Implications of Abnormal Exercise Electrocardiography With Normal Stress Echocardiography

Predicting angiographic coronary artery disease using machine learning and high-frequency QRS

AIM

Exercise stress ECG is a common diagnostic test for stable coronary artery disease, but its sensitivity and specificity need to be further improved. In this paper, we construct a machine learning model for the prediction of angiographic coronary artery disease by HFQRS analysis of cycling exercise ECG.

METHODS AND RESULTS

This study prospectively included 140 inpatients and 59 healthy volunteers undergoing cycling exercise ECG. The CHD group (N=104) and non-CHD group (N=95) were determined by coronary angiography gold standard. Automated HF QRS analysis was performed by the blinded method. The coronary group was predominantly male, with a higher prevalence of age, BMI, hypertension, and diabetes than the non-coronary group ( P < 0.001 ), higher lipid levels in the coronary group ( P < 0.005 ), significantly longer QRS duration during exercise testing ( P < 0.005 ), more positive leads ( P < 0.001 ), and a greater proportion of significant changes in HFQRS ( P < 0.001 ). Age, Gender, Hypertension, Diabetes, and HF QRS Conclusions were screened by correlation analysis and multifactorial retrospective analysis to construct the machine learning models of the XGBoost Classifier, Logistic Regression, LightGBM Classifier, RandomForest Classifier, Artificial Neural Network and Support Vector Machine, respectively.

CONCLUSION

Male, elderly, with hypertension, diabetes mellitus, and positive exercise stress test HFQRS conclusions suggested a high risk of CHD. The best performance of the Logistic Regression model was compared, and a column line graph for assessing the risk of CHD was further developed and validated.

Diagnosing Coronary Artery Disease in the Patient Presenting with Stable Ischemic Heart Disease: The Role of Anatomic versus Functional Testing

There are unique advantages and disadvantages to functional versus anatomic testing in the work-up of patients who present with symptoms suggestive of obstructive coronary artery disease. Evaluation of these individuals starts with an assessment of pre-test probability, which guides subsequent testing decisions. The choice between anatomic and functional testing depends on this pre-test probability. In general, anatomic testing has particular utility among younger individuals and women; while functional testing can be helpful to rule-in ischemia and guide revascularization decisions. Ultimately, selection of the most appropriate test should be individualized to the patient and clinical scenario.

Significance of abnormal stress electrocardiography with normal cardiac imaging during stress testing-a meta-analysis

BACKGROUND AND AIMS

Diagnostic testing for coronary artery disease frequently involves functional stress testing where imaging is often coupled with electrocardiogram (ECG) analysis. While decision-making is straightforward when both functional testing and ECG are either positive or negative, interpretation is challenging and prognostic importance uncertain with positive ECG and negative imaging since imaging is considered more sensitive. Prior studies have demonstrated mixed results. We sought to perform a meta-analysis of published studies to determine the significance of this particular type of discordant stress test result.

METHODS AND RESULTS

PubMed, Cochrane, and Google Scholar were searched to identify studies reporting results of functional imaging (pharmacological exercise echocardiography or SPECT) and ECG analysis, along with the major adverse cardiovascular events (MACE) at patient follow-up. Studies were stratified based on functional imaging modality used. Primary outcome was a composite of all-cause death or myocardial infarction, and secondary outcome was the need for coronary revascularization. Random effects model was used to calculate risk ratios (RR), and heterogeneity among studies was assessed using the Higgins I2 value. Nine studies with a total of 23,715 patients were included. Primary end point was more common with discordant results with exercise stress echocardiography (RR 1.33, 95% confidence intervals [1.08-1.63]) or pharmacological SPECT (RR 6.53 95% CI [2.31-18.48]).

CONCLUSIONS

Patients in the discordant exercise stress echocardiography and pharmacological SPECT groups were more likely to suffer the primary end point than those with a normal stress test. Discordant results should be interpreted carefully in the clinical context, given their prognostic impact based on the stress modality used.

