Value of Exercise ECG for Risk Stratification in Suspected or Known CAD in the Era of Advanced Imaging Technologies

Machine learning in cardiac stress test interpretation: a systematic review

Coronary artery disease (CAD) is a leading health challenge worldwide. Exercise stress testing is a foundational non-invasive diagnostic tool. Nonetheless, its variable accuracy prompts the exploration of more reliable methods. Recent advancements in machine learning (ML), including deep learning and natural language processing, have shown potential in refining the interpretation of stress testing data. Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a systematic review of ML applications in stress electrocardiogram (ECG) and stress echocardiography for CAD prognosis. Medical Literature Analysis and Retrieval System Online, Web of Science, and the Cochrane Library were used as databases. We analysed the ML models, outcomes, and performance metrics. Overall, seven relevant studies were identified. Machine-learning applications in stress ECGs resulted in sensitivity and specificity improvements. Some models achieved rates of above 96% in both metrics and reduced false positives by up to 21%. In stress echocardiography, ML models demonstrated an increase in diagnostic precision. Some models achieved specificity and sensitivity rates of up to 92.7 and 84.4%, respectively. Natural language processing applications enabled the categorization of stress echocardiography reports, with accuracy rates nearing 98%. Limitations include a small, retrospective study pool and the exclusion of nuclear stress testing, due to its well-documented status. This review indicates the potential of artificial intelligence applications in refining CAD stress testing assessment. Further development for real-world use is warranted.

Which Test Should I Order for an Inpatient Evaluation of Cardiac Ischemia?

AbstractTesting for cardiac ischemia, or for the obstructive coronary artery disease (CAD) that causes cardiac ischemia, is common among hospitalized patients. Many testing options exist. Choosing an appropriate test can be challenging and requires accurate risk stratification. Two major categories of testing are available: stress testing (also known as functional testing) and anatomical testing. Stress testing evaluates specifically for ischemia and can be conducted with or without imaging. Anatomical testing visualizes the obstructive CAD that causes ischemia. This article reviews how to choose an appropriate test for the evaluation of cardiac ischemia in the inpatient setting, using case examples to illustrate the considerations involved.

Enhancing the diagnosis of functionally relevant coronary artery disease with machine learning

Functionally relevant coronary artery disease (fCAD) can result in premature death or nonfatal acute myocardial infarction. Its early detection is a fundamentally important task in medicine. Classical detection approaches suffer from limited diagnostic accuracy or expose patients to possibly harmful radiation. Here we show how machine learning (ML) can outperform cardiologists in predicting the presence of stress-induced fCAD in terms of area under the receiver operating characteristic (AUROC: 0.71 vs. 0.64, p = 4.0E-13). We present two ML approaches, the first using eight static clinical variables, whereas the second leverages electrocardiogram signals from exercise stress testing. At a target post-test probability for fCAD of <15%, ML facilitates a potential reduction of imaging procedures by 15-17% compared to the cardiologist's judgement. Predictive performance is validated on an internal temporal data split as well as externally. We also show that combining clinical judgement with conventional ML and deep learning using logistic regression results in a mean AUROC of 0.74.

Relevance of the Get Active Questionnaire for Pre-Participation Exercise Screening in the General Population in a Tropical Environment

The Get Active Questionnaire (GAQ), developed by the Canadian Society for Exercise Professionals (CSEP), was recently recommended for pre-participation screening of the general population in Singapore before increasing their exercise levels. This literature review examines the evidence behind the GAQ and its relevance to our tropical environment. Searches were carried out via Pubmed, MEDLINE and the Cochrane Central Register of Controlled Trials. Resources referenced by the CSEPs were hand searched. The CSEP was also contacted for further information. The evidence behind each GAQ question was compared to international literature and guidelines, where applicable. Out of 273 studies, 49 were suitable for analysis. Two GAQ studies commissioned by the CSEP showed a high negative predictive value but high false negative rate. Of the nine GAQ questions, those on dizziness, joint pains and chronic diseases appear to be justified. Those on heart disease/stroke, hypertension, breathlessness and concussion require modification. The one on syncope can be amalgamated into the dizziness question. The remaining question may be deleted. No long-term studies were available to validate the use of the GAQ. Heat disorders were not considered in the GAQ. Modification of the GAQ, including the inclusion of environmental factors, may make it more suitable for the general population and should be considered.

The Application of Conditional Probability to Harmonize Nuclear Cardiology Test Results

Both exercise single photon emission computed tomography (SPECT) imaging and myocardial perfusion imaging with positron emission tomography produce multiple outcome variables. These include the stress electrocardiogram (ECG), visual perfusion assessment and quantitative myocardial blood flow. Bayes' analysis using conditional probability allows the distillation of multiple test results into a single probability of disease for individual patients. This paper examines the application of conditional probability analysis to two noninvasive modalities that generate multiple outcome results: exercise ECG combined with SPECT imaging and vasodilator RB-82 positron emission tomography perfusion imaging combined with quantitative measure of absolute myocardial blood flow. In this manner, a single probability of disease incorporating all the available data is generated for an individual patient.

Sixty years of the Bruce protocol: reappraising the contemporary role of exercise stress testing with electrocardiographic monitoring

The cardiovascular response to exercise has long been a focus of interest. Over a century ago, the first descriptions of electrocardiographic changes occurring during exercise highlighted the possible relevance of this dynamic assessment. In this background, the inception of the Bruce protocol circa 60 years ago allowed for a major leap in this field by providing a standardized framework with which to address this issue, by means of an integrated and structured methodology. Since then, exercise stress testing with electrocardiographic monitoring (ExECG) has become one of the most widely appraised tests in cardiovascular medicine. Notably, past few decades have been profoundly marked by substantial advances in the approach to cardiovascular disease, challenging prior notions concerning both its physiopathology and overall management. Among these, the ever-evolving presentations of cardiovascular disease coupled with the development and implementation of several novel diagnostic modalities (both invasive and noninvasive) has led to a shifting paradigm in the application of ExECG. This technique, however, has continuously shown to be of added value across various momentums of the cardiovascular continuum, as depicted in several contemporary guidelines. This review provides a pragmatical reflexion on the development of ExECG, presenting a comprehensive overview concerning the current role of this modality, its challenges, and its future perspectives.

Prognostic value of peak work rate indexed by left ventricular diameter

Left ventricular diameter (LVEDD) increases with systematic endurance training but also in various cardiac diseases. High exercise capacity associates with favorable outcomes. We hypothesized that peak work rate (W_peak) indexed to LVEDD would carry prognostic information and aimed to evaluate the association between W_peak/LVEDD_rest and cardiovascular mortality. W_peak/LVEDD_rest (W/mm) was calculated in patients with an echocardiographic examination within 3 months of a maximal cycle ergometer exercise test. Low W_peak/LVEDD_rest was defined as a value below the sex- and age-specific 5th percentile among lower-risk subjects. The association with cardiovascular mortality was evaluated using Cox regression. In total, 3083 patients were included (8.0 [5.4-11.1] years of follow-up, 249 (8%) cardiovascular deaths). W_peak/LVEDD_rest (W/mm) was associated with cardiovascular mortality (adjusted hazard ratio (HR) 0.28 [0.22-0.36]), similar to W_peak in % of predicted, with identical prognostic strength when adjusted for age and sex (C-statistics 0.87 for both). A combination of low W_peak/LVEDD_rest and low W_peak was associated with a particularly poor prognosis (adjusted HR 6.4 [4.0-10.3]). W_peak/LVEDD_rest was associated with cardiovascular mortality but did not provide incremental prognostic value to W_peak alone. The combination of a low W_peak/LVEDD_rest and low W_peak was associated with a particularly poor prognosis.

