Patient Management After Noninvasive Cardiac Imaging

Lipid-Lowering Medication and Outcomes After Anatomical and Functional Imaging in Suspected Coronary Artery Disease

BACKGROUND

Anatomical and functional imaging identify different phenotypes of coronary artery disease (CAD) that may have implications for lipid-lowering medication (LLM).

OBJECTIVES

The aim of this study was to assess the associations between LLM and long-term outcomes after combined anatomical and functional imaging in patients with suspected obstructive CAD.

METHODS

Consecutive patients (n = 1,973; 41% men; median age: 63 years) underwent coronary computed tomography angiography (CTA) because of suspected CAD. Patients in whom obstructive CAD was not ruled out by CTA underwent ischemia testing by positron emission tomography. Data on LLM purchases were collected until 2 years, and the combined endpoints of death, myocardial infarction, and unstable angina pectoris were assessed at a median of 6.7 years.

RESULTS

After imaging, LLM was used by 24% of patients with no CAD, 51% of patients with nonobstructive CAD, 72% of patients with obstructive CAD on CTA without myocardial ischemia, and 91% of patients with myocardial ischemia. The use of LLM decreased during follow-up, with 77% of patients with myocardial ischemia using LLM for 2 years. The use of LLM was associated with a lower annual rate of adverse events in patients with myocardial ischemia (6.1% vs 2.8%; P = 0.032) or obstructive CAD without myocardial ischemia (2.9% vs 1.4%; P = 0.004) but not in patients with nonobstructive CAD (1.5% vs 1.4%; P = 0.89) or no CAD (0.3% vs 0.3%; P = 0.68).

CONCLUSIONS

The CAD phenotype defined by anatomical and functional imaging guides the use of LLM. The presence of myocardial ischemia and anatomical obstructive coronary lesions were associated with a long-term outcome benefit from LLM.

Comparative effectiveness of positron emission tomography and single-photon emission computed tomography myocardial perfusion imaging for predicting risk in patients with cardiometabolic disease

BACKGROUND

The epidemiology of coronary artery disease (CAD) has shifted, with increasing prevalence of cardiometabolic disease and decreasing findings of obstructive CAD on myocardial perfusion imaging (MPI). Coronary microvascular dysfunction (CMD), defined as impaired myocardial flow reserve (MFR) by positron emission tomography (PET), has emerged as a key mediator of risk. We aimed to assess whether PET MFR provides additive value for risk stratification of cardiometabolic disease patients compared with single-photon emission computed tomography (SPECT) MPI.

METHODS

We retrospectively followed patients referred for PET, exercise SPECT, or pharmacologic SPECT MPI with cardiometabolic disease (obesity, diabetes, or chronic kidney disease) and without known CAD. We compared rates and hazards of composite major adverse cardiovascular events (MACEs) (annualized cardiac mortality or acute myocardial infarction) among propensity-matched PET and SPECT patients using Poisson and Cox regression. Normal SPECT was defined as a total perfusion deficit (TPD) of <5%, reflecting the absence of obstructive CAD. Normal PET was defined as a TPD of <5% plus an MFR of ≥2.0.

RESULTS

Among 21,544 patients referred from 2006 to 2020, cardiometabolic disease was highly prevalent (PET: 2308 [67%], SPECT: 9984 [55%]) and higher among patients referred to PET (P < 0.001). Obstructive CAD findings (TPD > 5%) were uncommon (PET: 21% and SPECT: 11%). Conversely, impaired MFR on PET (<2.0) was common (62%). In a propensity-matched analysis over a median 6.4-year follow-up, normal PET identified low-risk (0.9%/year MACE) patients, and abnormal PET identified high-risk (4.2%/year MACE) patients with cardiometabolic disease; conversely, those with normal pharmacologic SPECT remained moderate-risk (1.6%/year, P < 0.001 compared to normal PET).

CONCLUSIONS

Cardiometabolic disease is common among patients referred for MPI and is associated with a heterogenous level of risk. Compared with pharmacologic SPECT, PET with MFR can detect nonobstructive CAD including CMD and can more accurately discriminate low-risk from higher-risk individuals.

Dual-Energy and Photon-Counting Computed Tomography in Vascular Applications-Technical Background and Post-Processing Techniques

The field of computed tomography (CT), which is a basic diagnostic tool in clinical practice, has recently undergone rapid technological advances. These include the evolution of dual-energy CT (DECT) and development of photon-counting computed tomography (PCCT). DECT enables the acquisition of CT images at two different energy spectra, which allows for the differentiation of certain materials, mainly calcium and iodine. PCCT is a recent technology that enables a scanner to quantify the energy of each photon gathered by the detector. This method gives the possibility to decrease the radiation dose and increase the spatial and temporal resolutions of scans. Both of these techniques have found a wide range of applications in radiology, including vascular studies. In this narrative review, the authors present the principles of DECT and PCCT, outline their advantages and drawbacks, and briefly discuss the application of these methods in vascular radiology.

Changes in use of preventive medications after assessment of chest pain by coronary computed tomography angiography: A meta-analysis

BACKGROUND

Coronary computed tomography angiogram (CCTA) is a crucial tool for diagnosing CAD, but its impact on altering preventive medications is not well-documented. This systematic review aimed to compare changes in aspirin and statin therapy following CCTA and functional stress testing in patients with suspected CAD, and in those underwent CCTA when stratified by the presence/absence of plaque.

RESULTS

Eight studies involving 42,812 CCTA patients and 64,118 cardiac stress testing patients were analyzed. Compared to functional testing, CCTA led to 66 ​% more changes in statin therapy (pooled RR, 95 ​% CI [1.28-2.15]) and a 74 ​% increase in aspirin prescriptions (pooled RR, 95 ​% CI [1.34-2.26]). For medication modifications based on CCTA results, 13 studies (47,112 patients with statin data) and 11 studies (12,089 patients with aspirin data) were included. Patients with any plaque on CCTA were five times more likely to use or intensify statins compared to those without CAD (pooled RR, 5.40, 95 ​% CI [4.16-7.00]). Significant heterogeneity remained, which decreased when stratified by diabetes rates. Aspirin use increased eightfold after plaque detection (pooled RR, 8.94 [95 ​% CI, 4.21-19.01]), especially with obstructive plaque findings (pooled RR, 9.41, 95 ​% CI [2.80-39.02]).

