappa = 0.57), survey participant response and consensus (kappa = 0.68) and consensus and CA results (kappa = 0.40). In the validation survey, the agreement between clinical reads and consensus (kappa = 0.75) and survey participant response and consensus (kappa = 0.81) remained excellent. Independent consensus is achievable and offers a fair comparison for stress echocardiographic interpretation. Future validation work, in other laboratories, and against hard outcomes, is necessary to test the feasibility and effectiveness of this approach.

Evolving, innovating, and revolutionary changes in cardiovascular imaging: We've only just begun!

In this review, we highlight the need for innovation and creativity to reinvent the field of nuclear cardiology. Revolutionary ideas brought forth today are needed to create greater value in patient care and highlight the need for more contemporary evidence supporting the use of nuclear cardiology practices. We put forth discussions on the need for disruptive innovation in imaging-guided care that places the imager as a central force in care coordination. Value-based nuclear cardiology is defined as care that is both efficient and effective. Novel testing strategies that defer testing in lower risk patients are examples of the kind of innovation needed in today's healthcare environment. A major focus of current research is the evolution of the importance of ischemia and the prognostic significance of non-obstructive atherosclerotic plaque and coronary microvascular dysfunction. Embracing novel paradigms, such as this, can aid in the development of optimal strategies for coronary disease management. We hope that our article will spurn the field toward greater innovation and focus on transformative imaging leading the way for new generations of novel cardiovascular care.

Use of echocardiography at diagnosis and detection of acute cardiac disease in youth with systemic lupus erythematosus

Objectives There are no guidelines on the use of echocardiography to detect cardiac manifestations of childhood-onset systemic lupus erythematosus (SLE). We quantify the prevalence of acute cardiac disease in youth with SLE, describe echocardiogram utilization at SLE diagnosis, and compare regional echocardiogram use with incident cardiac diagnoses. Methods Using the Clinformatics® DataMart (OptumInsight, Eden Prairie, MN) de-identified United States administrative database from 2000 to 2013, we identified youth ages 5-24 years with new-onset SLE (≥3 ICD-9 SLE codes 710.0, > 30 days apart) and determined the prevalence of diagnostic codes for pericardial disease, myocarditis, endocarditis, and valvular insufficiency. Multiple logistic regression was used to identify factors associated with echocardiography during the baseline period, up to one year before or six months after SLE diagnosis. We calculated a regional echocardiogram utilization index, which is the ratio of observed use over the mean predicted probability based on all available baseline characteristics. Spearman's rank correlation coefficient was used to evaluate the association between regional echocardiogram utilization indices and percentage of imaged youth diagnosed with their first cardiac manifestation following echocardiography. Results Among 699 youth with new-onset SLE, 18% had ≥ 1 diagnosis code for acute cardiac disease, of which valvular insufficiency and pericarditis were most common. Twenty-five percent of all youth underwent echocardiogram during the baseline period. Regional echocardiogram use was positively correlated with the percentage of imaged youth found to have cardiac disease (ρ = 0.71, p = 0.05). There was up to a five-fold difference in adjusted odds of baseline echocardiography between low- and high-utilizing regions (OR = 0.19, p = 0.007). Conclusion Nearly one-fifth of youth with new-onset SLE have acute cardiac manifestations; however, use of echocardiograms at SLE diagnosis is highly variable. There may be incremental diagnostic value to early use of echocardiography, but prospective studies are needed to determine whether greater use of echocardiograms modifies outcomes.

Clinical Outcomes After Cardiac Stress Testing Among US Patients Younger Than 65 Years

Background

Scientific statements have championed the measurement of clinical outcomes after cardiac stress testing to better define their value. Using contemporary national data, we sought to describe the characteristics of patients who experience outcomes after stress testing.

