ACC/AHA 2002 guideline update for exercise testing: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1997 Exercise Testing Guidelines)

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

Comparative Analysis of Respiratory and Functional Outcomes in Children Post-Fontan Procedure Versus Healthy Peers

Studies have shown that respiratory muscle training enhances functional capacity and pulmonary function in Fontan patients. However, diaphragm muscle characteristics in Fontan children have not been fully elucidated. The aim of this study was to compare respiratory function, maximal and submaximal functional capacities, and quality of life, as well as to assess diaphragm mobility and thickness, between Fontan patients aged 8 to 12 years and healthy individuals. This cross-sectional study included 45 children-27 Fontan patients, Fontan Group (FG) and 18 healthy control Group (CG) subjects. Different examinations were performed: spirometry was used to analyze pulmonary volume and capacity; manovacuometry was used to determine respiratory muscle strength; chest ultrasound was used to determine diaphragm muscle characteristics; cardiopulmonary exercise and the six-minute walk test (6MWT) were used to determine functional capacity; the AUQEI questionnaire was used to determine quality of life. Descriptive analysis and intergroup comparisons were performed for all the data. Compared with the CG, the FG exhibited impaired pulmonary function and reduced functional capacity. Significant differences in median values were noted for forced expiratory volume in one second (FEV1): 2.39 L/min, p = 0.002; forced vital capacity (FVC): 1.73 vs. 3.06 L/min, p = 0.002; maximal inspiratory pressure: - 73 vs. - 117 cmH2O, p = 0.007; absolute peak VO2: 1.09 vs. 1.51 L/min, p < 0.001; relative peak VO2: 31.9 vs. 42.5 mL/kg/min, p = 0.003; and 6MWT distance: 420 vs. 586 m, p < 0.001. Diaphragmatic thickness, mobility and quality of life were similar between the groups. Despite the reduced functional capacity, impaired pulmonary volume and capacity, and respiratory muscle weakness of the FG compared to those of the CG, the diaphragm characteristics and quality of life were similar between the groups.

Diltiazem reduces levels of NT-proBNP and improves symptoms compared with metoprolol in patients with permanent atrial fibrillation

AIMS

Short-term treatment with calcium channel blockers lowers levels of N-terminal pro B-type natriuretic peptide (NT-proBNP) and reduces rhythm-related symptoms compared to treatment with beta-blockers. The aim of this study was to compare the effects of metoprolol and diltiazem for rate control in patients with permanent atrial fibrillation (AF) after 6 months.

METHODS AND RESULTS

Men and women with permanent AF and preserved left ventricular systolic function were randomized to receive either diltiazem 360 mg or metoprolol 100 mg once daily. The primary endpoint was the level of NT-proBNP after a 6-month treatment period. Secondary endpoints included heart rate, rhythm-related symptoms and exercise capacity. A total of 93 patients (mean age 71 ± 7 years, 28 women) were randomized. After 6-months' treatment, mean levels of NT-proBNP decreased in the diltiazem group and increased in the metoprolol group, with a significant between-group difference (409.8 pg/mL, 95% CI: 230.6-589.1, P < 0.001). Treatment with diltiazem significantly reduced rhythm-related symptoms compared to baseline, but no change was observed in the metoprolol group. Diltiazem and metoprolol had similar effects on heart rate and exercise capacity.

CONCLUSION

Diltiazem reduced NT-proBNP levels and improved rhythm-related symptoms. Metoprolol increased peptide levels but had no impact on symptoms despite similar heart rate reduction. Non-dihydropyridine calcium channel blockers should be considered more often for rate control in permanent AF.

Prognostic significance of preoperative exercise tolerance in patients with early-stage lung cancer

OBJECTIVE

To investigate the influence of simple preoperative exercise tests as prognostic factors for early-stage lung cancer.

METHODS

This single-institution retrospective study included consecutive patients who underwent pulmonary resection for stage 0 to I lung cancer between April 2017 and December 2019. Before surgery, 7 metabolic equivalents of task in the double Master 2-step test were loaded into the exercise echocardiogram. The relationship between prognosis and exercise stress test results in terms of availability, symptoms, and saturation of percutaneous oxygen was investigated.