Incremental Value of Exercise ECG to Myocardial Perfusion Single-Photon Emission Computed Tomography for Prediction of Cardiac Events

Background Both myocardial perfusion single-photon emission computed tomography (MPS) and exercise ECG (Ex-ECG) carry prognostic information in patients with stable chest pain. However, it is not fully understood if combining the findings of MPS and Ex-ECG improves risk prediction. Current guidelines no longer recommend Ex-ECG for diagnostic evaluation of chronic coronary syndrome, but Ex-ECG could still be of incremental prognostic importance. Methods and Results This study comprised 908 consecutive patients (age 63.3±9.4 years, 49% male) who performed MPS with Ex-ECG. Subjects were followed for 5 years. The end point was a composite of cardiovascular death, acute myocardial infarction, unstable angina, and unplanned percutaneous coronary intervention. National registry data and medical charts were used for end point allocation. Combining the findings of MPS and Ex-ECG resulted in concordant evidence of ischemia in 72 patients or absence of ischemia in 634 patients. Discordant results were found in 202 patients (MPS-/Ex-ECG+, n=126 and MPS+/Ex-ECG-, n=76). During follow-up, 95 events occurred. Annualized event rates significantly increased across groups (MPS-/Ex-ECG- =1.3%, MPS-/Ex-ECG+ =3.0%, MPS+/Ex-ECG- =5.1% and MPS+/Ex-ECG+ =8.0%). In multivariable analyses MPS was the strongest predictor regardless of Ex-ECG findings (MPS+/Ex-ECG-, hazard ratio [HR], 3.0, P=0.001 or MPS+/Ex-ECG+, HR,4.0, P<0.001). However, an abnormal Ex-ECG almost doubled the risk in subjects with normal MPS (MPS-/Ex-ECG+, HR, 1.9, P=0.04). Conclusions In patients with chronic coronary syndrome, combining the results from MPS and Ex-ECG led to improved risk prediction. Even though MPS is the stronger predictor, there is an incremental value of adding data from Ex-ECG to MPS, especially in patients with normal MPS.

The incremental significance of heart rate recovery as a predictor during exercise-stress myocardial perfusion SPECT imaging in individuals with suspected coronary artery disease

Background

Major adverse cardiac events (MACE) are more likely to occur when abnormal heart rate recovery (HRR). This study aimed to assess the incremental predictive significance of HRR over exercise stress myocardial perfusion single-photon emission computed tomography (MPS) results for MACE in individuals with suspected coronary artery disease (CAD).

Methods

Between January 2014 and December 2017, we continually gathered data on 595 patients with suspected CAD who received cycling exercise stress MPS. HRR at 1, 2, 3, and 4 min were used as study variables to obtain the optimal cut-off values of HRR for MACE. The difference between the peak heart rate achieved during exercise and the heart rate at 1, 2, 3, and 4 min was used to calculate the HRR, as shown in HRR3. Heart rate variations between two locations in time, such as HRR_{2 min-1 min}, were used to establish the slope of HRR. All patients were followed for a minimum of 4 years, with MACE as the follow-up goal. The associations between HRR and MACE were assessed using Cox proportional hazards analyses.

Results

Patients with MACE were older (P = 0.001), and they also had higher rates of hypertension, dyslipidemia, diabetes, abnormal MPS findings (SSS ≥ 5%), medication history (all P < 0.001), and lower HRR values (all P < 0.01). Patients with and without MACE did not significantly vary in their HRR_{4 min-3 min}. The optimal cut-off of HRR1, 2, and 3 combined with SSS can stratify the risk of MACE in people with suspected CAD (all P < 0.001). HRR 1, 2, and 3 and its slope were linked to MACE in multivariate analysis, where HRR3 was the most significant risk predictor. With a global X² increase from 101 to 126 (P < 0.0001), HRR3 demonstrated the greatest improvement in the model's predictive capacity, incorporating clinical data and MPS outcomes.

Conclusions

HRR at 3 min has a more excellent incremental prognostic value for predicting MACE in patients with suspected CAD following cycling exercise stress MPS. Therefore, incorporating HRR at 3 min into known predictive models may further improve the risk stratification of the patients.

Is fear of falling key to identifying gait and balance abnormalities in community-dwelling older adults? Protocol of a mixed-methods approach

INTRODUCTION

The ageing population poses an increasing burden to public health systems, particularly as a result of falls. Falls have been associated with poor gait and balance, as measured by commonly used clinical tests for poor gait and balance. Falls in older adults have the potential to lead to long-term issues with mobility and a fear of falling (FoF). FoF is measured by a variety of instruments; the Falls Efficacy Scale International (FES-I) version is widely used within clinical and research arenas. The ability of the FoF, as measured by the FES-I to predict gait and balance abnormalities (GABAb) has not previously been measured; this study aims to be the first to investigate this prospective relationship.

METHODS AND ANALYSES

To investigate the ability of the FES-I to predict GABAb a mixed-methods approach will be used, including quantitative, qualitative and health economics approaches. Initially the ability of the FES-I to identify poor gait and balance will be investigated, along with whether the measure is able to assess change in gait and balance in response to exercise training. The ability of an online FES-I tool to assess poor gait and balance in an alternative pre-existing online strength and balance programme will also be investigated. Interviews will be carried out to investigate participant experiences and motivations of those that are offered Age UK Strength and Balance Training, along with the views of healthcare professionals and Age UK staff involved within the process.

ETHICS AND DISSEMINATION

NHS REC Approval has been granted (IRAS ID 314705). Study participation is voluntary; participants will be provided with all necessary information within the participant information sheet, with written consent being sought. Study findings will be disseminated through manuscripts in peer-reviewed journals, at scientific conferences and in a short report to participants and the funding body.

Abnormal vasodilator stress electrocardiogram with normal myocardial perfusion: Clinical decision-making and review of literature

Ischemic electrocardiographic (ECG) changes during vasodilator stress testing in the presence of abnormal myocardial perfusion imaging (MPI) are associated with more severe coronary artery disease (CAD). However, significance of ECG changes during vasodilator stress test with normal MPI has been controversial. Here, we discuss two cases of significant ischemic ECG changes with vasodilator stress and normal MPI, whose subsequent workup revealed severe obstructive CAD. We also review the available literature on the occurrence and mechanism of these discrepant findings and propose recommendations for management.