Methods and Results

Using administrative claims from a large national private insurer, we conducted an observational cohort study of patients without cardiovascular disease aged 25 to 64 years who underwent stress testing from 2006 to 2011 and had at least 1 year of membership in the insurance company before and after testing. We used Kaplan–Meier time‐to‐event analyses to determine rates of acute myocardial infarction (AMI), elective coronary revascularization, and coronary angiography without revascularization in the year following testing. We used logistic regression to determine factors associated with outcomes, and stratified the cohort into quintiles based on likelihood of experiencing AMI and/or revascularization to describe the characteristics of patients at highest and lowest risk. Among 553 027 patients who underwent stress testing (mean age 50 years, 49% women, 73% white), 0.8% were hospitalized for AMI, 1.8% underwent elective coronary revascularization, and 2.5% underwent coronary angiography without revascularization within 1 year. Patients who were older, male, and white were more likely to undergo subsequent revascularization. Patients in the lowest likelihood quintile were young (mean age 40 years), frequently women (84.7%), had a low incidence of coexisting conditions (5.2% with diabetes mellitus), and had a 0.5% rate of AMI and/or revascularization.

Conclusions

The proportion of US patients younger than 65 who had AMI and/or coronary revascularization after stress testing was low. Assessing risk of subsequent outcomes may be useful in improving patient referrals for stress testing.

Coronary artery disease reporting and data system (CAD-RADSTM): Inter-observer agreement for assessment categories and modifiers

BACKGROUND

The Coronary Artery Disease Reporting and Data System (CAD-RADS) provides a lexicon and standardized reporting system for coronary CT angiography.

OBJECTIVES

To evaluate inter-observer agreement of the CAD-RADS among an panel of early career and expert readers.

METHODS

Four early career and four expert cardiac imaging readers prospectively and independently evaluated 50 coronary CT angiography cases using the CAD-RADS lexicon. All readers assessed image quality using a five-point Likert scale, with mean Likert score ≥4 designating high image quality, and <4 designating moderate/low image quality. All readers were blinded to medical history and invasive coronary angiography findings. Inter-observer agreement for CAD-RADS assessment categories and modifiers were assessed using intra-class correlation (ICC) and Fleiss' Kappa (κ).The impact of reader experience and image quality on inter-observer agreement was also examined.

RESULTS

Inter-observer agreement for CAD-RADS assessment categories was excellent (ICC 0.958, 95% CI 0.938-0.974, p < 0.0001). Agreement among expert readers (ICC 0.925, 95% CI 0.884-0.954) was marginally stronger than for early career readers (ICC 0.904, 95% CI 0.852-0.941), both p < 0.0001. High image quality was associated with stronger agreement than moderate image quality (ICC 0.944, 95% CI 0.886-0.974 vs. ICC 0.887, 95% CI 0.775-0.95, both p < 0.0001). While excellent inter-observer agreement was observed for modifiers S (stent) and G (bypass graft) (both κ = 1.0), only fair agreement (κ = 0.40) was observed for modifier V (high risk plaque).

CONCLUSION

Inter-observer reproducibility of CAD-RADS assessment categories and modifiers is excellent, except for high-risk plaque (modifier V) which demonstrates fair agreement. These results suggest CAD-RADS is feasible for clinical implementation.

Defining Quality in Cardiovascular Imaging: A Scientific Statement From the American Heart Association

The aims of the current statement are to refine the definition of quality in cardiovascular imaging and to propose novel methodological approaches to inform the demonstration of quality in imaging in future clinical trials and registries. We propose defining quality in cardiovascular imaging using an analytical framework put forth by the Institute of Medicine whereby quality was defined as testing being safe, effective, patient-centered, timely, equitable, and efficient. The implications of each of these components of quality health care are as essential for cardiovascular imaging as they are for other areas within health care. Our proposed statement may serve as the foundation for integrating these quality indicators into establishing designations of quality laboratory practices and developing standards for value-based payment reform for imaging services. We also include recommendations for future clinical research to fulfill quality aims within cardiovascular imaging, including clinical hypotheses of improving patient outcomes, the importance of health status as an end point, and deferred testing options. Future research should evolve to define novel methods optimized for the role of cardiovascular imaging for detecting disease and guiding treatment and to demonstrate the role of cardiovascular imaging in facilitating healthcare quality.

Comparative Effectiveness Trials of Imaging-Guided Strategies in Stable Ischemic Heart Disease

The evaluation of patients with suspected stable ischemic heart disease is among the most common diagnostic evaluations with nearly 20 million imaging and exercise stress tests performed annually in the United States. Over the past decade, there has been an evolution in imaging research with an ever-increasing focus on larger registries and randomized trials comparing the effectiveness of varying diagnostic algorithms. The current review highlights recent randomized trial evidence with a particular focus comparing the effectiveness of cardiac imaging procedures within the stable ischemic heart disease evaluation for coronary artery disease detection, angina, and other quality of life measures, and major clinical outcomes. Also highlighted are secondary analyses from these trials on the economic findings related to comparative cost differences across diagnostic testing strategies.

