ACC/AHA guidelines for exercise testing: executive summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Exercise Testing)

Validity of the Ekblom-Bak Cycle Ergometer Test in Patients with Cardiovascular Disease

OBJECTIVE

To assess the validity of the Ekblom-Bak cycle ergometer test in patients with cardiovascular disease admitted to cardiac rehabilitation.

METHODS

Estimated peak oxygen consumption from the Ekblom-Bak test was compared with directly measured peak oxygen consumption from a treadmill cardiopulmonary exercise test. Patients completed the cardiopulmonary exercise test first, followed by the Ekblom-Bak test after 24 h rest. Pearson's correlation coefficient (r) was used to establish the correlation between estimated and measured peak oxygen consumption, and Bland-Altman plots with limits of agreement were used to determine the bias between the 2 tests.

RESULTS

Twenty-six patients were included in the final analysis. The Ekblom-Bak test significantly overestimated peak oxygen consumption. Agreement between estimated and measured peak oxygen consumption was: bias = 4.3 mL/kg/min (limits of agreement: -4.0-12.6 mL/kg/min).

CONCLUSION

The Ekblom-Bak test overestimated peak oxygen consumption to such an extent that it cannot accurately assess cardiorespiratory fitness in patients with cardiovascular disease. Thus, the cardiopulmonary exercise test remains the test of choice.

Development of a Pediatric Cardiology Cardiopulmonary Exercise Testing Database

Cardiopulmonary exercise testing (CPET) provides clinicians with information vital to the management of pediatric cardiology patients. CPET can also be used to measure cardiorespiratory fitness (CRF) in these patients. CRF is a robust marker of overall health in children. However, a complete understanding of CRF in pediatric cardiology patients is limited by lack of large, standardized CPET databases. Our purpose was to develop a standardized CPET database, describe available data at our institution, and discuss challenges and opportunities associated with this project. CPETs performed from 1993 to present in an urban pediatric hospital were collected and compiled into a research database. Historical data included demographic and clinical variables and CPET outcomes, and additional variables were calculated and coded to facilitate analyses in these cohorts. Patient diagnoses were coded to facilitate sub-analyses of specific cohorts. Quality assurance protocols were established to ensure future database contributions and promote inter-institutional collaborations. This database includes 10,319 CPETs (56.1% male), predominantly using the Bruce Protocol. Patients ranging from ages 6 to 18 years comprise 86.8% of available CPETs. Diagnosis classification scheme includes patients with structurally normal hearts (n = 3,454), congenital heart disease (n = 3,614), electrophysiological abnormalities (n = 2,082), heart transplant or cardiomyopathy (n = 833), and other diagnoses (n = 336). Historically, clinicians were provided with suboptimal interpretive resources for CPET, often generalizing inferences from these resources to non-representative clinical populations. This database supports representative CRF comparisons and establishes a framework for future CRF-based registries in pediatric patients referred for CPET, ultimately improving clinical decision-making regarding fitness in these populations.

Longitudinal strain correlates with 6-minute walk distance whereas ejection fraction and diastolic parameters do not

BACKGROUND

Impaired functional capacity is a common symptom in patients with heart failure. Standard measures of left ventricular (LV) function, such as ejection fraction (EF) and LV diastolic parameters, do not correlate with measures of functional capacity. The aim of this study is to determine if measures of global and regional LV strain better correlate with 6-minute walk distance than does EF or measures of LV diastolic function.

METHODS

120 patients referred to a cardiology clinic for evaluation of known or suspected heart failure were approached for enrollment. Of those 120 patients, 58 had an echocardiogram within 3 months of enrollment with images adequate for regional and global strain assessment, had no contra-indication to exercise testing, and had no previously documented non-cardiac explanation for dyspnea on exertion. In those 58 patients, 6-minute walk distance was measured, LV EF was determined with Simpson's biplane method, and global and regional longitudinal strain were measured with TomTec Image Arena 4.5.1 software.

RESULTS

LV EF had no correlation with 6-minute walk distance (r = 0.22, p = 0.09) even when controlling for age, gender, and BMI (p = 0.07). No measures of LV diastolic function (including E velocity, Deceleration Time, e' annular velocities, or E/e') had a correlation with 6-minute walk distance. Multiple measures of global and regional LV longitudinal systolic function had a correlation with 6-minute walk distance. Longitudinal strain of the basal LV segments had the strongest correlation with 6-minute walk distance (r= -0.36, p = 0.005), and correlation persisted after controlling for age, gender, BMI, and systolic blood pressure (p = 0.004).

CONCLUSIONS

Longitudinal strain correlates with a measure of functional capacity, but LVEF and traditional measures of LV diastolic dysfunction do not. Measures of longitudinal strain, especially in basal LV segments, will likely be an important marker of clinically relevant LV function.

Evaluating current assessment techniques of cardiorespiratory fitness

INTRODUCTION

Considerable and convincing global data from cohorts across the health spectrum (i.e. apparently healthy to known disease) indicate that cardiorespiratory fitness (CRF) is a major predictor of overall and cardiovascular disease (CVD)-survival, seemingly with greater prognostic resolution compared to other traditional CVD risk factors. Therefore, the assessment of CRF in research and clinical settings is of major importance.

AREAS COVERED

In this manuscript, we review the technology of measuring CRF assessed by the 'gold standard,' cardiopulmonary exercise testing (CPET), as well as with various other methods (e.g. estimated metabolic equivalents, 6-minute walk tests, shuttle tests, and non-exercise equations that estimate CRF), all of which provide significant prognostic information for CVD- and all-cause survival. The literature through May 2024 has been cited.

EXPERT OPINION

The promotion of physical activity in efforts to improve levels of CRF is needed throughout the world to improve lifespan and, more importantly, healthspan. The routine assessment of CRF should be considered a vital sign that is routinely assessed in clinical practice.

Cardiac Dysfunction and Exercise Tolerance in Patients after Complex Treatment for Cranial and Craniospinal Tumors in Childhood

State-of-the-art therapy improves the five-year survival rate of patients under the age of 20 with cranial and craniospinal tumors by up to 74%. The urgency of dealing effectively with late treatment-associated cardiovascular complications is rising. Objective: We aimed to assess echocardiographic parameters and exercise performance in subjects with a history of complex treatment for cranial and craniospinal tumors in childhood. Methods: the study of 48 subjects who underwent cranial and craniospinal irradiation for CNS tumors in childhood and 20 healthy age- and sex-matched volunteers was conducted. The examination included hormone studies, cardiopulmonary exercise testing, and, in the main group, echocardiography (ECHO). Results: In five (10.4%) patients, ECHO changes were detected after complex anti-cancer treatment: thickening and calcification of the aortic valve leaflets (2%), and reduction in the systolic LV and RV function (8% and 6%, respectively). Irradiation of various areas was a significant predictor for reduced exercise tolerance, hyperventilation at rest and upon exertion, and an increased ventilatory equivalent for carbon dioxide. Low exercise tolerance was associated with a younger age at the time of treatment initiation. Significant differences were noted between the control group and the childhood cancer survivors with endocrine disorders. Conclusions: The obtained data confirm the importance of regular cardiovascular and endocrine monitoring of this group of cancer survivors.

Impact of Gender on Chronic Complications in Participants With Type 2 Diabetes: Evidence From a Cross-Sectional Study

INTRODUCTION

This study aimed to assess and compare the prevalence of diabetes complications between men and women with Type 2 diabetes (T2D), as well as how gender relates to these complications.

METHODS

In this cross-sectional study, complications of diabetes, including coronary artery disease (CAD), retinopathy, neuropathy and diabetic kidney disease (DKD), were evaluated in 1867 participants with T2D. Additionally, baseline characteristics of the individuals, including anthropometric measurements, metabolic parameters and the use of dyslipidaemia drugs and antihyperglycaemic agents, were assessed. Gender differences in complications were examined using the chi-squared test. Multivariate logistic regression was employed to investigate the relationship between gender and T2D complications, with and without adjusting for the characteristics of the studied population.

RESULTS

In the studied population, 62.1% had at least one complication, and complications were 33.5% for DKD, 29.6% for CAD, 22.9% for neuropathy and 19.1% for retinopathy. The prevalence of CAD and neuropathy was higher in men. However, DKD and retinopathy were more prevalent among women. Odds ratios of experiencing any complication, CAD and retinopathy in men compared with women were 1.57 (95% CI: 1.27-2.03), 2.27 (95% CI: 1.72-2.99) and 0.72 (95% CI: 0.52-0.98), respectively, after adjusting for demographic factors, anthropometric measures, metabolic parameters and the consumption of dyslipidaemia drugs and antihyperglycaemic agents.