CONCLUSION

In conclusion, CCTA resulted in higher changes in statin and aspirin therapy compared to cardiac stress testing. Detection of plaque by CCTA significantly increased statin and aspirin therapy.

Evaluation of stable angina by coronary computed tomographic angiography versus standard of care: A systematic review and meta-analysis

INTRODUCTION

There is limited data comparing Coronary Computed Tomography Angiography (CCTA) versus the usual Standard of care (SOC) in patients with suspected stable coronary artery disease (CAD). We aimed to perform a systematic review and meta-analysis to compare CCTA versus SOC in patients with stable CAD.

METHODS

We searched multiple databases for randomized controlled trials (RCTs) comparing CCTA with SOC, which included various functional testing approaches for evaluating stable CAD. We used a random-effects model to calculate risk ratios (RRs) with 95 % confidence intervals (CIs). Outcomes included all-cause mortality, myocardial infarction (MI), hospitalization for unstable angina (UA), invasive angiography, revascularization, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG).

RESULTS

We identified 6 RCTs with 19,881 patients with stable CAD, of which 9995 underwent CCTA, and 9886 underwent SOC. There were no significant differences between CCTA and SOC in terms of all-cause mortality (RR: 0.91; 95 % CI: 0.70-1.19; p = 0.50), MI (RR: 0.78; 95 % CI: 0.58-1.05; p = 0.11), hospitalizations for UA (RR: 1.20; 95 % CI: 0.95-1.51;p = 0.12), invasive angiography (RR: 0.71; 95 % CI: 0.32-1.61; p = 0.42), revascularization (RR:1.25; 95 % CI: 0.83-1.89; p = 0.29), PCI (RR: 1.20; 95 % CI: 0.78-1.85; p = 0.40), and CABG rates (RR: 0.89; 95 % CI: 0.530-1.49; p = 0.65).

CONCLUSION

In patients with stable CAD, CCTA is associated with similar outcomes compared to the usual Standard of care. Given its potential to quickly rule out severe obstructive disease, its ability to provide non-invasive physiology and identify non-obstructive CAD with plaque information makes it an attractive addition to the available armamentarium to evaluate chest pain.

The Use and Efficacy of FFR-CT: Real-World Multicenter Audit of Clinical Data With Cost Analysis

BACKGROUND

Fractional flow reserve-computed tomography (FFR-CT) is endorsed by UK and U.S. chest pain guidelines, but its clinical effectiveness and cost benefit in real-world practice are unknown.

OBJECTIVES

The purpose of this study was to audit the use of FFR-CT in clinical practice against England's National Institute for Health and Care Excellence guidance and assess its diagnostic accuracy and cost.

METHODS

A multicenter audit was undertaken covering the 3 years when FFR-CT was centrally funded in England. For coronary computed tomographic angiograms (CCTAs) submitted for FFR-CT analysis, centers provided data on symptoms, CCTA and FFR-CT findings, and subsequent management. Audit standards included using FFR-CT only in patients with stable chest pain and equivocal stenosis (50%-69%). Diagnostic accuracy was evaluated against invasive FFR, when performed. Follow-up for nonfatal myocardial infarction and all-cause mortality was undertaken. The cost of an FFR-CT strategy was compared to alternative stress imaging pathways using cost analysis modeling.

RESULTS

A total of 2,298 CCTAs from 12 centers underwent FFR-CT analysis. Stable chest pain was the main symptom in 77%, and 40% had equivocal stenosis. Positive and negative predictive values of FFR-CT were 49% and 76%, respectively. A total of 46 events (2%) occurred over a mean follow-up period of 17 months; FFR-CT (cutoff: 0.80) was not predictive. The FFR-CT strategy costs £2,102 per patient compared with an average of £1,411 for stress imaging.

CONCLUSIONS

In clinical practice, the National Institute for Health and Care Excellence criteria for using FFR-CT were met in three-fourths of patients for symptoms and 40% for stenosis. FFR-CT had a low positive predictive value, making its use potentially more expensive than conventional stress imaging strategies.

Warranty period of coronary computed tomography angiography and [15O]H2O positron emission tomography in symptomatic patients

AIMS

Data on the warranty period of coronary computed tomography angiography (CTA) and combined coronary CTA/positron emission tomography (PET) are scarce. The present study aimed to determine the event-free (warranty) period after coronary CTA and the potential additional value of PET.

METHOD AND RESULTS

Patients with suspected but not previously diagnosed coronary artery disease (CAD) who underwent coronary CTA and/or [15O]H2O PET were categorized based upon coronary CTA as no CAD, non-obstructive CAD, or obstructive CAD. A hyperaemic myocardial blood flow (MBF) ≤ 2.3 mL/min/g was considered abnormal. The warranty period was defined as the time for which the cumulative event rate of death and non-fatal myocardial infarction (MI) was below 5%. Of 2575 included patients (mean age 61.4 ± 9.9 years, 41% male), 1319 (51.2%) underwent coronary CTA only and 1237 (48.0%) underwent combined coronary CTA/PET. During a median follow-up of 7.0 years 163 deaths and 68 MIs occurred. The warranty period for patients with no CAD on coronary CTA was ≥10 years, whereas patients with non-obstructive CAD had a 5-year warranty period. Patients with obstructive CAD and normal hyperaemic MBF had a 2-year longer warranty period compared to patients with obstructive CAD and abnormal MBF (3 years vs. 1 year).

CONCLUSION

As standalone imaging, the warranty period for normal coronary CTA is ≥10 years, whereas patients with non-obstructive CAD have a warranty period of 5 years. Normal PET yielded a 2-year longer warranty period in patients with obstructive CAD.

Impact of Gd-153 scanning line source attenuation correction on downstream invasive testing

BACKGROUND

Attenuation correction (AC) using hardware and software solutions has been shown to increase the specificity of SPECT MPI by decreasing false positive results and improving prognostic ability. Theoretically this should reduce downstream testing and unnecessary costs. We sought to assess the consequences of the use of Gd-153 scanning line source attenuation correction during SPECT myocardial perfusion imaging (MPI) on downstream invasive testing.