Cardiac Stress Test Trends Among US Patients Younger Than 65 Years, 2005-2012

Importance

After a period of rapid growth, use of cardiac stress testing has recently decreased among Medicare beneficiaries and in a large integrated health system. However, it is not known whether declines in cardiac stress testing are universal or are confined to certain populations.

Objective

To determine trends in rates of cardiac stress testing among a large and diverse cohort of commercially insured patients.

Design, Setting, and Participants

A serial cross-sectional study with time trends was conducted using administrative claims from all members aged 25 to 64 years belonging to a large, national managed care company from January 1, 2005, to December 31, 2012. Linear trends in rates were determined using negative binomial regression models with procedure count as the dependent variable, calendar quarter as the key independent variable, and the size of the population as a logged offset term. Data analysis was performed from January 1, 2005, to December 31, 2012.

Main Outcomes and Measures

Age- and sex-adjusted rates of cardiac stress tests per calendar quarter (reported as number of tests per 100 000 person-years).

Results

A total of 2 085 591 cardiac stress tests were performed among 32 921 838 persons (mean [SD] age, 43.2 [10.9] years; 16 625 528 women [50.5%] and 16 296 310 [49.5%] men; 7 604 945 nonwhite [23.1%]). There was a 3.0% increase in rates of cardiac stress testing from 2005 (3486 tests; 95% CI, 3458-3514) to 2012 (3589 tests; 95% CI, 3559-3619; P = .01 for linear trend). Use of nuclear single-photon emission computed tomography decreased by 14.9% from 2005 (1907 tests; 95% CI, 1888-1926) to 2012 (1623 tests; 95% CI, 1603-1643; P = .03). Use of stress echocardiography increased by 27.8% from 2005 (709 tests; 95% CI, 697-721) to 2012 (906 tests; 95% CI, 894 to 920; P < .001). Use of exercise electrocardiography increased by 12.5% from 2005 (861 tests; 95% CI, 847-873) to 2012 (969 tests; 95% CI, 953-985; P < .001). Use of other stress testing modalities increased 65.5% from 2006 (55 tests; 95% CI, 51-59) to 2012 (91 tests; 95% CI, 87-95; P < .001). For individuals aged 25 to 34 years, rates of cardiac stress testing increased 59.1% from 2005 (543 tests; 95% CI, 532-554) to 2012 (864 tests; 95% CI, 852-876; P < .001). For individuals aged 55 to 64 years, rates of cardiac stress testing decreased by 12.3% from 2005 (7894 tests; 95% CI, 7820-7968) to 2012 (6923 tests; 95% CI, 6853-6993; P < .001).

Conclusions and Relevance

In contrast to declines in the use of cardiac stress testing in some health care systems, we observed a small increase in its use among a nationally representative cohort of commercially insured patients. Our findings suggest that observed trends in the use of cardiac stress testing may have been driven more by unique characteristics of populations and health systems than national efforts to reduce the overuse of testing.

Credentials of Professionals Performing Echocardiography

We examined the IAC-Echocardiography applications database to describe the board certification of physicians and registration of sonographers and explored how staff credentials affected initial laboratory accreditation decision. Deidentified IAC-Echocardiography applications from January 2012 to December 2013 were reviewed, including size and setting of echocardiography laboratories, National Board of Echocardiography (NBE) testamur status of physicians, and registered credential status of sonographers. Multivariate logistic regression models evaluated associations between echocardiography laboratory characteristics and accreditation and deficiencies in peer-reviewed domains (staff, imaging protocols, image quality, reporting, and quality assurance) of accreditation. During the study period, 1921 echocardiography laboratories representing 10 602 physicians and 6841 sonographers applied for IAC-Echocardiography accreditation; 26.9% of physicians were NBE testamurs and 79.5% of sonographers were registered. NBE status of medical directors did not reach statistical significance for accreditation success (AOR 1.15 [0.93-1.42]), but number of registered sonographers per applicant did (AOR 1.13 [1.04-1.23]). NBE testamur medical directors were associated with fewer deficiencies in image quality (AOR 0.61 [0.48-0.79]) and reports (AOR 0.72 [0.56-0.92]). Applicants whose technical director was a physician rather than a sonographer were more likely to have deficiencies in image quality (AOR 1.84 [1.06-3.21]). Registered sonographers were associated with fewer deficiencies in the domains of staff credentials (AOR 0.84 [0.78-0.92]), reporting (AOR 0.88 [0.81-0.96]), and quality assurance (AOR 0.91 [0.84-0.98]). Registration status of sonographers, but not NBE testamur status of physicians, was positively associated with accreditation decisions. The overall interaction between individual certification and laboratory accreditation suggests a complementary role for both.

