Temporal trends in the utilization of diagnostic testing and treatments for cardiovascular disease in the United States, 1993-2001

Comparing Costs of Noninvasive Cardiac Diagnostic Tests-a Population-Based Study

INTRODUCTION

Noninvasive cardiac diagnostic tests (NITs) for the diagnosis of coronary artery disease have been estimated to cost >$3 billion annually in the United States alone and have recently undergone scrutiny over concerns of overuse. Consequently, comparing costs of different NIT testing strategies is of urgent importance to health care planning.

METHODS

We utilized population-based administrative and clinical data from Ontario, Canada, to compare downstream costs between 4 available NIT testing strategies (graded exercise stress testing [GXT], stress echocardiography, cardiac computed tomography angiography [CCTA], and myocardial perfusion imaging [MPI] as well as no testing), among patients evaluated for chest pain. To compare costs among the tested (overall and by testing strategy) and nontested groups, we used a log-gamma generalized linear model to account for the skewed distribution of health care cost data, adjusting for relevant clinical covariates.

RESULTS

A total of 2,340,699 patients were included in our cohort, of whom 481,170 (21%) patients received 1 of the 4 NITs. Among patients who received a NIT, 254,492 (53%) received a GXT as their initial test, 154,137 (32%) received MPI, 69,160 (14%) received a stress echo, and 3,381 (<1%) received a CCTA. After adjustment for differences in baseline patient characteristics, receipt of any NIT was associated with an approximate 12% reduction in downstream 1-year mean costs (cost ratio = 0.88; 95% CI, 0.87, 0.89) compared with those without any testing. Comparing the different testing strategies with no testing, both GXT (cost ratio = 0.80; 95% CI, 0.79-0.81) and stress echocardiography (cost ratio = 0.82; 95% CI, 0.81-0.83) were associated with the lower downstream costs, while both MPI (cost ratio = 1.26; 95% CI, 1.25, 1.27) and CCTA (cost ratio = 1.29; 95% CI, 1.23, 1.35) were associated with higher downstream costs.

CONCLUSIONS

In a large population-based cohort consisting of >2 million people evaluated for chest pain, we report that receipt of noninvasive testing was associated with a 12% reduction in downstream costs when compared with no testing. Graded exercise stress testing and stress echocardiography were associated with the least downstream costs, whereas CCTA and MPI were associated with higher costs when compared with no testing. These findings may help inform testing decisions in chest pain patients.

On-site CT-derived cFFR in patients with suspected coronary artery disease: Feasibility on a 128-row CT scanner in everyday clinical practice

PURPOSE

 Technical feasibility of CT-based calculation of fractional flow reserve (cFFR) using a 128-row computed tomography scanner in an everyday routine setting. Post-processing and everyday practicability should be analyzed on the scanner on-site in connection with clinical parameters.

MATERIALS AND METHODS

 This single-center retrospective analysis included 230 patients (74 female; mean age 63.8 years) with CCTA within 21 months between 01/2018 and 09/2019 without non-pathological examinations. cFFR values were obtained using a deep learning-based non-commercial research prototype (cFFR Version3.5.0; Siemens Healthineers GmbH, Erlangen). cFFR values were evaluated at two points: at the maximum point of the stenosis and 1.0 cm distal to the stenosis. Comparison with invasive coronary angiography in 57/230 patients (24.7 %) was performed. CT parameters and quality were evaluated. Further subgroup classification concerning criteria of technical postprocessing was performed: no changes necessary, minor corrections necessary, major corrections necessary, and no evaluation was possible. The required time from starting the software to the final result was evaluated.

RESULTS

 A total of 116/448 (25.9 %) mild, 223/448 (49.8 %) moderate, and 109/448 (24.3 %) obstructive stenoses was found. The mean cFFR at the maximum point of the stenosis was 0.92 ± 0.09 and significantly higher than the cFRR value of 0.89 ± 0.13 distal to the stenosis (p < 0.001*). The mean degree of stenosis was 44.02 ± 26.99 % (range: 1-99 %) with an area of 5.39 ± 3.30 mm2. In a total of 45 patients (19.1 %), a relevant reduction in cFFR below 0.80 was determined. Overall, in 57/230 patients (24.8 %), catheter angiography was performed. No significant difference in the degree of maximal stenosis (CAD-RADS 0-2/3/4) was detected between the classification of CCTA and ICA (p = 0.171). The mean post-processing time varied significantly with 8.34 ± 4.66 min. in single-vessel CAD vs. 12.91 ± 3.92 min. in two-vessel CAD vs. 21.80 ± 5.94 min. in three-vessel CAD (each p < 0.001).

CONCLUSION

 Noninvasive onsite quantification of cFFR is feasible with minimal observer interaction in a routine real-world setting on a 128-row scanner. Deep learning-based algorithms allow a robust and semi-automatic on-site determination of cFFR based on data from standard CT scanners.

KEY POINTS

· Non-invasive on-site quantification of cFFR is feasible with minimal observer interaction.. · Deep-learning based algorithms allow robust and semi-automatic on-site determination of cFFR.. · The mean follow-up time varied significantly with the extent of vascular CAD..

Diagnostic and prognostic value of H-ficolin for functionally relevant coronary artery disease

BACKGROUND

We aimed to test the diagnostic and prognostic ability of H-ficolin, an initiator of the lectin pathway of the complement system, for functionally relevant coronary artery disease (fCAD), and explore its determinants.

METHODS

The presence of fCAD was adjudicated using myocardial perfusion imaging single-photon emission tomography and coronary angiography. H-ficolin levels were measured by a sandwich-type immunoassay at rest, peak stress-test, and 2 h after stress-test. Cardiovascular death and non-fatal myocardial infarction were assessed during 5-year follow-up.

RESULTS

Among 1,571 patients (32.3 % women), fCAD was detected in 462 patients (29.4 %). H-ficolin concentration at rest was 18.6 (15.3-21.8) µg/ml in patients with fCAD versus 17.8 (15.4-21.5) µg/ml, p = 0.33, in patients without fCAD, resulting in an AUC of 0.53 (95 %CI 0.48-0.56). During follow-up, 107 patients (6.8 %) had non-fatal myocardial infarction and 99 patients (6.3 %) experienced cardiovascular death. In Cox regression analysis, H-ficolin was not a predictor of events in the overall cohort. Subgroup analysis suggested a potential link between H-ficolin and non-fatal myocardial infarction in patients without fCAD (adjusted HR 1.03, 95 % CI 1.02-1.15, p = 0.005). H-ficolin concentration showed a weak positive correlation with systolic (r = 0.069, p < 0.001) and diastolic blood pressure (r = 0.111, p < 0.001).

CONCLUSION

H-ficolin concentration did not have diagnostic and/or prognostic value in patients referred for fCAD work-up.

Sex and Race Differences in Cardiac Sarcoidosis Presentation, Treatment and Outcomes

BACKGROUND

Although sex- and race-based patterns have been described in the extracardiac organ involvement of sarcoidosis, cardiac sarcoidosis (CS)-specific studies are lacking.

METHODS

We studied CS presentation, treatment and outcomes based on sex and race in a tertiary-center cohort. Multivariable adjusted Cox proportional hazards and survival analyses were performed for primary composite outcomes (left ventricular assist device, heart transplantation, all-cause death) and for secondary outcomes (ventricular arrhythmia and all-cause death.

RESULTS

We identified 252 patients with CS (108 female, 109 Black). At presentation with CS, females vs males (P = 0.001) and Black vs White individuals (P = 0.001) more commonly had symptomatic heart failure (HF), with HF most common in Black females (ANOVA P < 0.001). Treatment differences included more corticosteroid use (90% vs 79%; P = 0.020), higher 1-year prednisone dosage (13 vs 10 mg; P = 0.003) and less frequent early steroid-sparing agent use in males (29% vs 40%; P = 0.05). Black participants more frequently received a steroid-sparing agent (75% vs 60%; P = 0.023). Composite outcome-free survival did not differ by sex or race. Male sex had an adjusted hazard ratio of 2.34 (95% CI 1.13, 4.80; P = 0.021) for ventricular arrhythmia.

CONCLUSION

CS course may differ by sex and race and may contribute to distinct clinical CS phenotypes.

Effect of 320-Row Computed Tomography Acquisition Technology on Coronary Computed Tomography Angiography-Derived Fractional Flow Reserve Based on Machine Learning: Systolic and Diastolic Scan Acquisition

BACKGROUND

The aim of the study is to investigate the performance of coronary computed tomography angiography (CCTA)-derived fractional flow reserve (CT-FFR) in the same patient evaluated by different systolic and diastolic scans, aiming to explore whether 320-slice CT scanning acquisition protocol has an impact on CT-FFR value.

METHODS

One hundred forty-six patients with suspected coronary artery stenosis who underwent CCTA examination were included into the study. The prospective electrocardiogram gated trigger sequence scan was performed and electrocardiogram editors selected 2 optimal phases of systolic phase (preset collection trigger at 25% of R-R interval) and diastolic phase (preset collection trigger at 75% of R-R interval) for reconstruction. The lowest CT-FFR value (the CT-FFR value at the distal end of each vessel) and the lesion CT-FFR value (at 2 cm distal to the stenosis) after coronary artery stenosis were calculated for each vessel. The difference of CT-FFR values between the 2 scanning techniques was compared using paired Wilcoxon signed-rank test. Pearson correlation value and Bland-Altman were performed to evaluate the consistency of CT-FFR values.