METHODS

All patients who underwent a clinically indicated Tc-99m stress SPECT MPI study from 2013 to 2015 at five hospitals (2 with AC and 3 without) were retrospectively reviewed. Patient demographics, results of testing, subsequent coronary angiography within 3 months, and revascularization were recorded. The results of the MPI studies, downstream angiogram utilization, and results of angiography were compared and a propensity matched subgroup analysis was performed.

RESULTS

A total of 9968 patients underwent SPECT MPI during the study time period (6106 performed with AC and 3862 without). Out of 3928 patients included in the propensity matched cohort, there was no difference in the proportion of abnormal MPI results between the two groups (31.5% vs 30.4%, P = 0.47), however, more patients underwent coronary angiography within 90 days in the AC group (10.6% vs 8.7%, P = 0.05). There was no significant difference in the proportion of patients with angiographically significant obstructive disease (53.4% vs 56.1%, P = 0.19), however, fewer patients in the AC group with obstructive coronary disease were revascularized (36.1% vs 46.8%, P = 0.04). The findings remained consistent after sub-group analysis in patients without known coronary disease.

CONCLUSION

The use of scanning line source AC did not meaningfully influence the rate of abnormal MPI results or downstream invasive testing in this cohort. The clinical utility of scanning line source AC may be limited to facilitating stress-first imaging protocols.

Healthcare resource utilization among patients receiving non-invasive testing for coronary artery disease in an outpatient setting: A cohort study reflecting daily practice trends

BACKGROUND

Accurate, early diagnosis and the initiation of appropriate treatment is central to reducing the clinical burden of coronary artery disease (CAD); however, real-world evidence characterizing healthcare resource utilization (HCRU) associated with testing for CAD is lacking.

METHODS AND RESULTS

Using a non-interventional, retrospective, secondary database analysis, patients aged ≥18 years who underwent outpatient non-invasive cardiac diagnostic testing were identified. The primary objective was to gain an understanding of pre- and post-assessment care pathways and the associated interventions for patients who underwent non-invasive testing for CAD in either an outpatient or emergency department setting. Overall, chest pain was the primary reason for the index visit (54.8%), followed by shortness of breath (23.7%), myocardial infarction (MI), coronary artery disease (CAD) or congestive heart failure (CHF) (3.8%), and other (46.8%); 3.0% of patients had no apparent reason for testing in the last 45 days. Single-photon emission computed tomography (SPECT) was the dominant diagnostic testing modality (40.3%). During the 90-day follow-up, 7.3% (n = 22,083) of patients were diagnosed with CAD; among these patients, 19.4% had repeat diagnostic testing, 26.0% of patients had a revascularization procedure, and 65.6% underwent cardiac catheterization. These rates varied by testing modality.

CONCLUSIONS

In this study of a large real-world data sample, variability in the use of non-invasive tests and HCRU were evident. These results may assist efforts to optimize system-wide care/diagnostic pathways and value-based treatment decisions for patients.

Perspectives in noninvasive imaging for chronic coronary syndromes

Both the latest European guidelines on chronic coronary syndromes and the American guidelines on chest pain have underlined the importance of noninvasive imaging to select patients to be referred to invasive angiography. Nevertheless, although coronary stenosis has long been considered the main determinant of inducible ischemia and symptoms, growing evidence has demonstrated the importance of other underlying mechanisms (e.g., vasospasm, microvascular disease, energetic inefficiency). The search for a pathophysiology-driven treatment of these patients has therefore emerged as an important objective of multimodality imaging, integrating "anatomical" and "functional" information. We here provide an up-to-date guide for the choice and the interpretation of the currently available noninvasive anatomical and/or functional tests, focusing on emerging techniques (e.g., coronary flow velocity reserve, stress-cardiac magnetic resonance, hybrid imaging, functional-coronary computed tomography angiography, etc.), which could provide deeper pathophysiological insights to refine diagnostic and therapeutic pathways in the next future.

Benefit of Early Revascularization Based on Inducible Ischemia and Left Ventricular Ejection Fraction

BACKGROUND

The utility of performing early myocardial revascularization among patients presenting with inducible myocardial ischemia and low left ventricular ejection fraction (LVEF) is currently unknown.

OBJECTIVES

In this study, we sought to assess the relationship between stress-induced myocardial ischemia, revascularization, and all-cause mortality (ACM) among patients with normal vs low LVEF.

METHODS

We evaluated 43,443 patients undergoing stress-rest single-photon emission computed tomography myocardial perfusion imaging from 1998 to 2017. Median follow-up was 11.4 years. Myocardial ischemia was assessed for its interaction between early revascularization and mortality. A propensity score was used to adjust for nonrandomization to revascularization, followed by multivariable Cox modeling adjusted for the propensity score and clinical variables to predict ACM.

RESULTS

The frequency of myocardial ischemia varied markedly according to LVEF and angina, ranging from 6.7% among patients with LVEF ≥55% and no typical angina to 64.0% among patients with LVEF <45% and typical angina (P < 0.001). Among 39,883 patients with LVEF ≥45%, early revascularization was associated with increased mortality risk among patients without ischemia and lower mortality risk among patients with severe (≥15%) ischemia (HR: 0.70; 95% CI: 0.52-0.95). Among 3,560 patients with LVEF <45%, revascularization was not associated with mortality benefit among patients with no or mild ischemia, and was associated with decreased mortality among patients with moderate (10%-14%) (HR: 0.67; 95% CI: 0.49-0.91) and severe (≥15%) (HR: 0.55; 95% CI: 0.38-0.80) ischemia.

CONCLUSIONS

Within this cohort, early myocardial revascularization was associated with a significant reduction in mortality among both patients with normal LVEF and severe inducible myocardial ischemia and patients with low LVEF and moderate or severe inducible myocardial ischemia.

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.

Reasons for discordance between positron emission tomography (PET) myocardial perfusion imaging (MPI) results and subsequent management

BACKGROUND

Referral patterns to coronary angiography following positron emission tomography (PET) myocardial perfusion imaging (MPI) and reasons for non-referral following abnormal PET MPI are largely unknown.

METHODS

Referral rates to coronary angiography within 90 days post PET MPI were determined. A random subset of 100 patients with severe (≥ 10%) ischemia on MPI between 2014-16 who were not referred for angiography were examined to better understand reasons as to why patients with high-risk MPI findings did not undergo coronary angiography.

