Exercise-induced ST depression in the diagnosis of coronary artery disease. A meta-analysis

Assessment of cardiovascular risk and physical activity: the role of cardiac-specific biomarkers in the general population and athletes

The first part of this Inter-Society Document describes the mechanisms involved in the development of cardiovascular diseases, particularly arterial hypertension, in adults and the elderly. It will also examine how consistent physical exercise during adolescence and adulthood can help maintain blood pressure levels and prevent progression to symptomatic heart failure. The discussion will include experimental and clinical evidence on the use of specific exercise programs for preventing and controlling cardiovascular diseases in adults and the elderly. In the second part, the clinical relevance of cardiac-specific biomarkers in assessing cardiovascular risk in the general adult population will be examined, with a focus on individuals engaged in sports activities. This section will review recent studies that suggest a significant role of biomarkers in assessing cardiovascular risk, particularly the presence of cardiac damage, in athletes who participate in high-intensity sports. Finally, the document will discuss the potential of using cardiac-specific biomarkers to monitor the effectiveness of personalized physical activity programs (Adapted Physical Activity, APA). These programs are prescribed for specific situations, such as chronic diseases or physical disabilities, including cardiovascular diseases. The purposes of this Inter-Society Document are the following: 1) to discuss the close pathophysiological relationship between physical activity levels (ranging from sedentary behavior to competitive sports), age categories (from adolescence to elderly age), and the development of cardiovascular diseases; 2) to review in detail the experimental and clinical evidences supporting the role of cardiac biomarkers in identifying athletes and individuals of general population at higher cardiovascular risk; 3) to stimulate scientific societies and organizations to develop specific multicenter studies that may take into account the role of cardiac biomarkers in subjects who follow specific exercise programs in order to monitor their cardiovascular risk.

Clinical Validation of a Machine-Learned, Point-of-Care System to IDENTIFY Functionally Significant Coronary Artery Disease

Many clinical studies have shown wide performance variation in tests to identify coronary artery disease (CAD). Coronary computed tomography angiography (CCTA) has been identified as an effective rule-out test but is not widely available in the USA, particularly so in rural areas. Patients in rural areas are underserved in the healthcare system as compared to urban areas, rendering it a priority population to target with highly accessible diagnostics. We previously developed a machine-learned algorithm to identify the presence of CAD (defined by functional significance) in patients with symptoms without the use of radiation or stress. The algorithm requires 215 s temporally synchronized photoplethysmographic and orthogonal voltage gradient signals acquired at rest. The purpose of the present work is to validate the performance of the algorithm in a frozen state (i.e., no retraining) in a large, blinded dataset from the IDENTIFY trial. IDENTIFY is a multicenter, selectively blinded, non-randomized, prospective, repository study to acquire signals with paired metadata from subjects with symptoms indicative of CAD within seven days prior to either left heart catheterization or CCTA. The algorithm's sensitivity and specificity were validated using a set of unseen patient signals (n = 1816). Pre-specified endpoints were chosen to demonstrate a rule-out performance comparable to CCTA. The ROC-AUC in the validation set was 0.80 (95% CI: 0.78-0.82). This performance was maintained in both male and female subgroups. At the pre-specified cut point, the sensitivity was 0.85 (95% CI: 0.82-0.88), and the specificity was 0.58 (95% CI: 0.54-0.62), passing the pre-specified endpoints. Assuming a 4% disease prevalence, the NPV was 0.99. Algorithm performance is comparable to tertiary center testing using CCTA. Selection of a suitable cut-point results in the same sensitivity and specificity performance in females as in males. Therefore, a medical device embedding this algorithm may address an unmet need for a non-invasive, front-line point-of-care test for CAD (without any radiation or stress), thus offering significant benefits to the patient, physician, and healthcare system.

Cardiological Functional Assessment of National Olympic Team of Kazakhstan

Athletes carry an increased risk of cardiovascular (CV) conditions. Due to the relatively high loads and intensity of the training process, athletes' CV systems undergo various adaptations, which can combine in the future and provoke unexpected outcomes. Most CV screening protocols have several successive steps. The aim of our study was to perform a cardiological functional assessment of the National Olympic Team of Kazakhstan via several noninvasive protocols to close the gaps between the approaches and collect solid data for the prevention of sudden cardiac death (SCD) incidence among Kazakhstani athletes.

METHODS

The methods used in this study were 12-lead resting electrocardiography (ECG), echocardiography, cardiointervalography, cardiopulmonary exercise testing (CPET), and HyperQ stress testing.

RESULTS

One case was detected via 12-lead resting ECG. Another case of the slowdown of the heart rate (HR) recovery was detected via cardiointervalography with no clinical signs and normal ECG. The HyperQ stress testing of the women's basketball team detected a positive result in four leads in one athlete.

CONCLUSION

Our results demonstrate that the CV systems of athletes require the implementation of several diagnostic methods in rest and stress conditions for more precise evaluation, with each of the methods fulfilling the whole picture for the prevention of such tragic events as sudden cardiac death and sudden cardiac arrest.

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.

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

Diagnosis of cardiovascular disease in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular disease (CVD) and cardiovascular death. Identifying and monitoring cardiovascular complications and hypertension is important for managing patients with CKD or kidney failure and transplant recipients. Biomarkers of myocardial ischaemia, such as troponins and electrocardiography (ECG), have limited utility for diagnosing cardiac ischaemia in patients with advanced CKD. Dobutamine stress echocardiography, myocardial perfusion scintigraphy and dipyridamole stress testing can be used to detect coronary disease in these patients. Left ventricular hypertrophy and left ventricular dysfunction can be detected and monitored using various techniques with differing complexity and cost, including ECG, echocardiography, nuclear magnetic resonance, CT and myocardial scintigraphy. Atrial fibrillation and other major arrhythmias are common in all stages of CKD, and ambulatory heart rhythm monitoring enables precise time profiling of these disorders. Screening for cerebrovascular disease is only indicated in asymptomatic patients with autosomal dominant polycystic kidney disease. Standardized blood pressure is recommended for hypertension diagnosis and treatment monitoring and can be complemented by ambulatory blood pressure monitoring. Judicious use of these diagnostic techniques may assist clinicians in detecting the whole range of cardiovascular alterations in patients with CKD and enable timely treatment of CVD in this high-risk population.

Which Biomarker(s) Augment the Diagnostic Value of the Positive Exercise Electrocardiography Test: Systemic Inflammatory Index, Plasma Atherogenic Index, or Monocyte/HDL-C Ratio?