Clinical Significance of Ventricular Premature Contraction Provoked by the Treadmill Test

Background and Objectives: The treadmill test (TMT) is a predictive tool for myocardial ischemia. Recently, exercise-provoked ventricular premature contracture (VPC) during TMT was shown to have a relation with coronary artery disease and cardiovascular mortality. Therefore, we evaluate clinical correlates of exercise-provoked VPC and compare the predictive power for myocardial ischemia and cardiovascular events. Method: Data of 408 patients (≥18 years of age) who underwent TMT for work up of angina, palpitation, dyspnea, syncope, or arrhythmia between February 2015, and January 2016, were collected with consent at Samsung Medical Center, Seoul, Republic of Korea. Among total of 408 patients, 208 were excluded according to the previous history of PCI or CABG, previous MI, decreased left ventricular ejection fraction lower than 50%, arrhythmia that could affect ST-segment change on ECG. Results: Among 200 patients, 32 (16.0%) developed exercise-provoked VPC (21 patients in the exercise phase, 20 patients in the recovery phase). Of them, 20 patients (10.0%) showed positive TMT, and 4 patients (2.0%) underwent revascularization after TMT. Among 21 patients showing exercise phase VPC, 5 (23.8%) showed positive TMT results. In patients younger than 65 years, exercise phase VPC was associated with positive TMT (odds ratio 6.879, 1.458–32.453) considering demographics and previous medical history in multivariable analysis. Among the 20 patients showing recovery phase VPC, 2 (10.0%) underwent revascularization after TMT. In multivariable analysis, recovery phase VPC was associated with revascularization (odds ratio 9.381, 1.144–76.948) considering age, sex, BMI, and TMT result. Conclusion: VPC during the treadmill test was a useful predictor of myocardial ischemia in this study.

The role of cardiac computed tomography in sports cardiology: back to the future!

In recent years, the role of pre-participation evaluation (PPE) in the prevention of sudden cardiac death in competitive athletes has become evident. Most physicians routinely supplement assessment by resting electrocardiogram with imaging techniques, such as echocardiography. The primary goal of imaging in the clinical assessment of competitive athletes is to exclude cardiovascular conditions associated with adverse outcomes. Cardiac computed tomography is emerging as an important technique for stratifying cardiovascular risk and assessing coronary artery disease (CAD), particularly in master athletes. Conversely, in young athletes, this technique has the best non-invasive coronary artery resolution and provides valuable details on coronary artery anatomy. Recent technical developments have brought about a dramatic reduction in radiation exposure, a major drawback of this diagnostic method; nowadays cardiac computed tomography may be performed at a dose of barely one millisievert. The present review provides a practical guide for the use of cardiac computed tomography in the PPE of competitive athletes, with a specific focus on its value for detecting congenital coronary anomalies and CAD in young and master athletes, respectively.

Exertional Dyspnea as the Main Symptom in an Adolescent Athlete With Coronary Artery Anomaly – A Case Report

Coronary artery anomalies (CAA) are associated with sudden cardiac death (SCD) and the majority of those events occur during exercise. Depending on the anatomic features and severity, CAA usually provoke clinical symptoms of coronary ischemia, mainly syncope and (exertional) chest pain. Here we present a case of a female adolescent athlete with a high-risk CAA variant and an unusual clinical presentation, which delayed diagnosis 2 years after first symptoms were reported. After successful surgical management of the anomalous artery, the patient was determined eligible for competitive sports with unremarkable follow-up examinations.

Exercise ECG Testing and Stress Cardiac Magnetic Resonance for Risk Prediction in Patients With Chronic Coronary Syndrome

PURPOSE

Vasodilator stress cardiac magnetic resonance (VS-CMR) has become crucial in the workup of patients with known or suspected chronic coronary syndrome (CCS). Whether traditional exercise ECG testing (ExECG) contributes prognostic information beyond VS-CMR is unclear.

METHODS

We retrospectively included 288 patients with known or suspected CCS who had undergone ExECG and subsequent VS-CMR in our institution. Clinical, ExECG, and VS-CMR variables were recorded. We defined the serious adverse events (SAE) as a combined endpoint of acute coronary syndrome, admission for heart failure, or all-cause death.

RESULTS

During a mean follow-up of 4.2 ± 2.15 yr, we registered 27 SAE (15 admissions for acute coronary syndrome, eight admissions for heart failure, and four all-cause deaths). Once adjusted for clinical, ExECG, and VS-CMR parameters associated with SAE, the only independent predictors were HRmax in ExECG (HR = 0.98: 95% CI, 0.96-0.99; P = .01) and more extensive stress-induced perfusion defects (PDs, number of segments) in VS-CMR (HR = 1.19: 95% CI, 1.07-1.34; P < .01). Adding HRmax significantly improved the predictive power of the multivariable model for SAE, including PDs (continuous reclassification improvement index: 0.47: 95% CI, 0.10-0.81; P < .05). The annualized SAE rate was 1% (if PD < 2 segments and HRmax > 130 bpm), 2% (if PD < 2 segments and HRmax ≤ 130 bpm), 3.2% (if PD ≥ 2 segments and HRmax > 130 bpm), and 6.3% (if PD ≥ 2 segments and HRmax ≤ 130 bpm), P < .01, for the trend. In patients on β-blocker therapy, however, only PDs in VS-CMR, but not HRmax, predicted SAE.

CONCLUSIONS

We conclude that ExECG contributes significantly to prognostic information beyond VS-CMR in patients with known or suspected CCS.

Combining flow and reserve measurement during myocardial perfusion imaging: A new era for myocardial perfusion scintigraphy?

Myocardial flow reserve represents the ratio of myocardial blood flow between stress and rest, giving functional information about both macrocirculation and microcirculation; it has been reported extensively in positron emission tomography, with an increase in diagnostic performance, providing important prognostic information and being a powerful tool to guide therapy. Advances in single photon emission computed tomography, with the widespread availability of "cadmium zinc telluride" single photon emission computed tomography cameras, raise the question of myocardial flow reserve use in daily clinical practice. In this article, we review the pathophysiology of myocardial blood flow and myocardial flow reserve, and the initial data available from single photon emission computed tomography myocardial blood flow and myocardial flow reserve evaluation; we also discuss potential limitations to the wider implementation of flow evaluation in single photon emission computed tomography.

Performance and Interpretation of Office Exercise Stress Testing

In an era where cardiovascular disease continues to increase in prevalence, chest pain is a commonly encountered complaint in the outpatient setting. Clinicians are often tasked with the challenge of selecting the most appropriate screening tool in the evaluation of a patient with suspected coronary artery disease. With proper consideration of indications and contraindications, exercise electrocardiogram (ECG) stress testing is an accessible, cost-conscious, and validated outpatient diagnostic modality for predicting coronary artery disease.

The additional prognostic value of myocardial perfusion SPECT in patients with known coronary artery disease with high exercise capacity

BACKGROUND

The prognostic value of myocardial perfusion imaging (MPI) in patients with known coronary artery disease (CAD) and high exercise capacity is still unknown. We sought to determine the MPI additional prognostic value over electrocardiography (ECG) stress testing alone in patients with known CAD who achieved ≥ 10 metabolic equivalents (METs).

METHODS AND RESULTS

We evaluated 926 patients with known CAD referred for MPI with exercise stress. Patients were followed for a mean of 32.4 ± 9.7 months for the occurrence of all-cause death or nonfatal myocardial infarction (MI). Those achieving ≥ 10 METs were younger, predominantly male, and had lower prevalence of cardiovascular risk factors. Patients reaching ≥ 10 METs had a lower annualized rate of hard events compared to their counterparts achieving < 10 METs (1.13%/year vs 3.95%/year, P < .001). Patients who achieved ≥ 10 METs with abnormal scans had a higher rate of hard events compared to those with normal scans (3.37%/year vs 0.57%/year, P = .023). Cardiac workload < 10 METs and an abnormal MPI scan were independent predictors of hard events.