RESULTS

Among 19,282 unique patients, overall rate of 90-day coronary angiography was 18.5% (3574/19282). Among patients with severe ischemia, 64.1% (1930/3011) underwent angiography within 90 days; the rate was lower in those with mild-moderate (20.6% [1010/4898]) and no ischemia (5.6% [634/11373]). In the random sample of 100 patients, the most common physician reasons for non-referral were uncertainty regarding whether the test results were responsible for the patient's presenting symptoms, renal failure, and patient age, frailty, or cognitive status, while patient preference for medical management was by far the most common patient reason.

CONCLUSION

Referral rates for coronary angiography after PET correlate with severity of ischemia. However, there appear to be opportunities to reconsider testing for instances when results will not change clinical management.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

Coronary Revascularization in Patients With Stable Coronary Artery Disease: The Role of Imaging

In the last decades, the effective management of some cardiovascular risk factors in the general population has led to a progressive decrease in the prevalence of coronary artery disease (CAD). Nevertheless, coronary heart disease remains the major cause of death in developed and developing countries and chronic coronary syndromes (CCS) are still a major target of utilization of non-invasive cardiac imaging and invasive procedures. Current guidelines recommend the use of non-invasive imaging in patients with CCS to identify subjects at higher risk to be referred for invasive coronary angiography and possible revascularization. These recommendations are challenged by two opposite lines of evidence. Recent trials have somewhat questioned the efficacy of coronary revascularization as compared with optimal medical therapy in CCS. As a consequence the role of imaging in these patients and in in patients with ischemic cardiomyopathy is under debate. On the other hand, real-life data indicate that a consistent proportion of patients undergo invasive procedure and are revascularized without any previous non-invasive imaging characterization. On top of this, the impact of COVID-19 pandemic on the sanitary systems caused a change in the current management of patients with CAD. In the present review we will discuss these conflicting data analyzing the evidence which has been recently accumulated as well as the gaps of knowledge which should still be filled.

Virtual non-calcium dual-energy CT: clinical applications

Dual-energy CT (DECT) has emerged into clinical routine as an imaging technique with unique postprocessing utilities that improve the evaluation of different body areas. The virtual non-calcium (VNCa) reconstruction algorithm has shown beneficial effects on the depiction of bone marrow pathologies such as bone marrow edema. Its main advantage is the ability to substantially increase the image contrast of structures that are usually covered with calcium mineral, such as calcified vessels or bone marrow, and to depict a large number of traumatic, inflammatory, infiltrative, and degenerative disorders affecting either the spine or the appendicular skeleton. Therefore, VNCa imaging represents another step forward for DECT to image conditions and disorders that usually require the use of more expensive and time-consuming techniques such as magnetic resonance imaging, positron emission tomography/CT, or bone scintigraphy. The aim of this review article is to explain the technical background of VNCa imaging, showcase its applicability in the different body regions, and provide an updated outlook on the clinical impact of this technique, which goes beyond the sole improvement in image quality.

Clinical experience with regadenoson SPECT myocardial perfusion imaging: insights into patient characteristics, safety, and impact of results on clinical management

The Henry Ford Hospital (HFH) regadenoson (REG) registry includes patients with a variety of comorbidities allowing for the evaluation of outcomes in a large, unselected population. Using a database of electronic medical records and nuclear cardiology reports, patients aged > 18 years who underwent REG-facilitated single-photon emission computed tomography (SPECT) testing at HFH between January 2009 and August 2012 were identified. The primary objective was to describe the clinical and demographic characteristics of patients who had undergone REG only vs REG WALK (REG + low-level exercise) SPECT. A total of 2104 patients were included in the analysis (mean age 65.3 years; 50% women; 51% African American, 43% Caucasian). For the REG only (n = 1318) and REG WALK (n = 786) cohorts, SPECT was abnormal in 37% of patients (REG only, 39%; REG WALK, 34%; P < 0.01). No differences in diagnostic modalities or interventions in 90 days after SPECT were observed. Immediate safety analysis showed no deaths 48 h after REG SPECT testing. Although they guide invasive therapy, abnormal scans do not automatically lead to invasive testing. This demonstrates the focus on initial medical management, which reflects the existing evidence of initial goal-directed medical management of stable coronary disease.

Prognostic durability of coronary computed tomography angiography

AIMS

This large prospective cohort study sought to confirm the incremental prognostic value of coronary computed tomographic angiography (CCTA) measured over a prolonged follow-up duration. CCTA has diagnostic and prognostic value but data supporting its long-term prognostic value in a large prospectively recruited cohort with suspected coronary artery disease (CAD) has been limited.

METHODS AND RESULTS

Consecutive patients (without history of myocardial infarction, revascularization, cardiac transplantation, and congenital heart disease) were prospectively enrolled. CCTA was evaluated for CAD severity, total plaque score (TPS), and left ventricular ejection fraction. Patients were followed for major adverse events (MAE) and major adverse cardiac events (MACE).Over a total of 99 months, 8667 consecutive CCTA patients (mean age = 57.1 ± 11.1 years, 52.9% men) were prospectively enrolled and followed for a mean duration of 7.0 ± 2.6 years. At follow-up, there were a total of 723 MAE, 278 MACE, 547 all-cause deaths, 110 cardiac deaths, and 104 non-fatal myocardial infarction. Patients without coronary atherosclerosis at the time of CCTA had a very low annual event rate for both MAE and MACE (0.45%/year and 0.19%/year, respectively). Both MAE and MACE increased with increasing TPS and severity of CAD. In patients with non-obstructive CAD and who were statin-naive, TPS ≥5 had MACE rates >0.75%/year. Patients with high-risk CAD had an annual MAE and MACE rates of 3.52%/year and 2.58%/year, respectively. Adjusted hazard ratio of the severity of CAD based on multivariable analyses indicated that the prognostic values were incremental.

CONCLUSION

CCTA has independent and incremental prognostic value that is durable over time. The absence of coronary atherosclerosis portends an excellent prognosis. Patients with increasing non-obstructive plaque burden have worse prognosis and a TPS threshold ≥5 may identify a population that may benefit from statin therapy.

Development and Piloting of a Patient-Centered Report Design for Stress Myocardial Perfusion Imaging Results

IMPORTANCE

The management of coronary disease epitomizes the call to better engage patients in shared medical decision-making. Myocardial perfusion imaging (MPI) is the foundation of diagnosis, risk stratification, and subsequent therapy; however, MPI reports are currently interpretable by specialists but not patients.