CONCLUSION

The prevalence of diabetes complications was significantly higher in men with diabetes, highlighting the need for better treatment adherence. CAD was associated with the male gender, whereas retinopathy was associated with the female gender. Men and women with diabetes should be monitored closely for CAD and retinopathy, respectively, regardless of their age, diabetes duration, anthropometric measures, laboratory findings and medications.

QTc intervals at rest and during exercise assessed by group correction formulas in survivors of childhood acute lymphoblastic leukemia

INTRODUCTION

Early signs of subclinical cardiac damage must be identified before they turn into clinical manifestations. Tailoring a formula is relevant for precise QTc evaluation in childhood acute lymphoblastic leukemia (ALL) survivors considering they are at risk of long-term cardiac problems. Therefore, we aim to develop group heart rate correction formulas for QT intervals in childhood ALL survivors at rest and during exercise, and to assess the applicability of these methods across a variety of risk groups exposed to diverse chemotherapy dosages.

METHODS

Two hundred and fifty childhood ALL survivors in the PETALE study were classified into 3 groups depending on their prognostic risk group. ECG measurements (QT and RR intervals) were made at rest and during a cardiopulmonary exercise test. QT correction for heart rate was applied using 5 different formulas, which included 2 previously published formulas and 3 group-specific formulas for each sex.

RESULTS

The QT/RR relation showed 2 different curves between rest and during exercise, which was worse for females. Group-specific QTc formulas allowed adequate heart rate-corrected QT interval, independently of the cumulative dose of doxorubicin received during treatment. Group-specific formulas showed significantly shorter QTc intervals than QTc from Bazett's formula. QTc (Bazett's formula) values surpassed the established clinical norm in 22 males (11%) and 22 females (11%), with a majority occurring during exercise, affecting 15 males (7.5%) and 10 females (5%).

CONCLUSION

This study shows the applicability of personalized group correction of QT/RR data in childhood ALL survivors. Our comprehensive assessments (spanning rest, exercise, and recovery) is an effective approach for risk stratification of cardiac complications in childhood ALL survivors.

An initiative to promote value-based stress test selection in primary care and cardiology clinics: A mixed methods evaluation

OBJECTIVES

Exercise stress echocardiograms (stress echos) are overused, whereas exercise stress electrocardiograms (stress ECGs) can be an appropriate, lower-cost substitute. In this post hoc, mixed methods evaluation, we assessed an initiative promoting value-based, guideline-concordant ordering practices in primary care (PC) and cardiology clinics.

METHODS

Change in percent of stress ECGs ordered of all exercise stress tests (stress ECGs and echos) was calculated between three periods: baseline (January 2019-February 2020); Period 1 with reduced stress ECG report turnaround time + PC-targeted education (began June 2020); and Period 2 with the addition of electronic health record-based alternative alert (AA) providing point-of-care clinical decision support. The AA was deployed in two of five PC clinics in July 2020, two additional PC clinics in January 2021, and one of four cardiology clinics in February 2021. Nineteen primary care providers (PCPs) and five cardiologists were interviewed in Period 2.

RESULTS

Clinicians reported reducing ECG report turnaround time was crucial for adoption. PCPs specifically reported that value-based education helped change their practice. In PC, the percent of stress ECGs ordered increased by 38% ± 6% (SE) (p < 0.0001) from baseline to Period 1. Most PCPs identified the AA as the most impactful initiative, yet stress ECG ordering did not change (6% ± 6%; p = 0.34) between Periods 1 and 2. In contrast, cardiologists reportedly relied on their expertise rather than AAs, yet their stress ECGs orders increased from Period 1 to 2 to a larger degree in the cardiology clinic with the AA (12% ± 5%; p = 0.01) than clinics without the AA (6% ± 2%; p = 0.01). The percent of stress ECGs ordered was higher in Period 2 than baseline for both specialties (both p < 0.0001).

CONCLUSIONS

This initiative influenced ordering behaviour in PC and cardiology clinics. However, clinicians' perceptions of the initiative varied between specialties and did not always align with the observed behaviour change.

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.

Prognostic Role of Metabolic Exercise Testing in Heart Failure

Heart failure is a clinical syndrome with significant heterogeneity in presentation and severity. Serial risk-stratification and prognostication can guide management decisions, particularly in advanced heart failure, when progression toward advanced therapies or end-of-life care is warranted. Each currently utilized prognostic marker carries its own set of challenges in acquisition, reproducibility, accuracy, and significance. Left ventricular ejection fraction is foundational for heart failure syndrome classification after clinical diagnosis and remains the primary parameter for inclusion in most clinical trials; however, it does not consistently correlate with symptoms and functional capacity, which are also independently prognostic in this patient population. Utilizing the left ventricular ejection fraction as the sole basis of prognostication provides an incomplete characterization of this condition and is prone to misguide medical decision-making when used in isolation. In this review article, we survey and exposit the important role of metabolic exercise testing across the heart failure spectrum, as a complementary diagnostic and prognostic modality. Metabolic exercise testing, also known as cardiopulmonary exercise testing, provides a comprehensive evaluation of the multisystem (i.e., neurological, respiratory, circulatory, and musculoskeletal) response to exercise performance. These differential responses can help identify the predominant contributors to exercise intolerance and exercise symptoms. Additionally, the aerobic exercise capacity (i.e., oxygen consumption during exercise) is directly correlated with overall life expectancy and prognosis in many disease states. Specifically in heart failure patients, metabolic exercise testing provides an accurate, objective, and reproducible assessment of the overall circulatory sufficiency and circulatory reserve during physical stress, being able to isolate the concurrent chronotropic and stroke volume responses for a reliable depiction of the circulatory flow rate in real time.

Exercise-induced B-lines for the diagnosis of heart failure with preserved ejection fraction: a two-centre study

BACKGROUND

Diagnosis of heart failure with preserved ejection fraction (HFpEF) remains challenging despite the use of scores/algorithms. This study intended to assess the diagnostic value of exercise lung ultrasound (LUS) for HFpEF diagnosis.

METHODS

We studied two independent case-control studies of HFpEF patients and control subjects undergoing different exercise protocols: (i) submaximal exercise stress echocardiography (ESE) with LUS performed by expert cardiologists (N = 116, HFpEF = 65.5%), and (ii) maximal cycle ergometer test (CET) (N = 54, HFpEF = 50%) with LUS performed by unexperienced physicians shortly trained for the study. B-line kinetics (i.e. peak values and their changes from rest) were assessed.

RESULTS

In the ESE cohort, the C-index (95% CI) of peak B-lines for HFpEF diagnosis was 0.985 (0.968-1.000), whereas the C-index of rest and exercise HFA-PEFF scores (i.e. including stress echo findings) were < 0.90 (CI 0.823-0.949), and that of H2FPEF score was < 0.70 (CI 0.558-0.764). The C-index increase of peak B-lines on top of the above-mentioned scores was significant (C-index increase > 0.090 and P-value < 0.001 for all). Similar results were observed for change B-lines. Peak B-lines > 5 (sensitivity = 93.4%, specificity = 97.5%) and change B-lines > 3 (sensitivity = 94.7%, specificity = 87.5%) were the best cutoffs for HFpEF diagnosis. Adding peak or change B-lines on top of HFpEF scores and BNP significantly improved diagnostic accuracy. Peak B-lines showed a good diagnostic accuracy in the LUS beginner-led CET cohort (C-index = 0.713, 0.588-0.838).

CONCLUSIONS

Exercise LUS showed excellent diagnostic value for HFpEF diagnosis regardless of different exercise protocols/level of expertise, with additive diagnostic accuracy on top of available scores and natriuretic peptides.

Heart Rate Recovery Assessed by Cardiopulmonary Exercise Testing in Patients with Cardiovascular Disease: Relationship with Prognosis

BACKGROUND

The use of exercise testing has expanded in recent decades and there is a wealth of information examining the prognostic significance of exercise variables, such as peak oxygen consumption or ventilatory measures whilst exercising. However, a paucity of research has investigated the use of recovery-derived parameters after exercise cessation. Heart rate recovery (HRR) has been considered a measure of the function of the autonomic nervous system and its dysfunction is associated with cardiovascular risk.

OBJECTIVES

We aim to provide an overview of the literature surrounding HRR and its prognostic significance in patients with cardiovascular disease undertaking an exercise test.