CONCLUSIONS

MPI is able to stratify patients with known CAD achieving ≥ 10 METs for the occurrence of all-cause death and nonfatal MI, with incremental prognostic value over ECG stress test alone.

Coronary Artery Anomalies

Coronary artery anomalies (CAAs) are a group of congenital conditions characterized by abnormal origin or course of any of the 3 main epicardial coronary arteries. Although CAAs have been identified as a common underlying condition in young athletes with sudden cardiac death, the widespread use of invasive and noninvasive coronary imaging has led to increased recognition of CAAs among adults. CAAS are often discovered as an incidental finding during the diagnostic workup for ischemic heart disease. The clinical correlates and prognostic implication of CAAs remain poorly understood in this context, and guideline-recommended therapeutic choices are supported by a low level of scientific evidence. Several studies have examined whether assessment of CAA-related myocardial ischemia can improve risk stratification in these patients, suggesting that multimodality imaging and functional tests may be key in the management of CAAs. The aim of this review is to outline definitions, classification, and epidemiology of the most relevant CAAs, highlighting recent advances and the potential impact of multimodality evaluation, and to discuss current therapeutic opportunities.

Cardiopulmonary exercise capacity and limitations 3 months after COVID-19 hospitalisation

Background

This study aimed to describe cardiopulmonary function during exercise 3 months after hospital discharge for COVID-19 and compare groups according to dyspnoea and intensive care unit (ICU) stay.

Methods

Participants with COVID-19 discharged from five large Norwegian hospitals were consecutively invited to a multicentre, prospective cohort study. In total, 156 participants (mean age 56.2 years, 60 females) were examined with a cardiopulmonary exercise test (CPET) 3 months after discharge and compared with a reference population. Dyspnoea was assessed using the modified Medical Research Council (mMRC) dyspnoea scale.

Results

Peak oxygen uptake (V′_O2 peak) <80% predicted was observed in 31% (n=49). Ventilatory efficiency was reduced in 15% (n=24), while breathing reserve <15% was observed in 16% (n=25). Oxygen pulse <80% predicted was found in 18% (n=28). Dyspnoea (mMRC ≥1) was reported by 47% (n=59). These participants had similar V′_O2 peak (p=0.10) but lower mean±sdV′_O2 peak·kg⁻¹ % predicted compared with participants without dyspnoea (mMRC 0) (76±16% versus 89±18%; p=0.009) due to higher body mass index (p=0.03). For ICU- versus non-ICU-treated participants, mean±sdV′_O2 peak % predicted was 82±15% and 90±17% (p=0.004), respectively. Ventilation, breathing reserve and ventilatory efficiency were similar between the ICU and non-ICU groups.

Conclusions

One-third of participants experienced V′_O2 peak <80% predicted 3 months after hospital discharge for COVID-19. Dyspnoeic participants were characterised by lower exercise capacity due to obesity and lower ventilatory efficiency. Ventilation and ventilatory efficiency were similar between ICU- and non-ICU-treated participants.

Oxygen uptake was reduced in one-third of participants 3 months after hospitalisation for COVID-19. The most common exercise limitation was deconditioning. Circulatory limitations to exercise were more common than ventilatory limitations.https://bit.ly/3jmVDQ6

Prognostic Value of Cardiovascular Testing in Asymptomatic Patients With a History of Cardiovascular Disease: A Review of Contemporary Medical Literature

The cardiac stress testing, carotid duplex, coronary artery calcium (CAC) scoring, myocardial perfusion imaging, coronary angiography, C-reactive protein (CRP), glycated hemoglobin (HbA1C), total serum cholesterol, duplex ultrasonography, digital subtraction angiography, magnetic resonance angiography (MRA), computed tomography angiography (CTA), digital subtraction angiography, and ankle-brachial index (ABI) independently predict the risks and prognostic outcomes in asymptomatic cardiovascular disease (CVD) patients. The peripheral artery disease (PAD) screening guides the diagnosis, management, and prognosis of hemodynamically significant arterial stenosis, calcification, and malignant hypertension in patients with CVD without symptoms. The 79% sensitivity and 96% specificity of ABI screening, 90% sensitivity and 97% specificity of MRA, and 95% sensitivity and 50% specificity of CTA for tracking arterial occlusion indicate the high prognostic value of these tests in the setting of CVD. The 85% specificity and 60-70% sensitivity of cardiac stress testing substantiate its suitability to determine asymptomatic CVD prognosis related to myocardial ischemia, heart failure, multivessel disease, and unstable angina. The carotid duplex ultrasound potentially identifies long-term mortality, stroke, atherosclerosis, plaque instability, and angiographic stenosis among asymptomatic CVD patients with 94% specificity and 90% sensitivity. The CAC scoring has a positive predictive value (PPV) of 45.7% for identifying aortic valve calcium and PPV of 79.3% for tracking thoracic artery calcium. The medical literature provides substantial evidence concerning the validity, reliability, and prognostic value of cardiovascular testing for asymptomatic patients. Future studies are needed to undertake detailed assessments of benefits versus adverse outcomes associated with the prospective scaling (of cardiovascular testing) across asymptomatic CVD patients.

Silent coronary artery disease in asymptomatic patients with severe aortic stenosis and normal exercise testing

OBJECTIVE

There are no data about the prevalence of silent coronary artery disease in asymptomatic severe aortic stenosis patients with normal exercise testing. Importantly, unmasking significant coronary artery disease in patients with aortic stenosis could influence the choice/timing of treatment in these patients.

METHOD

Exercise testing was performed on semi-supine ergobicycle. Cardiopulmonary analysis during exercise testing, echocardiography, and laboratory analysis at rest was done. Standard clinical/electrocardiography criteria were assessed for symptoms/signs of ischemia during/after exercise testing. In patients with normal exercise testing coronary angiography was performed using standard femoral/radial percutaneous approach. Coronary stenosis was considered significant if >70% of vessel diameter or 50%-70% with fractional flow reserve ≤0.8.

RESULTS

Total of 96 patients with normal exercise testing were included (67.6 years, 50.6% males). No patient had any complication or adverse event. The Pmean was 52.7 mmHg, mean indexed aortic valve area was 0.36 cm/m and left ventricular ejection fraction, 69.5%. 19/96 patients (19.8%) had significant coronary artery disease on coronary angiography. Multivariate logistic regression analysis revealed brain natriuretic peptide and blood glucose as independent predictors of silent coronary artery disease. Brain natriuretic peptide value of 118 pg/ml had sensitivity/specificity of 63%/73% for predicting coronary artery disease (area under the curve 0.727, P = 0.006).

CONCLUSION

Our results are the first to show that in patients with severe aortic stenosis, normal left ventricular ejection fraction,, and normal exercise testing, significant coronary artery disease is present in as many as 1/5 patients. In such patients, further prospective studies are warranted to address the diagnostic value of brain natriuretic peptide in detecting silent coronary artery disease.