RESULTS

A total of 366 coronary arteries from the remaining 122 patients were analyzed. There was no significant difference regarding the lowest CT-FFR values between systole phase and diastole phase across all vessels. In addition, there was no significant difference in the lesion CT-FFR value after coronary artery stenosis between systole phase and diastole phase across all vessels. The CT-FFR value between the 2 reconstruction techniques had excellent correlation and minimal bias in all groups. The correlation coefficient of the lesion CT-FFR values for left anterior descending branch, left circumflex branch, and right coronary artery were 0.86, 0.84, and 0.76, respectively.

CONCLUSIONS

Coronary computed tomography angiography-derived fractional flow reserve based on artificial intelligence deep learning neural network has stable performance, is not affected by the acquisition phase technology of 320-slice CT scan, and has high consistency with the evaluation of hemodynamics after coronary artery stenosis.

Serum neurofilament light chain in functionally relevant coronary artery disease and adverse cardiovascular outcomes

Background: Functionally relevant coronary artery disease (fCAD), causing symptoms of myocardial ischemia, can currently only be reliably detected with advanced cardiac imaging. Serum neurofilament light chain (sNfL) is a biomarker for neuro-axonal injury known to be elevated by cardiovascular (CV) risk factors and cerebrovascular small-vessel diseases. Due to their pathophysiological similarities with fCAD and the link to CV risk factors, we hypothesised that sNfL may have diagnostic and prognostic value for fCAD and adverse cardiovascular outcomes.Methods: Of the large prospective Basel VIII study (NCT01838148), 4'016 consecutive patients undergoing cardiac work-up for suspected fCAD were included (median age 68 years, 32.5% women, 46.9% with history of CAD). The presence of fCAD was adjudicated using myocardial perfusion imaging single-photon emission tomography (MPI-SPECT) and coronary angiography. sNfL was measured using a high-sensitive single-molecule array assay. All-cause and cardiovascular death, myocardial infarction (MI), and stroke/transient ischaemic attack (TIA) during 5-year follow-up were the prognostic endpoints.Results: The diagnostic accuracy of sNfL for fCAD as quantified by the area under the curve (AUC) was low (0.58, 95%CI 0.56-0.60). sNfL was strongly associated with age, renal dysfunction, and body mass index and was a strong and independent predictor of all-cause death, cardiovascular death, and stroke/TIA but not MI. Time-dependent AUC for cardiovascular-death at 1-year was 0.85, 95%CI 0.80-0.89, and 0.81, 95%CI 0.77-0.86 at 2-years.Conclusion: While sNfL concentrations did not show a diagnostic role for fCAD, in contrast, sNfL was a strong and independent predictor of cardiovascular outcomes, including all-cause death, cardiovascular death and stroke/TIA.

The use and the cost of outpatient diagnostic procedures for cardiovascular diseases in Isfahan province: A utilization study

BACKGROUND

Cardiovascular diseases (CVDs) are among the most important causes of premature death, disability, disease burden, and increasing the cost of healthcare worldwide. Having an overview of service utilization can help policymakers to plan more effective use of those services and to cut costs. Thus, this study aims to determine the amount of use as well as the cost of various outpatient diagnostic procedures for CVDs in Isfahan province of Iran from 2011 to 2017.

MATERIALS AND METHODS

This descriptive study used insurance claim data (time period: 2011-2017) from Health Insurance Organization in Isfahan province to determine the amount of use and the cost of various outpatient diagnostic procedures for CVDs. Afterward, based on these data, the use and the cost of various outpatient diagnostic procedures for CVDs were estimated for the total population of Isfahan province. The list of outpatient diagnostic procedures for CVDs was carefully chosen according to experts' opinions.

RESULTS

The use and the cost of outpatient diagnostic procedures for CVDs have drastically increased in the study period (2011-2017). Since 2011, the number of procedures and their related costs have increased 6.6 and 30.76 times (11.74 times, adjusted with PPP conversion factor), respectively. Per capita use (per thousand people) was 18.75 in 2011, reaching 116.51 in 2017. Per capita cost (per thousand people) was 1,887,660 IRR (355 PPP$) in 2011, reaching 54,660,365 IRR (3920 PPP$) in 2017. The highest cost and use were related to echocardiography and electrocardiography, respectively. A notable increase has been observed in the share of radionuclide myocardial perfusion scan and analysis of pacemakers and ICDs of the total cost.

CONCLUSIONS

The use of outpatient diagnostic procedures for CVDs has drastically increased during the studied period. Consequently, the cost borne by the health system and the patients have notably increased. This may be because of the increase in the incidence and prevalence of CVDs during the study period. Greater access to related health services can be mentioned as another reason for this increase. Further research is needed to explain all potential reasons and their importance, which can provoke a suitable health policy reaction.

Non-traditional factors affecting referral for coronary angiography following SPECT myocardial perfusion imaging

BACKGROUND

The use of myocardial perfusion imaging (MPI) in the management of coronary artery disease (CAD) is well established. Although prior studies have shown disparities in the use of invasive angiography in patients with acute MI, data on factors affecting referral to angiography post-MPI are lacking. We sought to evaluate the primary determinants of referral to invasive angiography post-MPI and specifically assess the role of non-traditional non-clinical factors such as race/ethnicity, socioeconomic factors, insurance status, and marital status.

METHODS

All patients without known CAD who underwent stress SPECT MPI over 15 years were reviewed and the performance of coronary angiography within 90 days of their MPI was recorded. Multiple factors were analyzed for an association with referral to angiography, including exercise and MPI results, baseline demographics, traditional cardiac risk factors, and non-traditional factors such as ethnicity, insurance, marital and socioeconomic status. In a secondary analysis, these factors were assessed with regard to abnormal MPI results.

RESULTS

Out of 27,895 total patients, 2,150 (7.7%) underwent invasive coronary angiography. On multivariate analysis, inpatient location, positive ECG response, and abnormal MPI results were the strongest predictors of angiography. Non-traditional factors such as race/ethnicity and insurance status had a significant association with referral to angiography with Caucasians (OR 1.42, 95% CI 1.18-1.71, P < .0001) and those with private insurance (OR 1.35, 95% CI 1.13-1.62, P = .001) or Medicare (OR 1.30, 95% CI 1.08-1.56, P = .006) having higher rates of angiography despite controlling for traditional risk factors and test results.

CONCLUSION

Our study results indicate that non-traditional factors such as race/ethnicity and insurance status influence patient management decisions and impact the performance of downstream cardiac invasive testing after stress MPI. Higher rates of angiography in Caucasians, privately insured and Medicare patients were seen despite controlling for traditional risk factors and abnormal test results. Further research is needed to better understand these disparities, especially in the current healthcare environment.

Patient, physician and geographic predictors of cardiac stress testing strategy in Ontario, Canada: a population-based study

OBJECTIVES

To identify patient, physician and geographic level factors that are associated with variation in initial stress testing strategy in patients evaluated for chest pain.

DESIGN

Retrospective cohort study.

SETTING

Population-based study of patients undergoing evaluation for chest pain in Ontario, Canada between 1 January 2011 and 31 March 2018.

PARTICIPANTS

103 368 patients who underwent stress testing (graded exercise stress testing (GXT), stress echocardiography (stress echo) or myocardial perfusion imaging (MPI)) following evaluation for chest pain.

PRIMARY AND SECONDARY OUTCOME MEASURES

To identify the patient, physician and geographic level factors associated with variation in initial test selection, we fit two separate 2-level hierarchical multinomial logistic regression models for which the outcome was initial stress testing strategy (GXT, MPI or stress echo).

RESULTS

There was significant variability in the initial type of stress test performed, with approximately 50% receiving a GXT compared with approximately 36% who received MPI and 14% who received a stress echo. Physician-level factors were key drivers of this variation, accounting for up to 59.0% of the variation in initial testing. Physicians who graduated medical school >30 years ago were approximately 45% more likely to order an initial stress echo (OR 1.45, 95% CI 1.17 to 1.80) than a GXT. Cardiovascular disease specialists were approximately sevenfold more likely to order an initial MPI (OR 7.35, 95% CI 5.38 to 10.03) than a GXT. Patients aged >70 years were approximately fivefold more likely to receive an MPI (OR 4.74, 95% CI 4.42 to 5.08) and approximately 26% more likely to receive a stress echo (OR 1.26, 95% CI 1.15 to 1.38) than a GXT.

CONCLUSIONS

We report significant variability in initial stress testing strategy in Ontario. Much of that variability was driven by physician-level factors that could potentially be addressed through educational campaigns geared at reducing this variability and improving guideline adherence.

Exposure to low-dose ionising radiation from cardiac catheterisation and risk of cancer: the COCCINELLE study cohort profile

PURPOSE

The COCCINELLE study is a nationwide retrospective French cohort set up to evaluate the risk of cancer in patients who undergone cardiac catheterisation (CC) procedures for diagnosis or treatment of congenital heart disease during childhood.