The clinical use of stress echocardiography in chronic coronary syndromes and beyond coronary artery disease: a clinical consensus statement from the European Association of Cardiovascular Imaging of the ESC

Since the 2009 publication of the stress echocardiography expert consensus of the European Association of Echocardiography, and after the 2016 advice of the American Society of Echocardiography-European Association of Cardiovascular Imaging for applications beyond coronary artery disease, new information has become available regarding stress echo. Until recently, the assessment of regional wall motion abnormality was the only universally practiced step of stress echo. In the state-of-the-art ABCDE protocol, regional wall motion abnormality remains the main step A, but at the same time, regional perfusion using ultrasound-contrast agents may be assessed. Diastolic function and pulmonary B-lines are assessed in step B; left ventricular contractile and preload reserve with volumetric echocardiography in step C; Doppler-based coronary flow velocity reserve in the left anterior descending coronary artery in step D; and ECG-based heart rate reserve in non-imaging step E. These five biomarkers converge, conceptually and methodologically, in the ABCDE protocol allowing comprehensive risk stratification of the vulnerable patient with chronic coronary syndromes. The present document summarizes current practice guidelines recommendations and training requirements and harmonizes the clinical guidelines of the European Society of Cardiology in many diverse cardiac conditions, from chronic coronary syndromes to valvular heart disease. The continuous refinement of imaging technology and the diffusion of ultrasound-contrast agents improve image quality, feasibility, and reader accuracy in assessing wall motion and perfusion, left ventricular volumes, and coronary flow velocity. Carotid imaging detects pre-obstructive atherosclerosis and improves risk prediction similarly to coronary atherosclerosis. The revolutionary impact of artificial intelligence on echocardiographic image acquisition and analysis makes stress echo more operator-independent and objective. Stress echo has unique features of low cost, versatility, and universal availability. It does not need ionizing radiation exposure and has near-zero carbon dioxide emissions. Stress echo is a convenient and sustainable choice for functional testing within and beyond coronary artery disease.

Association of abnormal electrocardiography response on dobutamine stress echocardiogram with longer-term major adverse cardiovascular events in women with symptoms of ischemic heart disease

Background

Prior work demonstrates patients with positive (+) electrocardiogram (ECG) but negative (-) echocardiogram wall motion abnormalities (WMAs) on dobutamine stress echocardiography (DSE) testing have an elevated of major adverse cardiovascular events (MACEs). In this study, we aimed to evaluate the long-term prognosis of women with suspected ischemia with no obstructive coronary artery (INOCA) disease by utilizing core lab read DSE, specifically focusing on those with + ECG findings.

Methods

Among women with signs and symptoms of myocardial ischemia undergoing clinically indicated coronary angiography enrolled in the Women's Ischemia Syndrome Evaluation (WISE) [1997-2001], a prospective cohort study, 99 underwent standardized DSE by site design. Women with positive DSE (n=17), defined as an increase in score based on wall motion scoring index were excluded except for akinetic to dyskinetic (n=10), providing 82 patients in this analysis. ECG was assessed by core laboratory and (+) ECG was defined as >1 mm ST change. Non-obstructive coronary artery disease (CAD) was assessed by core laboratory quantitative coronary angiography and defined as <50% epicardial stenosis. All-cause death follow-up was an average of 8 years, while adjudicated MACE [all-cause mortality, nonfatal myocardial infarction (MI), nonfatal stroke, heart failure hospitalization] was an average of 5.5 years. Comparisons among subject groups [i.e., (+) ECG and (-) ECG] were made using chi-square or Fisher's exact tests for categorical variables and t-test or Wilcoxon rank-sum test for continuous variables.

Results

Demographic profile included a mean age 59±10 years; 55% had hypertension (HTN), 29% diabetes mellitus (DM), and 72% non-obstructive CAD. Overall, 9/82 women (11%) had (+) ECG in the absence of WMAs. There were significant differences in family history of CAD (P=0.009) and vasodilator (P=0.042) use between the (+) ECG and (-) ECG groups, but otherwise had no significant demographic or clinical differences. At longer-term follow up, patients with (+) ECG had higher risk of MACE [unadjusted hazard ratio (HR): 4.91, 95% confidence interval (CI): 1.83, 13.19, P=0.002].