The exercise electrocardiography test (EET) is still used before coronary angiography in the diagnosis of chronic coronary syndromes. This study aimed to demonstrate the value of the combination of a positive EET with the systemic inflammatory index (SII), the plasma atherogenic index (PAI), and the monocyte/HDL-C ratio (MHR) in the determination of obstructive coronary artery disease (CAD). This single-center, retrospective study included 540 patients who underwent coronary angiography after ETT. The patients were separated into Group 1, comprising 434 patients with normal coronary arteries and non-obstructive CAD, and Group 2, including 106 with obstructive CAD. In Group 2, the patients were separated into SYNTAX ≤ 22 or ≥23. Glucose, low-density lipoprotein, white blood cells, and MHR were determined to be significantly higher in Group 2 (p < 0.05). According to the multivariate logistic regression analysis, age, gender, diabetes mellitus, and low-density lipoprotein were determined to be independent predictors of CAD. In the ROC curve analysis, a cut-off value of 12 for the MHR in the determination of obstructive CAD had a sensitivity of 60.4% and a specificity of 53.0%. The main result of this study was that a high MHR is an indicator of obstructive CAD in patients with positive EET and suspected CAD.

Ultra-High-Resolution Electrocardiography Enables Earlier Detection of Transmural and Subendocardial Myocardial Ischemia Compared to Conventional Electrocardiography

The sensitivity of exercise ECG is marginally sufficient for the detection of mild reduction of coronary blood flow in patients with early coronary atherosclerosis. Here, we describe the application of a new technique of ECG registration/analysis-ultra-high-resolution ECG (UHR ECG)-for early detection of myocardial ischemia (MIS). The utility of UHR ECG vs. conventional ECG (C ECG) was tested in anesthetized rats and pigs. Transmural MIS was induced in rats by the ligation of the left coronary artery (CA). In pigs, subendocardial ischemia of a variable extent was produced by stepwise inflation of a balloon within the right CA, causing a 25-100% reduction of its lumen. In rats, a reduction in power spectral density (PSD) in the high-frequency (HF) channel of UHR ECG was registered at 60 s after ischemia (power 0.81 ± 0.14 vs. 1.25 ± 0.12 mW at baseline, p < 0.01). This was not accompanied by any ST segment elevation on C ECG. In pigs, PSD in the HF channel of UHR ECG was significantly decreased at a 25% reduction of CA lumen, while the ST segment on C ECG remained unchanged. In conclusion, UHR ECG enabled earlier detection of transmural MIS compared to C ECG. PSD in the HF channel of UHR ECG demonstrated greater sensitivity in the settings of subendocardial ischemia.

Validity of the Maximal Heart Rate Prediction Models among Runners and Cyclists

Maximal heart rate (HRmax) is a widely used measure of cardiorespiratory fitness. Prediction of HRmax is an alternative to cardiopulmonary exercise testing (CPET), but its accuracy among endurance athletes (EA) requires evaluation. This study aimed to externally validate HRmax prediction models in the EA independently for running and cycling CPET. A total of 4043 runners (age = 33.6 (8.1) years; 83.5% males; BMI = 23.7 (2.5) kg·m^-2) and 1026 cyclists (age = 36.9 (9.0) years; 89.7% males; BMI = 24.0 (2.7) kg·m^-2) underwent maximum CPET. Student t-test, mean absolute percentage error (MAPE), and root mean square error (RMSE) were applied to validate eight running and five cycling HRmax equations externally. HRmax was 184.6 (9.8) beats·min^-1 and 182.7 (10.3) beats·min^-1, respectively, for running and cycling, p = 0.001. Measured and predicted HRmax differed significantly (p = 0.001) for 9 of 13 (69.2%) models. HRmax was overestimated by eight (61.5%) and underestimated by five (38.5%) formulae. Overestimated HRmax amounted to 4.9 beats·min^-1 and underestimated HRmax was in the range up to 4.9 beats·min^-1. RMSE was 9.1-10.5. MAPE ranged to 4.7%. Prediction models allow for limited precision of HRmax estimation and present inaccuracies. HRmax was more often underestimated than overestimated. Predicted HRmax can be implemented for EA as a supplemental method, but CPET is the preferable method.

Assessment of Vascular and Valvular Calcification Improves Screening for Coronary Artery Disease Before Liver Transplantation

Coronary artery disease (CAD) is common in patients with cirrhosis who underwent orthotopic liver transplantation (OLT) evaluation and stress echocardiogram (echo) has a low sensitivity in these patients. This study aimed to assess the impact of vascular and valvular calcification on the ability to identify CAD before OLT. We performed a case-control study of 88 patients with and 97 without obstructive CAD who underwent OLT evaluation. All patients had a preoperative stress echo, abdominal computed tomography, and cardiac catheterization. A series of nested logistic regression models of CAD were fit by adding independent variables of vascular (including coronary) calcification, aortic and mitral valve calcification, age, gender, and history of diabetes mellitus requiring insulin to a baseline model of abnormal stress echo. Compared with stress echo alone, identification of the presence or absence of vascular and valvular calcification on routine preoperative computed tomography and echo improved the diagnostic performance for the detection of CAD based on coronary angiogram when combined with stress echo in patients with cirrhosis who underwent OLT evaluation (area under the curve 0.58 vs 0.73, p <0.001), which is even further improved when age, gender, and history of diabetes mellitus requiring insulin are considered (area under the curve 0.58 vs 0.80, p <0.001). Achieving target heart rate (p = 0.92) or rate-pressure product >25,000 (p = 0.63) did not improve the ability of stress echo to identify CAD. In conclusion, the use of abdominal vascular, coronary artery, and valvular calcification, along with stress echo, improves the ability to identify and rule out obstructive CAD before OLT compared with stress echo alone.

The 50 most-cited review papers on physical activity and depression: A bibliometric analysis

A growing body of literature has demonstrated the preventive role of physical activity in depression, and relevant research is rapidly on the rise. The aim of this study was to conduct a bibliometric analysis of the 50 most-cited review papers on physical activity and depression, thus identifying important research topics and future research directions.

METHODS

The 50 most-cited review articles were identified and extracted from the Web of Science Core Collection database (on 31^st October 2022), and a bibliometric citation analysis was performed using the Microsoft Excel and VOSviewer software (Version 1.6.18). Information on the country, authors of publications, publishing journals, citations (i.e., total or annual), keywords, and other meaningful data was analysed comprehensively.

RESULTS

The 50 most-cited review articles received, on average, 247.5 citations per article. Most review articles were from England, with contributions from some highly cited researchers and research teams. Western countries/regions, such as England, Australia, and the USA were the most influential in publishing review articles on physical activity and depression. The Journal of Affective Disorders and Cochrane Database of Systematic Reviews were the journals that published the most highly cited review articles on physical activity and depression. Important research topics on the literature on physical activity and depression focused on (1) different types of physical activity and depression; (2) intervention studies related to physical activity and depression; (3) fitness and physical activity levels in people with depression; (4) methodological analyses in physical activity and depression studies; and (5) the impact of physical activity on depression in different populations.

CONCLUSION

This study reveals that review studies on physical activity and depression have great potential to develop further knowledge. This study also highlights some future research directions, which can serve to effectively advance the knowledge base.