PARTICIPANTS

Children who undergone CC procedures from 1 January 2000 to 31 December 2013, before the age of 16 in one of the 15 paediatric cardiology departments which perform paediatric CC in mainland France were included. The follow-up started at the date of the first recorded CC procedure until the exit date, that is, the date of death, the date of first cancer diagnosis, the date of the 18th birthday or the 31 December 2015, whichever occurred first. The cohort was linked to the National Childhood Cancer Registry to identify patients diagnosed with cancer and with the French National Directory for the Identification of Natural Persons to retrieve the patients' vital status.

FINDINGS TO DATE

A total of 17 104 children were included in the cohort and followed for 110 335 person-years, with 22 227 CC procedures collected. Among the patients, 81.6% received only one procedure. Fifty-nine cancer cases were observed in the cohort. Standardised incidence ratios (SIRs) were increased for all-cancer (SIR=3.8, 95% CI: 2.9 to 4.9), leukaemia (SIR=3.3, 95% CI: 2.0 to 5.4), lymphoma (SIR=14.9, 95% CI: 9.9 to 22.5) and solid cancers excluding central nervous system (CNS) tumours (SIR=3.3, 95% CI: 2.0 to 5.5) compared with the general population.

FUTURE PLANS

Dose reconstruction is currently underway to estimate individual cumulative doses absorbed to relevant organs, including red bone marrow and brain for respectively haematologic disorders and CNS tumours risk estimation. A dose-response analysis will be conducted with consideration to confounding factors such as age at exposure, gender, predisposing factors to cancer and other sources of medical diagnostic low-dose ionising radiation.

Discrimination capability of pretest probability of stable coronary artery disease: a systematic review and meta-analysis suggesting how to improve validation procedures

OBJECTIVE

Externally validated pretest probability models for risk stratification of subjects with chest pain and suspected stable coronary artery disease (CAD), determined through invasive coronary angiography or coronary CT angiography, are analysed to characterise the best validation procedures in terms of discriminatory ability, predictive variables and method completeness.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Global Health (Ovid), Healthstar (Ovid) and MEDLINE (Ovid) searched on 22 April 2020.

ELIGIBILITY CRITERIA

We included studies validating pretest models for the first-line assessment of patients with chest pain and suspected stable CAD. Reasons for exclusion: acute coronary syndrome, unstable chest pain, a history of myocardial infarction or previous revascularisation; models referring to diagnostic procedures different from the usual practices of the first-line assessment; univariable models; lack of quantitative discrimination capability.

METHODS

Eligibility screening and review were performed independently by all the authors. Disagreements were resolved by consensus among all the authors. The quality assessment of studies conforms to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). A random effects meta-analysis of area under the receiver operating characteristic curve (AUC) values for each validated model was performed.

RESULTS

27 studies were included for a total of 15 models. Besides age, sex and symptom typicality, other risk factors are smoking, hypertension, diabetes mellitus and dyslipidaemia. Only one model considers genetic profile. AUC values range from 0.51 to 0.81. Significant heterogeneity (p<0.003) was found in all but two cases (p>0.12). Values of I² >90% for most analyses and not significant meta-regression results undermined relevant interpretations. A detailed discussion of individual results was then carried out.

CONCLUSIONS

We recommend a clearer statement of endpoints, their consistent measurement both in the derivation and validation phases, more comprehensive validation analyses and the enhancement of threshold validations to assess the effects of pretest models on clinical management.

PROSPERO REGISTRATION NUMBER

CRD42019139388.

Appropriate use criteria implementation with modified Haller index for predicting stress echocardiographic results and outcome in a population of patients with suspected coronary artery disease

The hypothesis that modified Haller index (MHI) integration with the existing appropriate use criteria (AUC) categories may predict exercise stress echocardiography (ESE) results and outcome of patients with suspected coronary artery disease (CAD) has never been previously investigated. We retrospectively analyzed 1230 consecutive patients (64.8 ± 13.1 years, 58.9% men) who underwent ESE for suspected CAD between February 2011 and September 2019 at our institution. MHI (chest transverse diameter over the distance between sternum and spine) was assessed in all patients. A true positive (TP) ESE was a positive ESE with obstructive CAD according to subsequent coronary angiography. During follow-up time, we evaluated the occurrence of any of the following: (1) cardiovascular (CV) hospitalizations; (2) Cardiac death or sudden death. Overall, 734 (59.7%), 357 (29.0%) and 139 (11.3%) indications for ESE were classified as appropriate (Group 1), rarely appropriate (Group 2) and which may be appropriate (Group 3), respectively. A funnel chest (defined by an MHI > 2.5) was detected in 30.3%, 82.1% and 49.6% of Groups 1, 2 and 3 subjects, respectively (p < 0.0001). On multivariate logistic regression analysis, male sex (OR 1.41, 95%CI 1.02-2.03, p = 0.01) and type-2 diabetes (OR 3.63, 95%CI 2.49-5.55, p = 0.001) were directly correlated to a TP ESE, while "rarely appropriate" indication for ESE with MHI > 2.5 (OR 0.16, 95%CI 0.11-0.22, p < 0.0001) showed a significant inverse correlation with the outcome. During a mean follow-up of 2.5 ± 1.9 years, 299 CV events occurred: 76.4%, 3.5% and 20.1% in Groups 1, 2 and 3, respectively. On multivariate Cox regression analysis, smoking (HR 1.33, 95%CI 1.19-1.48), type 2 diabetes (HR 2.28, 95%CI 1.74-2.97), dyslipidemia (HR 3.51, 95%CI 2.33-5.15), beta-blockers (HR 0.55, 95%CI 0.41-0.75), statins (HR 0.60, 95%CI 0.45-0.80), peak exercise average E/e' ratio (HR 1.08, 95%CI 1.06-1.09), positive ESE (HR 3.12, 95%CI 2.43-4.01) and finally "rarely appropriate" indication for ESE with MHI > 2.5 (HR 0.15, 95%CI 0.08-0.23) were independently associated with CV events. The implementation of AUC categories with MHI assessment may select a group of patients with extremely low probability of both TP ESE and adverse CV events over a medium-term follow-up. A simple noninvasive chest shape assessment could reduce unnecessary exams.

Appropriate use of multimodality stress testing for chest pain in new patient referrals to cardiologists

OBJECTIVE

In response to the growing use of imaging-based cardiac stress tests in the evaluation of stable ischemic heart disease, professional societies have developed appropriate use criteria (AUC). AUC will soon be linked to reimbursement of advanced diagnostic imaging for Medicare beneficiaries via Clinical Decision Support Mechanisms (CDSMs). We sought to characterize the frequency and type of stress test utilization for chest pain referrals evaluated by cardiologists and determine appropriateness.

METHODS

We conducted a retrospective review of new patient referrals seen by general cardiologists at an academic medical center between 2016 and 2017 for a diagnosis of chest pain or angina. Type of stress test ordered, if any, and its appropriateness (Appropriate, May be appropriate, and Rarely appropriate) were ascertained based on the 2013 multimodality AUC guideline document.

RESULTS

There were 535 total outpatients. After applying exclusion criteria, there were 349 patients in the sample; the average age was 52 ± 15 years and 53% were female. Most chest pain was nonanginal (65%). Pretest probability of CAD was most commonly intermediate (54%). A total of 183 patients (52%) were referred for stress testing. The majority of stress tests were considered appropriate (82%) by AUC.

CONCLUSION

Most patients referred to cardiologists for evaluation of chest pain or angina had nonanginal chest pain and an intermediate pretest probability of CAD. Stress testing was ordered in about half of these patients and the majority were considered appropriate by AUC. These findings suggest that indiscriminate use of CDSMs may not be warranted.

High-frequency QRS analysis to supplement ST evaluation in exercise stress electrocardiography: Incremental diagnostic accuracy and net reclassification

BACKGROUND

Exercise stress electrocardiography (ECG) alone is underutilized in part due to poor diagnostic accuracy. High-frequency QRS analysis (HF-QRS) is a novel tool to supplement ST evaluation during stress ECG. We compared the diagnostic accuracy and net reclassification of HF-QRS analysis compared with ST evaluation for substantial myocardial ischemia by exercise SPECT myocardial perfusion imaging (MPI).

METHODS AND RESULTS

Exercise SPECT MPI was performed in 257 consecutive eligible patients (mean age 59 ± 12, 67% male). An ischemic HF-QRS pattern was defined as a ≥ 1 µV absolute reduction and a ≥ 50% relative reduction of the root-mean-square of the 150-250 Hz band signal in ≥ 3 leads. Left ventricular ischemia of ≥ 10% on SPECT MPI was the diagnostic standard for substantial myocardial ischemia. HF-QRS analysis demonstrated incremental diagnostic value to ST evaluation plus clinical risk factors (AUC 0.804 vs 0.749, P < .0001). A HF-QRS + ST -analysis strategy identified 92.3% of subjects with substantial ischemia and no abnormality in 59.9% of the cohort. No cardiac events occurred in patients without substantial ischemia identified by HF-QRS analysis.

CONCLUSIONS

In this prospective analysis, exercise stress ECG with HF-QRS analysis identified any and substantial ischemia with high diagnostic accuracy and may allow more than half of referred patients to safely avoid imaging.