DATA SOURCES

In December 2020, searches of PubMed, Scopus, and ScienceDirect were performed using key search terms and Boolean operators.

STUDY SELECTION

Articles were manually screened and selected as per the inclusion criteria.

RESULTS

Nineteen articles met inclusion criteria and were reviewed. Disagreement exists in methodologies used for measuring and assessing HRR. However, HRR provides prognostic mortality information for use in clinical practice.

CONCLUSIONS

HRR is a simple, non-invasive measure which independently predicts mortality in patients with heart failure and coronary artery disease; HRR should be routinely incorporated into clinical exercise testing.

Hypoxia Altitude Simulation and Reduction of Cerebral Oxygenation in COPD Patients

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is highly prevalent and often associated with chronic hypoxia. Previous studies have shown alterations of cerebral oxygenation and cardiac repolarization in COPD patients (GOLD stage II-IV). Airplane travel is common in patients with COPD; however, the clinical effects of a diminished oxygen partial pressure in aircraft cabin environments at cruising altitude remain elusive. The aim of this study was to assess changes of cerebral oxygenation as well as parameters of cardiac repolarization during a hypoxia altitude simulation combined with mild physical activity in these patients.METHODS: Patients with COPD and healthy subjects (10 per group) randomly selected from the Charité outpatient clinic conducted a hypoxia altitude simulation test which consisted of three phases. The regional cerebral oxygen saturation (rSO₂) of the frontal cortex was measured at rest using near-infrared spectroscopy (NIRS). Furthermore, oxygen saturation (S_pO₂), blood pressure, and heart rate values, as well as a 12-lead-ECG, were recorded. Subsequently, a mild treadmill exercise program (25 W) was divided into 10 min of normoxia (pre-hypoxia), 30 min of mild hypoxia (F_IO₂ = 0.15), followed by a second 10-min period of normoxia (post-hypoxia). Meanwhile, mentioned parameters were recorded in 2-min intervals. P, PQ, QRS, QT, QTc, QTd, T-peak-T-end interval (TpTe), and corrected TpTe (TpTec) were measured on three ECG complexes, each at baseline, at the end of the normoxic phase, and at the end of the hypoxic phase.RESULTS: A total of 10 patients with COPD and 10 control subjects were included in this study. S_pO₂ was significantly lower in COPD patients throughout the whole test. Frontal cerebral rSO₂ was significantly lower in the left hemisphere during hypoxia altitude simulation in COPD patients (59.5 ± 8.5 vs. 67.5 ± 5.7).CONCLUSIONS: We show reduced left frontal cerebral oxygenation during hypoxia and mild exercise in patients with COPD, suggesting diminished altitude resilience and altitude capabilities. Preflight hypoxia assessment might be recommended to patients with severe COPD.Dehe L, Hohendanner F, Gültekin E, Werth G, Wutzler A, Bender TO. Hypoxia altitude simulation and reduction of cerebral oxygenation in COPD patients. Aerosp Med Hum Perform. 2023; 94(3):102-106.

Clinical significance of the hemodynamic gain index in patients undergoing exercise stress testing and coronary computed tomography angiography

BACKGROUND

Many hemodynamic parameters provide limited information regarding obstructive coronary artery disease (CAD) during exercise stress testing particularly when exercise is suboptimal. Hemodynamic gain index (HGI) is a recent sensitive indicator of ischemia and has been associated with increased mortality. This study evaluated the clinical impact of HGI in patients who underwent concomitant exercise stress testing and coronary computed tomography angiography (CCTA).

METHODS

A total of 284 consecutive patients from the executive health program between 2010 and 2018 were identified. Resting and peak heart rate (HR) as well as systolic blood pressure (SBP) measurements were recorded. Framingham risk score (FRS), Duke treadmill score (DTS) and HGI [Formula: see text] were calculated. The latter was divided into quartiles. CCTA was used as a reference test to detect any CAD. Multivariate analysis and artificial neural network were used to determine the independent predictors of obstructive CAD.

RESULTS

Mean age was 53 ± 12 years with 83% male. Mean HGI was 1.74 ± 0.67, with cut-off value of severely blunted HGI ≤ 1.25 (Quartile 4). Patients with severely blunted HGI were older, had higher FRS, and worse DTS. Patients with obstructive CAD had lower HGI when compared to those with normal CCTA/non-obstructive CAD (1.36 ± 0.53 vs. 1.77 ± 0.67, P = 0.005), and showed a higher prevalence of severely blunted HGI (44% vs. 22%, P = 0.019). After adjusting for traditional risk factors, HGI remained an independent predictor of obstructive CAD while severely blunted HGI was associated with threefold increased odds of having obstructive CAD (P = 0.05). Using artificial intelligence analysis, severely blunted HGI independently predicted obstructive CAD with an area under the curve of 0.83 and 0.96, and normalized importance of HGI of 100% and 63%, respectively for different models.

CONCLUSIONS

Among patients who underwent concomitant exercise stress testing and CCTA, severely blunted HGI independently predicted obstructive CAD after multivariate adjustment for traditional risk factors.

An evaluation of cardiopulmonary endurance and muscular strength in adults living with sickle cell disease

There have been limited investigations into exercise in sickle cell disease (SCD). In the general population, health is reflected in general physical fitness. It is unclear if the same associations are seen in people with SCD. Here, we report a cross-sectional assessment of two important measures of physical fitness, muscle strength and cardiorespiratory endurance, in adults with SCD. A total of 29 adults with SCD (aged 24-62 years; 72% female) completed cardiopulmonary and muscular strength testing using a cycle ergometer and an isokinetic dynamometer. Adults with SCD had lower median values for cardiorespiratory endurance (the median [interquartile range, IQR] peak oxygen uptake [VO₂ ] 16.1 [6.3] vs. 42.65 [11.3] ml/kg/min, p < 0.001) and knee strength (median [IQR] flexor torque 26.91[22.5] vs. 55.6 [22.7] Nm, p < 0.001) compared to controls and predicted values. Interestingly, there was a very positive association between muscular strength and peak VO₂ values for adults with SCD (r = 0.53, p = 0.003) suggesting these values may be useful in determining cardiopulmonary health.

Thirty years of research on physical activity, mental health, and wellbeing: A scientometric analysis of hotspots and trends

The sheer volume of research publications on physical activity, mental health, and wellbeing is overwhelming. The aim of this study was to perform a broad-ranging scientometric analysis to evaluate key themes and trends over the past decades, informing future lines of research. We searched the Web of Science Core Collection from inception until December 7, 2021, using the appropriate search terms such as "physical activity" or "mental health," with no limitation of language or time. Eligible studies were articles, reviews, editorial material, and proceeding papers. We retrieved 55,353 documents published between 1905 and 2021. The annual scientific production is exponential with a mean annual growth rate of 6.8% since 1989. The 1988-2021 co-cited reference network identified 50 distinct clusters that presented significant modularity and silhouette scores indicating highly credible clusters (Q = 0.848, S = 0.939). This network identified 6 major research trends on physical activity, namely cardiovascular diseases, somatic disorders, cognitive decline/dementia, mental illness, athletes' performance, related health issues, and eating disorders, and the COVID-19 pandemic. A focus on the latest research trends found that greenness/urbanicity (2014), concussion/chronic traumatic encephalopathy (2015), and COVID-19 (2019) were the most active clusters of research. The USA research network was the most central, and the Chinese research network, although important in size, was relatively isolated. Our results strengthen and expand the central role of physical activity in public health, calling for the systematic involvement of physical activity professionals as stakeholders in public health decision-making process.

Exercise Stress Testing in Athletes

Exercise stress testing (EST) is indicated for diagnostic and prognostic purposes in the general population. In athletes, stress tests can also be useful to inform the risk of high-intensity training and competition, to assess athletic conditioning, and to refine training regimens. Many specific indications for EST are unique to athletes. Treadmill and cycle ergometer protocols each have their strengths and disadvantages; extensive protocol customization may be necessary to answer the clinical question at hand. A comprehensive understanding of the available tools for exercise testing, their strengths, and their limitations is crucial to providing cardiovascular care to athletic individuals.

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

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

Evaluation of the Ostium in Anomalous Origin of the Right Coronary Artery with an Interarterial Course Using Dynamic Cardiac CT and Implications of Ostial Findings

OBJECTIVE

We aimed to evaluate the ostium of right coronary artery of anomalous origin from the left coronary sinus (AORL) with an interarterial course throughout the cardiac cycle on CT and analyze the clinical significance of the ostial findings.