Ten things to know about ten imaging studies: A preventive cardiology perspective ("ASPC top ten imaging")

Knowing the patient's current cardiovascular disease (CVD) status, as well as the patient's current and future CVD risk, helps the clinician make more informed patient-centered management recommendations towards the goal of preventing future CVD events. Imaging tests that can assist the clinician with the diagnosis and prognosis of CVD include imaging studies of the heart and vascular system, as well as imaging studies of other body organs applicable to CVD risk. The American Society for Preventive Cardiology (ASPC) has published "Ten Things to Know About Ten Cardiovascular Disease Risk Factors." Similarly, this "ASPC Top Ten Imaging" summarizes ten things to know about ten imaging studies related to assessing CVD and CVD risk, listed in tabular form. The ten imaging studies herein include: (1) coronary artery calcium imaging (CAC), (2) coronary computed tomography angiography (CCTA), (3) cardiac ultrasound (echocardiography), (4) nuclear myocardial perfusion imaging (MPI), (5) cardiac magnetic resonance (CMR), (6) cardiac catheterization [with or without intravascular ultrasound (IVUS) or coronary optical coherence tomography (OCT)], (7) dual x-ray absorptiometry (DXA) body composition, (8) hepatic imaging [ultrasound of liver, vibration-controlled transient elastography (VCTE), CT, MRI proton density fat fraction (PDFF), magnetic resonance spectroscopy (MRS)], (9) peripheral artery / endothelial function imaging (e.g., carotid ultrasound, peripheral doppler imaging, ultrasound flow-mediated dilation, other tests of endothelial function and peripheral vascular imaging) and (10) images of other body organs applicable to preventive cardiology (brain, kidney, ovary). Many cardiologists perform cardiovascular-related imaging. Many non-cardiologists perform applicable non-cardiovascular imaging. Cardiologists and non-cardiologists alike may benefit from a working knowledge of imaging studies applicable to the diagnosis and prognosis of CVD and CVD risk - both important in preventive cardiology.

Ischemic Heart Disease: Noninvasive Imaging Techniques and Findings

Ischemic heart disease is a leading cause of death worldwide and comprises a large proportion of annual health care expenditure. Management of ischemic heart disease is now best guided by the physiologic significance of coronary artery stenosis. Invasive coronary angiography is the standard for diagnosing coronary artery stenosis. However, it is expensive and has risks including vascular access site complications and contrast material–induced nephropathy. Invasive coronary angiography requires fractional flow reserve (FFR) measurement to determine the physiologic significance of a coronary artery stenosis. Multiple noninvasive cardiac imaging modalities can also anatomically delineate or functionally assess for significant coronary artery stenosis, as well as detect the presence of myocardial infarction (MI). While coronary CT angiography can help assess the degree of anatomic stenosis, its inability to assess the physiologic significance of lesions limits its specificity. Physiologic significance of coronary artery stenosis can be determined by cardiac MR vasodilator or dobutamine stress imaging, CT stress perfusion imaging, FFR CT, PET myocardial perfusion imaging (MPI), SPECT MPI, and stress echocardiography. Clinically unrecognized MI, another clear indicator of physiologically significant coronary artery disease, is relatively common and is best evaluated with cardiac MRI. The authors illustrate the spectrum of imaging findings of ischemic heart disease (coronary artery disease, myocardial ischemia, and MI); highlight the advantages and disadvantages of the various noninvasive imaging methods used to assess ischemic heart disease, as illustrated by recent clinical trials; and summarize current indications and contraindications for noninvasive imaging techniques for detection of ischemic heart disease.

Online supplemental material is available for this article.

Published under a CC BY 4.0 license.

Exercise ECG for coronary artery disease screening in people living with HIV

BACKGROUND

Coronary artery disease (CAD) is one of the leading causes of death among people living with HIV (PLWH). We evaluated ECG stress testing (EST) for detecting CAD in PLWH with multiple cardiovascular risk factors.

METHODS

CORDIS was a cross-sectional study conducted in PLWH. Inclusion criteria were men at least 50 years or postmenopausal women, HIV-1 RNA less than 50 copies/ml and at least one of the following cardiovascular risk factor: familial history of CAD, smoking, hypertension, hypercholesterolemia or diabetes. Patients with a previous diagnosis of CAD or with cardiac symptoms were excluded. EST was performed concomitantly with bilateral carotid color-Doppler ultrasonography (CDU) and evaluated by a cardiologist. Results were described by median (interquartile range) or frequency (%). Logistic regression was applied to evaluate predictive factors of inducible myocardial ischemia (IMI).

RESULTS

EST and CDU were performed in 309 individuals; IMI prevalence was 7.4% [95% confidence interval (CI): 5.0-11.0%]. Among patients with a normal CDU, no cases of IMI were observed. In people with abnormal CDU, IMI prevalence increased accordingly with the atherosclerotic cardiovascular disease (ASCVD) risk score: 10.2%, 16.9%, 19.7%, 27.8% and 30.4% among individuals with ASCVD score 7.5% or less, more than 7.5%, more than 10%, more than 15% and more than 20%, respectively (P for trend: 0.02). At multivariate analysis, ASCVD risk score was associated with EST suggestive of IMI (adjusted odds ratio for 1% increase = 1.08; 95% CI: 1.02-1.13, P = 0.005) and with confirmed IMI (adjusted odds ratio for 1% increase = 1.11; 95% CI: 1.04-1.19, P = 0.003).

CONCLUSION

Prevalence of IMI was 7.4% in the CORDIS study. We suggest EST as first-line screening for CAD in PLWH without cardiac symptoms, with an abnormal CDU and a high ASCVD risk score.

Usefulness of the Duke Activity Status Index to Select an Optimal Cardiovascular Exercise Stress Test Protocol

Exercise testing represents the preferred stress modality for individuals undergoing evaluation of suspected myocardial ischemia. Patients with limited functional status may be unable to achieve an adequate exercise stress, thus influencing the diagnostic sensitivity of the results. The Duke Activity Status Index (DASI) is a clinically applicable tool to estimate exercise capacity. The purpose of the current study was to assess the utility of the DASI to identify patients unable to achieve an adequate exercise stress result. Patients referred for exercise stress testing were administered the DASI pre-exercise. Baseline characteristics and exercise variables were evaluated including DASI-metabolic equivalents (DASI-METs), peak METs, exercise time (ET), and %-predicted maximal heart rate (%PMHR). Criteria for determining adequate exercise stress was defined as ≥85%PMHR or ≥ 5-METs at peak exercise. In 608 cardiovascular stress tests performed during the study period; 314 were exercise stress. The median DASI-METs (8.4 [interquartile range; 6.7 to 9.9]) was associated with estimated peak exercise METs (R=0.50, p <0.001), ET (R=0.29, p <0.001), and %PMHR (R=0.19, p = 0.003). DASI-METs were different between those with < or ≥85%PMHR (7.9 [6.6-9.0] vs. 8.9 [7.1-9.9], P=0.025) and those with < or ≥5-METs (5.8 [4.6 to 6.6] versus 8.9 [7.3-9.9], p <0.001). Receiver operating characteristic curve analysis identified a DASI-MET threshold of ≤/>7.4 to optimally predict adequate exercise stress (sensitivity=93%, specificity=71%). In conclusion, the DASI correlates with peak METs, ET, and %PMHR among patients referred for exercise testing and can be used to identify patients with an increased likelihood of an inadequate stress test result.

Clinical judgement in chest pain: a case report

Background

Cardiac stress testing is a validated diagnostic tool to assess symptomatic patients with intermediate pretest probability of coronary artery disease (CAD). However, in some cases, the cardiac stress test may provide inconclusive results and the decision for further workup typically depends on the clinical judgement of the physician. These decisions can greatly affect patient outcomes.