Diagnostic performance of exercise stress tests for detection of epicardial and microvascular coronary artery disease: the UZ Clear study

BACKGROUND

Cardiac stress tests remain the cornerstone for evaluating patients suspected of having obstructive coronary artery disease (CAD). Coronary microvascular dysfunction (CMD) can lead to abnormal non-invasive tests.

AIMS

We sought to assess the diagnostic performance of exercise stress tests with indexes of epicardial and microvascular resistance as reference.

METHODS

This was a prospective, single-arm, multicentre study of patients with an intermediate pretest probability of CAD and positive exercise stress tests who were referred for invasive angiography. Patients underwent an invasive diagnostic procedure (IDP) with measurement of fractional flow reserve (FFR) and index of microvascular resistance (IMR) in at least one coronary vessel. Obstructive CAD was defined as diameter stenosis (DS) >50% by quantitative coronary angiography (QCA). The objective was to determine the false discovery rate (FDR) of cardiac exercise stress tests with both FFR and IMR as references.

RESULTS

One hundred and seven patients (137 vessels) were studied. The mean age was 62.1±8.7, and 27.1% were female. The mean diameter stenosis was 37.2±27.5%, FFR was 0.84±0.10, coronary flow reserve was 2.74±2.07, and IMR 20.3±11.9. Obstructive CAD was present in 39.3%, whereas CMD was detected in 20.6%. The FDR was 60.7% and 62.6% with QCA and FFR as references (p-value=0.803). The combination of FFR and IMR as clinical reference reduced the FDR by 25% compared to QCA (45.8% vs 60.7%; p-value=0.006).

CONCLUSIONS

In patients with evidence of ischaemia, an invasive functional assessment accounting for the epicardial and microvascular compartments led to an improvement in the diagnostic performance of exercise tests, driven by a significant FDR reduction.

Prevalence of coronary calcification on preoperative computed tomography and its management in thoracic surgery

PURPOSE

We investigated the preoperative assessment of coronary artery calcification using computed tomography for appropriate intraoperative management to reduce the risk of perioperative cardiac complications during pulmonary resection.

METHODS

Patients (n = 665) who underwent anatomical lung resection were examined. The extent of preoperative asymptomatic coronary artery stenosis or cardiac complications in patients with coronary artery calcification was assessed. In addition, the risk factors for perioperative cardiac complications were determined.

RESULTS

Coronary artery calcification was detected in 233 (35.0%) asymptomatic patients. Nineteen (8.2%) patients with coronary artery calcification had coronary artery stenosis ≥ 75%. Percutaneous coronary intervention was performed preoperatively (n = 3) and postoperatively (n = 10), and preoperative drug intervention was performed in 10 cases. One case of severe postoperative cardiac complications and 20 cases of mild postoperative cardiac complications, including those without coronary artery calcification, occurred. Patients with calcified coronary arteries were at risk of cardiovascular complications in the perioperative period. However, patients with coronary artery calcification who underwent preoperative cardiology intervention had no significant perioperative cardiovascular complications.

CONCLUSIONS

Coronary artery calcification detected on preoperative computed tomography is a risk factor for perioperative cardiovascular complications. Early intervention may reduce the risk of such complications.

Development and validation of a machine learned algorithm to IDENTIFY functionally significant coronary artery disease

Introduction

Multiple trials have demonstrated broad performance ranges for tests attempting to detect coronary artery disease. The most common test, SPECT, requires capital-intensive equipment, the use of radionuclides, induction of stress, and time off work and/or travel. Presented here are the development and clinical validation of an office-based machine learned algorithm to identify functionally significant coronary artery disease without radiation, expensive equipment or induced patient stress.

Materials and methods

The IDENTIFY trial (NCT03864081) is a prospective, multicenter, non-randomized, selectively blinded, repository study to collect acquired signals paired with subject meta-data, including outcomes, from subjects with symptoms of coronary artery disease. Time synchronized orthogonal voltage gradient and photoplethysmographic signals were collected for 230 seconds from recumbent subjects at rest within seven days of either left heart catheterization or coronary computed tomography angiography. Following machine learning on a proportion of these data (N = 2,522), a final algorithm was selected, along with a pre-specified cut point on the receiver operating characteristic curve for clinical validation. An unseen set of subject signals (N = 965) was used to validate the algorithm.

Results

At the pre-specified cut point, the sensitivity for detecting functionally significant coronary artery disease was 0.73 (95% CI: 0.68–0.78), and the specificity was 0.68 (0.62–0.74). There exists a point on the receiver operating characteristic curve at which the negative predictive value is the same as coronary computed tomographic angiography, 0.99, assuming a disease incidence of 0.04, yielding sensitivity of 0.89 and specificity of 0.42. Selecting a point at which the positive predictive value is maximized, 0.12, yields sensitivity of 0.39 and specificity of 0.88.

Conclusion

The performance of the machine learned algorithm presented here is comparable to common tertiary center testing for coronary artery disease. Employing multiple cut points on the receiver operating characteristic curve can yield the negative predictive value of coronary computed tomographic angiography and a positive predictive value approaching that of myocardial perfusion imaging. As such, a system employing this algorithm may address the need for a non-invasive, no radiation, no stress, front line test, and hence offer significant advantages to the patient, their physician, and healthcare system.

Emerging ECG methods for acute coronary syndrome detection: Recommendations & future opportunities

Despite being the mainstay for the initial noninvasive assessment of patients with symptomatic coronary artery disease, the 12‑lead ECG remains a suboptimal diagnostic tool for myocardial ischemia detection with only acceptable sensitivity and specificity scores. Although myocardial ischemia affects the configuration of the QRS complex and the STT waveform, current guidelines primarily focus on ST segment amplitude, which constitutes a missed opportunity and may explain the suboptimal diagnostic performance of the ECG. This possible opportunity and the low cost and ease of use of the ECG provide compelling motivation to enhance the diagnostic accuracy of the ECG to ischemia detection. This paper describes numerous computational ECG methods and approaches that have been shown to dramatically increase ECG sensitivity to ischemia detection. Briefly, these emerging approaches can be conceptually grouped into one of the following four approaches: (1) leveraging novel ECG waveform features and signatures indicative of ischemic injury other than the classical ST-T amplitude measures; (2) applying body surface potentials mapping (BSPM)-based approaches to enhance the spatial coverage of the surface ECG to detecting ischemia; (3) developing an inverse ECG solution to reconstruct anatomical models of activation and recovery pathways to detect and localize injury currents; and (4) exploring artificial intelligence (AI)-based techniques to harvest ECG waveform signatures of ischemia. We present recent advances, shortcomings, and future opportunities for each of these emerging ECG methods. Future research should focus on the prospective clinical testing of these approaches to establish clinical utility and to expedite potential translation into clinical practice.