MATERIALS AND METHODS

From January 2011 to December 2015, 68 patients (41 male, 57.3 ± 12.1 years) with AORL with an interarterial course and retrospective cardiac CT data were included. AORL was classified as high or low ostial location based on the pulmonary annulus in the diastolic and systolic phases on cardiac CT. In addition, the height, width, height/width ratio, area, and angle of the ostium were measured in both cardiac phases. After cardiac CT, patients were followed until December 31, 2020 for major adverse cardiac events (MACE). Clinical and CT characteristics associated with MACE were explored using Cox regression analysis.

RESULTS

During a median follow-up period of 2071 days (interquartile range, 1180.5-2747.3 days), 13 patients experienced MACE (19.1%, 13/68). Seven (10.3%, 7/68) had the ostial location change from high in the diastolic phase to low in the systolic phase. In the univariable analysis, younger age (hazard ratio [HR] = 0.918, p < 0.001), high ostial location (HR = 4.008, p = 0.036), larger height/width ratio (HR = 5.621, p = 0.049), and smaller ostial angle (HR = 0.846, p = 0.048) in the systolic phase were significant predictors of MACE. In multivariable cox regression analysis, younger age (adjusted HR = 0.917, p = 0.002) and high ostial location in the systolic phase (adjusted HR = 4.345, p = 0.026) were independent predictors of MACE.

CONCLUSION

The ostial location of AORL with an interarterial course can change during the cardiac cycle, and high ostial location in the systolic phase was an independent predictor of MACE.

Exercise characteristics and incidence of abnormal electrocardiogram response in long-distance runners with exercise-induced hypertension

While long‐distance running has important health benefits, chronic elevation of blood pressure during exercise might induce cardiac events and sudden death. This study aimed to investigate characteristics of exercise and incidence of abnormal exercise electrocardiography findings in long‐distance runners with exercise‐induced hypertension. Long‐distance runners (n = 606) underwent a questionnaire survey, history taking, and exercise stress testing, and they were classified into the non‐exercise‐induced (n = 268) and exercise‐induced (n = 338) hypertension groups. Exercise‐induced hypertension was defined as systolic blood pressure ≥210 mm Hg during maximal exercise. Abnormal electrocardiogram response (AER) were defined as abnormal electrocardiography findings, such as arrhythmias or ST‐segment changes, during exercise stress testing. There were no differences in general and exercise‐related characteristics between the non‐exercise‐induced and exercise‐induced hypertension groups. The AER group (AERg, n = 37) had a significantly longer training history and total exercise time than the non‐AER group (non‐AERg, n = 569) (p < .05). Atrial arrhythmias and ST‐segment depression were more prevalent in the exercise‐induced hypertension group than in the non‐exercise‐induced hypertension group (atrial arrhythmias: 5% [17/338] vs. 1.9% [5/268]; ST‐segment depression: 2.7% [9/338] vs. .4% [1/268]; p < .05). The incidence of AER was significantly higher in the exercise‐induced hypertension group (n = 30, 8.8%) than in the non‐exercise‐induced hypertension group (n = 7, 2.6%) (p < .05). This study showed that long‐distance runners with AER had a longer training history and total exercise time than those without AER, and the exercise‐induced hypertension group had a higher rate of AER.

The Discriminatory Ability of Renalase and Biomarkers of Cardiac Remodeling for the Prediction of Ischemia in Chronic Heart Failure Patients With the Regard to the Ejection Fraction

Background: Renalase has been implicated in chronic heart failure (CHF); however, nothing is known about renalase discriminatory ability and prognostic evaluation. The aims of the study were to assess whether plasma renalase may be validated as a predictor of ischemia in CHF patients stratified to the left ventricular ejection fraction (LVEF) and to determine its discriminatory ability coupled with biomarkers representing a range of heart failure (HF) pathophysiology: brain natriuretic peptide (BNP), soluble suppressor of tumorigenicity (sST2), galectin-3, growth differentiation factor 15 (GDF-15), syndecan-1, and cystatin C.

Methods: A total of 77 CHF patients were stratified according to the LVEF and were subjected to exercise stress testing. Receiver operating characteristic curves were constructed, and the areas under curves (AUC) were determined, whereas the calibration was evaluated using the Hosmer-Lemeshow statistic. A DeLong test was performed to compare the AUCs of biomarkers.

Results: Independent predictors for ischemia in the total HF cohort were increased plasma concentrations: BNP (p = 0.008), renalase (p = 0.012), sST2 (p = 0.020), galectin-3 (p = 0.018), GDF-15 (p = 0.034), and syndecan-1 (p = 0.024), whereas after adjustments, only BNP (p = 0.010) demonstrated predictive power. In patients with LVEF <45% (HFrEF), independent predictors of ischemia were BNP (p = 0.001), renalase (p < 0.001), sST2 (p = 0.004), galectin-3 (p = 0.003), GDF-15 (p = 0.001), and syndecan-1 (p < 0.001). The AUC of BNP (0.837) was statistically higher compared to those of sST2 (DeLong test: p = 0.042), syndecan-1 (DeLong: p = 0.022), and cystatin C (DeLong: p = 0.022). The AUCs of renalase (0.753), galectin-3 (0.726), and GDF-15 (0.735) were similar and were non-inferior compared to BNP, regarding ischemia prediction. In HFrEF patients, the AUC of BNP (0.980) was statistically higher compared to those of renalase (DeLong: p < 0.001), sST2 (DeLong: p < 0.004), galectin-3 (DeLong: p < 0.001), GDF-15 (DeLong: p = 0.001), syndecan-1 (DeLong: p = 0.009), and cystatin C (DeLong: p = 0.001). The AUC of renalase (0.814) was statistically higher compared to those of galectin-3 (DeLong: p = 0.014) and GDF-15 (DeLong: p = 0.046) and similar to that of sST2. No significant results were obtained in the patients with LVEF >45%.

Conclusion: Plasma renalase concentration provided significant discrimination for the prediction of ischemia in patients with CHF and appeared to have similar discriminatory potential to that of BNP. Although further confirmatory studies are warranted, renalase seems to be a relevant biomarker for ischemia prediction, implying its potential contribution to ischemia-risk stratification.

Additional roles of diastolic parameters in the diagnosis of obstructive coronary artery disease

BACKGROUND

A recent guideline emphasizes the role of four indicators, including annular e´ velocity, E/e´, left atrial (LA) size, and peak tricuspid regurgitation (TR) velocity, in the assessment of left ventricular (LV) diastolic dysfunction. This study was performed to determine the relationships among these four parameters and obstructive coronary artery disease (CAD).

METHODS

The study data were obtained from a nation-wide registry, composed of 1307 patients (age, 60.4 ± 10.8 years; 964 women) with normal LV ejection fraction (LVEF) who underwent invasive coronary angiography in the suspicion of CAD. Septal e´, E/e´, LA dimension (LAd), and TR velocity were assessed by transthoracic echocardiography.

RESULTS

Compared with patients without obstructive CAD, those with obstructive CAD showed changes in diastolic parameters indicating more progressed LV diastolic dysfunction in univariate analyses. In multiple logistic regression analysis, low septal e´ velocity (<7 cm/s) was identified as an independent risk factor associated with obstructive CAD (odd ratio, 1.91; 95% confidence interval, 1.08-3.36; P = 0.026). Receiver-operating characteristic curve analysis showed that septal e´ velocity had the most powerful value in the detection of obstructive CAD than the other three diastolic parameters (P < 0.01 for each comparison). Septal e´ velocity significantly increased diagnostic value of treadmill exercise test (TET) in the detection of obstructive CAD (P < 0.001 for integrated discrimination improvement index).

CONCLUSIONS

Among the four diastolic parameters, septal e´ velocity had the most powerful relationship with obstructive CAD in stable patients with normal LVEF. The addition of septal e´ velocity could improve the diagnostic value of TET.

Association of post-diagnosis cardiorespiratory fitness with cause-specific mortality in cancer

AIMS

The prognostic importance of post-diagnosis assessment of cardiorespiratory fitness (CRF) in cancer patients is not well established. We sought to examine the association between CRF and mortality in cancer patients.