Use of Cardiac Noninvasive Testing After Emergency Department Discharge: Association of Hospital Network Testing Intensity and Outcomes in Ontario, Canada

Background

The relationship between noninvasive cardiac diagnostic testing intensity and downstream clinical outcomes is unclear. Our objective was to examine the relationship between hospital network noninvasive cardiac diagnostic testing intensity and downstream clinical outcomes in patients who were discharged from the emergency department after assessment for chest pain.

Methods and Results

We employed a retrospective cohort study design of 387 809 patients evaluated for chest pain in the emergency department between April 1, 2010 and March 31, 2016. Hospital networks were divided into tertiles based on usage of noninvasive cardiac diagnostic testing. The primary outcome was a composite of acute myocardial infarction or all‐cause mortality. Adjusted Cox proportional hazards models were used to compare the hazard of the composite outcome of myocardical infarction and/or all‐cause mortality between the tertiles. After adjustment for clinically relevant covariates, patients evaluated for chest pain in intermediate noninvasive cardiac diagnostic testing usage tertile hospital networks did not have significantly different hazards of the composite outcome when compared with those evaluated in low usage tertile hospital networks >90 days (hazard ratio [HR], 1.00; 95% CI, 0.83–1.21), 6 months (HR, 1.07; 95% CI, 0.92–1.24), and 1 year (HR, 1.03; 95% CI, 0.94–1.14). Patients evaluated in the high usage tertile also did not have significantly different hazards of the composite outcome compared with those evaluated in the low usage tertile at 90 days (HR, 0.98; 95% CI, 0.80–1.19), 6 months (HR, 1.01; 95% CI, 0.87–1.17); and 1 year (HR, 0.95; 95% CI, 0.86–1.05).

Conclusions

Our population‐based study demonstrated that high noninvasive cardiac diagnostic testing use intensity was not associated with reductions in downstream myocardial infarction or all‐cause mortality.

Prediction of obstructive coronary artery disease and prognosis in patients with suspected stable angina

AIMS

We hypothesized that the modified Diamond-Forrester (D-F) prediction model overestimates probability of coronary artery disease (CAD). The aim of this study was to update the prediction model based on pre-test information and assess the model's performance in predicting prognosis in an unselected, contemporary population suspected of angina.

METHODS AND RESULTS

We included 3903 consecutive patients free of CAD and heart failure and suspected of angina, who were referred to a single centre for assessment in 2012-15. Obstructive CAD was defined from invasive angiography as lesion requiring revascularization, >70% stenosis or fractional flow reserve <0.8. Patients were followed (mean follow-up 33 months) for myocardial infarction, unstable angina, heart failure, stroke, and death. The updated D-F prediction model overestimated probability considerably: mean pre-test probability was 31.4%, while only 274 (7%) were diagnosed with obstructive CAD. A basic prediction model with age, gender, and symptoms demonstrated good discrimination with C-statistics of 0.86 (95% CI 0.84-0.88), while a clinical prediction model adding diabetes, family history, and dyslipidaemia slightly improved the C-statistic to 0.88 (0.86-0.90) (P for difference between models <0.0001). Quartiles of probability of CAD from the clinical prediction model provided good diagnostic and prognostic stratification: in the lowest quartiles there were no cases of obstructive CAD and cumulative risk of the composite endpoint was less than 3% at 2 years.

CONCLUSION

The pre-test probability model recommended in current ESC guidelines substantially overestimates likelihood of CAD when applied to a contemporary, unselected, all-comer population. We provide an updated prediction model that identifies subgroups with low likelihood of obstructive CAD and good prognosis in which non-invasive testing may safely be deferred.

Clinical Effectiveness of Cardiac Noninvasive Diagnostic Testing in Outpatients Evaluated for Stable Coronary Artery Disease

Background

Despite more than 4 million cardiac noninvasive diagnostic tests (NIT) being performed annually for stable coronary artery disease in the United States, it is unclear whether they are associated with downstream improvements in outcomes when compared with no testing. We sought to determine whether NIT was associated with reduced downstream major adverse cardiovascular events when compared with not testing.

Methods and Results

We conducted a population‐based study of ≈1.5 million patients undergoing chest pain evaluation in Ontario, Canada. Patients were categorized into NIT and no‐testing groups. Cause‐specific proportional hazards models were used to compare the rate of major adverse cardiovascular events (composite outcome of unstable angina, acute myocardial infarction or cardiovascular mortality and each constituent) between the 2 groups after adjusting for clinically relevant covariates. The rate of the composite outcome was ≈25% lower for patients undergoing noninvasive testing (hazard ratio [HR], 0.77; 95% CI, 0.75–0.79). The benefits of testing were consistent for all 3 constituents of the composite; unstable angina (HR, 0.87; 95% CI, 0.82–0.93 for the NIT versus the no‐testing group), myocardial infarction (HR, 0.83; 95% CI, 0.79–0.86 for the NIT versus the no‐testing group) and cardiovascular mortality (HR, 0.68; 95% CI, 0.65–0.72 for the NIT versus the no‐testing group).

Conclusions

Our large population‐based study reports an ≈25% reduction in major adverse cardiovascular events that was independently associated with NIT in outpatients being evaluated for stable angina. This study demonstrates the prognostic importance of NIT versus no testing on the health of contemporary populations.

Coronary Disease Surveillance in the Community: Angiography and Revascularization

Background Temporal declines in cardiac stress tests results, coronary revascularization, and cardiovascular mortality have suggested a decline in the population burden of coronary disease until the 2000s. However, recent data indicate these favorable trends could be ending. We aimed to assess the evolution of the population burden of coronary disease in the community by examining trends in angiography and revascularization. Methods and Results We analyzed age- and sex-adjusted trends from all coronary angiographic diagnostic procedures and revascularizations performed in Olmsted County, MN from 2000 to 2018. A total of 12 981 invasive angiograms were performed among 9049 individuals (64% men; 55% aged ≥65 years). Adjusted angiography rates decreased by 30% (95% CI, 25%-34%) between 2000 and 2009 and leveled off thereafter. Including computed tomography, angiography uncovered an increase in angiography use in recent years (risk ratio=1.15 [95% CI, 1.07-1.23] for 2018 versus 2014) and a decline in the prevalence of anatomic CAD from 2000 to 2018. CAD severity declined substantially from 2000 to 2009, followed by a plateau. Among 6570 revascularizations (72% men; 57% aged ≥65 years), 77% were percutaneous coronary interventions and 23% coronary artery bypass graft surgeries. The adjusted revascularization rates declined by 34% (95% CI, 27%-39%) from 2000 to 2009, followed by a plateau (risk ratio=1.10 [95% CI, 1.00-1.22]). Conclusions Between 2000 and 2018 in the community, coronary angiography use declined initially, leveled off, and then increased. Trends in CAD severity and revascularization use decreased then plateaued. The most recent trends are concerning as they suggest the burden of coronary disease is no longer declining. This warrants reinvigorated primary prevention and population surveillance.

Cardiac intervention rates for older patients with acute myocardial infarction in the United States and Ontario, 2003-2013: a retrospective cohort study

BACKGROUND

Previous work showed lower cardiac intervention rates for patients with acute myocardial infarction (AMI) in Ontario than in the United States. We assessed whether Ontario's efforts to improve access to rapid percutaneous coronary intervention (PCI) for AMI were associated with improved timeliness of care and whether this closed the gap between the 2 jurisdictions.

METHODS

In this retrospective cohort study, we followed adults aged 66-99 years in the US and Ontario for 30 days after admission for incident AMI between 2003 and 2013 using health administrative data from both countries. We calculated the proportion of patients who received cardiac catheterization, PCI and coronary artery bypass grafting on the day of and within 30 days of admission overall and according to AMI type (ST-segment elevation AMI [STEMI] v. non-STEMI) and risk group (low, medium or high predicted risk of 30-d mortality).

RESULTS

We followed 414 216 patients in the US and 112 484 in Ontario. The large disparities in cardiac intervention rates observed in 2003 mostly disappeared over time. By 2013, the proportion of patients who received same-day PCI was only slightly higher in the US than in Ontario (22.3% v. 19.2%), whereas the converse was true for 30-day PCI (44.0% v. 41.3%). In 2013, patients with STEMI in the US and Ontario received PCI at nearly identical rates on the day of admission (66.3% v. 63.8%); however, more patients at high risk with STEMI in the US than in Ontario received PCI, both on the day of admission (55.5% v. 44.7%) and by 30 days (60.5% v. 55.0%).

INTERPRETATION

Despite differences in resources and organization of delivery systems, by 2013, timely receipt of PCI by Ontario patients with AMI lagged only slightly behind that by US patients. A higher supply of PCI centres in the US may have facilitated earlier intervention among patients at high risk with STEMI.

Impact of Clinician Engagement on Implementation of the Pediatric Echocardiography Appropriate Use Criteria

We sought to determine whether awareness of the pediatric appropriate use criteria (AUC) affected transthoracic echocardiogram (TTE) ordering by cardiologists; evaluate for differences in classification of an encounter's AUC clinical scenario by investigator chart review compared with clinicians at the time of the encounter; and assess TTE yield by appropriateness rating. AUC clinical scenario(s) were assigned to patients without prior TTE by investigator chart review of visits in 2014 (n = 209) and 2016 (n = 199), and by clinician classification in 2016 (n = 671). Investigators documented TTE utilization and findings. Between 2014 and 2016, TTE utilization decreased from 54 to 33% (p < 0.001) of "rarely appropriate" (R) encounters, resulting in a decrease in overall TTE utilization from 73 to 55% of encounters (p < 0.001). There was only moderate agreement of AUC appropriateness by investigator chart review and clinician classification (κ = 0.533, p < 0.001). Abnormal TTE findings were detected in 18.7% of R encounters, with 21 of 24 abnormalities in infants younger than 4 months presenting with murmur. A decrease in TTE utilization for R encounters may represent a change in practice from increased awareness of the AUC. AUC scenario classification by clinicians at the time of the encounter could be superior to chart review. TTE abnormalities may be missed in infants younger than 4 months of age when evaluated for murmurs with the AUC.