RESULTS

This study included 862 patients with pathological stage 0 to I lung cancer. Among the 862 patients, 673 patients (78.1%) who were able to complete 7 metabolic equivalents of task exercise for 3 minutes without assistance were classified into the complete group. The 5-year survival of the complete group was significantly better than that of the incomplete group. Multivariable analysis revealed that age (hazard ratio, 1.06; P = .008), male sex (hazard ratio, 2.23; P = .011), carcinoembryonic antigen level >5 ng/mL (hazard ratio, 2.33; P = .011), and inability to complete 7 metabolic equivalents of task exercise (hazard ratio, 3.90; P < .001) were the prognostic factors. Patients in the older group who had the ability to complete exercise had a better prognosis than those in the younger group without the ability (P = .003).

CONCLUSIONS

Preoperative exercise ability is a prognostic factor for early-stage lung cancer. Patients who can tolerate an exercise load of 7 metabolic equivalents of task, even if they are aged 70 years or older, have a better prognosis than patients younger than age 70 years without exercise tolerance.

Efficacy of Diagnostic Testing of Suspected Coronary Artery Disease: A Contemporary Review

BACKGROUND

Coronary artery disease (CAD) is a highly prevalent condition which can lead to myocardial ischemia as well as acute coronary syndrome. Early diagnosis of CAD can improve patient outcomes through guiding risk factor modification and treatment modalities.

SUMMARY

Testing for CAD comes with increased cost and risk; therefore, physicians must determine which patients require testing, and what testing modality will offer the most useful data to diagnose patients with CAD. Patients should have an initial risk stratification for pretest probability of CAD based on symptoms and available clinical data. Patients with a pretest probability less than 5% should receive no further testing, while patients with a high pretest probability should be considered for direct invasive coronary angiography. In patients with a pretest probability between 5 and 15%, coronary artery calcium score and or exercise electrocardiogram can be obtained to further risk stratify patients to low-risk versus intermediate-high-risk. Intermediate-high-risk patients should be tested with coronary computed tomography angiography (preferred) versus positron emission tomography or single photon emission computed tomography based on their individual patient characteristics and institutional availability.

KEY MESSAGES

This comprehensive review aimed to describe the available CAD testing modalities, detail their risks and benefits, and propose when each should be considered in the evaluation of a patient with suspected CAD.

Screening Sportsmen and Sportswomen Over Age 35: The Relevance of an Exercise Electrocardiogram. Data From the SEEPRED Study

INTRODUCTION

The importance of exercise electrocardiogram (ECG) is still controversial in the prevention of cardiovascular events among sportsmen and sportswomen. The aim of this study was to assess the relevance of exercise ECG as a screening tool to prevent cardiovascular events when any cardiovascular disease (CVD) risk factors are present.

METHODS

The study included leisure time asymptomatic sportsmen and sportswomen over age 35 evaluated from 2011 to 2016 at the University Hospital of Saint-Etienne (France). Major adverse cardiovascular events (MACE) and atrial fibrillation were collected at 3 years.

RESULTS

Of the cohort of 2457 sportsmen and sportswomen (mean age 50.2 ± 9.4 years), 50 (2%) had a high-risk SCORE2. A total of 256 exercise ECGs (10%) were defined as positive, most of them due to silent myocardial ischemia (SMI) (n = 196; 8%). These 196 SMI cases led to 33 coronary angiograms (1%), which revealed 23 significant coronary stenoses requiring revascularization. In multivariate logistic regression analysis, having at least two CVD risk factors was independently associated with (1) positive exercise ECG (OR = 1.80 [95% CI: 1.29-2.52], p = 0.0006), with (2) suspected SMI (OR = 2.57 [95% CI: 1.10-6.02], p = 0.0304), with (3) confirmed SMI (OR = 8.20 [95% CI: 3.46-19.46], p < 0.0001) and with (4) cardiovascular events (MACE or atrial fibrillation) (OR = 6.95 [95% CI: 3.49-13.81], p < 0.0001) at 3 years (median).