METHODS AND RESULTS

This was a single-centre cohort analysis of 1632 patients (58% male; 64 ± 12 years) with adult-onset cancer who were clinically referred for exercise treadmill testing a median of 7 [interquartile range (IQR): 3-12] years after primary diagnosis. Cardiorespiratory fitness was defined as peak metabolic equivalents (METs) achieved during standard Bruce protocol and categorized by tertiles. The association between CRF and all-cause and cause-specific mortality was assessed using multivariable Cox proportional hazard models adjusting for important covariates. Median follow-up was 4.6 (IQR: 2.6-7.0) years; a total of 411 deaths (229, 50, and 132 all-cause, cardiovascular (CV), and cancer related, respectively) occurred during this period. Compared with low CRF (range: 1.9-7.6 METs), the adjusted hazard ratio (HR) for all-cause mortality was 0.38 [95% confidence interval (CI): 0.28-0.52] for intermediate CRF (range: 7.7-10.6 METs) and 0.17 (95% CI: 0.11-0.27) for high CRF (range: 10.7-22.0 METs). The corresponding HRs were 0.40 (95% CI: 0.19-0.86) and 0.41 (95% CI: 0.16-1.05) for CV mortality and 0.40 (95% CI: 0.26-0.60) and 0.16 (95% CI: 0.09-0.28) for cancer mortality, respectively. The adjusted risk of all-cause, CV, and cancer mortality decreased by 26%, 14%, and 25%, respectively with each one MET increment in CRF.

CONCLUSION

Cardiorespiratory fitness is a strong, independent predictor of all-cause, CV, and cancer mortality, even after adjustment for important clinical covariates in patients with certain cancers.

Exercise cardiovascular magnetic resonance: development, current utility and future applications

Stress cardiac imaging is the current first line investigation for coronary artery disease diagnosis and decision making and an adjunctive tool in a range of non-ischaemic cardiovascular diseases. Exercise cardiovascular magnetic resonance (Ex-CMR) has developed over the past 25 years to combine the superior image qualities of CMR with the preferred method of exercise stress. Presently, numerous exercise methods exist, from performing stress on an adjacent CMR compatible treadmill to in-scanner exercise, most commonly on a supine cycle ergometer. Cardiac conditions studied by Ex-CMR are broad, commonly investigating ischaemic heart disease and congenital heart disease but extending to pulmonary hypertension and diabetic heart disease. This review presents an in-depth assessment of the various Ex-CMR stress methods and the varied pulse sequence approaches, including those specially designed for Ex-CMR. Current and future developments in image acquisition are highlighted, and will likely lead to a much greater clinical use of Ex-CMR across a range of cardiovascular conditions.

Moderated mediation for exercise maintenance in pain and posttraumatic stress disorder: A randomized trial

This study utilizes the Science of Behavior Change (SOBC) experimental medicine approach to evaluate the effects of a 3-month, individually prescribed progressive exercise training program on neurobiological, cognitive and motivational mechanisms by which our exercise-training paradigm may foster exercise maintenance. We will investigate hypothesized relationships between exercise-training associated augmentation of neuropeptide Y (NPY) system function and improvements in self-regulation and reward sensitivity-cognitive control and motivational processes posited to promote self-efficacy and intrinsic motivation, which have been shown to predict exercise maintenance. This study will recruit Veterans with chronic low back pain and posttraumatic stress disorder (PTSD). Procedures include a baseline, acute cardiopulmonary exercise challenge assessment that will inform the exercise prescription for a 12-week progressive exercise training program comprised of three 45-minute aerobic exercise sessions per week-all of which will be supervised by an exercise physiologist. Additionally, a week-7 and week-14 exercise challenge assessment will track changes in NPY system function and the variables of interest. We hypothesize that increases in the capacity to release NPY in response to acute exercise testing will be associated with improvements in self-regulation and reward sensitivity, which will in turn be associated with self-efficacy and intrinsic motivation to maintain regular exercise. Ninety participants will be randomized either to the "active exercise training condition" or to the "wait list symptom monitoring condition". The study aims to demonstrate the feasibility of procedures and elucidate mechanisms relevant to developing individually prescribed, motivationally based exercise regimens to reduce negative consequences of PTSD and low back pain over the long-term. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Exercise Treadmill Test in Patients with Diabetes Mellitus Type 2

There is a concern regarding the high incidence of coronary heart disease (CHD) among patients with diabetes mellitus (DM) type 2 since it is a leading cause of mortality in those patients. Exercise treadmill test (ETT) is proposed as a suitable, non-invasive method for identifying asymptomatic patients with ischemic changes, who would benefit from pharmacological treatment, thus contributing to a reduction of adverse cardiovascular events. Therefore the objective of our study was to evaluate myocardial ischemia in asymptomatic patients with DM type 2 by performing ETT. The present investigation was conducted in Health Center Pozega during the year 2018. 40 insulin-dependent, aged 33.05 ± 2.01 years, with DM type 2 were included in the study. They had nor history nor symptoms of cardiac disease. All patients underwent ETT according to Bruce protocol, while 12-lead ECG was recorded and blood pressure was monitored. All patients had negative ETT results. Also no ST segment depression, no signs of insufficiency of peripheral circulation, no changes in heart rhythm, no symptoms by the central nervous system were observed. Additionally response of heart rate and blood pressure to exercise was within physiological range. These promising findings indicate that diabetes didn’t alter myocardial integrity and function, thus suggesting that coronary reserve in examined patients was preserved.

Value of myocardial work for assessment of myocardial adaptation to increased afterload in patients with high blood pressure at peak exercise

Non-invasive myocardial work (MW) indices are superior to global longitudinal strain (GLS) to assess left ventricular (LV) mechanics in situations where afterload is abnormally high. The rotational motion of the apex provides an accurate index of LV contractility. To date, there are no data about MW values during stress echocardiography (SE), particularly for the apex. Our study aims at assessing MW indices at peak exercise to better understand LV mechanics in patients with high peak systolic blood pressure (SBP). A total of 81 patients without structural or ischemic heart disease referred for SE between January and June 2019 were included. BP measurements, GLS and MW indices were performed at rest and peak exercise. In order to quantify the role of the apex, apical work fraction (AWF) was also calculated and further stratified by peak SBP. A peak SBP > 180 mmHg was considered abnormally high. There were 36 (44%) patients who had peak SBP > 180 mmHg. They showed similar resting GLS and MW values when compared to control. However, peak stress global work index, constructive work and wasted work (GWW) increased significantly (P-value < 0.05), with a relatively constant global work efficiency. In the multivariate analysis, peak SBP > 180 mmHg was associated with threefold increased odds of abnormal peak GWW > 96.5 mmHg% (median value) (odds ratio 3.0, P-value 0.003). Apical work increased significantly when stratified by peak SBP (P-value 0.003) and AWF increased from 33 ± 3% to 37 ± 3% (rest-stress), P-value < 0.0001, but remained constant when stratified by peak SBP. Our analysis provides new data on MW indices at peak stress, particularly for patients with abnormal peak SBP response, and supports the role and the contribution of the apex to MW.

Relationship of HIV Status and Fatigue, Cardiorespiratory Fitness, Myokines, and Physical Activity

People living with HIV (PLWH) experience high rates of fatigue, which can be improved with physical activity. We examined relationships between HIV infection, fatigue, cardiorespiratory fitness, physical activity, and myokines. Twenty PLWH and 20 HIV-uninfected adults completed a fatigue assessment, a maximal cardiometabolic exercise test, serum measures of myokines, and wore an accelerometer for 7 days. Measures were completed at baseline, 3 months, and 6 months. At baseline, PLWH had more fatigue (4.7 ± 2.6 vs. 2.8 ± 2.5, p = .01) and higher peak ventilatory efficiency (VE/VCO2; 33 ± 5.5 vs. 30.2 ± 2.5; p = .06). Half of PLWH engaged in at least one 10-minute bout of physical activity in the previous week, compared with control subjects (65%). Over time, HIV infection and fibroblast growth factor 21 were associated with fatigue (p < .05). People living with HIV have more fatigue and a higher ventilatory efficiency; expression of fibroblast growth factor 21 may underpin this relationship.