Conclusions

Abnormal stress ECG findings on dobutamine stress testing with a negative DSE should be viewed as an indicator of longer-term risk in women with signs and symptoms of ischemia.

Chest Pain Evaluation: Diagnostic Testing

Chest pain/discomfort (CP) is a common symptom and can be a diagnostic dilemma for many clinicians. The misdiagnosis of an acute or progressive chronic cardiac etiology may carry a significant risk of morbidity and mortality. This review summarizes the different options and modalities for establishing the diagnosis and severity of coronary artery disease. An effective test selection algorithm should be individually tailored to each patient to maximize diagnostic accuracy in a timely fashion, determine short- and long-term prognosis, and permit implementation of evidence-based treatments in a cost-effective manner. Through collaboration, a decision algorithm was developed (www.chowmd.ca/cadtesting) that could be adopted widely into clinical practice.

Exaggerated Systolic Blood Pressure Increase with Exercise and Myocardial Ischemia on Exercise Stress Echocardiography

BACKGROUND

Central Illustration : Exaggerated Systolic Blood Pressure Increase with Exercise and Myocardial Ischemia on Exercise Stress Echocardiography ESBPRE: exaggerated systolic blood pressure response to exercise; HR: heart rate; SBP: systolic blood pressure.

BACKGROUND

The association between exaggerated systolic blood pressure response to exercise (ESBPRE) and myocardial ischemia is controversial and little studied in patients with established or suspected chronic coronary syndrome.

OBJECTIVE

To verify the relationship between myocardial ischemia and ESBPRE in patients undergoing exercise stress echocardiography (ESE).

METHODS

This is a cross-sectional study with 14,367 patients undergoing ESE, from January 2000 to January 2022, divided into the following 2 groups: G1, composed of patients whose peak systolic pressure increased ≥ 90 mmHg (value corresponding to the 95th percentile of the study population), and G2, patients who did not demonstrate an exaggerated hypertensive response. The groups were compared using Student's t and chi-square tests. P values < 0.05 were considered significant. Logistic regression was also performed to identify independent risk factors for myocardial ischemia, ESBPRE, complaints of typical chest pain prior to the exam, and angina during the test.

RESULTS

Of the 14,367 patients, 1,500 (10.4%) developed ESBPRE, and 7,471 (52.0%) were female. The percentages of previous complaints of typical chest pain, angina during the test, and myocardial ischemia in patients with ESBPRE were 5.8%, 2.4% and 18.1%, compared to 7.4%, 3.9%, and 24.2%, in patients without ESBPRE, respectively (p = 0.021,p = 0.004, p < 0.001). In multivariate analysis, ESBPRE was independently associated with a lower probability of myocardial ischemia (odds ratio: 0.73; 95% confidence interval: 0.58 to 0.93; p = 0.009).

CONCLUSION

Exaggerated increase in systolic blood pressure during ESE may be a marker for excluding myocardial ischemia.

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.

Exercise Stress Echocardiography for Stable Coronary Artery Disease: Succumbed to the Modern Conceptual Revolution or Still Alive and Kicking?

The modern conceptual revolution in managing patients with stable coronary artery disease (CAD), based on improvement in preventive and pharmacological therapy, advocates coronary artery revascularization only for smaller group of patients with refractory angina, poor left ventricular systolic function, or high-risk coronary anatomy. Therefore, our conventional wisdom about stress testing must be questioned within this new and revolutionary paradigm. Exercise stress echocardiography (ESE) is still a well-known technique for assessing known or suspected stable CAD, it is safe, accessible, and well-tolerated, and there is an widespread evidence base. ESE has been remarkably resilient throughout years of innovation in noninvasive cardiology. Its value is not to be determined over the short portion of diagnostic accuracy but mainly through its prognostic value evident in a wide range of patient subsets. It is coming very close to the modern profile of a leading test that should include, in addition to an essential accettable diagnostic and prognostic accuracy, qualities of low cost, no radiation exposure, and minor environmental traces. In this review, we will discuss advantages, diagnostic accuracy, prognostic value in general and special populations, cost-effectiveness, and changes in referral patterns of ESE in the modern era.