OBJECTIVE

To design and test a patient-centered report for stress MPI test results.

DESIGN, SETTING, AND PARTICIPANTS

This qualitative study of outpatients who underwent an MPI stress test and clinicians used a mixed methods approach. Phase 1 (December 2018 to July 2019) used qualitative methods to design a patient-centered reporting tool, with 5 focus groups with 36 patients and 2 focus groups with 27 clinicians. Phase 2 (June to September 2019) consisted of pilot testing the reporting tool with feedback from a structured survey given to patients who received MPI reports before and after implementing the tool.

MAIN OUTCOMES AND MEASURES

Key themes around patient experiences with the current MPI reporting and their desire for a more useful report were identified, which led to a sample reporting tool after serial iterations with feedback. Differences in patient knowledge and engagement were assessed between patients before and after implementation of the new reporting tool using χ2 tests.

RESULTS

From patient focus groups (26 patients; mean [SD] age, 66.3 [9.6] years, 9 [35%] women), 3 themes on the inadequacies of current MPI reporting were identified: (1) inconsistent delivery of results, (2) use of medical jargon, and (3) unclear posttest course. We identified 5 themes for a more patient-centered MPI report: desire for written information, discussion of the report with medical personnel, presentation of results in simple language with use of visual graphics, comparisons with normal results, and personalized risk estimates. In a pilot survey with 123 patients split into a pre-implementation group (69 patients; mean [SD] age, 68.2 [8.5] years; 27 [51%] women) and a postimplementation group (54 patients; mean [SD] age, 66.4 [8.7] years; 30 [56%] women), the patient-centered report led to more patients reading the entire report (45 [83%] vs 46 [67%]; P = .04) and improved knowledge of future risk of cardiac events (41 [76%] vs 20 [29%]; P < .001). There was also a numerically higher percentage of patients who found the report easy to read (45 [83%] vs 44 [68%]; P = .05) and understand (42 [78%] vs 43 [66%]; P = .16), although these results were not statistically significant.

CONCLUSIONS AND RELEVANCE

This study identified key elements of a patient-centered report design for stress MPI test results, which improved patient engagement and knowledge. These preliminary data support further implementation and study of a more patient-centered MPI report.

Design and rationale of the randomized trial of comprehensive lifestyle modification, optimal pharmacological treatment and utilizing PET imaging for quantifying and managing stable coronary artery disease (the CENTURY study)

BACKGROUND

The literature reports no randomized trial in chronic coronary artery disease (CAD) of a comprehensive management strategy integrating intense lifestyle management, maximal medical treatment to specific goals and high precision quantitative cardiac positron emission tomography (PET) for identifying high mortality risk patients needing essential invasive procedures. We hypothesize that this comprehensive strategy achieves greater risk factor reduction, lower major adverse cardiovascular events and fewer invasive procedures than standard practice.

METHODS

The CENTURY Study (NCT00756379) is a randomized-controlled-trial study in patients with stable or at high risk for CAD. Patients are randomized to standard of care (Standard group) or intense comprehensive lifestyle-medical treatment to targets and PET guided interventions (Comprehensive group). Comprehensive Group patients are regularly consulted by the CENTURY team implementing diet/lifestyle/exercise program and medical treatment to target risk modification. Cardiac PET at baseline, 24-, and 60-months quantify the physiologic severity of CAD and guide interventions in the Comprehensive group while patients and referring physicians of the Standard group are blinded to PET results. The primary end-point is the CENTURY risk score reduction during 5 years follow-up. The secondary endpoint is a composite of death, non-fatal myocardial infarction, stroke, and coronary revascularization.

CONCLUSIONS

The CENTURY Study is the first study in stable CAD to test the incremental benefit of a comprehensive strategy integrating intense lifestyle modification, medical treatment to specific goals, and high-precision quantitative myocardial perfusion imaging to guide revascularization. A total of 1028 patients have been randomized, and the 5 years follow-up will conclude in 2022.

Prevalence of microvascular angina among patients with stable symptoms in the absence of obstructive coronary artery disease: a systematic review

Our purpose was to perform a systematic review to assess the prevalence of microvascular angina (MVA) among patients with stable symptoms in the absence of obstructive coronary artery disease (CAD). We performed a systematic review of the literature to group the prevalence of MVA, based on diagnostic pathways and modalities. We defined MVA using three definitions: (i) suspected MVA using non-invasive ischaemia tests; proportion of patients with non-obstructive CAD among patients with symptoms and a positive non-invasive ischaemia test result, (ii) suspected MVA using specific modalities for MVA; proportion of patients with evidence of impaired microvascular function among patients with symptoms and non-obstructive CAD, and (iii) definitive MVA; proportion of patients with positive ischaemia test results among patients with an objectified impaired microvascular dysfunction. We further examined the ratio of women-to-men for the different groups. Of the 4547 abstracts, 20 studies reported data on MVA prevalence. The median prevalence was 43% for suspected MVA using non-invasive ischaemia test, 28% for suspected MVA using specific modalities for MVA, and 30% for definitive MVA. Overall, more women were included in the studies reporting sex-specific data. The women-to-men ratio for included participants was 1.29. However, the average women-to-men ratio for the MVA cases was 2.50. In patients with stable symptoms of ischaemia in the absence of CAD, the prevalences of suspected and definitive MVA are substantial. The results of this study should warrant cardiologists to support, promote and facilitate the comprehensive evaluation of the coronary microcirculation for all patients with symptoms and non-obstructive CAD.

Screening coronary artery disease with computed tomography angiogram should limit normal invasive coronary angiogram, regardless of pretest probability

BACKGOUND

Performing functional testing (FT) or a computed tomography angiogram (CCTA) before invasive coronary angiogram (ICA) is recommended for coronary artery disease (CAD). We aimed to evaluate, in a real life setting, the rate of strictly normal ICA following a positive noninvasive test result.

METHODS

We included all patients who underwent an ICA with a prior positive FT or CCTA. Patients were categorized in 5 subgroups, according to pretest probability (PTP) of having a CAD. Main results of ICA were defined as normal ICA, nonobstructive CAD (non-oCAD), and obstructive CAD (oCAD).