CONCLUSIONS

The study supports the European recommendations for the use of exercise ECG in evaluation of asymptomatic leisure time sportsmen over age 35. Having at least two CVD risk factors was the best predictor for presence of coronary artery stenosis that may increase the risk for adverse events.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT06024863.

Predicting heart failure outcomes by integrating breath-by-breath measurements from cardiopulmonary exercise testing and clinical data through a deep learning survival neural network

Aims

Mathematical models previously developed to predict outcomes in patients with heart failure (HF) generally have limited performance and have yet to integrate complex data derived from cardiopulmonary exercise testing (CPET), including breath-by-breath data. We aimed to develop and validate a time-to-event prediction model using a deep learning framework using the DeepSurv algorithm to predict outcomes of HF.

Methods and results

Inception cohort of 2490 adult patients with high-risk cardiac conditions or HF underwent CPET with breath-by-breath measurements. Potential predictive features included known clinical indicators, standard summary statistics from CPETs, and mathematical features extracted from the breath-by-breath time series of 13 measurements. The primary outcome was a composite of death, heart transplant, or mechanical circulatory support treated as a time-to-event outcomes. Predictive features ranked as most important included many of the features engineered from the breath-by-breath data in addition to traditional clinical risk factors. The prediction model showed excellent performance in predicting the composite outcome with an area under the curve of 0.93 in the training and 0.87 in the validation data sets. Both the predicted vs. actual freedom from the composite outcome and the calibration of the prediction model were excellent. Model performance remained stable in multiple subgroups of patients.

Conclusion

Using a combined deep learning and survival algorithm, integrating breath-by-breath data from CPETs resulted in improved predictive accuracy for long-term (up to 10 years) outcomes in HF. DeepSurv opens the door for future prediction models that are both highly performing and can more fully use the large and complex quantity of data generated during the care of patients with HF.

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

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

Comparison of 10 × 1-minute high-intensity interval training (HIIT) versus 4 × 4-minute HIIT on glucose control and variability in females with type 2 diabetes

Two high-intensity interval training (HIIT) regimens are often used in research and clinical settings. Yet, there has been no direct comparison to determine if one can improve glucose control and variability to a greater extent in individuals living with type 2 diabetes (T2D). Fourteen older females with T2D participated in a semi-randomized control trial where HIIT10 (10 × 1-min intervals at 90% heart rate max; HRmax) and HIIT4 (4 × 4-min intervals at 90% of HRmax) were compared to a control condition (CON; no exercise). Continuous glucose monitoring was used to assess glucose control and variability over 24 h after each condition. Both HIIT10 (-2.1 ± 1.1 mmol/L) and HIIT4 (-2.1 ± 1.3 mmol/L) acutely lowered glucose compared to CON (-0.7 ± 0.8 mmol/L; p = 0.001), with no difference between exercise conditions. This glucose-lowering effect did not persist over the 24-h post-exercise period, as both mean glucose (p = 0.751) and glucose variability (p = 0.168) were not significantly different among conditions. However, exploratory analyses focusing on individuals with less optimal glucose control (above median 24-h mean glucose in the CON condition; n = 7) revealed that 24-h mean glucose (7.4 [7.14-8.92] vs. 8.4 [7.5-9.9] mmol/L; p = 0.048), glucose variability (p = 0.010), and peak glucose (p = 0.048) were lower following HIIT10 compared to CON, while HIIT4 reduced time spent in moderate hyperglycemia compared to CON (p = 0.023). Both HIIT10 and HIIT4 acutely lower glycemia, but the effect does not persist over 24 h. However, in individuals with worse glucose control, HIIT10 may improve mean 24-h glucose and glycemic variability, while HIIT4 may reduce time spent in moderate hyperglycemia.

Cardiovascular risk factors and development of nomograms in an Italian cohort of patients with suspected coronary artery disease undergoing SPECT or PET stress myocardial perfusion imaging

Introduction

Single-photon emission computed tomography (SPECT) and positron emission tomography (PET) are non-invasive nuclear medicine techniques that can identify areas of abnormal myocardial perfusion. We assessed the prevalence of cardiovascular risk factors in patients with suspected coronary artery disease (CAD) undergoing SPECT or PET stress myocardial perfusion imaging (MPI). Based on significant risk factors associated with an abnormal MPI, we developed a nomogram for each cohort as a pretest that would be helpful in decision-making for clinicians.