Exercise-induced hypertension can increase the prevalence of coronary artery plaque among middle-aged male marathon runners

Marathon runners demonstrate a high incidence of coronary artery plaque; however, studies on runners with exercise-induced hypertension (EIH) are sparse. We aimed to investigate the prevalence of coronary artery plaque among marathon runners with EIH.Veteran male marathon runners (≥40 and <60 years) underwent an exercise stress test. They were divided into 2 groups: normal blood pressure group (NBPG, n = 22), with resting systolic blood pressure (SBP)/diastolic blood pressure <140/90 mm Hg and maximal exercise SBP <210 mm Hg, and EIH group (EIHG, n = 28), with resting blood pressure <140/90 mm Hg and maximal exercise SBP ≥210 mm Hg. Coronary artery plaque and stenosis were compared using multi-detector computed tomography.The proportion of subjects with a coronary artery calcium (CAC) score ≥10 or ≥100 units, 1 or ≥2 plaques, or plaques in ≥2 blood vessels was higher in the EIHG than in the normal blood pressure group (NBPG) (P<.05). The absolute CAC score was higher in the EIHG (42.6 ± 67.8) than in the NBPG (2.8 ± 6.0; P < .05). The CAC score distribution was higher in the EIHG (5-300 units) than in the NBPG (P < .05). The prevalence of coronary plaques and maximal luminal artery stenosis was higher in the EIHG than in the NBPG (P < .05). The EIHG showed 12 cases of stenosis, whereas the NBPG showed only 1 case (P < .05).In marathon runners, EIH was associated with increased prevalence of coronary artery plaques and could be a new risk factor for coronary artery plaque formation. Therefore, preventive measures and EIH monitoring using an exercise stress test, alongside multi-detector computed tomography, are recommended.

Frequency and Influence of Exercise-Induced Artifact in Electrocardiograms During Exercise Treadmill Testing for Detection of Myocardial Ischemia

BACKGROUND

Exercise treadmill testing (ETT) is frequently utilized for noninvasive detection of myocardial ischemia and coronary artery disease. The frequency of electrocardiogram (ECG) artifacts (ECGA) during ETT and their influence on the identification of exercise-induced ischemia are not known.

METHODS

We reviewed all ETTs with ST segment depression in the University of California, Davis, Medical Center treadmill database during each of the years 2012 and 2016 to identify tests with exercise-induced ST segment depression in the inferior and inferolateral leads. We identified cases with ECGA during progressive phases of the test, and we assessed the influence of comorbidities and the impact of ECGA on the diagnosis of coronary artery disease. Tests were considered false or true positive based on the result of confirmatory tests.

RESULTS

Of 2,100 tests, we identified 123 patients with exercise-induced ST segment depression in inferior or inferolateral leads (men, 43%; mean age, 59 ± 10 years; white, 59%). Tests were symptom-limited: maximum heart rate, 153 ± 18; peak METs (metabolic equivalents of resting total oxygen consumption), 9.4 ± 2.7; ECGA occurred in 91% of tests at peak exercise with earlier occurrence among females. Tests were less likely to be true positive with peak ECGA than those without ECGA (13% vs. 50%, p = 0.05).

CONCLUSIONS

ECGA at peak exercise are frequent and related to peak heart rate and peak metabolic equivalents of resting total oxygen consumption, suggesting a motion effect. ECGA affected the diagnostic accuracy of ETT examinations, indicating that algorithms to reduce artifact for improved diagnosis of ETT require further investigation.

Adherence to American Heart Association and American College of Cardiology guidelines for exercise tolerance test in cardiovascular clinics

Introduction: Considering the increased expenditure in public health sector, especially the increased cost in hospitals and clinics, there is an urgent need to control these costs mainly by ensuring adherence to clinical guidelines for diagnostic procedures. In this study we aim to investigate the adherence of heart clinics to guideline for exercise tolerance test.

Methods: This cross-sectional study was performed on 308 patients who were referred for ECG exercise test in 3 clinics located in the city of Shiraz, Iran in 2018. Demographic and clinical data were recorded and the indications of exercise test for each patient was reviewed according to the ACC/AHA guideline for exercise tolerance test.

Results: Exercise tests were found to be inappropriately done in 121 (39.3%) participants. Among the patients for whom the test was done without indication 79 (65.3%) were women and the gender difference was statistically significant (P < 0.01); women were 18.5% more likely to undergo exercise test without indication. There was more inappropriate tests among nonanginal pain subsets comparing to other presenting symptoms (P < 0.001). Age, coronary risk factors, reason for performing exercise tests and private health system were not predictors of inappropriate use (P > 0.05).

Conclusion: This study confirms that more than one third of exercise tests done in the participants are inappropriate. Wide availability of exercise test makes it vulnerable to overuse and additional unnecessary cost to health care systems.

Aerobic Exercise Improves Microvascular Function in Older Adults

Microvascular function is reduced with age, disease, and inactivity. Exercise is well known to improve vascular health and has the potential to improve microvascular function in aging and disease.

PURPOSE

The study aimed to assess changes in peripheral microvascular function in sedentary older adults after aerobic exercise training.

METHODS

Twenty-three sedentary older adults (67 ± 5 yr, body mass index = 29 ± 5, mean ± SD) successfully completed a randomized 12-wk graded treadmill walking intervention. The exercise group (EX) performed 40 min of uphill walking 4 d·wk at 70% heart rate reserve. The control group (CON) maintained a sedentary lifestyle for 12 wk. Blood oxygen level-dependent (BOLD) responses of the soleus measured by magnetic resonance imaging were used to evaluate microvascular function; brief (1 s) maximal plantarflexion contractions were performed. Separately, blood flow in the popliteal artery was measured by ultrasound after brief contraction. Phosphorus magnetic resonance spectroscopy of the calf was used to examine muscle oxidative capacity, and whole-body peak oxygen consumption (V˙O2peak) was used to confirm training-induced cardiorespiratory adaptations.

RESULTS

Peak postcontraction BOLD response increased by 33% in EX (PRE, 3.3% ± 1.0%; POST, 4.4% ± 1.4%) compared with CON (PRE, 3.0% ± 1.3%; POST, 3.2% ± 1.5%), P < 0.05. EX with hypertension tended to show a blunted peak BOLD increase (n = 6, 15%) compared with EX normotensive (n = 7, 50%), P = 0.056. Peak postcontraction blood flow increased by 39% in EX (PRE, 217 ± 88 mL·min; POST, 302 ± 167 mL·min) compared with CON (PRE, 188 ± 54 mL·min; POST, 184 ± 44 mL·min), P < 0.05. EX muscle oxidative capacity (kPCr) improved by 40% (PRE, 1.60 ± 0.57 min; POST, 2.25 ± 0.80 min) compared with CON (PRE, 1.69 ± 0.28 min; POST, 1.76 ± 0.52 min), P < 0.05. V˙O2peak increased by 9% for EX (PRE, 19.0 ± 3.1 mL·kg·min; POST, 20.8 ± 2.9 mL·kg·min) compared with a 7% loss in CON (PRE, 21.9 ± 3.6 mL·kg·min; POST, 20.4 ± 3.5 mL·kg·min), P < 0.05.

CONCLUSION

Moderate aerobic exercise significantly improved microvascular function of the leg in older adults.

The Influence of Exercise on Cardiovascular Health in Sedentary Adults With Human Immunodeficiency Virus

BACKGROUND

Lifestyle physical activity (ie, moderate physical activity during routine daily activities most days of the week) may benefit human immunodeficiency virus (HIV)-positive adults who are at high risk for cardiovascular disease.

OBJECTIVE

The aims of this study were to describe lifestyle physical activity patterns in HIV-positive adults and to examine the influence of lifestyle physical activity on markers of cardiovascular health. Our secondary objective was to compare these relationships between HIV-positive adults and well-matched HIV-uninfected adults.

METHODS

A total of 109 HIV-positive adults and 20 control participants wore an ActiGraph accelerometer, completed a maximal graded cardiopulmonary exercise test, completed a coronary computed tomography, completed anthropomorphic measures, and had lipids and measures of insulin resistance measured from peripheral blood.

RESULTS

Participants (N = 129) had a mean age of 52 ± 7.3 years, 64% were male (n = 82), and 88% were African American (n = 112). On average, HIV-positive participants engaged in 33 minutes of moderate-to-vigorous physical activity per day (interquartile range, 17-55 minutes) compared with 48 minutes in controls (interquartile range, 30-62 minutes, P = .05). Human immunodeficiency virus-positive adults had poor fitness (peak oxygen uptake [VO2], 16.8 ± 5.2 mL/min per kg; and a ventilatory efficiency, 33.1 [4.6]). A marker of HIV disease (current CD4+ T cell) was associated with reduced peak VO2 (r = -0.20, P < .05) and increased insulin resistance (r = 0.25, P < .01) but not with physical activity or other markers of cardiovascular health (P ≥ 0.05). After controlling for age, gender, body mass index, and HIV status, physical activity was not significantly associated with peak VO2 or ventilatory efficiency.

CONCLUSION

Human immunodeficiency virus-positive adults have poor physical activity patterns and diminished cardiovascular health. Future longitudinal studies should examine whether HIV infection blunts the beneficial effects of physical activity on cardiovascular health.