RESULTS

For 4,952 patients who underwent ICA following either a positive FT (3276, 66.2%) or CCTA (1676, 33.8%) result, the PTP was (1) low (<15%; n = 968, 19.5%), (2) lower intermediate (15%-35%; n = 1336, 27.0%), (3) higher intermediate (35%-50%; n = 806, 16.3%), (4) high (50%-65%; n = 806, 17.7%), and (5) very high (> 65%; n = 965, 19.5%). ICA showed no CAD (819 patients, 16.5%), non-oCAD (1,193 patients, 24.1%), or oCAD (2940 patients, 59.4%). Without considering the PTP values, CCTA compared to FT showed less frequently normal ICA (7% vs 16.5%), and more frequently CAD (non-oCAD 27.9% vs 22.2%; oCAD 65.1% vs 56.4%) (all P < .0001). When we considered the different PTP values, CCTA always showed lower rates of normal ICA than the FT. In low- and lower intermediate-risk patients, CCTA detected more frequently oCAD compared to FT (P < .001).

CONCLUSIONS

CCTA is a better alternative than FT to limit unnecessary ICA regardless of PTP value, without missing abnormal ICA.

Comparison of coronary CT angiography versus functional imaging for CABG patients: A resource utilization analysis

AIMS

The impact of anatomical versus functional testing in patients with prior coronary artery bypass surgery (CABG) is poorly defined. We therefore sought to determine the rates of downstream investigations and the attendant healthcare costs in CABG patients undergoing CCTA versus SPECT.

METHODS AND RESULTS

2754 consecutive CABG patients were imaged by SPECT (2163) or CCTA (591). 425 patients (15.4%) underwent downstream testing which was more common in those imaged with CCTA versus SPECT (23.18% vs 13.31% respectively, p < 0.01). When a propensity score adjustment was made for differences in baseline characteristics, the findings in downstream testing persisted (p < 0.01). When patients who subsequently underwent repeat revascularization (arguably the highest risk patients) were removed from the analysis, downstream testing remained more frequent in CCTA (12.7%) versus SPECT imaged patients (8.8%) (p = 0.01). Costs of downstream tests per patient were two-fold greater in the CCTA group in comparison to the SPECT group ($366.79 ± 29.59 vs $167.35 ± 10.12 respectively, p < 0.01). Conversely, total costs which included the index costs were less in the CCTA group, $764.66 ± 29.59 versus $1396.73 ± 1012 for the SPECT cohort, p < 0.0001).

CONCLUSIONS

Index imaging with SPECT versus CCTA in CABG patients was associated with fewer downstream tests, less ICA, less repeat revascularization but greater expense. Cost however is only part of the decision making process that determines an optimal index test. Until CCTA demonstrates improved risk stratification over SPECT in CABG patients it is likely SPECT will remain the preferred first imaging test.

Temporal trends in test utilization and prevalence of ischaemia with positron emission tomography myocardial perfusion imaging

AIMS

To examine whether test utilization and prevalence of ischemia with positron emission tomography (PET) myocardial perfusion imaging (MPI) follow the previously described trends with single photon computed tomography (SPECT).

METHODS AND RESULTS

MPI studies performed between January 2003 and December 2017 were identified. Number of PET and SPECT MPI studies performed per year was determined. Trends in the proportion of studies showing any ischaemia (>0%) with both modalities were compared before and after adjusting for baseline differences in patient characteristics using propensity scores. Interaction between imaging modality and year of testing was examined using modified Poisson regression. A total of 156 244 MPI studies were performed (30% PET and 70% SPECT). Between 2003 and 2017, the number of PET studies increased from 18 to 61 studies/1000 patient encounters, while SPECT volumes declined from 169 to 34/1000 patient encounters (P < 0.001 for within-group comparisons). The prevalence of any ischaemia in SPECT-tested patients declined from 53.9% to 28.3% between 2003 and 2017, whereas ischaemia prevalence in PET-tested patients declined from 57.2% to 38.2% (P < 0.001 for within-modality comparisons), with more PET studies showing ischaemia compared to SPECT [relative risk (RR) 1.44, 95% confidence interval (CI) 1.42-1.47; P < 0.001]. After propensity score matching of 26 066 patients tested with SPECT with 26 066 patients tested with PET, the between-modality difference in ischaemia prevalence was significantly attenuated, with a slightly higher overall likelihood of detecting ischaemia with PET compared to SPECT (RR 1.08, 95% CI 1.05-1.11; P < 0.001).

CONCLUSIONS

Utilization of PET MPI at a large-volume referral centre increased significantly between 2003 and 2017. Despite a significant decrease in the prevalence of ischaemia with SPECT and PET during the same period, the decline was less with PET, perhaps related to baseline risk of tested patients.

How Do PET Myocardial Blood Flow Reserve and FFR Differ?

PURPOSE OF REVIEW

This review discusses similarities and differences between cardiac positron emission tomography (PET), absolute myocardial blood flow, and flow reserve with invasive fractional flow reserve (FFR).

RECENT FINDINGS

Fundamentally, cardiac PET measures absolute myocardial blood flow whereas FFR provides a relative flow reserve. Cardiac PET offers a non-invasive and therefore lower risk alternative, able to image the entire left ventricle regardless of coronary anatomy. While cardiac PET can provide unique information about the subendocardium, FFR pullbacks offer unparalleled spatial resolution. Both diagnostic tests provide a highly repeatable and technically successful index of coronary hemodynamics that accounts for the amount of distal myocardial mass, albeit only indirectly with FFR. The randomized evidence base for FFR and its associated cost effectiveness remains unsurpassed. Cardiac PET and FFR have been intertwined since the very development of FFR over 25 years ago. Recent work has emphasized the ability of both techniques to guide revascularization decisions by high-quality physiology. In the past few years, cardiac PET has expanded its evidence base regarding clinical outcomes, whereas FFR has solidified its position in randomized studies as the invasive reference standard.

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.

Coronary computed tomography angiography vs. myocardial single photon emission computed tomography in patients with intermediate risk chest pain: a randomized clinical trial for cost-effectiveness comparison based on real-world cost

AIMS

To compare the cost-effectiveness of coronary computed tomography angiography (CCTA) vs. myocardial single photon emission computed tomography (SPECT) in patients with stable intermediate risk chest pain.