Trends in Characteristics and Outcomes of Patients Undergoing Coronary Revascularization in the United States, 2003-2016

IMPORTANCE

Data on the contemporary changes in risk profile and outcomes of patients undergoing percutaneous coronary intervention (PCI) or coronary bypass grafting (CABG) are limited.

OBJECTIVE

To assess the contemporary trends in the characteristics and outcomes of patients undergoing PCI or CABG in the United States.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used a national inpatient claims-based database to identify patients undergoing PCI or CABG from January 1, 2003, to December 31, 2016. Data analysis was performed from July 15 to October 4, 2019.

MAIN OUTCOMES AND MEASURES

Demographic characteristics, prevalence of risk factors, and clinical presentation divided into 3 eras (2003-2007, 2008-2012, and 2013-2016) and in-hospital mortality of PCI and CABG stratified by clinical indication.

RESULTS

A total of 12 062 081 revascularization hospitalizations were identified: 8 687 338 PCIs (72.0%; mean [SD] patient age, 66.0 [10.8] years; 66.2% male) and 3 374 743 CABGs (28.0%; mean [SD] patient age, 64.5 [12.4] years; 72.1% male). The annual PCI volume decreased from 366 to 180 per 100 000 US adults and the annual CABG volume from 159 to 82 per 100 000 US adults. A temporal increase in the proportions of older, male, nonwhite, and lower-income patients and in the prevalence of atherosclerotic and nonatherosclerotic risk factors was found in both groups. The percentage of revascularization for myocardial infarction (MI) increased in the PCI group (22.8% to 53.1%) and in the CABG group (19.5% to 28.2%). Risk-adjusted mortality increased slightly after PCI for ST-segment elevation MI (4.9% to 5.3%; P < .001 for trend) and unstable angina or stable ischemic heart disease (0.8% to 1.0%; P < .001 for trend) but remained stable after PCI for non-ST-segment elevation MI (1.6% to 1.6%; P = .18 for trend). Risk-adjusted CABG morality markedly decreased in patients with MI (5.6% to 3.4% for all CABG and 4.8% to 3.0% for isolated CABG) and in those without MI (2.8% to 1.7% for all CABG and 2.1% to 1.2% for isolated CABG) (P < .001 for all).

CONCLUSIONS AND RELEVANCE

Significant changes were found in the characteristics of patients undergoing PCI and CABG in the United States between 2003 and 2016. Risk-adjusted mortality decreased significantly after CABG but not after PCI across all clinical indications.

Adoption of coronary artery disease - Reporting and Data System (CAD-RADS™) and observed impact on medical therapy and systolic blood pressure control

BACKGROUND

CAD-RADS was developed to standardize communication of per-patient maximal stenosis on coronary CT angiography (CCTA) and provide treatment recommendations and may impact primary prevention care and resource utilization. The authors sought to evaluate CAD-RADS adoption on preventive medical therapy and risk factor control amongst a mixed provider population.

METHODS

Statins, aspirin (ASA), systolic blood pressure and, when available, lipid panel changes were abstracted for 1796 total patients undergoing CCTA in the 12 months before (non-standard reporting, NSR, cohort) and after adoption of the CAD-RADS reporting template. Only initiation of a medication in a treatment naïve patient, escalation from baseline dose, or transition to a higher potency was considered an escalation/initiation in lipid therapy.

RESULTS

The CAD-RADS reporting template was utilized in 83.7% (751/897) of CCTAs after the CAD-RADS adoption period. After adjusting for any coronary artery disease (CAD) on CCTA, statin initiation/escalation was more commonly observed in the CAD-RADS cohort (aOR 1.46; 95%CI 1.12-1.90, p = 0.005), driven by higher rates of new statin initiation (aOR 1.79; 95%CI 1.23-2.58, p = 0.002). This resulted in a higher observed rates of total cholesterol improvement in the CAD-RADS cohort (58% vs 49%, p = 0.016). New ASA initiation was similar between reporting templates after adjustment for CAD on CCTA (aOR 1.40; 95%CI 0.97-2.02, p = 0.069). The ordering provider's specialty (cardiology vs non-cardiology) did not significantly impact the observed differences in initiation/escalation of statins and ASA (pinteraction = NS).

CONCLUSIONS

Adoption of CAD-RADS reporting was associated with increased utilization of preventive medications, regardless of ordering provider specialty.

Testing Real-World Application of Appropriateness Criteria of Single Photon Emission Computed Tomography (SPECT) In Two Egyptian Hospitals

BACKGROUND

The American College of Cardiology pioneered appropriateness criteria for single-photon emission computed tomography myocardial perfusion imaging in 2005 to account for evidence-based clinical relevance of stress perfusion imaging. Our aim was to assess and compare appropriateness use criteria in in Kobry al Kobba military hospital and Ain Shams University hospitals.

METHODS

All patients were subjected to thorough history taking, calculation of pretest probability and Framingham risk score, determination of appropriateness use criteria and stress-rest Tc 99m imaging to detect the presence of ischemia and one day Tc 99m imaging to detect viability.

RESULTS

The study included 442 patients with mean age of 56.5 years, with male predominance (77%), 38% were diabetics and 58% had hypertension. Seventy-eight percent of patients had appropriate tests, uncertain tests in 12% and 10% inappropriate studies. 47% of appropriate tests show positive results of SPECT.

CONCLUSION

We concluded that appropriateness criteria are effective in identifying appropriateness of SPECT in a diverse patient population.

Diagnostic Accuracy of Three-Dimensional Whole-Heart Magnetic Resonance Angiography to Detect Coronary Artery Disease with Invasive Coronary Angiography as a Reference: A Meta-Analysis

Objective: We aimed to evaluate the diagnostic performance of three-dimensional whole-heart magnetic resonance coronary angiography (MRCA) in detecting coronary artery disease (CAD) with invasive coronary angiography as the reference standard.Methods: We searched PubMed and Embase for studies evaluating the diagnostic performance of three-dimensional whole-heart MRCA for the diagnosis of CAD with invasive coronary angiography as the reference standard. The bivariate mixed-effects regression model was applied to synthesize available data. The clinical utility of whole-heart MRCA was calculated by the posttest probability based on Bayes’s theorem.Results: Eighteen studies were included, of which 16 provided data at the artery level. Patient-based analysis revealed a pooled sensitivity of 0.90 (95% confidence interval [CI] 0.87‐0.93) and specificity of 0.79 (95% CI 0.73‐0.84), while the pooled estimates were 0.86 (95% CI 0.82‐0.89) and 0.89 (95% CI 0.84‐0.92), respectively, at the artery level. The areas under the summary receiver operating characteristic curve were 0.93 (95% CI 0.90‐0.95) and 0.92 (95% CI 0.90‐0.94) at the patient and artery levels, respectively. With a pretest probability of 50%, the patients’ posttest probabilities of CAD were 81% for positive results and 11% for negative results.Conclusions: Whole-heart MRCA can be an alternative noninvasive method for diagnosis and assessment of CAD.

APPLICATION OF TIME-AVERAGED AND INTEGRAL-BASED MEASURE FOR MEASUREMENT RESULTS VARIABILITY REDUCTION IN GSM/DCS/UMTS SYSTEMS

Since EMF levels from wireless telecommunication networks are non-stationary and exhibit large temporal variations, the use of continuous measurements during extended periods (preferably 24 h or longer) with a data-logging system is required. Because of the short-term variations of E field, the 6-min measurements and 6-min averaged results to obtain the mean level strength at a given place appear to be dependent on the time of measurements during the day. This paper presents a new (integral-based) measure to evaluate electromagnetic exposure. The new measure is a pure physical descriptor of the amount of exposed energy density (a parameter accumulated from instantaneous power density values in time). To confirm previous observations, continuous measurements with personal exposure metre were recorded 24 h a day for two weeks at every location in urban area, 14 different locations in total. Additionally, to check temporal variations and repeatability of exposure assessment, a week of prolonged measurements was taken 6 months later, making in total three weeks of measurements at 2 locations. Day-to-day repeatability of RF-EMF exposure was analysed through the time-averaged and integral-based measure. The analysis is based on approximately 5.1 million data samples (1.7 million for each band). The ratio between the maximum and minimum instantaneous (maximum and minimum 6-min averaged) E field values during the day could reach up to 25 dB (20 dB). Therefore, great variability in the results may occur. By applying the 24 h time-averaged and integral-based measure on a 24 h data set of measurements, the variability of daily exposure could stay within ±20% of the week mean level obtained either with the time-averaged or integral-based measure. Both, the time-averaged E field and integral-based power density exposures of the general public in all locations were found to be well below the general public exposure limits of the ICNIRP guidelines.