What are the prognostic implications and factors relating to exercise induced electrocardiographic ST segment changes in the setting of a non-ischemic stress echocardiogram?

BACKGROUND

Electrocardiographic (ECG) changes during stress testing are a common and perplexing finding during non-ischemic stress echocardiography (niSE). Research has provided conflicting results regarding the implications.

METHODS

SE was performed after maximal Bruce protocol treadmill exercise.

RESULTS

3020 consecutive patients, mean age 58 ± 12 years, 36% female, were followed-up for up to 9 years (mean 36 ± 21 months) post niSE. Time to first cardiac event (composite of heart failure admission, worsening New York Heart Association class, worsening ejection fraction, acute coronary syndrome, revascularization, angina or cardiovascular death) was analysed and adjusted using Cox proportional hazards regression. Prognostic significance was found with 1.5 mm of downsloping or horizontal ST depression. Adjusting for baseline differences, increased risk of composite major adverse cardiac events was shown with at least 1.5 mm of exercise induced ST depression (Hazard ratio [HR] of 2.47, 95% Confidence ratio [CI] 1.67-3.72, p < 0.0001). Patients achieving high level exercise capacity (≥13 metabolic equivalents or METs) with ST depression lower risk of cardiac events during follow-up.

CONCLUSION

Patients with ST segment depression but non-ischemic stress imaging have a poorer prognosis compared to patients with niSE with normal stress ECGs. ST depression of 1.5 mm or more was established as a prognostically significance value. High exercise capacity was associated with an improved prognosis, and ECG changes in that setting can be regarded as false positives. All niSE have low risk of a cardiac event in the very short term (<12 months). Overall, ST depression during non-ischaemic stress imaging is not a benign finding.

Role of Exercise Treadmill Testing in the Assessment of Coronary Microvascular Disease

OBJECTIVES

The authors aimed to study the sensitivity and specificity of exercise treadmill testing (ETT) in the diagnosis of coronary microvascular disease (CMD), as well as the prognostic implications of ETT results in patients with CMD.

BACKGROUND

ETT is validated to evaluate for flow-limiting coronary artery disease (CAD), however, little is known about its use for evaluating CMD.

METHODS

We retrospectively studied 249 consecutive patients between 2006 and 2016 who underwent ETT and positron emission tomography within 12 months. Patients with obstructive CAD or left ventricular systolic dysfunction were excluded. CMD was defined as a coronary flow reserve <2. Patients were followed for the occurrence of a first major adverse event (composite of death or hospitalization for myocardial infarction or heart failure).

RESULTS

The sensitivity and specificity of a positive ETT to detect CMD were 34.7% (95% CI: 25.4%-45.0%) and 64.9% (95% CI: 56.7%-72.5%), respectively. The specificity of a positive ETT to detect CMD increased to 86.8% (95% CI: 80.3%-91.7%) when only classifying studies with ischemic electrocardiogram changes that lasted at least 1 minute into recovery as positive, although at a cost of lower sensitivity (15.3%; 95% CI: 8.8%-24.0%). Over a median follow-up of 6.9 years (IQR: 5.1-8.2 years), 30 (12.1%) patients met the composite endpoint, including 13 (13.3%) with CMD (n = 98). In patients with CMD, ETT result was not associated with the composite endpoint (P = 0.076).

CONCLUSIONS

Our data suggest limited sensitivity of ETT to detect CMD. However, a positive ETT with ischemic changes that persist at least 1 minute into recovery in the absence of obstructive CAD should raise suspicion for the presence of CMD given a high specificity. Further study is needed with larger patient sample sizes to assess the association between ETT results and outcomes in patients with CMD.

Stress Electrocardiography Testing in Coronary Artery Disease: Is It Time for Its Swan Song or To Redefine Its Role in the Modern Era ?