METHODS AND RESULTS

Non-acute patients with 10-90% pre-test probability of coronary artery disease from three high-volume centres in Korea (n = 965) were randomized 1:1 to CCTA or myocardial SPECT as the initial non-invasive imaging test. Medical costs after randomization, the downstream outcome, including all-cause death, acute coronary syndrome, cerebrovascular accident, repeat revascularization, stent thrombosis, and significant bleeding following the initial test and the quality-adjusted life-years (QALYs) gained by the EuroQoL-5D questionnaire was compared between the two groups. In all, 903 patients underwent the initially randomized study (n = 460 for CCTA, 443 for SPECT). In all, 65 patients underwent invasive coronary angiography (ICA) in the CCTA and 85 in the SPECT group, of which 4 in the CCTA and 30 in the SPECT group demonstrated no stenosis on ICA [6.2% (4/65) vs. 35.3% (30/85), P-value < 0.001]. There was no difference in the downstream clinical events. QALYs gained was higher in the SPECT group (0.938 vs. 0.955, P-value = 0.039) but below the threshold of minimal clinically important difference of 0.08. Overall cost per patient was lower in the CCTA group (USD 4514 vs. 5208, P-value = 0.043), the tendency of which was non-significantly opposite in patients with 60-90% pre-test probability (USD 5807 vs. 5659, P-value = 0.845).

CONCLUSION

CCTA is associated with fewer subsequent ICA with no difference in downstream outcome. CCTA may be more cost-effective than SPECT in Korean patients with stable, intermediate risk chest pain.

Randomized Comparison of Clinical Effectiveness of Pharmacologic SPECT and PET MPI in Symptomatic CAD Patients

OBJECTIVES

This study compared the clinical effectiveness of pharmacologic stress myocardial perfusion imaging (MPI) plus positron emission tomography (PET) with single-photon emission computed tomography (SPECT) in patients with known coronary artery disease (CAD) presenting with symptoms suggestive of ischemia.

BACKGROUND

Although PET MPI has been shown to have higher diagnostic accuracy in detecting hemodynamically significant CAD than SPECT MPI, whether this impacts downstream management has not been formally evaluated in randomized trials.

METHODS

This study consisted of a single-center trial in which patients with known CAD and suspected ischemia were randomized to undergo PET or attenuation-corrected SPECT MPI between June 2009 and September 2013. Post-test management was at the discretion of the referring physician, and patients were followed for 12 months. The primary endpoint was diagnostic failure, defined as unnecessary angiography (absence of ≥50% stenosis in ≥1 vessel) or additional noninvasive testing within 60 days of the MPI. Secondary endpoints were post-test escalation of antianginal therapy, referral for angiography, coronary revascularization, and health status at 3, 6, and 12 months.

RESULTS

A total of 322 patients with an evaluable MPI were randomized (n = 161 in each group). At baseline, 88.8% of patients were receiving aspirin therapy, 76.7% were taking beta-blockers, and 77.3% were taking statin therapy. Diagnostic failure within 60 days occurred in only 7 patients (2.2%) (3 [1.9%] in the PET group and 4 [2.5%] in the SPECT group; p = 0.70). There were no significant differences between the 2 groups in subsequent rates of coronary angiography, coronary revascularization, or health status at 3, 6, and 12 months of follow-up (all p values ≥0.20); however, when subjects were stratified by findings on MPI in a post hoc analysis, those with high-risk MPI on PET testing had higher rates of angiography and revascularization on follow-up than those who had SPECT MPI, whereas those undergoing low-risk PET studies had lower rates of both procedures than those undergoing SPECT (interaction between randomized modality ∗high-risk MPI for 12-month catheterization [p = 0.001] and 12-month revascularization [p = 0.09]).

CONCLUSIONS

In this contemporary cohort of symptomatic CAD patients who were optimally medically managed, there were no discernible differences in rates of diagnostic failure at 60 days, subsequent coronary angiography, revascularization, or patient health status at 1 year between patients evaluated by pharmacologic PET compared with those evaluated by SPECT MPI. Downstream invasive testing rates with PET MPI were more consistent with high-risk features than those with SPECT MPI. (Effectiveness Study of Single Photon Emission Computed Tomography [SPECT] Versus Positron Emission Tomography [PET] Myocardial Perfusion Imaging; NCT00976053).

Diagnosis and Prognosis of Coronary Artery Disease with SPECT and PET

PURPOSE OF REVIEW

Radionuclide myocardial perfusion imaging (MPI) continues to be the most reliable modality for diagnosis of hemodynamically significant coronary artery disease (CAD). The application of radionuclide MPI using single photon emission computed tomography (SEPCT) and positron emission tomography (PET) for CAD is reviewed, with emphasis on diagnosis and risk stratification.

RECENT FINDINGS

Contemporary studies have reported the diagnostic and prognostic value of novel imaging protocols, employing stress-first or stress-only approach. In addition, the superior diagnostic value of PET has been established with a role of assessment of myocardial blood flow to improve risk stratification. The utility of MPI in special populations, such as the elderly, women, and diabetic patients has also been recently evaluated. Furthermore, multicenter studies have reported a similar diagnostic and prognostic value of radionuclide MPI compared with other functional and anatomical techniques for CAD. Radionuclide MPI with SPECT and PET are efficacious for diagnosis and prognosis of CAD. Its universal application in varied patient populations highlights its excellent clinical effectiveness.

The Clinical Utility of a Precision Medicine Blood Test Incorporating Age, Sex, and Gene Expression for Evaluating Women with Stable Symptoms Suggestive of Obstructive Coronary Artery Disease: Analysis from the PRESET Registry

Background: Evaluating women with symptoms suggestive of coronary artery disease (CAD) remains challenging. A blood-based precision medicine test yielding an age/sex/gene expression score (ASGES) has shown clinical validity in the diagnosis of obstructive CAD. We assessed the effect of the ASGES on the management of women with suspected obstructive CAD in a community-based registry.

Materials and Methods: The prospective PRESET (A Registry to Evaluate Patterns of Care Associated with the Use of Corus^® CAD in Real World Clinical Care Settings) Registry (NCT01677156) enrolled 566 patients presenting with symptoms suggestive of stable obstructive CAD from 21 United States primary care practices from 2012 to 2014. Demographics, clinical characteristics, and referrals to cardiology or further functional and/or anatomical cardiac studies after ASGES testing were collected for this subgroup analysis of women from the PRESET Registry. Patients were followed for 1-year post-ASGES testing.