Diagnostic performance of non-invasive imaging for stable coronary artery disease: A meta-analysis

BACKGROUND

To determine diagnostic performance of non-invasive tests using invasive fractional flow reserve (FFR) as reference standard for coronary artery disease (CAD).

METHODS

Medline, Embase, and citations of articles, guidelines, and reviews for studies were used to compare non-invasive tests with invasive FFR for suspected CAD published through March 2017.

RESULTS

Seventy-seven studies met inclusion criteria. The diagnostic test with the highest sensitivity to detect a functionally significant coronary lesion was coronary computed tomography (CT) angiography [88%(85%-90%)], followed by FFR derived from coronary CT angiography (FFR_CT) [85%(81%-88%)], positron emission tomography (PET) [85%(82%-88%)], stress cardiac magnetic resonance (stress CMR) [81%(79%-84%)], stress myocardial CT perfusion combined with coronary CT angiography [79%(74%-83%)], stress myocardial CT perfusion [77%(73%-80%)], stress echocardiography (Echo) [72%(64%-78%)] and stress single-photon emission computed tomography (SPECT) [64%(60%-68%)]. Specificity to rule out CAD was highest for stress myocardial CT perfusion added to coronary CT angiography [91%(88%-93%)], stress CMR [91%(90%-93%)], and PET [87%(86%-89%)].

CONCLUSION

A negative coronary CT angiography has a higher test performance than other index tests to exclude clinically-important CAD. A positive stress myocardial CT perfusion added to coronary CT angiography, stress cardiac MR, and PET have a higher test performance to identify patients requiring invasive coronary artery evaluation.

Clinical Effectiveness of Cardiac Noninvasive Diagnostic Testing in Patients Discharged From the Emergency Department for Chest Pain

Background

More than 4 million cardiac noninvasive diagnostic tests are performed annually in the United States. However, questions remain regarding their effectiveness in improving clinical outcomes. We sought to evaluate whether noninvasive diagnostic tests were associated with lower rates of myocardial infarction or cardiovascular death when compared with no testing.

Methods and Results

We performed a retrospective, population‐based cohort study of adults evaluated for chest pain and discharged home from an emergency department in Ontario, Canada. Propensity score matching was employed to reduce confounding between the testing and nontesting groups. There were 370 863 patients evaluated in our cohort. Rates of the composite outcome were low for both groups after propensity‐score matching (0.29% and 0.78% for the nontesting group at 90 days and 1 year, respectively, and 0.34% and 0.68% for the noninvasive diagnostic test group at 90 days and 1 year respectively). Over 1 year, patients undergoing noninvasive diagnostic testing had a small but statistically significant lower hazard of developing the composite outcome of myocardial infarction or cardiovascular mortality (hazard ratio, 0.87; 95% CI, 0.78–0.96 [P<0.01]), which appears to be driven by the high‐risk subgroup (hazard ratio, 0.75; 95% CI, 0.61–0.92 [P<0.01]).

Conclusions

We report a lower observed rate of the composite outcome of cardiovascular death or myocardial infarction associated with noninvasive diagnostic testing following evaluation for chest pain in the emergency department. This lower rate was driven by the high‐risk subgroup. These results suggest that risk‐based testing should be considered for patients discharged from the emergency department for chest pain.

Determinants of Rejection Rate for Coronary CT Angiography Fractional Flow Reserve Analysis

Background Coronary artery fractional flow reserve (FFR) derived from CT angiography (FFT_CT) enables functional assessment of coronary stenosis. Prior clinical trials showed 13%-33% of coronary CT angiography studies had insufficient quality for quantitative analysis with FFR_CT. Purpose To determine the rejection rate of FFR_CT analysis and to determine factors associated with technically unsuccessful calculation of FFR_CT. Materials and Methods Prospectively acquired coronary CT angiography scans submitted as part of the Assessing Diagnostic Value of Noninvasive FFR_CT in Coronary Care (ADVANCE) registry (https://ClinicalTrials.gov: NCT02499679) and coronary CT angiography series submitted for clinical analysis were included. The primary outcome was the FFR_CT rejection rate (defined as an inability to perform quantitative analysis with FFR_CT). Factors that were associated with FFR_CT rejection rate were assessed with multiple linear regression. Results In the ADVANCE registry, FFR_CT rejection rate due to inadequate image quality was 2.9% (80 of 2778 patients; 95% confidence interval [CI]: 2.1%, 3.2%). In the 10 621 consecutive patients who underwent clinical analysis, the FFR_CT rejection rate was 8.4% (n = 892; 95% CI: 6.2%, 7.2%; P < .001 vs the ADVANCE cohort). The main reason for the inability to perform FFR_CT analysis was the presence of motion artifacts (63 of 80 [78%] and 729 of 892 [64%] in the ADVANCE and clinical cohorts, respectively). At multivariable analysis, section thickness in the ADVANCE (odds ratio [OR], 1.04; 95% CI: 1.001, 1.09; P = .045) and clinical (OR, 1.03; 95% CI: 1.02, 1.04; P < .001) cohorts and heart rate in the ADVANCE (OR, 1.05; 95% CI: 1.02, 1.08; P < .001) and clinical (OR, 1.06; 95% CI: 1.05, 1.07; P < .001) cohorts were independent predictors of rejection. Conclusion The rates for technically unsuccessful CT-derived fractional flow reserve in the ADVANCE registry and in a large clinical cohort were 2.9% and 8.4%, respectively. Thinner CT section thickness and lower patient heart rate may increase rates of completion of CT fractional flow reserve analysis. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Sakuma in this issue.

Damage Caps and Defensive Medicine: Reexamination with Patient-Level Data

Physicians often claim that they practice "defensive medicine," including ordering extra imaging and laboratory tests, due to fear of malpractice liability. Caps on noneconomic damages are the principal proposed remedy. Do these caps in fact reduce testing, overall health-care spending, or both? We study the effects of "third-wave" damage caps, adopted in the 2000s, on specific areas that are expected to be sensitive to med mal risk: imaging rates, cardiac interventions, and lab and radiology spending, using patient-level data, with extensive fixed effects and patient-level covariates. We find heterogeneous effects. Rates for the principal imaging tests rise, as does Medicare Part B spending on laboratory and radiology tests. In contrast, cardiac intervention rates (left-heart catheterization, stenting, and bypass surgery) do not rise (and likely fall). We find some evidence that overall Medicare Part B rises, but variable results for Part A spending. We find no evidence that caps affect mortality.

The distribution of cardiac diagnostic testing for acute coronary syndrome in the Brazilian healthcare system: A national geospatial evaluation of health access

BACKGROUND

Little is known about the utilization of cardiac diagnostic testing in Brazil and how such testing is related with local rates of acute coronary syndrome (ACS)-related mortality.

METHODS AND RESULTS

Using data from DATASUS, the public national healthcare database, absolute counts of diagnostic tests performed were calculated for each of the 5570 municipalities and mapped. Spatial error regression and geographic weighted regression models were used to describe the geographic variation in the association between ACS mortality, income, and access to diagnostic testing. From 2008 to 2014, a total of 4,653,884 cardiac diagnostic procedures were performed in Brazil, at a total cost of $271 million USD. The overall ACS mortality rate during this time period was 133.8 deaths per 100,000 inhabitants aged 20 to 79. The most commonly utilized test was the stress ECG (3,015,993), followed by catheterization (862,627), scintigraphy (669,969) and stress echocardiography (105,295). The majority of these procedures were conducted in large urban centers in more economically developed regions of the country. Increased access to testing and increased income were not uniformly associated with decreased ACS mortality, and tremendous geographic heterogeneity was observed in the relationship between these variables.

CONCLUSIONS

The majority of testing for ACS in Brazil is conducted at referral centers in developed urban settings. Stress ECG is the dominant testing modality in use. Increased access to diagnostic testing was not consistently associated with decreased ACS mortality across the country.

Mapping the Gaps: Gender Differences in Preventive Cardiovascular Care among Managed Care Members in Four Metropolitan Areas

BACKGROUND

Prior research documents gender gaps in cardiovascular risk management, with women receiving poorer quality routine care on average, even in managed care systems. Although population health management tools and quality improvement efforts have led to better overall care quality and narrowing of racial/ethnic gaps for a variety of measures, we sought to quantify persistent gender gaps in cardiovascular risk management and to assess the performance of routinely used commercial population health management tools in helping systems narrow gender gaps.

METHODS

Using 2013 through 2014 claims and enrollment data from more than 1 million members of a large national health insurance plan, we assessed performance on seven evidence-based quality measures for the management of coronary artery disease and diabetes mellitus, a cardiac risk factor, across and within four metropolitan areas. We used logistic regression to adjust for region, demographics, and risk factors commonly tracked in population health management tools.

FINDINGS

Low-density lipoprotein (LDL) cholesterol control (LDL < 100 mg/dL) rates were 5 and 15 percentage points lower for women than men with diabetes mellitus (p < .0001), and coronary artery disease (p < .0001), respectively. Adjusted analyses showed women were more likely to have gaps in LDL control, with an odds ratio of 1.31 (95% confidence interval, 1.27-1.38) in diabetes mellitus and 1.88 (95% confidence interval, 1.65-2.10) in coronary artery disease.