Stress electrocardiography (sECG) or treadmill stress testing is a well validated noninvasive diagnostic modality available to clinicians at low cost yet providing valuable functional data for coronary artery disease (CAD) diagnostic and prognostic evaluation. With the advances in cardiac imaging in both functional and anatomic fronts and the existing limitations of sECG testing, this modality appears less favored worldwide as reflected in some recent guideline updates. We review the past present and future of sECG to provide a viewpoint on where it stands in CAD evaluation and if it will remain relevant as a diagnostic modality or be retired going forward. We also provide our perspectives on how sECG can co-exist with other modalities such as calcium scoring and discuss the role of such testing in the Indian population.

Gender-Related Differences in Chest Pain Syndromes in the Frontiers in CV Medicine Special Issue: Sex & Gender in CV Medicine

Coronary artery disease (CAD) is the leading cause of morbidity and mortality among both women and men, yet women continue to have delays in diagnosis and treatment. The lack of recognition of sex-specific biological and socio-cultural gender-related differences in chest pain presentation of CAD may, in part, explain these disparities. Sex and gender differences in pain mechanisms including psychological susceptibility, the autonomic nervous system (ANS) reactivity, and visceral innervation likely contribute to chest pain differences. CAD risk scores and typical/atypical angina characterization no longer appear relevant and should not be used in women and men. Women more often have ischemia with no obstructive CAD (INOCA) and myocardial infarction, contributing to diagnostic and therapeutic equipoise. Existing knowledge demonstrates that chest pain often does not relate to obstructive CAD, suggesting a more thoughtful approach to percutaneous coronary intervention (PCI) and medical therapy for chest pain in stable obstructive CAD. Emerging knowledge regarding the central and ANS and visceral pain processing in patients with and without angina offers explanatory mechanisms for chest pain and should be investigated with interdisciplinary teams of cardiologists, neuroscientists, bio-behavioral experts, and pain specialists. Improved understanding of sex and gender differences in chest pain, including biological pathways as well as sociocultural contributions, is needed to improve clinical care in both women and men.

Relationship of Stress Test Findings to Anatomic or Functional Extent of Coronary Artery Disease Assessed by Coronary Computed Tomography Angiography-Derived Fractional Flow Reserve

Background

In the United States, functional stress testing is the primary imaging modality for patients with stable symptoms suspected to represent coronary artery disease (CAD). Coronary computed tomography angiography (CTA) is excellent at identifying anatomic coronary artery disease (CAD). The application of computational fluid dynamics to coronary CTA allows fractional flow reserve (FFR) to be calculated noninvasively (FFR_CT). The relationship of noninvasive stress testing to coronary CTA and FFR_CT in real-world clinical practice has not been studied.

Methods

We evaluated 206 consecutive patients at Loyola University Chicago with suspected CAD who underwent noninvasive stress testing followed by coronary CTA and FFR_CT when indicated. Patients were categorized by stress test results (positive, negative, indeterminate, and equivocal). Duke treadmill score (DTS), METS, exercise duration, and chest pain with exercise were analyzed. Lesions ≥ 50%stenosis were considered positive by coronary CTA. FFR_CT < 0.80 was considered diagnostic of ischemia.

Results

Two hundred and six patients had paired noninvasive stress test and coronary CTA/FFR_CT results. The median time from stress test to coronary CTA was 49 days. Average patient age was 60.3 years, and 42% were male. Of the 206 stress tests, 75% were exercise (70% echocardiographic, 26% nuclear, and 4% EKG). There were no associations of stress test results with CAD > 50% or FFR_CT < 0.80 (p = 0.927 and p = 0.910, respectively). Of those with a positive stress test, only 30% (3/10) had CAD > 50% and only 50% (5/10) had FFR_CT < 0.80. Chest pain with exercise did not correlate with CAD > 50% or FFR_CT < 0.80 (p = 0.66 and p = 0.12, respectively). There were no significant correlations between METS, DTS, or exercise duration and FFR_CT (r = 0.093, p = 0.274; r = 0.012, p = 0.883; and r = 0.034, p = 0.680; respectively).

Conclusion

Noninvasive stress testing, functional capacity, chest pain with exercise, and DTS are not associated with anatomic or functional CAD using a diagnostic strategy of coronary CTA and FFR_CT.