Association of Liability Concerns with Decisions to Order Echocardiography and Cardiac Stress Tests with Imaging

BACKGROUND

Professional societies have made efforts to curb overuse of cardiac imaging and decrease practice variation by publishing appropriate use criteria. However, little is known about the impact of physician-level determinants such as liability concerns and risk aversion on decisions to order testing.

METHODS

A web-based survey was administered to cardiologists and general practice physicians affiliated with two academic institutions. The survey consisted of four clinical scenarios in which appropriate use criteria rated echocardiography or stress testing as "may be appropriate." Respondents' degree of liability concerns and risk aversion were measured using validated tools. The primary outcome variable was tendency to order imaging, calculated as the average likelihood to order an imaging test across the clinical scenarios (1 = very unlikely, 6 = very likely). Linear regression models were used to evaluate the association between tendency to order imaging and physician characteristics.

RESULTS

From 420 physicians invited to participate, 108 complete responses were obtained (26% response rate, 54% cardiologists). There was no difference in tendency to order imaging between cardiologists and general practice physicians (3.46 [95% CI, 3.12-3.81] vs 3.15 [95% CI, 2.79-3.51], P = .22). On multivariate analysis, a higher degree of liability concerns was the only significant predictor of decisions to order imaging (mean difference in tendency to order imaging, 0.36; 95% CI, 0.09-0.62; P = .01).

CONCLUSION

In clinical situations in which performance of cardiac imaging is rated as "may be appropriate" by appropriate use criteria, physicians with higher liability concerns ordered significantly more testing than physicians with lower concerns.

Implementing a Continuous Quality Improvement Program in a High-Volume Clinical Echocardiography Laboratory: Improving Care for Patients With Aortic Stenosis

BACKGROUND

The management of aortic stenosis rests on accurate echocardiographic diagnosis. Hence, it was chosen as a test case to examine the utility of continuous quality improvement (CQI) approaches to increase echocardiographic data accuracy and reliability. A novel, multistep CQI program was designed and prospectively used to investigate whether it could minimize the difference in aortic valve mean gradients reported by echocardiography when compared with cardiac catheterization.

METHODS AND RESULTS

The Duke Echo Laboratory compiled a multidisciplinary CQI team including 4 senior sonographers and MD faculty to develop a mapped CQI process that incorporated Intersocietal Accreditation Commission standards. Quarterly, the CQI team reviewed all moderate- or greater-severity aortic stenosis echocardiography studies with concomitant catheterization data, and deidentified individual and group results were shared at meetings attended by cardiologists and sonographers. After review of 2011 data, the CQI team proposed specific amendments implemented over 2012: the use of nontraditional imaging and Doppler windows as well as evaluation of aortic gradients by a second sonographer. The primary outcome measure was agreement between catheterization- and echocardiography-derived mean gradients calculated by using the coverage probability index with a prespecified acceptable echocardiography-catheterization difference of <10 mm Hg in mean gradient. Between January 2011 and January 2014, 2093 echocardiograms reported moderate or greater aortic stenosis. Among cases with available catheterization data pre- and post-CQI, the coverage probability index increased from 54% to 70% (P=0.03; 98 cases, year 2011; 70 cases, year 2013). The proportion of patients referred for invasive valve hemodynamics decreased from 47% pre-CQI to 19% post-CQI (P<0.001).

CONCLUSIONS

A laboratory practice pattern that was amenable to reform was identified, and a multistep modification was designed and implemented that produced clinically valuable performance improvements. The new protocol improved aortic stenosis mean gradient agreement between echocardiography and catheterization and was associated with a measurable decrease in referrals of patients for invasive studies.