Case presentation

We present an interesting case of a 54-year-old Caucasian male with history of tobacco use and gastroesophageal reflux disease (GERD) who presented with atypical chest pain. He had an asymptomatic electrocardiogram (EKG) stress test with intermediate probability of ischemia. Further workup with coronary computed tomography angiography (CCTA) and cardiac catheterization revealed multivessel CAD requiring a bypass surgery. In this case, the patient only had a history of tobacco use but no other significant comorbidities. He was clinically stable during his hospital stay and his testing was anticipated to be negative. However to complete workup, cardiology recommended anatomical testing with CCTA given the indeterminate EKG stress test results but the results of significant stenosis were surprising with the patient eventually requiring coronary artery bypass grafting (CABG).

Conclusion

As a result of the availability of multiple noninvasive diagnostic tests with almost similar sensitivities for CAD, physicians often face this dilemma of choosing the right test for optimal evaluation of chest pain in patients with intermediate pretest probability of CAD. Optimal test selection requires an individualized patient approach. Our experience with this case emphasizes the role of history taking, clinical judgement, and the risk/benefit ratio in deciding further workup when faced with inconclusive stress test results. Physicians should have a lower threshold for further workup of patients with inconclusive or even negative stress test results because of the diagnostic limitations of the test. Instead, utilizing a different, anatomical test may be more valuable. Specifically, the case established the usefulness of CCTA in cases such as this where other CAD diagnostic testing is indeterminate.

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.

A high exercise workload of ≥ 10 METS predicts a low risk of significant ischemia and cardiac events in older adults

BACKGROUND

Patients who achieve ≥ 10 METS during exercise SPECT myocardial perfusion imaging (MPI) have very low rates of significant ischemia and major adverse cardiac events (MACE). It is unknown how many older adults can achieve ≥ 10 METS, and if low risk extends to this subgroup.

METHODS AND RESULTS

We examined the workload achieved, prevalence and predictors of ischemia, and MACE (cardiac death, non-fatal MI, late revascularization) in a cohort of 382 patients ≥ 65 years of age who underwent exercise 99mTc SPECT MPI. The cohort was 64.4% male and 36.9% had known coronary artery disease (CAD). All achieved ≥ 85% of maximum age-predicted heart rate. A workload of ≥ 10 METS was achieved in 25.4%; 50.3% attained 7-9 METS, and 24.4% reached < 7 METS. There was a stepwise decrease in prevalence of any ischemia and significant ischemia (≥ 10% of the left ventricle (LV)) as workload increased (P = 0.037). Patients achieving ≥ 10 METS had a 3.1% prevalence of ≥ 10% LV ischemia (1.2% in those without ST depression). Cardiac death and MACE rates in the ≥ 10 METS subgroup were 0.6%/year and 2.6%/year over a median 7.0 years of follow-up.

CONCLUSIONS

A substantial proportion of older adults who undergo exercise SPECT MPI can achieve ≥ 10 METS. This subgroup has low rates of significant LV ischemia and MACE. The favorable diagnostic and prognostic implications of achieving a high workload in an older adult population suggest it is feasible, with certain exceptions, to include this subgroup in workload-based strategies of provisional imaging.

Baseline Characteristics and Risk Profiles of Participants in the ISCHEMIA Randomized Clinical Trial

Importance

It is unknown whether coronary revascularization, when added to optimal medical therapy, improves prognosis in patients with stable ischemic heart disease (SIHD) at increased risk of cardiovascular events owing to moderate or severe ischemia.

Objective

To describe baseline characteristics of participants enrolled and randomized in the International Study of Comparative Health Effectiveness With Medical and Invasive Approaches (ISCHEMIA) trial and to evaluate whether qualification by stress imaging or nonimaging exercise tolerance test (ETT) influenced risk profiles.

Design, Setting, and Participants

The ISCHEMIA trial recruited patients with SIHD with moderate or severe ischemia on stress testing. Blinded coronary computed tomography angiography was performed in most participants and reviewed by a core laboratory to exclude left main stenosis of at least 50% or no obstructive coronary artery disease (CAD) (<50% for imaging stress test and <70% for ETT). The study included 341 enrolling sites (320 randomizing) in 38 countries and patients with SIHD and moderate or severe ischemia on stress testing. Data presented were extracted on December 17, 2018.

Main Outcomes and Measures

Enrolled, excluded, and randomized participants' baseline characteristics. No clinical outcomes are reported.

Results

A total of 8518 patients were enrolled, and 5179 were randomized. Common reasons for exclusion were core laboratory determination of insufficient ischemia, unprotected left main stenosis of at least 50%, or no stenosis that met study obstructive CAD criteria on study coronary computed tomography angiography. Randomized participants had a median age of 64 years, with 1168 women (22.6%), 1726 nonwhite participants (33.7%), 748 Hispanic participants (15.5%), 2122 with diabetes (41.0%), and 4643 with a history of angina (89.7%). Among the 3909 participants randomized after stress imaging, core laboratory assessment of ischemia severity (in 3901 participants) was severe in 1748 (44.8%), moderate in 1600 (41.0%), mild in 317 (8.1%) and none or uninterpretable in 236 (6.0%), Among the 1270 participants who were randomized after nonimaging ETT, core laboratory determination of ischemia severity (in 1266 participants) was severe (an eligibility criterion) in 1051 (83.0%), moderate in 101 (8.0%), mild in 34 (2.7%) and none or uninterpretable in 80 (6.3%). Among the 3912 of 5179 randomized participants who underwent coronary computed tomography angiography, 79.0% had multivessel CAD (n = 2679 of 3390) and 86.8% had left anterior descending (LAD) stenosis (n = 3190 of 3677) (proximal in 46.8% [n = 1749 of 3739]). Participants undergoing ETT had greater frequency of 3-vessel CAD, LAD, and proximal LAD stenosis than participants undergoing stress imaging.

Conclusions and Relevance

The ISCHEMIA trial randomized an SIHD population with moderate or severe ischemia on stress testing, of whom most had multivessel CAD.

Trial Registration

ClinicalTrials.gov Identifier: NCT01471522.

Exploring Armenian Ethnicity as an Independent Risk Factor for Cardiovascular Disease: Findings from a Prospective Cohort of Patients in a County Hospital

OBJECTIVES

While several studies have examined the risk of cardiovascular disease (CVD) in larger racial and ethnic groups within the United States, limited information is available on smaller sub-populations, such as Armenians, with high rates of CVD in their home country. This study examined the association between Armenian ethnicity and a positive exercise treadmill test (ETT).

DESIGN

Prospective cohort study of patients at a 377-bed county hospital in Los Angeles, California from 2008-2011.

SETTING

All patients were interviewed at the time of ETT to assess their cardiovascular risk factors at the cardiac laboratory of the hospital.

PARTICIPANTS

5,006 patients between 18-89 years of age, of whom 12.6% were of Armenian ethnicity and 54.4% were female.Main Outcome Measure: ETT results as a proxy for CVD risk.