Characteristics of Second-Line Investigations of Middle-Aged Athletes Who Failed Preparticipation Examinations

OBJECTIVE

The role of exercise testing during preparticipation examinations (PPEs) of middle-aged athletes is uncertain. This study examined the characteristics of disqualifications after an initial PPE that includes an exercise test in competitive athletes older than 30 years. We investigated disqualification rates and reasons, second-line investigations performed, and final decisions regarding competitive sports participation.

DESIGN

Chart review.

SETTING

Sports medicine clinic.

PARTICIPANTS

Athletes aged >30 years that performed an exercise test as part of their annual PPE at our sports medicine clinic (n = 866).

INDEPENDENT VARIABLES

Age, sex, height, weight, sport type, cardiovascular risk factors, and abnormal PPE findings.

MAIN OUTCOME MEASURES

Additional investigations performed, approval/disqualification regarding competitive sports participation.

RESULTS

The initial disqualification rate of athletes was 9.8%. Three (3.6%) athletes were disqualified following questionnaire and physical examination, 19 (22.4%) because of resting electrocardiogram findings, and 65 (76.5%) following the exercise test. After additional work-up, only 5 athletes (0.4%) were ultimately found ineligible for competitive sports. From those, only 2 athletes (0.2%) were disqualified because of exercise test findings, which were episodes of supraventricular tachycardia and not ischemia-related.

CONCLUSIONS

The addition of an exercise test to the PPE of middle-aged athletes is of limited value. If exercise testing of older athletes is performed, arrhythmias are probably of higher significance than ST-T changes.

Evaluation of the QRS score for diagnosing coronary artery disease in women: A Finnish cardiovascular study

BACKGROUND

Exercise electrocardiography is a widely used diagnostic modality for diagnosing coronary artery disease. This method has been used for both sexes; however, its diagnostic accuracy in women is limited.

METHODS

The study analyzed 332 women participating in the Finnish Cardiovascular Study. Among 332 women, 125 with angiographically proven coronary artery disease (mean age 62.1 ± 9.5 years), 91 with a low likelihood of coronary artery disease (mean age 47.3 ± 13.5 years), and 116 without angiographically proven coronary artery disease (mean age 56.3 ± 9.9 years) were analyzed. The Q, R, S, and ST-segment changes and QRS score were determined by subtracting the Q, R, S, and ST-segment amplitudes immediately after the maximal exercise changes from their rest values (Δ). Receiver operating characteristic curve analysis was performed to evaluate the overall diagnostic performance of the parameters for predicting coronary artery disease.

RESULTS

The areas under the receiver operating characteristic curve between coronary artery disease and low likelihood of coronary artery disease groups for the QRS score and ΔSTV5, ΔQaVF, and ΔRaVF were 0.75, 0.73, 0.71, and 0.71, respectively. These areas were lower (0.62, 0.57, 0.60, and 0.60, respectively) between the groups with and without angiographically proven coronary artery disease. QRS score demonstrated the highest sensitivity at 80% specificity (61.5%) and the highest specificity at 80% sensitivity (57.6%).

CONCLUSIONS

This study suggests that the QRS and ST-segment depression have a moderate diagnostic ability to predict coronary artery disease in women. Q and R waves in lead aVF showed good diagnostic ability.

Preoperative Master's double two-step test may predict survival after lobectomy in patients with lung cancer

Background

The Master’s double two-step test (MDT), which is used to screen for coronary heart disease, is difficult for physically impaired patients to complete. The purpose of this study was to clarify the relationship between the results of the MDT and prognosis after lung cancer surgery.

Methods

Between May 2004 and September 2019, 1,434 patients underwent complete resection for lung cancer at our hospital. Among them, 418 with pathological stage I disease who underwent lobectomy were evaluated. We defined patients who could accomplish the MDT as the complete MDT group and those who could not as the incomplete MDT group. Patients who could not perform the MDT due to physical problems were included in the incomplete MDT group. We explored the prognostic impact of the MDT results in these patients.

Results

Fifty-three patients (12.7%) were in the incomplete MDT group; compared with the complete MDT group, they were older and had poorer performance status and respiratory function. However, the incidence of postoperative complications and 90-day mortality did not differ significantly between groups. Multivariate analyses revealed that age (p < 0.001), Charlson comorbidity index (p = 0.013), incomplete MDT (p = 0.049) and carcinoembryonic antigen (CEA) level (p = 0.003) were prognostic factors for worse overall survival; age (p < 0.001) and incomplete MDT (p = 0.022) were prognostic factors for worse non-cancer-specific survival.

Conclusions

Although incomplete MDT was not associated with postoperative complications, 90-day mortality or cancer-specific survival, MDT results may be significantly associated with non-cancer-specific survival.

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.

QT variability unrelated to RR variability during stress testing for identification of coronary artery disease

Stress test electrocardiogram (ECG) analysis is widely used for coronary artery disease (CAD) diagnosis despite its limited accuracy. Alterations in autonomic modulation of cardiac electrical activity have been reported in CAD patients during acute ischemia. We hypothesized that those alterations could be reflected in changes in ventricular repolarization dynamics during stress testing that could be measured through QT interval variability (QTV). However, QTV is largely dependent on RR interval variability (RRV), which might hinder intrinsic ventricular repolarization dynamics. In this study, we investigated whether different markers accounting for low-frequency (LF) oscillations of QTV unrelated to RRV during stress testing could be used to separate patients with and without CAD. Power spectral density of QTV unrelated to RRV was obtained based on time-frequency coherence estimation. Instantaneous LF power of QTV and QTV unrelated to RRV were obtained. LF power of QTV unrelated to RRV normalized by LF power of QTV was also studied. Stress test ECG of 100 patients were analysed. Patients referred to coronary angiography were classified into non-CAD or CAD group. LF oscillations in QTV did not show significant differences between CAD and non-CAD groups. However, LF oscillations in QTV unrelated to RRV were significantly higher in the CAD group as compared with the non-CAD group when measured during the first phases of exercise and last phases of recovery. ROC analysis of these indices revealed area under the curve values ranging from 61 to 73%. Binomial logistic regression analysis revealed LF power of QTV unrelated to RRV, both during the first phase of exercise and last phase of recovery, as independent predictors of CAD. In conclusion, this study highlights the importance of removing the influence of RRV when measuring QTV during stress testing for CAD identification and supports the added value of LF oscillations of QTV unrelated to RRV to diagnose CAD from the first minutes of exercise. This article is part of the theme issue 'Advanced computation in cardiovascular physiology: new challenges and opportunities'.

Machine learning of treadmill exercise test to improve selection for testing for coronary artery disease

BACKGROUND AND AIMS

The high false-positive rate of the treadmill exercise test (TET) may lead to unnecessary invasive coronary angiography. We aimed to develop a machine learning-based algorithm to improve the diagnostic performance of TET.