The prognostic value of regadenoson myocardial perfusion imaging

BACKGROUND

Regadenoson (REGA), a selective adenosine A2A receptor agonist, is the most widely used stress agent for SPECT myocardial perfusion imaging (MPI) in the United States. The diagnostic accuracy of REGA MPI is comparable to Adenosine MPI, but its prognostic value is not well defined.

METHODS

We categorized 1,400 patients (700 consecutive normal and 700 consecutive abnormal REGA-MPIs) into 4 groups based on the perfusion defect size using automated quantitative analysis: Group 1: normal perfusion; Group 2: <10% of left ventricle; Group 3: 10%-20%; Group 4: >20%. The primary outcome was a composite of cardiac death, myocardial infarction (MI), and late coronary revascularization (CR >90 days after MPI).

RESULTS

Of the 1,400 patients (42% male, 37% diabetes, 21% heart failure, 26% end-stage renal disease), the primary outcome occurred in 23% (17% cardiac death, 4% MI, 6% late CR) during 46 ± 18 months of follow-up and 8% had early CR (within 90 days of MPI). Early CR occurred in 0.4%, 9%, 17%, and 17% and the primary outcome in 10%, 27%, 31%, and 43% in Groups 1-4, respectively (P < .001 for both). In an adjusted Cox proportional model, the hazard ratio for the primary outcome was 2.68 (1.77-4.06), 3.32 (2.28-4.83), and 4.05 (2.78-5.91) for Groups 2-4 compared to Group 1.

CONCLUSION

REGA MPI provides powerful prognostic information that has important implications in patient management and can guide clinical practice.

The incremental impact of cardiac MRI on clinical decision-making

OBJECTIVE

Despite a significant expansion in the use of cardiac MRI (CMR), there is inadequate evaluation of its incremental impact on clinical decision-making over and above other well-established modalities. We sought to determine the incremental utility of CMR in routine practice.

METHODS

629 consecutive CMR studies referred by 44 clinicians from 9 institutions were evaluated. Pre-defined algorithms were used to determine the incremental influence on diagnostic thinking, influence on clinical management and thus the overall clinical utility. Studies were also subdivided and evaluated according to the indication for CMR.

RESULTS

CMR provided incremental information to the clinician in 85% of cases, with incremental influence on diagnostic thinking in 85% of cases and incremental impact on management in 42% of cases. The overall incremental utility of CMR exceeded 90% in 7 out of the 13 indications, whereas in settings such as the evaluation of unexplained ventricular arrhythmia or mild left ventricular systolic dysfunction, this was <50%.

CONCLUSION

CMR was frequently able to inform and influence decision-making in routine clinical practice, even with analyses that accepted only incremental clinical information and excluded a redundant duplication of imaging. Significant variations in yield were noted according to the indication for CMR. These data support a wider integration of CMR services into cardiac imaging departments.

ADVANCES IN KNOWLEDGE

These data are the first to objectively evaluate the incremental value of a UK CMR service in clinical decision-making. Such data are essential when seeking justification for a CMR service.

Variation in use of echocardiography among veterans who use the Veterans Health Administration vs Medicare

BACKGROUND

Rapid growth in the provision of cardiac imaging tests has led to concerns about overuse. Little is known about the degree to which health care delivery system characteristics influence use and variation in echocardiography.

METHODS

We analyzed administrative claims of veterans with heart failure older than 65 years from 2007 to 2010 across 34 metropolitan service areas (MSAs). We compared overall rates and geographic variation in use of transthoracic echocardiography (TTE) between veterans who used the Veterans Health Administration (VA) and propensity-matched veterans who used Medicare. "Dual users" were excluded.

RESULTS

There were no significant differences in clinical characteristics or mortality between the propensity-matched cohorts (overall n = 30,404 veterans, mean age 76 years, mortality rate 52%). The Medicare cohort had a significantly higher overall rate of TTE use compared with the VA cohort (1.25 vs 0.38 TTEs per person-year, incidence rate ratio 2.89 [95% CI 2.80-3.00], both P < .001), but a similar coefficient of variation across MSAs (0.36 [95% CI 0.27-0.45] vs 0.48 [95% CI 0.37-0.59]). There was a moderate to strong correlation in variation at the MSA level between cohorts (Spearman r = 0.58, P < .001).