RESULTS

After adjusting for cardiovascular risk factors, Armenian ethnicity was significantly associated with higher odds of positive ETT (OR = 1.40, p = 0.01). Known coronary artery disease CAD (OR = 2.28, p < 0.01), hyperlipidemia (OR = 1.37, p < 0.01), and hypertension (OR = 1.24, p = 0.05) were significantly associated with higher odds of a positive ETT. In subgroup analyses, hyperlipidemia was the only significant predictor of positive ETT (OR = 1.92, p = 0.02) among Armenians, while patient history of CAD (OR = 2.49, p < 0.01), hyperlipidemia (OR = 1.29, p = 0.03), and age (OR = 1.04, p < 0.01) were significant predictors among non-Armenians. Armenian ethnicity remained associated with higher odds of positive ETT (OR = 1.40, p < 0.01) when patients with CAD were excluded.

CONCLUSION

Armenian ethnicity may be an independent risk factor for CVD, influenced by the uniformity of the genetic pool and cultural and dietary exposures.

Value of exercise stress electrocardiography for stratification of exercise capacity and left ventricular systolic and diastolic function on coronary slow flow: case-control study

Background

Coronary slow flow phenomenon (CSFP) is an angiographic entity characterized by delayed coronary opacification in absence of evident obstructive lesion in the epicardial coronary artery. However, whether patients with CSFP exhibit differing responses to exercise is still not known. This study aimed to evaluate results of exercise stress electrocardiography (ExECG) and left ventricular (LV) function during exercise, and study the value of ExECG for stratification of exercise capacity and LV function in patients with CSFP.

Methods

Thirty patients with CSFP and 24 controls were enrolled in the study. Diagnosis of CSFP was made by Thrombolysis in Myocardial Infarction frame count. ExECG and LV function measured by echocardiography at rest, during exercise and recovery phase were evaluated.

Results

Negative ExECG was found in 24 (80%) patients with CSFP. At rest, LV global longitudinal strain (GLS) decreased and mitral average E/e’ increased in patients with CSFP compared with controls; however, there were no differences in these parameters between CSFP patients with negative ExECG and patients with positive ExECG. During exercise, CSFP patients with negative ExECG and controls had significantly increased LV GLS and decreased mitral average E/e’, but CSFP patients with positive ExECG had significantly decreased LV GLS and increased mitral average E/e’.

Conclusions

About 80% patients with CSFP exhibited negative ExECG. CSFP patients with negative ExECG exhibited improved LV function but CSFP patients with positive ExECG exhibited impaired LV function during exercise. ExECG may aid in the stratification of exercise capacity and LV function in patients with CSFP.

A wide range gate data acquisition for diagnosing coronary artery disease

BACKGROUND

The turbulence of blood flow caused by stenosis has an impact on the surrounding coronary artery tissue and creates an audio-frequency vibration to the adjacent myocardial wall. We investigated the diagnostic feasibility of a novel diagnostic method using wide range gate (WRG) ultrasound data acquisition for diagnosing coronary artery disease (CAD). WRG data acquisition detects high-frequency vibrations from coronary artery stenosis, using pulse-wave Doppler ultrasound.

METHODS

We used a Verasonics ultrasound data acquisition system to implement the WRG data acquisition. Investigators performed clinical trials for 80 subjects, with suspected CAD. All enrolled patients participated in WRG data acquisition before coronary angiography (CAG).

RESULTS

As compared with the results of CAG, the sensitivity and specificity of the WRG data analysis were 80% and 84%, respectively. The WRG data analysis showed that the sensitivity and specificity were 81% and 79% in the left anterior descending artery, respectively, 75% and 89% in the left circumflex artery, respectively, and 85% and 82% in the right coronary artery, respectively. In a multivariate analysis, a positive vibrometry result was an independent predictive factor for CAD.

CONCLUSIONS

We proposed a new diagnostic method for detecting CAD using ultrasound. The new data acquisition method showed good potential as an initial diagnostic tool for CAD.

Serum sclerostin level and its relation to subclinical atherosclerosis in subjects with type 2 diabetes

BACKGROUND

Sclerostin, a Wnt-signalling inhibitor, is an established negative regulator of bone formation. However, data regarding its potential importance in vascular disease are less clear. Common carotid artery media thickness (CIMT) assessment and plaque identification using ultrasound imaging are well-recognized tools for identifying and monitoring atherosclerosis. The aim of the present study is to examine the relationship between serum sclerostin and subclinical atherosclerosis (as evidenced by CIMT).

METHODS

This cross-sectional study included 50 subjects with T2DM and 20 subjects as a control group. Multivariable linear regression models were used to assess the association of sclerostin with subclinical atherosclerosis.

RESULTS

Serum sclerostin levels in T2DM patients were significantly higher compared to the control group (167.16 ± 63.60 versus 85.98 ± 23.74 pg/ml, P < 0.0001). A concentration of ≥162.5 pg/ml showed a sensitivity of 90% and a specificity of 86.67% to detect an increased risk of subclinical atherosclerosis. Univariate analysis revealed a significant positive correlation between serum sclerostin and CIMT (r = 0.635, P < 0.001). Sclerostin concentrations remained independently associated with CIMT (β = 63.188 [6.919-119.456], P = 0.017) after adjusting for age and gender.

CONCLUSION

Our data suggest a positive correlation between serum sclerostin level and subclinical atherosclerosis in subjects with type 2 diabetes mellitus.

ST-Segment Elevation During Treadmill Exercise Test in a Patient without Prior Myocardial Infarction. A Case Report and Literature Review

Exercise-induced ST-elevation is extremely uncommon especially in patients without prior myocardial infarction. It is more common among post-infarction patients with Q waves on the resting ECG. In the current case we report a 50-year-old man with a history of chest pain on exertion started four months ago. During the exercise test, ST-elevation was observed in leads II, III, AVF. Coronary angiography revealed significant stenoses in the right coronary artery and left circumflex artery, which were treated with percutaneous coronary intervention. This case highlights the rare finding of exercise-induced ST-elevation and reviews possible mechanisms.

Cardiac stress testing review for the primary care provider

Various modes of cardiac stress testing are conducted in outpatient practices today. This article presents information on the current methods of testing to help primary care providers gain confidence in test selection, the testing process, and interpreting results.

Risk stratification for coronary artery disease in multi-ethnic populations: Are there broader considerations for cost efficiency?

Coronary artery disease (CAD) screening and diagnosis are core cardiac specialty services. From symptoms, autopsy correlations supported reductions in coronary blood flow and dynamic epicardial and microcirculatory coronaries artery disease as etiologies. While angina remains a clinical diagnosis, most cases require correlation with a diagnostic modality. At the onset of the evidence building process much research, now factored into guidelines were conducted among population and demographics that were homogenous and often prior to newer technologies being available. Today we see a more diverse multi-ethnic population whose characteristics and risks may not consistently match the populations from which guideline evidence is derived. While it would seem very unlikely that for the majority, scientific arguments against guidelines would differ, however from a translational perspective, there will be populations who differ and importantly there are cost-efficacy questions, e.g., the most suitable first-line tests or what parameters equate to an adequate test. This article reviews non-invasive diagnosis of CAD within the context of multi-ethnic patient populations.

Treadmill stress tests should not be part of "routine health check package"

A treadmill ECG stress test (TMT) often forms part of the popular health check packages recommended for people who are asymptomatic on the premise that it can detect disease at an early stage and treatment be prescribed to prevent or reduce future morbidity and mortality. Such a recommendation does not take into account the properties of this procedure as a diagnostic test. It has an average sensitivity and specificity of 68% and 77%, respectively. However, these figures depend on the probability of coronary artery disease (CAD) in the test subject. In asymptomatic persons with few or no risk factors, the likelihood of a false positive is high and will result in psychological stress and/or expensive and possibly invasive test. Recommendation for a TMT should be made by a physician after evaluating the subject to have at least an intermediate risk of having CAD.