METHODS

Study included 2325 patients who underwent TET and subsequent coronary angiography within one-year interval. The mean age was 58.7 (48.1-69.3) years, 1731 (74.5%) were male, 1858 (79.9%) had positive TET result, and 812 (34.9%) had obstructive coronary artery disease (≥70% stenosis in at least one vessel). The study population were randomly divided into training (70%) and testing (30%) groups for algorithm development. A total of 93 features, including exercise performance, hemodynamics and ST-segment changes were extracted from the TET results. Clinical features included comorbidity, smoking, height, weight, and Framingham risk score. Support vector machine, logistic regression, random forest, k-nearest neighbor and extreme gradient boosting machine learning algorithms were used to build the predictive models. The performance of each model was compared with that of conventional TET.

RESULTS

Four of the five models exhibited comparable diagnostic performance and were better than conventional TET. The random forest algorithm had an area under the curve (AUC) of 0.73. When used with clinical features, the AUC improved to 0.74. The major advantage of the algorithm is the reduction of the false-positive rate compared with conventional TET (55% vs. 76.3%, respectively), while maintaining comparable sensitivity (85%).

CONCLUSIONS

Using the information obtained from conventional TET, a more accurate diagnosis can be made by incorporating an artificial intelligence-based model.

Utility of the oxygen pulse in the diagnosis of obstructive coronary artery disease in physically fit patients

Cardiopulmonary exercise testing (CPET) guidelines recommend analysis of the oxygen (O₂ ) pulse for a late exercise plateau in evaluation for obstructive coronary artery disease (OCAD). However, whether this O₂ pulse trajectory is within the range of normal has been debated, and the diagnostic performance of the O₂ pulse for OCAD in physically fit individuals, in whom V ˙ O 2 may be more likely to plateau, has not been evaluated. Using prospectively collected data from a sports cardiology program, patients were identified who were free of other cardiac disease and underwent clinically-indicated CPET within 90 days of invasive or computed tomography coronary angiography. The diagnostic performance of quantitative O₂ pulse metrics (late exercise slope, proportional change in slope during late exercise) and qualitative assessment for O₂ pulse plateau to predict OCAD was assessed. Among 104 patients (age:56 ± 12 years, 30% female, peak V ˙ O 2 119 ± 34% predicted), the diagnostic performance for OCAD (n = 24,23%) was poor for both quantitative and qualitative metrics reflecting an O₂ pulse plateau (late exercise slope: AUC = 0.55, sensitivity = 68%, specificity = 41%; proportional change in slope: AUC = 0.55, sensitivity = 91%, specificity = 18%; visual plateau/decline: AUC = 0.51, sensitivity = 33%, specificity = 67%). When O₂ pulse parameters were added to the electrocardiogram, the change in AUC was minimal (-0.01 to +0.02, p ≥ 0.05). Those patients without OCAD with a plateau or decline in O₂ pulse were fitter than those with linear augmentation (peak V ˙ O 2 133 ± 31% vs. 114 ± 36% predicted, p < 0.05) and had a longer exercise ramp time (9.5 ± 3.2 vs. 8.0 ± 2.5 min, p < 0.05). Overall, a plateau in O₂ pulse was not a useful predictor of OCAD in a physically fit population, indicating that the O₂ pulse should be integrated with other CPET parameters and may reflect a physiologic limitation of stroke volume and/or O₂ extraction during intense exercise.

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.

Screening for Asymptomatic Coronary Artery Disease via Exercise Stress Testing in Patients With Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Objectives: This meta-analysis aims to investigate the diagnostic value of exercise stress testing (EST) for asymptomatic coronary artery disease (CAD) among patients with type 2 diabetes mellitus (T2DM) and to ascertain the influence of different variables on the sensitivity and specificity of EST. Background: Asymptomatic CAD occurs in >1 in five diabetes mellitus patients, and it is associated with an increased risk of complications. Methods for screening asymptomatic CAD in T2DM patients are still not unified. Methods: MEDLINE (via Ovid), Embase (via Ovid), Cochrane Library, SCOPUS, PubMed, Ovid, EBSCO ASP, and Web of Science were systematically searched on June 8 and 9, 2021, for diagnostic cohort and case-control studies. We included studies that used EST to screen for CAD in asymptomatic patients with T2DM, and that used coronary angiography to diagnose CAD and had reported the basic diagnostic indicators. The Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to assess study quality. The combined effect sizes were calculated by overall analysis and multiple variable effects were explored by regression analysis and subgroup analysis. Results: Nine groups of data from eight diagnostic cohort studies, totaling 515 participants, were included. Included studies showed a low risk of bias in most items, except for flow and timing. The combined sensitivity and specificity of EST for asymptomatic CAD in patients with T2DM were 55 (48 to 61%) and 66 (61 to 70%), respectively. When non-diagnostic tests were excluded, sensitivity increased to 73 (56 to 88%). The proportion receiving angiography also significantly affected sensitivity. No significant difference was found in the duration of diabetes or other additional risk factors. Conclusions: EST is a tool of moderate sensitivity and specificity to be used for the initial screening of asymptomatic CAD in T2DM. It has the advantage of being non-invasive, relatively inexpensive, easily available in most settings, and has no radiation associated with its use. Additional research with higher quality studies in which tests that are non-diagnostic are included and flow and timing is described clearly, will be important to further our understanding of EST for asymptomatic CAD detection in patients with T2DM. Systematic review registration: PROSPERO CRD42021259555.

Significance of 'recovery ST-segment depression' in exercise stress test

Objective

To study the significance of ST-segment depression during ‘recovery’ compared to that ‘during stress’ and ‘both the phases’ in exercise stress test.

Methods

Patients with positive exercise stress test who underwent coronary angiography (CAG) from 1st January 2017 to 31st December 2018 were studied. Patients were divided into 3 groups- Group A with ST-depression restricted to recovery phase, group B with ST-depression restricted to stress phase and group C with ST-depression seen both during exercise and recovery. All patients underwent CAG. Sensitivity, specificity, and predictive values of each of these groups in diagnosis of significant coronary artery disease (CAD) were analysed and compared.

Results

Total 300 patients were studied. Mean age of the study population was 48.77 ± 7.94 years. 78.3% of patients with positive exercise stress test had significant CAD. 96% of patients in group A had significant CAD, which was higher than in group B (88.9%) & group C (70.1%). The specificity, positive predictive value and negative predictive value of ST-segment depression in group A (96.92%, 96% and 25.2% respectively) were higher than that of ST-depression in group B (89.23%, 88.89% and 24.47% respectively) and group C (13.85%, 70.05% and 7.96% respectively). Sensitivity and accuracy of ST-depression in group A were lower (20.43% and 37% respectively), compared to other 2 groups.

Conclusion

Patient with ST-depression restricted to recovery phase had highest specificity, positive predictive value, and negative predictive value. However, accuracy was highest in group with both stress phase and exercise ST-segment depression.