CONCLUSION

Overall rates of TTE use were significantly higher in a Medicare cohort compared with a propensity score-matched VA cohort of veterans with heart failure living in urban areas, with similar relative degrees of geographic variation and moderate to strong regional correlation. Rates of TTE use may be strongly influenced by health care system characteristics, but local practice styles influence echocardiography rates irrespective of health system.

Overview of quality in cardiovascular imaging and procedures for clinicians: focus on appropriate-use-criteria guidelines

Cardiovascular imaging and procedures have experienced exponential growth over the past 20 years in terms of new modalities, procedure volume, technological sophistication, and cost. As a result, related quality improvement tools have become multifaceted works in progress. This article briefly summarizes the evolution of the time-honored American College of Cardiology Foundation/American Heart Association clinical practice guidelines versus the newer American College of Cardiology Foundation appropriate-use-criteria guidelines and how these may interact with emerging performance measures, clinical data registries, and cardiovascular laboratory accreditation initiatives.

Comparison of the usefulness of heart rate variability versus exercise stress testing for the detection of myocardial ischemia in patients without known coronary artery disease

Heart rate variability (HRV) has been shown to be attenuated in patients with coronary artery disease (CAD) and may, therefore, be possibly used for the early detection of myocardial ischemia. We aimed to evaluate the diagnostic yield of a novel short-term HRV algorithm for the detection of myocardial ischemia in subjects without known CAD. We prospectively enrolled 450 subjects without known CAD who were referred to tertiary medical centers for exercise stress testing (EST) with single-photon emission computed tomography myocardial perfusion imaging (MPI). All subjects underwent 1-hour Holter testing with subsequent HRV analysis before EST with MPI. The diagnostic yield of HRV analysis was compared with EST, using MPI as the gold standard for the noninvasive detection of myocardial ischemia. All subjects had intermediate pretest probability for CAD. Mean age was 62 years, 38% were women, 51% had hypertension, and 25% diabetes mellitus. HRV analysis showed superior sensitivity (77%) compared with standard EST (27%). After multivariate adjustment, HRV was independently associated with an 8.4-fold (p <0.001) increased likelihood for the detection of myocardial ischemia by MPI, whereas EST did not show a statistically significant association with a positive MPI (odds ratio 2.1; p = 0.12). Of subjects who were referred for subsequent coronary angiography, the respective sensitivities of HRV and EST for the detection of significant CAD were 73% versus 26%. Our data suggest that HRV can be used as an important noninvasive technique for the detection of myocardial ischemia in subjects without known CAD, providing superior sensitivity to conventional EST in this population.

Incremental cost-effectiveness of dobutamine stress cardiac magnetic resonance imaging in patients at intermediate risk for coronary artery disease

Aims

The effectiveness of stress cardiac magnetic resonance (CMR) as a gatekeeper for coronary angiography (CA) has been established. Level five HTA studies according to the hierarchical model of diagnostic test evaluation are not available.

Methods

This cohort study included 1,158 consecutive patients (mean age 63 ± 11 years, 42 % women) presenting at our institution between January 1, 2003 and December 31, 2004 with suspected coronary artery disease (CAD) for an elective CA. The patients were assessed for eligibility and propensity score matching was applied to address selection bias regarding the patients’ allocation to CMR or direct CA. Median patient follow-up was 7.9 years (95 % CI 7.8–8.0 years). The primary effect was calculated as relative survival difference. The cost unit calculation (per patient) at our institute was the source of costs.

Results

Survival was similar in CMR and CA (p = 0.139). Catheterizations ruling out CAD were significantly reduced by the CMR gate-keeper strategy. Patients with prior CMR had significantly lower costs at the initial hospital stay and at follow-up (CMR vs. CA, initial: 2,904€ vs. 3,421€, p = 0.018; follow-up: 2,045€ vs. 3,318€, p = 0.037). CMR was cost-effective in terms of a contribution of 12,466€ per life year to cover a part of the CMR costs.

Conclusion

Stress CMR prior to CA was saving 12,466€ of hospital costs per life year. Lower costs at follow-up suggest sustained cost-effectiveness of the CMR-guided strategy.

Electronic supplementary material

The online version of this article (doi:10.1007/s00392-014-0793-0) contains supplementary material, which is available to authorized users.