Randomized Controlled Trial of the SystemCHANGE Intervention on Behaviors Related to Cardiovascular Risk in HIV+ Adults

OBJECTIVE

To examine the effect of a lifestyle behavior intervention (SystemCHANGE) on physical activity and diet quality among sedentary people living with HIV (PLHIV). All participants expressed a desire to improve lifestyle health behaviors.

METHODS

One hundred and seven HIV+ adults were randomized to either the intervention (6, in-person, standardized group sessions focusing on improving lifestyle behaviors) or a control condition (general advice on AHA diet and exercise guidelines). All participants wore an ActiGraph accelerometer and completed 24-hour dietary recalls at baseline, 3, and 6 months. Generalized estimating equations were used to examine intervention effects. The primary activity outcome was time spent in moderate-to-vigorous physical activity, and the primary dietary outcome was Healthy Eating Index.

RESULTS

Mean age was 53 years, 65% were male, and 86% African American. Approximately 90% attended at least half of the sessions and 60% attended 5 or more sessions. The intervention did not significantly improve our primary lifestyle behavior endpoints (P ≥ 0.05); however, intervention participants consumed fewer carbohydrates-primarily sugar-sweetened beverages-per day and lost 0.732 kg body weight compared with a 0.153 weight gain in the control group (P = 0.03).

CONCLUSIONS

Among sedentary PLHIV at high risk of cardiovascular disease, the SystemCHANGE intervention reduced daily carbohydrate intake and body weight, but did not increase physical activity or improve overall diet quality. Future work should identify fundamental personal, interpersonal, and contextual factors that will increase physical activity and improve overall diet quality among this population, and integrate these factors into tailored, lifestyle interventions for aging PLHIV.

Aerobic Interval vs. Continuous Training in Patients with Coronary Artery Disease or Heart Failure: An Updated Systematic Review and Meta-Analysis with a Focus on Secondary Outcomes

BACKGROUND

In a previous meta-analysis including nine trials comparing aerobic interval training with aerobic continuous training in patients with coronary artery disease, we found a significant difference in peak oxygen uptake favoring aerobic interval training.

OBJECTIVE

The objective of this study was to (1) update the original meta-analysis focussing on peak oxygen uptake and (2) evaluate the effect on secondary outcomes.

METHODS

We conducted a systematic review with a meta-analysis by searching PubMed and SPORTDiscus databases up to March 2017. We included randomized trials comparing aerobic interval training and aerobic continuous training in patients with coronary artery disease or chronic heart failure. The primary outcome was change in peak oxygen uptake. Secondary outcomes included cardiorespiratory parameters, cardiovascular risk factors, cardiac and vascular function, and quality of life.

RESULTS

Twenty-four papers were identified (n = 1080; mean age 60.7 ± 10.7 years). Aerobic interval training resulted in a higher increase in peak oxygen uptake compared with aerobic continuous training in all patients (1.40 mL/kg/min; p < 0.001), and in the subgroups of patients with coronary artery disease (1.25 mL/kg/min; p = 0.001) and patients with chronic heart failure with reduced ejection fraction (1.46 mL/kg/min; p = 0.03). Moreover, a larger increase of the first ventilatory threshold and peak heart rate was observed after aerobic interval training in all patients. Other cardiorespiratory parameters, cardiovascular risk factors, and quality of life were equally affected.

CONCLUSION

This meta-analysis adds further evidence to the clinically significant larger increase in peak oxygen uptake following aerobic interval training vs. aerobic continuous training in patients with coronary artery disease and chronic heart failure. More well-designed randomized controlled trials are needed to establish the safety of aerobic interval training and the sustainability of the training response over longer periods.

Association of carotid intima-media thickness with exercise tolerance test in type 2 diabetic patients

Aims

Atherosclerosis and ischemic heart disease are more common in diabetic patients. Atherosclerosis process can disturb the normal functioning of the vascular endothelium and increase vessel wall thickness. The aim of this study was the comparison of Carotid intima-media thickness (CIMT) with Exercise tolerance test as an alternative way to evaluate cardiac ischemia in diabetic patients.

Methods

In a cross-sectional study, 30 diabetic patients with positive exercise test and 30 diabetic patients with negative exercise test were enrolled. CIMT of the carotid artery in both groups of patients was measured.

Result

CIMT in the patients with positive and negative exercise test were 1.04 ± 0.21 mm and 0.61 ± 0.11 mm, respectively (P < 0.001). CIMT in positive exercise test group was positively associated with age and negatively associated with gender, FBS, HDL and LDL cholesterol and in negative exercise group was negatively associated with gender, age, FBS, HDL and LDL cholesterol.

Conclusion

Considering observed significant positive association between CIMT with result of exercise tolerance test (ETT) in type 2 diabetic patients, it may possible to use CIMT as an inexpensive and non-invasive method for evaluation of ischemic heart disease in diabetic patients.

Comparison of Preoperative Assessment of Patient's Metabolic Equivalents (METs) Estimated from History versus Measured by Exercise Cardiac Stress Testing

Background

Preoperative anesthetic evaluations of patients before surgery traditionally involves assessment of a patient's functional capacity to estimate perioperative risk of cardiovascular complications and need for further workup. This is typically done by inquiring about the patient's physical activity, with the goal of providing an estimate of the metabolic equivalents (METs) that the patient can perform without signs of myocardial ischemia or cardiac failure. We sought to compare estimates of patients' METs between preoperative assessment by medical history with quantified assessment of METs via the exercise cardiac stress test.

Methods

A single-center retrospective chart review from 12/1/2005 to 5/31/2015 was performed on 492 patients who had preoperative evaluations with a cardiac stress test ordered by a perioperative anesthesiologist. Of those, a total of 170 charts were identified as having a preoperative evaluation note and an exercise cardiac stress test. The METs of the patient estimated by history and the METs quantified by the exercise cardiac stress test were compared using a Bland-Altman plot and Cohen's kappa.

Results

Exercise cardiac stress test quantified METs were on average 3.3 METS higher than the METs estimated by the preoperative evaluation history. Only 9% of patients had lower METs quantified by the cardiac stress test than by history.

Conclusions

The METs of a patient estimated by preoperative history often underestimates the METs measured by exercise stress testing. This demonstrates that the preoperative assessments of patients' METs are often conservative which errs on the side of patient safety as it lowers the threshold for deciding to order further cardiac stress testing for screening for ischemia or cardiac failure.

Análise comparativa de fórmulas preditivas de avaliação da capacidade funcional com o teste cardiopulmonar de jogadoras de futebol profissional

RESUMO Comparar a validade de duas fórmulas de predição do consumo de oxigênio (VO2) com os valores obtidos no teste cardiopulmonar (TCP) em esteira ergométrica de jogadoras de futebol profissional. Dezoito jogadoras de futebol profissional foram submetidas ao TCP em esteira em um protocolo de carga incremental. Na sequência, foi determinado o VO2 da potência do limiar anaeróbio ventilatório (LAV) e no pico do exercício físico. Posteriormente, as fórmulas de predição de VO2 - i) VO2 = (0,2 x velocidade) + (0,9 x velocidade x inclinação) + 3,5 - velocidade em mph e inclinação %); e ii) MET (equivalente metabólica) = 6xHRI-5, onde HRI = frequência cardíaca máxima/frequência cardíaca de repouso - foram aplicadas nas mesmas potências para comparação. Para a primeira fórmula foi observado que tanto no LAV como no pico do TCP, os dados obtidos ficaram abaixo do previsto, sugerindo que a fórmula superestima o VO2 e, consequentemente, a capacidade e a potência aeróbicas. Na segunda fórmula foi observado que os valores ficaram abaixo do obtido, sugerindo que a fórmula subestimou o VO2 e, consequentemente a potência aeróbica, e mais uma vez a capacidade funcional. Diante disso, as fórmulas de predição não mostraram similaridade na determinação da capacidade funcional (CF) de jogadoras de futebol profissional, sugerindo não serem recomendadas para essa população.

Effects of Long-Distance Running on Cardiac Markers and Biomarkers in Exercise-Induced Hypertension Runners: An Observational Study

OBJECTIVE

To investigate changes of cardiac and muscle damage markers in exercise-induced hypertension (EIH) runners before running (pre-race), immediately after completing a 100-km ultramarathon race, and during the recovery period (24, 72, and 120 hours post-race).