CONCLUSIONS

Given our findings that gender gaps persist across both clinical and geographic variation, we identified additional steps health plans can take to reduce disparities. For measures where gaps have been consistently identified, we recommend that gender-stratified quality reporting and analysis be used to complement widely used algorithms to identify individuals with unmet needs for referral to population health and wellness behavior support programs.

Prior Authorization for Elective Diagnostic Catheterization: The Value of Reviewers in Cases with Clinical Ambiguity

BACKGROUND

In many situations, evidence-based guidelines cannot provide definitive guidance on the appropriateness of diagnostic catheterization. One specialty benefit management company has taken a 2-step approach to address this ambiguity by evaluating the appropriateness of diagnostic catheterization orders using a rule-based decision support system, and then having reviewers provide input through the consult system of a nondenial prior authorization program that involves peer discussion.

OBJECTIVE

To describe the outcomes of a 2-step approach to evaluating the appropriateness of elective diagnostic catheterization orders.

METHOD

This program evaluation used data from elective diagnostic catheterization orders from 2015 that pertained to 1 health insurer's Medicare Advantage plans. The classifications of orders by the rule-based system and the approval rates after review by the consult system are presented for these plans. Chi-square tests were conducted to examine whether classifications of the orders by the rule-based and consult systems were independent of plan type, specialty of the ordering physician, or state of residence of the patient.

RESULTS

A total of 3808 orders for elective diagnostic catheterization in 2015 met the inclusion criteria. Inadequate initial justification was provided for 699 (18.4%) of the orders; after inquiry through the consult system, 509 (72.8%) of the remaining orders were approved. Among the 344 (9%) orders that were deemed potentially nonindicated according to the rule-based system, the consult system approved 298 (86.6%). Of the 2765 (72.6%) orders that were deemed potentially appropriate by the rule-based system, the consult system approved 2740 (99.1%). Chi-square tests did not show a significant association between plan type or physician specialty and the classification produced by the rule-based system or the consult system. The patients' state of residence was significantly associated with the classification of orders for the rule-based system (P <.001), but not for the consult system.

CONCLUSION

Rule-based decision support can be combined with consult-based peer discussion to determine whether care is appropriate when guidelines are ambiguous. Poorly justified orders are often supportable after gathering information on the patient's presentation.

Use of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers for Geriatric Ischemic Stroke Patients: Are the Rates Right?

BACKGROUND

Our objective is to estimate the effects associated with higher rates of renin-angiotensin system antagonists, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ACEI/ARBs), in secondary prevention for geriatric (aged >65 years) patients with new ischemic strokes by chronic kidney disease (CKD) status.

METHODS AND RESULTS

The effects of ACEI/ARBs on survival and renal risk were estimated by CKD status using an instrumental variable (IV) estimator. Instruments were based on local area variation in ACEI/ARB use. Data abstracted from charts were used to assess the assumptions underlying the instrumental estimator. ACEI/ARBs were used after stroke by 45.9% and 45.2% of CKD and non-CKD patients, respectively. ACEI/ARB rate differences across local areas grouped by practice styles were nearly identical for CKD and non-CKD patients. Higher ACEI/ARB use rates for non-CKD patients were associated with higher 2-year survival rates, whereas higher ACEI/ARB use rates for patients with CKD were associated with lower 2-year survival rates. While the negative survival estimates for patients with CKD were not statistically different from zero, they were statistically lower than the estimates for non-CKD patients. Confounders abstracted from charts were not associated with the instrumental variable used.

CONCLUSIONS

Higher ACEI/ARB use rates had different survival implications for older ischemic stroke patients with and without CKD. ACEI/ARBs appear underused in ischemic stroke patients without CKD as higher use rates were associated with higher 2-year survival rates. This conclusion is not generalizable to the ischemic stroke patients with CKD, as higher ACEI/ARBS use rates were associated with lower 2-year survival rates that were statistically lower than the estimates for non-CKD patients.

Radical changes to the investigation of stable chest pain following the 2016 NICE update

The 2016 National Institute for Health and Care Excellence (NICE) guidelines mark a radical change in the diagnosis of patients with stable chest pain. Quantitative assessments of the disease probability are no longer considered necessary to determine the need and type of diagnostic testing. Instead, the recommendation is for no diagnostic test if the chest pain is judged to be "non-anginal" and CT coronary angiography (CTCA) in patients with "typical" or "atypical" chest pain. The new emphasis on anatomical, rather than functional testing is driven by the accuracy, safety and cost effectiveness of the different investigations as evaluated by NICE. Despite inevitable resource implications NICE calculates that annual savings will be significant.

Use of two-dimensional speckle tracking echocardiography to predict cardiac events: Comparison of patients with acute myocardial infarction and chronic coronary artery disease

BACKGROUND

Two-dimensional speckle strain (2D STE) echocardiography can aid in the prognosis of acute myocardial infarction (AMI) and chronic coronary artery disease (CAD).

HYPOTHESIS

Differences occur in the prediction of cardiac events using 2D STE in AMI vs CAD patients.

METHODS

In this prospective study, 94 patients with a first AMI and successful revascularization, and 137 patients with stable CAD after complete revascularization were included. In all patients, we performed echocardiography and myocardial deformation analysis for layer-specific global circumferential strain (GCS) and longitudinal strain. Receiver operating characteristic (ROC) curve analysis was used to predict the presence of a cardiac event using strain values and baseline characteristics in different regression models.

RESULTS

Patients were followed for 3.6 ± 0.8 years. Strain parameters in AMI and CAD patients were significantly different with respect to the occurrence of a cardiac event. Frequency of diabetes and hypertension was associated with the presence of a cardiac event in CAD patients. Furthermore, in CAD patients, ROC analysis demonstrated that the addition of endocardial GCS to baseline characteristics and ejection fraction to a regression model significantly improved the prediction of cardiac events (area under curve = 0.86, cutoff value: 20%, sensitivity: 79%, specificity: 84%). In contrast, the addition of strain parameters in AMI patients did not increase the prediction power for cardiac events.

CONCLUSIONS

Global strain parameters by 2D STE may be useful for the prediction of cardiac events in patients with CAD but add no supplemental information to baseline characteristic and ejection fraction in patients with AMI.

12-year Temporal Trend in Referral Pattern and Test Results of Stress Echocardiography in a Tertiary Care Referral Center with Moderate Volume Activities and Cath-lab Facility

Background

Data on stress echocardiography (SE) time-related changes in referral patterns and diagnostic yield for detection of inducible ischemia could enhance Echo Lab quality benchmarks and performance measures.

Aim

This study aims to evaluate temporal trends in SE test results among ambulatory patients with suspected or known coronary artery disease (CAD) in a tertiary care referral center with moderate (>100/year) volume SE activities and Cath-Lab facility.

Methods

From January 2004 to December 2015, 1954 patients (mean age 62 ± 12 years, 42% women, 27% with known CAD) underwent SE (1673 exercise SE, 86%, 246 pharmacological SE, 12%, 35 pacing SE, 2%). Time was grouped into three 4 year periods, where clinical data and test results were evaluated.

Results

Our series comprised low-to-intermediate pretest probability of CAD throughout the observation period (overall pretest probability of CAD 19% ± 15%). A progressive decline over time in the rate of pharmacological SE instead of a dramatic increment of exercise SE (79%-96%, P < 0.0001) was noted. The use of beta-blockers increased (from 43% to 66%, P < 0.0001), while the use of nitrates decreased (from 11% to 4%, P < 0.0001) over time. We noted a very uncommon occurrence of abnormal test results with a further decrease in the last period (from 11% to 3%, P < 0.0001).

Conclusions

We observed, over a 12-year period, a progressive decrease in the frequency of inducible myocardial ischemia among patients with known or suspected CADe referred to our Echo Lab for SE with Cath-Lab facility, and this trend was parallel to changes in SE referral practice. These findings are particularly relevant if we consider the practical implications on diagnostic SE accuracy and risk assessment.

Comparison of Rate of Utilization of Medicare Services in Private Versus Academic Cardiology Practice

Cardiovascular services are the third largest source of Medicare spending. We examined the rate of cardiovascular service utilization in the community of Glendale, CA, compared with the nearest academic medical center, the University of Southern California. Publicly available utilization data released by Medicare for the years 2012 and 2013 were used to identify all inpatient and outpatient cardiology services provided in each practice setting. The analysis included 19 private and 17 academic cardiologists. In unadjusted analysis, academic physicians performed half as many services per Medicare beneficiary per year as those in private practice: 2.3 versus 4.8, p <0.001. Other factors associated with higher utilization included male physician, international (vs US) medical school graduate, interventional (vs general) cardiologist, and more years in practice. Factors independently associated with higher utilization rates by multivariable analysis included private practice setting (odds ratio [OR] 1.84, 95% confidence interval [CI] 1.30 to 2.61, p <0.001), male physician (OR 1.64, 95% CI 1.00 to 2.67, p = 0.049), and international medical school graduate (OR 1.37, 95% CI 1.07 to 1.78, p = 0.014). In conclusion, in this analysis of 2 cardiology practice settings in southern California, medical service utilization per Medicare beneficiary was nearly 2-fold higher in private practice than in the academic setting, suggesting that there may be opportunity for substantially reducing costs of cardiology care in the community setting.