Prognostic value of electrocardiogram exercise testing for risk stratification in asymptomatic coronary artery disease

BACKGROUND

Several variables of electrocardiogram exercise testing (EET) predict cardiovascular events in the general population and in patients with coronary artery disease (CAD). However, most of the studies have not included patients with asymptomatic CAD. The aim of this study was to evaluate the prognostic value of EET in asymptomatic CAD patients.

PATIENTS AND METHODS

We carried out a retrospective single-center analysis including all patients with asymptomatic CAD documented by angiography who underwent EET from January 2010 to December 2013. A number of EET variables and three exercise scores [Duke Treadmill Score (DTS), Morise score, and FIT score] were analyzed. The primary endpoint was the combined incidence of myocardial infarction (MI), myocardial revascularization, and death from any cause during follow-up.

RESULTS

A total of 306 patients were included (mean age was 65±10 years, 61% had previous MI, and the median exercise capacity was 9.4±2.7 metabolic equivalent of task). The primary endpoint occurred in 15.7% of patients during 3.3 years of follow-up. The DTS and FIT were independent predictors of the primary endpoint unlike the Morise score (DTS: hazard ratio=0.91, 95% confidence interval: 0.85-0.99, P=0.018; FIT score: 0.99, 0.98-0.996, P=0.001; Morise score: 0.97, 0.93-1.02, P=0.20). The DTS was independent predictor of MI or revascularization, whereas FIT predicted death from any cause. Excluding patients with early revascularization, DTS had no predictive power at the composite endpoint.

CONCLUSION

In our population with asymptomatic CAD, FIT and DTS had significant value for risk prediction and consequently the EET can be a valid tool in the clinical follow-up of this population.

Prognostic value of one millisievert exercise myocardial perfusion imaging in patients without known coronary artery disease

The aim of this study was to assess the prognostic value of normal ultra-low-dose exercise MPI with a CZT camera.

METHODS

1901 consecutive patients without known CAD referred for exercise MPI with 1.8 MBq/kg (0.05 mCi) of Tc99m sestamibi or tetrofosmin and a CZT camera were included prospectively. Patients with an abnormal scan requiring an additional resting image (230) or a submaximal exercise test (271) were excluded. The 1400 remaining patients were followed for 39 months. The primary end-point was cardiac events (cardiac death, nonfatal myocardial infarction, and revascularization). The secondary end-point was noncardiac death.

RESULTS

The mean injected activity was 145 ± 37 MBq (3.9 ± 1 mCi), the mean acquisition duration was 10 ± 0.7 minutes, and the mean effective dose was 0.91 ± 0.13 mSv. 1288 patients (92%) achieved full follow-up. We observed 22 cardiac events and 16 noncardiac deaths. The annualized rates were equivalent to 0.55% for cardiac events and 0.37% for noncardiac mortality.

CONCLUSIONS

Normal ultra-low-dose exercise MPI with a CZT camera has a high negative predictive value. The effective dose was less than 1 mSv, and the study thus allays concerns about radiation burden.

Usefulness of Achieving ≥10 METs With a Negative Stress Electrocardiogram to Screen for High-Risk Obstructive Coronary Artery Disease in Patients Referred for Coronary Angiography After Exercise Stress Testing

Functional capacity in exercise stress testing is an independent predictor of cardiac events. Routine use of nuclear perfusion imaging increases radiation burden and cost. Our goal was to assess the clinical utility of exercise functional capacity with stress electrocardiogram (ECG) as an adjunct in predicting the presence of high-risk obstructive coronary artery disease (CAD) on diagnostic coronary angiography. We performed a retrospective study of patients who underwent exercise stress testing for the evaluation of chest pain and underwent diagnostic coronary angiography within the subsequent 3 months. High-risk CAD was defined as coronary artery diameter stenosis of ≥70% in the proximal left anterior descending artery, ≥70% diameter stenosis in 3 major epicardial arteries, or ≥50% diameter stenosis in the left main artery. Univariable and multivariable analyses were performed to identify predictors of high-risk CAD. Of the 412 patients, 105 (25%) had high-risk CAD on coronary angiography. On multivariate logistic regression, we found that positive stress ECG, abnormal stress imaging, left ventricular ejection fraction, and male gender were independent predictors of high-risk CAD. The strongest predictor was positive stress ECG (hazard ratio 3.16, 95% confidence interval 1.90 to 5.27, p <0.001). Functional capacity measures alone were not independent predictors of high-risk CAD. Achieving ≥10 METs with a negative stress ECG resulted in 94% sensitivity and 97% negative predictive value in identifying high-risk CAD. This supports the strategy for provisional use of myocardial perfusion imaging in patients with low functional capacity and/or abnormal stress ECG to minimize cost and radiation exposure.

Prevalence of ECG changes during adenosine stress and its association with perfusion defect on myocardial perfusion scintigraphy

OBJECTIVE

Myocardial perfusion scintigraphy (MPS) is a valuable, noninvasive imaging modality in the evaluation of patients with coronary artery disease. Adenosine stress may occasionally be associated with ECG changes. This study evaluated the strength of association between adenosine stress-related ECG changes and perfusion defects on Tc-MPS.

PATIENTS AND METHODS

117 (mean age: 61.25±9.27 years; sex: men 87, women 30) patients with known/suspected coronary artery disease underwent adenosine stress MPS. ECG was monitored continuously during adenosine stress for ST-depression. On the basis of the summed difference score, reversible perfusion defects were categorized as follows: normal: less than 4, mild: 4-8, moderate: 9-13, and severe: more than 13.

RESULTS

ST-depression was observed in 27/117 (23.1%) and reversible perfusion defects were observed in 18/27 (66.66%) patients. 2/27, 6/27, and 10/27 patients had mild, moderate, and severe ischemia, respectively. 9/27 patients had normal perfusion. ECG changes and perfusion defects showed a moderate strength of association (correlation coefficient r=0.35, P=0.006). The sensitivity, specificity, positive predictive value, and negative predictive value of ECG findings for prediction of ischemia were 35.29, 86.36, 67.67, and 63.33%, respectively.

CONCLUSION

ECG changes during adenosine stress are not uncommon. It shows a moderate strength of association with reversible perfusion defects. ECG changes during adenosine merit critical evaluation of MPS findings.

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

PURPOSE

To determine lifetime cost-effectiveness of diagnostic evaluation strategies for individuals with stable chest pain and suspected coronary artery disease (CAD).

METHODS

Exercise treadmill testing (ETT), stress echocardiography (SE), myocardial perfusion scintigraphy (MPS), coronary computed tomographic angiography (CCTA), and invasive coronary angiography (ICA) were assessed alone, or in succession to each other.

RESULTS

Initial ETT followed by imaging wherein ETT was equivocal or unable to be performed appeared more cost-effective than any strategy employing initial testing by imaging.

CONCLUSION

As pre-test likelihood of CAD varies, different modalities including SE, CCTA, and MPS result in improved costs and enhanced effectiveness.