Coronary artery calcium score: pivotal role as a predictor for detecting coronary artery disease in symptomatic patients

Chest pain and dyspnea are common presentations for symptomatic individuals with suspected coronary artery disease (CAD) in the primary care office and cardiology clinics. However, it is imperative to properly diagnose who should undergo further evaluation for cardiac etiologies of chest pain, with either noninvasive or invasive imaging tests. The purpose of this review is to highlight the role of coronary artery calcium (CAC) score as a screening tool for symptomatic patients to detect CAD. The purpose of CAC scoring is to establish the presence and severity of coronary atherosclerosis that can play a vital role in symptomatic patients. The use of CAC testing in symptomatic patients has traditionally been limited due to fundamental concerns, including the occurrence of coronary calcification relatively late in the atherosclerotic process and high prevalence of CAC in the population. Further issue relates to its low specificity for obstructive CAD, as well as demonstration of significant ethnic variability in plaque composition and calcification patterns. CAC testing gained attention as an inexpensive, rapid, reproducible and a well-tolerated alternative to exclude CAD in symptomatic patients and defer further invasive imaging tests. This article will review the available literature in regard to the use of CAC in symptomatic populations.

Selection of preoperative stress electrocardiography test for appropriate patients with non-small cell lung cancer

OBJECTIVE

Lobectomy is an established surgical procedure for treating non-small cell lung cancer; however, it significantly impacts postoperative cardiac function. The stress electrocardiography test is relatively easy to perform and is used to confirm the presence of coronary artery stenotic lesions. However, it has a low pre-test probability and may yield many false positives. We examined the factors that would enable the appropriate selection of patients for stress electrocardiography as a preoperative cardiovascular examination preceding lobectomy for non-small cell lung cancer.

METHODS

From June 2016 to July 2018, 240 patients at our institution who underwent stress electrocardiography before lobectomy for primary lung cancer were included in this study. Clinical information was extracted from electronic medical records and evaluated retrospectively. Smoking history, diabetes, hypertension, dyslipidemia, and ischemic heart disease were considered risk factors for coronary artery stenosis. We determined the coronary risk factors that were applicable to each participant and calculated the total number of coronary risk factors as a risk score.

RESULTS

Patients with coronary risk factor scores of ≥ 3 were significantly more likely to have abnormal stress electrocardiography results. In addition, these patients also underwent more comprehensive examinations to identify coronary diseases. There were no patients with complications that could be attributed to ischemic heart disease.

CONCLUSION

Stress electrocardiography may be more useful before lobectomy in non-small cell lung cancer patients if the patients are appropriately selected, with the test utilized mainly in patients with coronary risk factor scores of ≥ 3.

Addition of the duration of ST segment depression to Duke treadmill score for diagnostic accuracy of exercise electrocardiography to predict obstructive coronary artery disease

INTRODUCTION

Exercise electrocardiography (EET) is a safe and cost-effective method to predict the presence, prognosis, and severity of coronary artery disease (CAD). Various score models have been developed to increase predictive power of EET. In this study, we aimed to evaluate whether adding ST depression duration could have an effect on increasing the value of Duke treadmill score (DTS) in predicting obstructive CAD.

METHODS

In this single centred, cross-sectional study, we evaluated a total of 258 patients who presented with a complaint of chest pain and undergone coronary angiogram in result of a positive EET. DTS was calculated for all the patients. The new score-revised DTS- was calculated by adding total ST depression time to classical DS parameters. We compared area under the curve (AUC) of DTS and revised DTS by Delongi method.

RESULTS

Mean age of the group was 58.43 ± 9.37, and 37.2% (n = 96) were female. Mean total ST-depression duration was 171.72 ± 91.43 msec in normal artery group,241.54 ± 118.11 msec in non-obstructive CAD group, and 281.26 ± 113.64 in obstructive CAD group.ST-depression duration in both exercise and recovery, and total ST depression duration were significantly higher in obstructive CAD group than non-obstructive and normal artery groups (p = 0.024, p = 0.01, p < 0.01, and p < 0.01, respectively). Revised DTS had significantly higher predictive value of obstructive CAD compared to classical DS (AUC (95%CI): 0.744 vs. 0.626, p < 0.001). The AUC of DS was significantly lower than the new score (z-score:3.274, p = 0.011).

CONCLUSION

In conclusion, adding ST depression duration to DTS calculation is increasing the discriminative value of DTS to predict obstructive CAD. Benefits of EET within the context of the management of CAD is well-known, hence, it is clear that physicians may use revised DTS.

Comparative analysis of ischemic changes in electrocardiogram and coronary angiography results: A retrospective study

To improve the correct diagnosis rate of coronary heart disease and to explore the guiding value of electrocardiogram (ECG) ST-T ischemic changes in the clinical diagnosis of coronary heart disease.A retrospective analysis was conducted on a total of 310 cases who underwent a conventional 12-lead ECG, 12-lead dynamic ECG (DECG, Holter) with ST-T ischemic changes, and then coronary angiography (CA) within 1 week in Qingdao Sttarr Heart Hospital from June 2015 to April 2020 in the study. Ischemic ST-T changes were evaluated using conventional diagnostic criteria, and Judkins diagnostic criteria were used in CA. The sensitivity and specificity of ECG were analyzed.The specificity of ST-T changes in conventional ECG for the diagnosis of coronary heart disease is 33.7% and the sensitivity is 66.0%. The specificity of ST-T changes in Holter in the diagnosis of coronary heart disease is 55.6% and the sensitivity is 32.2%. The sensitivity of conventional ECG for the diagnosis of coronary heart disease is better than Holter, but its specificity is inferior to Holter. The negative likelihood ratios of the 2 ECGs for the diagnosis of coronary heart disease were 1.0 and 1.22, both >0.1, and the positive likelihood ratios were 0.99 and 0.73, both <10. The positive results of ST-T in conventional ECG were 128 males (65.7%), 77 females (66.9%), (P < .05), 148 cases (74.7%) in the group ≥60 years old, and 75 cases in the group less than 60 years (67%), (P > .05). The positive results of ST-T change of DECG were 135 males (69.2%), 69 females (60.0%), (P < .05), 152 cases (78.7%) in the group ≥60 years, and 83 cases (70.9%) in the group less than 60 years, (P > .05). Coronary heart disease-related factors: symptoms, hypertension, diabetes, cancer, family history, smoking history as independent variables, and a binary multivariate logistic regression analysis was performed.The sensitivity of DECG in the diagnosis of myocardial ischemia in women and the elderly was slightly higher than that in men and young cases. ST-T ischemic changes in ECG are more significant for the diagnosis of coronary heart disease in male patients. Smoking, hypertension, diabetes, and family history are all high-risk factors for coronary heart disease.