Appropriateness, diagnostic value, and outcomes of repeat testing following index echocardiography

AIMS

Emergency admission to hospital is associated with an economic burden and mortality. Echocardiography is often the first-line cardiovascular imaging investigation. Repeat testing is common; however, there are sparse data on the prevalence, appropriateness, or outcome of repeat testing.

METHODS

We performed an electronic database search for patients with emergency admissions to our institution in February 2015. An electronic patient record review of inpatient echocardiograms was undertaken. Indications for echocardiography were classified as appropriate, may be appropriate, or rarely appropriate. One-year follow-up for repeat testing and mortality was investigated.

RESULTS

A total of 409 of 2306 (17.7%) unplanned/emergency admissions underwent inpatient echocardiography. Abnormalities were identified in 165/409 (40.3%) of these patients; 154 of 409 (37.7%) had a repeat echocardiogram within the next year. Rarely appropriate indications for echocardiography occurred in 51 (33%) of repeat vs 53 (16%) of index echocardiograms, P < .0001. Repeat testing was associated with a change in findings in 17/154 (11%) patients overall. All of whom had an abnormal index echocardiogram and had an appropriate indication. There was no difference in mean survival time between patients who underwent repeat and those who only underwent a single index echocardiogram (310 days vs 327 days), P = .34.

CONCLUSION

Inpatient echocardiography in emergency hospital admissions identifies clinically important pathology. Repeated testing is common within 1 year of hospital admission. New diagnostic findings occurred in 11% of patients and only in patients with appropriate studies and an abnormal index echocardiogram. Identification of methods to reduce repeat testing and implement appropriateness criteria is warranted.

Appropriate Use Criteria for Cardiac Computed Tomography: Impact on Diagnostic Utility

BACKGROUND

Appropriate Use Criteria (AUC) guidelines for cardiac computed tomography (CCT) were developed to limit testing to reasonable clinical settings. However, significant testing is still done for inappropriate indications. This study investigates the impact of AUC on evaluability of CCT to determine if inappropriate tests result in a greater proportion of nondiagnostic results.

METHODS

Investigators reviewed the medical records of 2417 consecutive patients who underwent CCT at the University of Ottawa Heart Institute. We applied the 2010 AUC and classified them as appropriate, inappropriate, or uncertain. Unclassifiable tests, as well as those with uncertain appropriateness, were excluded from the final analysis. Cardiac computed tomography results were classified as diagnostic if (1) all coronary segments were visualized, evaluable, and without obstructive stenosis; or (2) obstructive coronary artery disease with greater than 50% diameter stenosis in at least 1 coronary artery. All other test results were considered nondiagnostic.

RESULTS

Of the 1984 patients included in the final analysis, 1522 patients (76.7%) had indications that were appropriate, whereas the remaining 462 (23.3%) were inappropriate. Inappropriate tests resulted in a higher rate of nondiagnostic results compared with appropriate CCT (9.0% vs 6.2%, P = 0.034). Inappropriate tests also had significantly more studies with nonevaluable segments than appropriate tests (24.5% vs 16.4%, P < 0.001) and were more likely to reveal obstructive coronary disease than appropriate CCT (50.5% vs 32.7%, P < 0.001).

CONCLUSIONS

Cardiac computed tomography done for inappropriate indications may be associated with lower diagnostic yield and could impact future downstream resource utilization and health care costs.

Electrocardiograms in Low-Risk Patients Undergoing an Annual Health Examination

Importance

Clinical guidelines advise against routine electrocardiograms (ECG) in low-risk, asymptomatic patients, but the frequency and impact of such ECGs are unknown.

Objective

To assess the frequency of ECGs following an annual health examination (AHE) with a primary care physician among patients with no known cardiac conditions or risk factors, to explore factors predictive of receiving an ECG in this clinical scenario, and to compare downstream cardiac testing and clinical outcomes in low-risk patients who did and did not receive an ECG after their AHE.

Design, Setting, and Participants

A population-based retrospective cohort study using administrative health care databases from Ontario, Canada, between 2010/2011 and 2014/2015 to identify low-risk primary care patients and to assess the subsequent outcomes of interest in this time frame. All patients 18 years or older who had no prior cardiac medical history or risk factors who received an AHE.

Exposures

Receipt of an ECG within 30 days of an AHE.

Main Outcomes and Measures

Primary outcome was receipt of downstream cardiac testing or consultation with a cardiologist. Secondary outcomes were death, hospitalization, and revascularization at 12 months.

Results

A total of 3 629 859 adult patients had at least 1 AHE between fiscal years 2010/2011 and 2014/2015. Of these patients, 21.5% had an ECG within 30 days after an AHE. The proportion of patients receiving an ECG after an AHE varied from 1.8% to 76.1% among 679 primary care practices (coefficient of quartile dispersion [CQD], 0.50) and from 1.1% to 94.9% among 8036 primary care physicians (CQD, 0.54). Patients who had an ECG were significantly more likely to receive additional cardiac tests, visits, or procedures than those who did not (odds ratio [OR], 5.14; 95% CI, 5.07-5.21; P < .001). The rates of death (0.19% vs 0.16%), cardiac-related hospitalizations (0.46% vs 0.12%), and coronary revascularizations (0.20% vs 0.04%) were low in both the ECG and non-ECG cohorts.

Conclusions and Relevance

Despite recommendations to the contrary, ECG testing after an AHE is relatively common, with significant variation among primary care physicians. Routine ECG testing seems to increase risk for a subsequent cardiology testing and consultation cascade, even though the overall cardiac event rate in both groups was very low.

[Left-heart catheterization followed by other invasive procedures: Regional comparisons reveal peculiar differences]

BACKGROUND AND AIMS

Diagnostic left heart catheterization (LHC) is recommended if the therapeutic consequences of a bypass operation or percutaneous coronary intervention (PCI) are being considered. The present study examines regional differences in healthcare provision and therapeutic consequences of LHC, differentiated by counties and hospitals of the German federal state of Saxony-Anhalt. In addition, it looks at which patient-related factors influence the proportion of follow-up interventions. The relation between the rates of LHC, interventions and hospital discharge due to myocardial infarction is examined.

METHODS

The data of 9,791 individuals having statutory health insurance coverage by the AOK Saxony-Anhalt with 10,906 anonymized inpatient cases of LHCs in 2011 were followed until 12/31/2012, and it was examined whether they subsequently received a coronary bypass or PCI. The data was used to compare both the counties of Saxony-Anhalt (according to residence, adjusted for age and sex) and their hospitals. Regression analysis was run to identify determinants of receiving a LHC without consequences.

RESULTS

Overall, 54.2 % of the patients with LHC had no invasive follow-up intervention. Regression analysis showed an approximately linear relationship for the counties: the number of LHCs provided correlates with the number of LHCs requiring no PCI or bypass within a period of at least 12 months. Regional LHC rates are not correlated with hospitalizations due to acute myocardial infarction. No bypass or PCI in the follow-up period was reported for 37 to 85 % of the cases, depending on the hospital providing the LHC. Women and younger patients have a higher risk to undergo LHC without therapeutic impact.

DISCUSSION

The analysis indicates that there are specific regions in Saxony-Anhalt and diagnoses where the indications for LHC should be more conservative. However, more detailed analyses are needed to verify the identified potentials for improving healthcare provision.

Temporal Trends of Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging in Patients With Coronary Artery Disease

Background—

There has been a gradual decline in the prevalence of abnormal stress single-photon emission computed tomography (SPECT) myocardial perfusion imaging studies among patients without history of coronary artery disease (CAD). The trends of SPECT studies among patients with known CAD have not been evaluated previously.

Methods and Results—

We assessed the Mayo Clinic nuclear cardiology database for all stress SPECT tests performed between January 1991 and December 2012 in patients with history of CAD defined as having previous myocardial infarction, percutaneous coronary intervention, and coronary artery bypass grafting. The study cohort was divided into 5 time periods: 1991 to 1995, 1996 to 2000, 2001 to 2005, 2006 to 2010, and 2011 to 2012. There were 19 373 patients with a history of CAD who underwent SPECT between 1991 and 2012 (mean age, 66.2±10.9 years; 75.4% men). Annual utilization of SPECT in these patients increased from an average of 495 tests per year in 1991 to 1995 to 1425 in 2003 and then decreased to 552 tests in 2012 without evidence for substitution with other stress modalities. Asymptomatic patients initially increased until 2006 and then decreased. Patients with typical angina decreased, whereas patients with dyspnea and atypical angina increased. High-risk SPECT tests significantly decreased, and the percentage of low-risk SPECT tests increased despite decreased SPECT utilization between 2003 and 2012. Almost 80% of all tests performed in 2012 had a low-risk summed stress score compared with 29% in 1991 ( P <0.001).

Conclusions—

In Mayo Clinic, Rochester, annual SPECT utilization in patients with previous CAD increased between 1992 and 2003, but then decreased after 2003. High-risk SPECT tests declined, whereas low-risk tests increased markedly. Our results suggest that among patients with a history of CAD, SPECT was being increasingly utilized in patients with milder CAD. This trend parallels reduced utilization of other stress modalities, coronary angiography, reduced smoking, and greater utilization of optimal medical therapy for prevention and treatment of CAD.