METHODS

In this observational study, volunteers were divided into EIH group (n=11) whose maximum systolic blood pressure was ≥210 mmHg in graded exercise testing and normal exercise blood pressure response (NEBPR) group (n=11). Their blood samples were collected at pre-race, immediately after race, and at 24, 72, and 120 hours post-race.

RESULTS

Creatine kinase (CK) and cardiac troponin I (cTnI) levels were significantly higher in EIH group than those in the NEBPR group immediately after race and at 24 hours post-race (all p<0.05). However, lactate dehydrogenase (LDH), creatine kinase-myocardial band (CKMB), or CKMB/CK levels did not show any significant differences between the two groups in each period. N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were significantly higher in EIH group than those in NEBPR group immediately after race and at 24 and 72 hours postrace (all p<0.05). A high sensitivity C-reactive protein (hs-CRP) level was significantly higher in EIH group than that in NEBPR group at 24 hours post-race (p<0.05).

CONCLUSION

The phenomenon of higher inflammatory and cardiac marker levels in EIH group may exaggerate cardiac volume pressure and blood flow restrictions which in turn can result in cardiac muscle damage. Further prospective studies are needed to investigate the chronic effect of such phenomenon on the cardiovascular system in EIH runners.

Sex Differences in Traditional and Nontraditional Risk Factors for Obstructive Coronary Artery Disease in Stable Symptomatic Patients

BACKGROUND

There have been limited data on sex-specific risk factors for coronary artery disease (CAD) in patients with stable chest pain. This study was performed to investigate whether risk factors for CAD differ by sex in stable symptomatic patients.

METHODS

Data were obtained from a nation-wide registry, enrolling 1025 patients (age, 62.0 ± 11.0 years, 587 women) with chest pain who underwent elective invasive coronary angiography under the suspicion of CAD.

RESULTS

A total of 373 patients (36.4%) had obstructive CAD (≥50% stenosis) (men vs. women: 33.8% vs. 38.3%, p = 0.135). In men, univariate analyses showed that age, renal function, total cholesterol, low-density lipoprotein cholesterol, triglyceride, C-reactive protein (CRP), left ventricular (LV) systolic function, and septal annular velocity of LV (e') were significantly associated with the presence of obstructive CAD. Among these factors, a high CRP level (≥0.50 mg/dL) was an independent predictor of CAD in multivariable analysis (odds ratio [OR], 2.93; 95% confidence interval [CI], 1.26-6.82; p = 0.012). In women, univariate analyses showed that age, waist circumference, heart rate, hypertension, diabetes mellitus, low high-density lipoprotein cholesterol, LV systolic function, LV mass index, e' velocity, E/e', and left atrial size were significantly associated with the presence of obstructive CAD. Among these factors, lower e' velocity (<6.35 cm/s) was an independent predictor of CAD in multivariable analysis (OR, 2.38; 95% CI, 1.21-4.70; p = 0.012).

CONCLUSIONS

Among patients with stable chest pain, inflammation and LV diastolic dysfunction are independently associated with obstructive CAD in men and women, respectively.

Consistent tracer administration profile improves test-retest repeatability of myocardial blood flow quantification with 82Rb dynamic PET imaging

OBJECTIVES

Quantification of myocardial blood flow (MBF) and stress/rest flow reserve is used increasingly to diagnose multi-vessel coronary artery disease and micro-vascular disease with PET imaging. However, variability in the measurements may limit physician confidence to direct revascularization therapies based on specific threshold values. This study evaluated the effects of rubidium-82 (82Rb) tracer injection profile using a constant-activity-rate (CA) vs a constant-flow-rate (CF) infusion to improve test-retest repeatability of MBF measurements.

METHOD

22 participants underwent single-session 82Rb dynamic PET imaging during rest and dipyridamole stress using one of 2 test-retest infusion protocols: CA-CA (n = 12) or CA-CF (n = 10). MBF was quantified using a single-tissue-compartment model (1TCM) and a simplified retention model (SRM). Non-parametric test-retest repeatability coefficients (RPCnp) were compared between groups. Myocardium-to-blood contrast and signal-to-noise ratios of the late uptake images (2 to 6 minutes) were also compared to evaluate standard myocardial perfusion image (MPI) quality.

RESULTS

MBF values in the CA-CA group were more repeatable (smaller RPCnp) than the CA-CF group using the 1TCM at rest alone, rest and stress combined, and stress/rest reserve (21% vs 36%, 16% vs 19%, and 20% vs 27%, P < 0.05, respectively), and using the SRM at Rest and Stress alone, Rest and Stress combined, and stress/rest reserve (21% vs 38%, 15% vs 25%, 22% vs 38%, and 23% vs 49%, P < 0.05, respectively). In terms of image quality, myocardium-to-blood contrast and signal-to-noise ratios were not significantly different between groups.

CONCLUSIONS

Constant-activity-rate 'square-wave' infusion of 82Rb produces more repeatable tracer injection profiles and decreases the test-retest variability of MBF measurements, when compared to a constant-flow-rate 'bolus' administration of 82Rb, especially with SRM, and without compromising standard MPI quality.

High-intensity interval training or continuous training, combined or not with fasting, in obese or overweight women with cardiometabolic risk factors: study protocol for a randomised clinical trial

INTRODUCTION

Physical inactivity and increased caloric intake play important roles in the pathophysiology of obesity. Increasing physical activity and modifying eating behaviours are first-line interventions, frequently hampered by lack of time to exercise and difficulties in coping with different diets. High-intensity interval training (HIIT) may be a time-efficient method compared with moderate-intensity continuous training (CT). Conversely, diets with a fasting component may be more effective than other complex and restrictive diets, as it essentially limits caloric intake to a specified period without major diet composition changes. Therefore, the combination of HIIT and fasting may provide incremental benefits in terms of effectiveness and time efficiency in obese and sedentary populations. The aim of this study is to determine the effect of HIIT versus CT, combined or not with fasting, on microcirculatory function, cardiometabolic parameters, anthropometric indices, cardiorespiratory fitness and quality of life in a population of sedentary overweight or obese women with cardiometabolic risk factors.

METHODS AND ANALYSIS

Sedentary women aged 30-50 years, with a body mass index ≥25 kg/m2 and cardiometabolic risk factors, will be randomised to HIIT performed in the fasting state, HIIT performed in the fed state, CT in the fasting state or CT in the fed state. Cardiometabolic parameters, anthropometric indices, cardiorespiratory fitness, quality of life and microvascular function (cutaneous capillary density and microvascular reactivity evaluated by laser speckle contrast imaging) will be evaluated before initiation of the interventions and 16 weeks thereafter.

ETHICS AND DISSEMINATION

The trial complies with the Declaration of Helsinki and has been approved by the local ethics committee (Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil). All patients provide written informed consent before enrolment and randomisation. The study's results will be disseminated to the healthcare community by publications and presentations at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT03236285.

Prognostic Performance of Heart Rate Recovery on an Exercise Test in a Primary Prevention Population

BACKGROUND

Heart rate (HR) recovery has been investigated in specific patient cohorts, but there is less information about the role of HR recovery in general populations. We investigated whether HR recovery has long-term prognostic significance in primary prevention.

METHODS AND RESULTS

Exercise tests performed between 1993 and 2010 on patients aged 30 to 79 years without cardiovascular disease were included. Mortality was determined from Mayo Clinic records and Minnesota Death Index. Total, cardiovascular, and non-cardiovascular mortality was reported according to HR recovery <13 bpm using Cox regression. 19 551 patients were included, 6756 women (35%), age 51±10 years. There were 1271 deaths over follow-up of 12±5 years. HR recovery declined after age 60, and was also lower according to diabetes mellitus, hypertension, obesity, current smoking, and poor cardiorespiratory fitness but not sex or β-blockers. Adjusting for these factors, abnormal HR recovery was a significant predictor of total (hazard ratio [95% confidence interval]=1.56 [1.384-1.77]), cardiovascular (1.95 [1.57-2.42]), and non-cardiovascular death (1.41 [1.22-1.64]). Hazard ratios for cardiovascular death according to abnormal HR recovery were significant in all age groups (30-59, 60-69, 70-79), in both sexes, in patients with and without hypertension, obesity, and diabetes mellitus, but not in patients taking β-blockers, current smokers, and patients with normal cardiorespiratory fitness.

CONCLUSIONS

HR recovery is a powerful prognostic factor predicting total, cardiovascular, and non-cardiovascular death in a primary prevention cohort. It performs consistently well according to sex, age, obesity, hypertension, and diabetes mellitus but shows diminished utility in patients taking β-blockers, current smokers, and patients with normal cardiorespiratory fitness.