Coronary Artery Disease Evaluation and Management Considerations for High Risk Occupations: Commercial Vehicle Drivers and Pilots

Optimal treatment of stable ischemic heart disease for those in the transportation industry is considered in the context of the individual's health, as well as with the perspective that sudden impairment could have catastrophic consequences for others. This article focuses on two high risk occupations that one may encounter in practice: commercial motor vehicle drivers and commercial pilots. This article discusses coronary heart disease in patients in high risk occupations and covers current guideline recommendations for screening, treatment, and secondary prevention. The importance of the complimentary perspectives of the regulatory agency, medical examiners, physicians, and pilot or driver are considered in this narrative review, as are considerations for future guideline updates.

Lead aVR predicts early revascularization but not long-term events in patients referred for stress electrocardiography

BACKGROUND

Exercise stress electrocardiography (ExECG) is recommended as a first-line tool to assess ischemia, but standard ST-analysis has limited diagnostic accuracy. ST elevation in lead aVR has been associated with left main and LAD disease in the population undergoing coronary angiography but has not been studied in the general population undergoing stress testing for the initial evaluation of CAD without coronary angiography. We sought to determine the predictive value of lead aVR elevation for ischemia, early revascularization, and subsequent cardiac events in consecutive patients undergoing ExECG.

METHODS AND RESULTS

The study cohort included 641 subjects referred for ExECG who were dichotomized by presence or absence of aVR elevation ≥1mm and compared for prevalence and predictors of ischemia and a composite of cardiac death, nonfatal myocardial infarction, and late revascularization. The cohort had a median age of 57 and 57% were male. The prevalence of aVR elevation was 11.5%. The prevalence of significant ischemia on patients who received imaging was significantly higher with aVR elevation (14.3% vs 2.3%, p<0.001). Early revascularization occurred in 10.9% with vs 0.2% without aVR elevation, p<0.001. No subjects without aVR elevation or ST-depression underwent early revascularization. However, cardiac event rates were similar over a median 4.0 years of follow-up with and without aVR elevation (2.8% vs. 2.6%, p = 0.80). aVR elevation did not predict long-term cardiac events by Kaplan-Meier survival analysis (p = 0.94) or Cox proportional hazards modeling (p = 0.35).

CONCLUSIONS

aVR elevation during ExECG predicts ischemia on imaging and early revascularization but not long-term outcomes and could serve as a useful adjunct to standard ST-analysis and potentially reduce the need for concurrent imaging.

Approach to stable angina in patients with advanced chronic kidney disease

PURPOSE OF REVIEW

Chronic kidney disease is one of the major risk factors for coronary artery disease. Both end-stage renal disease (ESRD) and advanced chronic kidney disease patients have atypical presentations of coronary artery disease (CAD) due to modifications in cardinal symptoms and clinical presentation. Data on evaluation and management of coronary artery or stable angina is limited in advanced chronic kidney disease (CKD) patients due to a limited number of trials. There are sparse data supporting either percutaneous coronary intervention (PCI) or coronary artery bypass graft in advanced CKD patients.

RECENT FINDINGS

The ISCHEMIA-CKD trial to date is the most extensive prospective randomized study looking at advanced CKD patients study looking at advanced CKD stage 4/5 patients randomized to medical treatment alone vs. invasive strategy for moderate to severe myocardial ischemia. There was no evidence found that an initial invasive strategy compared with conservative strategy with maximal medical management resulted in reduced risk of death or nonfatal myocardial infarction in patients with advanced CKD and coronary artery disease with stable angina.

SUMMARY

In this review, we will discuss the existing data on assessment and management of stable coronary artery disease/stable angina. And how this extrapolates to the application in advanced CKD patients awaiting kidney transplant.

Incremental value of high-frequency QRS analysis for diagnosis and prognosis in suspected exercise-induced myocardial ischaemia

Aim:

Exercise stress testing is used to detect myocardial ischaemia, but is limited by low sensitivity and specificity. The authors investigated the value of the analysis of high-frequency QRS components as a marker of abnormal depolarization in addition to standard ST-deviations as a marker of abnormal repolarization to improve the diagnostic accuracy.

Methods and results:

Consecutive patients undergoing bicycle exercise stress nuclear myocardial perfusion imaging were prospectively enrolled. Presence of myocardial ischaemia, the primary diagnostic endpoint, was adjudicated using MPI and coronary angiography. Automated high-frequency QRS analysis was performed in a blinded fashion. The prognostic endpoint was major adverse cardiac events (MACEs) during two years of follow-up. Exercise-induced ischaemia was detected in 147/662 patients (22%). The sensitivity of high-frequency QRS was similar to ST-deviations (46% vs. 43%, p=0.59), while the specificity was lower (75% vs. 87%, p&lt;0.001). The combined use of high-frequency QRS and ST-deviations classified 59% of patients as ‘rule-out’ (both negative), 9% as ‘rule-in’ (both positive) and 32% in an intermediate zone (one test positive). The sensitivity for ‘rule-out’ and the specificity for ‘rule-in’ improved to 63% and 97% compared with ST-deviation analysis alone (both p&lt;0.001). MACE-free survival was 90%, 80% and 42% in patients in the ‘rule-out’, intermediate and ‘rule-in’ groups (p&lt;0.001). After adjustment for age, gender, ST-deviations and clinical post-test probability of ischaemia, high-frequency QRS remained an independent predictor for the occurrence of MACEs.

Conclusion:

The use of high-frequency QRS analysis in addition to ST-deviation analysis improves the diagnostic accuracy during exercise stress testing and adds independent prognostic information.

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.

Cardiopulmonary exercise test in myocardial ischemia detection

Exercise electrocardiography has low sensitivity for detection of myocardial ischemia. However, when combined with cardiopulmonary exercise testing (CPEX), the sensitivity and specificity of ischemia detection improves significantly. CPEX offers unique advantages over imaging techniques in tricky situations such as balanced ischemia. Early abnormal oxygen uptake would point toward profound coronary stenosis that could be missed in perfusion imaging. CPEX could be an invaluable tool in asymptomatic left bundle branch block pattern, without exposing patients to the risks of computerized tomography or invasive coronary angiography. Normal oxygen uptake curves would rule out significant coronary stenosis as the cause of left bundle branch block pattern. Elseways, abnormal oxygen uptake in patients with normal coronary arteries could indicate microvascular angina. Furthermore, exercise capacity is an excellent predictor of cardiovascular risk in those with and without heart disease. Using two clinical cases we introduce the concept of gas-exchange and hemodynamic changes encountered in ischemic heart disease.