Results: This study cohort included 288 women with a median age 57 years. The median body mass index was 29.2, with hyperlipidemia and hypertension present in 48% and 43% of patients, respectively. Median ASGES was 8.5 (range 1–40), with 218 (76%) patients having low (≤15) ASGES. Clinicians referred 9% (20/218) low ASGES versus 44% (31/70) elevated ASGES women for further cardiac evaluation (odds ratio 0.14, p < 0.0001, adjusted for patient demographics and clinical covariates). Across the score range, higher ASGES were associated with a higher likelihood of posttest cardiac referral. At 1-year follow-up, low ASGES women experienced fewer major adverse cardiac events than elevated ASGES women (1.3% vs. 4.2% respectively, p = 0.16).

Conclusions: Incorporation of ASGES into the diagnostic workup demonstrated clinical utility by helping clinicians identify women less likely to benefit from further cardiac evaluation.

Quantifying Sex Differences in Cardiovascular Care Among Patients Evaluated for Suspected Ischemic Heart Disease

Background: Cardiovascular care sex differences are controversial. We examined sex differences in management and clinical outcomes among patients undergoing noninvasive testing for ischemic heart disease (IHD). Methods: In a rural integrated healthcare system, we identified adults age 40-79 without diagnosed IHD who underwent initial evaluation with a cardiac stress test with imaging or coronary computed tomographic angiography (CTA), 2013-2014. We assessed sex differences in statin/aspirin therapy, revascularization, and adverse cardiovascular events. The 2013 American College of Cardiology/American Heart Association statin guidelines and U.S. Preventive Services Task Force aspirin guidelines were applied. Results: Among 2213 patients evaluated for IHD, median age was 57 years, 48.8% were women, and 9% had a positive stress test/CTA. Women were more likely to be missing lipid values than men (p < 0.001). Mean ASCVD risk score at baseline was 7.2% in women versus 12.4% in men (p < 0.001). There was no significant sex difference in statin therapy at baseline or 60-day follow-up. Women were less likely than men to be taking aspirin at baseline (adj. diff. = -8.5%; 95% CI, -4.2 to -12.9) and follow-up (adj. diff. = -7.7%; 95% CI, -3.3 to -12.1). There were no sex differences in revascularization after accounting for obstructive CAD or adverse cardiovascular outcomes during median follow-up of 33 months. Conclusion: In this contemporary cohort of patients with suspected IHD, women were less likely to receive lipid testing and aspirin therapy, but not statin therapy. Women did not experience worse outcomes. Sex differences in statin therapy reported by others may be due to inadequate accounting for baseline risk.

Population-Based Study on Patterns of Cardiac Stress Testing After Percutaneous Coronary Intervention

BACKGROUND

The appropriate use criteria considers cardiac stress testing within 2 years after percutaneous coronary intervention (PCI) to be rarely appropriate, unless prompted by symptoms or change in clinical status. Little is known about the patterns of cardiac stress testing after PCI in the single-payer Canadian healthcare system, where mechanisms for reimbursement are different from the United States.

METHODS AND RESULTS

Frequency and timing of cardiac stress testing within 2 years of PCI performed between April 2004 and March 2013 in Ontario, Canada, was determined from linked provincial databases. Subsequent rates of coronary angiography and revascularization after stress testing were ascertained. Of the 112 691 patients with PCI, 67 442 (59.8%) underwent at least 1 stress test, with 38 267 (34.0%) undergoing repeat stress testing (ie, >1 stress test) within 2 years. Patients who underwent stress testing were younger, had less medical comorbidities, were more likely to reside in urban areas, and had higher incomes. Spikes in incidence of repeat stress testing were observed at 3 to 4 months, 6 to 7 months, and 12 to 13 months after the prior stress test. Of those tested, only 5.9% underwent subsequent coronary angiography, and only 3.1% underwent repeat revascularization within 60 days of stress testing.

CONCLUSIONS

More than half of all patients undergo cardiac stress testing within 2 years of PCI, with one third undergoing repeat stress tests. Only 1 of 30 tested patients underwent repeat revascularization. These findings reinforce the appropriate use criteria recommendations against routine stress testing after PCI. Further work is needed to aid with the selection of patients most likely to benefit from stress testing after PCI.

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.

Exercise Electrocardiogram Neither Predicts Nor Excludes Coronary Artery Disease in Women with Low to Intermediate Risk

AIM

The value of exercise electrocardiogram (ExECG) in symptomatic female patients with low to intermediate risk for significant coronary artery disease (CAD) has been under debate for many years, and nondiagnostic or even erroneous test results are frequently encountered. Cardiac-CT may be more appropriate to exclude CAD in women. This study compares the results of ExECGs with those of cardiac-CTs, performed within a time frame of 1 month in an all-comers female chest pain population.

PATIENTS AND METHODS

Five hundred fifty-one consecutive female patients from a patient registry were included. ExECGs were negative in 324 (59%), positive in 14 (3%), and nondiagnostic in 213 (39%) patients. CAD was revealed by cardiac-CT in 57% of the women with negative ExECG. No signs of CAD were present on cardiac-CT in 64% of the women with a positive ExECG. Cardiac-CT showed presence of CAD in 268/551 (49%) patients, of whom 56/268 (21%) was diagnosed with ≥50% stenosis. The ExECG of the latter group was negative in 26 (46%), inconclusive in 29 (52%), and positive in 1 (2%). Considering ≥50% stenosis at cardiac-CT as the reference, sensitivity, specificity, PPV, and NPV of ExECG for the present population were 3.7%, 95.7%, 7.1%, and 91.7%, respectively. Similar diagnostic performance was calculated when considering ≥70% stenosis at cardiac-CT as the reference.

CONCLUSION

ExECG failed to detect CAD in more than half of this cohort and in almost half of women with >50% stenosis at cardiac-CT. Importantly, no CAD was detected by cardiac-CT in 64% of women with a positive ExECG. ExECG is therefore questionable as a diagnostic strategy in women with low-to-intermediate risk of CAD, although prospective studies are warranted to determine whether replacing ExECG by cardiac-CT provides better prognoses.

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.