Metabolic alterations in acute myocardial ischemia-reperfusion injury and necrosis using in vivo hyperpolarized [1-13C] pyruvate MR spectroscopy

This study aimed to investigate real-time early detection of metabolic alteration in a rat model with acute myocardial ischemia-reperfusion (AMI/R) injury and myocardial necrosis, as well as its correlation with intracellular pH level using in vivo hyperpolarized [1-¹³C] pyruvate magnetic resonance spectroscopy (MRS). Hyperpolarized ¹³C MRS was performed on the myocardium of 8 sham-operated control rats and 8 rats with AMI/R injury, and 8 sham-operated control rats and 8 rats with AMI-induced necrosis. Also, the correlations of levels of [1-¹³C] metabolites with pH were analyzed by Spearman’s correlation test. The AMI/R and necrosis groups showed significantly higher ratios of [1-¹³C] lactate (Lac)/bicarbonate (Bicar) and [1-¹³C] Lac/total carbon (tC), and lower ratios of ¹³C Bicar/Lac + alanine (Ala), and ¹³C Bicar/tC than those of the sham-operated control group. Moreover, the necrosis group showed significantly higher ratios of [1-¹³C] Lac/Bicar and [1-¹³C] Lac/tC, and lower ratios of ¹³C Bicar/Lac + Ala and ¹³C Bicar/tC than those of the AMI/R group. These results were consistent with the pattern for in vivo the area under the curve (AUC) ratios. In addition, levels of [1-¹³C] Lac/Bicar and [1-¹³C] Lac/tC were negatively correlated with pH levels, whereas ¹³C Bicar/Lac + Ala and ¹³C Bicar/tC levels were positively correlated with pH levels. The levels of [1-¹³C] Lac and ¹³C Bicar will be helpful for non-invasively evaluating the early stage of AMI/R and necrosis in conjunction with reperfusion injury of the heart. These findings have potential application to real-time evaluation of cardiac malfunction accompanied by changes in intracellular pH level and enzymatic activity.

Changes in ventricular depolarisation vectors during exercise caused by regional myocardial ischaemia

Research at the Aga Khan University for several years has been directed to find a reliable, low-cost, portable, non-invasive method for identification of coronary artery disease, its location and extent. A new method has been devised to measure the magnitude and direction of cardiac electrical vectors in three perpendicular planes during physical exercise to identify reduction in myocardial excitability as the electrophysiological marker of hypoxia. This report shows that changes in electrical forces due to exercise-induced regional hypoxia serve as indicators of reversible myocardial ischaemia. Changes in the magnitude and direction of vectors at stages of the Bruce protocol were measured in healthy volunteers, and patients undergoing the same exercise protocol for distribution of a radioactive tracer injected intravenously at peak exercise and after recovery (myocardial perfusion scan). Alterations in the magnitude and direction of resultant vectors during exercise were scored to enable analysis. Analysis identified slow progression of myocardial depolarisation as the electrophysiological marker of regional hypoxia relative to physical work. Compared with myocardial perfusion scan the sensitivity and specificity of electrical vectors for identification of ischaemia were 88% and 71%, respectively. Accuracy of ischaemia shown by electrical vectors is being assessed in patients undergoing elective coronary angiography.

[Radiological imaging to assess individual cardiovascular risk]

CLINICAL/METHODICAL ISSUE

Radiologic imaging for the assessment of individual cardiovascular risk.

STANDARD RADIOLOGICAL METHODS

The correct estimation of the individual cardiovascular risk is prerequisite for the prevention of cardiovascular diseases. Here, extensive evidence is available for coronary calcium scans as well as coronary CT angiography (CTA).

METHODICAL INNOVATIONS

Summary of the available evidence for the use of calcium score and coronary CTA. Illustration of the significance of both tests in current guidelines.

PERFORMANCE

Both tests have high prognostic value, surpassing a risk-factor based assessment. In comparison with the calcium score, the CTA has higher incremental value.

ACHIEVEMENTS

Results from recent trials confirm an improvement of outcomes in symptomatic patients by performing a CTA compared with standard care.

PRACTICAL RECOMMENDATIONS

European and US guidelines recommend a calcium score for risk stratification of asymptomatic patients with a low to intermediate risk profile. For symptomatic patients with low to intermediate coronary artery disease pretest probability, a CTA is recommended.

Diagnostic Yield of Customized Exercise Provocation Following Routine Testing

Clinical guidelines advocate for customization of exercise testing to address patient-specific diagnostic goals, including reproduction of presenting exertional symptoms. However, the diagnostic yield of adding customized exercise testing to graded exercise in patients presenting with exertional complaints has not been rigorously examined and is the focus of this study. Using prospectively collected data, we analyzed the diagnostic yield of customized additional exercise provocation following inconclusive graded exercise test with measurement of gas exchange. Additional testing was defined as "positive" if it revealed a clinically-actionable diagnosis related to the chief complaint or reproduced symptoms in the absence of an explanatory diagnosis or pathology. Of 1,110 patients who completed a graded test, 122 (11%) symptomatic patients underwent additional customized exercise testing (e.g., sprint intervals and race simulations). Compared with those who did not undergo additional testing, this group was younger (29 [interquartile range 19 to 45] vs 46 [25 to 58] year old) and disproportionately female (43% vs 27%). Presenting symptoms included palpitations (46%), lightheadedness/syncope (25%), chest pain (14%), dyspnea (11%), and exertional intolerance (3%). Additional testing was "positive" in 48 of 122 (39%) of patients by revealing a clinically actionable diagnosis in 26 of 48 (54%) or reproducing symptoms without an explanatory diagnosis in 22 of 48 (46%). In conclusion, while patient-centered customization of exercise testing is suggested by clinical guidelines, these data are the first to demonstrate that the selective addition of customized exercise provocation following inconclusive graded exercise testing improves the diagnostic yield of exercise assessment.

Does stress echocardiography still have a role in the rapid access chest pain clinic post NICE CG95?

Introduction

The 2016 NICE clinical guideline 95 (CG95) demoted functional imaging to a second-line test following computed tomography coronary angiography (CTCA). Many cardiac CT services in the UK require substantial investment and growth to implement this. Chest pain services like ours are likely to continue to use stress testing for the foreseeable future. We share service evaluation data from our department to show that a negative stress echocardiogram can continue to be used for chest pain assessment.

Methods

1815 patients were referred to rapid access chest pain clinic (RACPC) between June 2013 and March 2015. 802 patients had stress echocardiography as the initial investigation. 446 patients had normal resting left ventricular (LV) systolic function and a negative stress echocardiogram. At least 24 months after discharge, a survey was carried out to detect major adverse cardiovascular events (MACE) (cardiac death, myocardial infarction, admission to hospital for heart failure or angina, coronary artery disease at angiography, revascularisation by angioplasty or coronary artery bypass grafting) within 2 years.

Results

Overall, 351 patients were successfully followed up. The mean Diamond-Forrester (D-F) score and QRISK2 suggested a high pre-test probability (PTP) of coronary artery disease (CAD). There were nine deaths (eight non-cardiac deaths and one cardiac death). MACE occurred in four patients with a mean time of 17.5 months (11.6–23.7 months). The annual event rate was 0.6%.

Conclusion

A negative stress echocardiogram can reliably reassure patients and clinicians even in high PTP populations with suspected stable angina. It can continue to be used to assess stable chest pain post CG95.