Methods

A total of 6,854 patients with suspected CAD who underwent stress myocardial perfusion imaging by SPECT or PET/CT was studied. As part of the baseline examination, clinical teams collected information on traditional cardiovascular risk factors: age, gender, body mass index, angina, dyspnea, diabetes, hypertension, hyperlipidemia, family history of CAD, and smoking.

Results

The prevalence of cardiovascular risk factors was different in the two cohorts of patients undergoing SPECT (n = 4,397) or PET (n = 2,457) myocardial perfusion imaging. A statistical significance was observed in both cohorts for age, gender, and diabetes. At multivariable analysis, only age and male gender were significant covariates in both cohorts. The risk of abnormal myocardial perfusion imaging related to age was greater in patients undergoing PET (odds ratio 4% vs. 1% per year). In contrast, male gender odds ratio was slightly higher for SPECT compared to PET (2.52 vs. 2.06). In the SPECT cohort, smoking increased the risk of abnormal perfusion of 24%. Among patients undergoing PET, diabetes and hypertension increased the risk of abnormal perfusion by 63% and 37%, respectively. For each cohort, we obtained a nomogram by significant risk factors at multivariable logistic regression. The area under the receiver operating characteristic curve associated with the nomogram was 0.67 for SPECT and 0.73 for the PET model.

Conclusions

Patients with suspected CAD belonging to two different cohorts undergoing SPECT or PET stress myocardial perfusion imaging can have different cardiovascular risk factors associated with a higher risk of an abnormal MPI study. As crude variables, age, gender, and diabetes were significant for both cohorts. Net of the effect of other covariates, age and gender were the only risk factors in common between the two cohorts. Furthermore, smoking and type of stress test were significant for the SPECT cohort, where as diabetes and hypertension were significant for the PET cohort. Nomograms obtained by significant risk factors for the two cohorts can be used by clinicians to evaluate the risk of an abnormal study.

Association between arterial stiffness and autonomic dysfunction in participants underwent treadmill exercise testing: a cross-sectional analysis

Data on the impact of arterial stiffness on autonomic function are limited. We sought to investigate whether heart rate recovery (HRR), a predictor of autonomic function, is impaired in patients with increased arterial stiffness. A total of 475 participants (mean age 55.8 ± 11.1 years, 34.3% women) who underwent a treadmill exercise test (TET) for the evaluation of chest pain were retrospectively analyzed. All patients underwent brachial-ankle pulse wave velocity (baPWV) measurement on the same day. HRR was defined as the difference in heart rate from maximal exercise to 1 min of recovery. Participants with the lowest HRR tertile were older and had more cardiovascular risk factors than those with the highest HRR tertile. Simple correlation analysis showed that baPWV was negatively correlated with HRR (r =  - 0.327, P < 0.001). In multiple linear regression analysis, there was a significant association between baPWV and HRR, even after adjusting for potential confounders (β =  - 0.181, P < 0.001). In participants who underwent TET, baPWV was negatively correlated with HRR. The results of our study indicate a potential relationship between arterial stiffness and the autonomic nervous system.

ChaMP-CMD: A Phenotype-Blinded, Randomized Controlled, Cross-Over Trial

BACKGROUND

Angina with nonobstructive coronary arteries is a common condition for which no effective treatment has been established. We hypothesized that the measurement of coronary flow reserve (CFR) allows identification of patients with angina with nonobstructive coronary arteries who would benefit from anti-ischemic therapy.

METHODS

Patients with angina with nonobstructive coronary arteries underwent blinded invasive CFR measurement and were randomly assigned to receive 4 weeks of amlodipine or ranolazine. After a 1-week washout, they crossed over to the other drug for 4 weeks; final assessment was after the cessation of study medication for another 4 weeks. The primary outcome was change in treadmill exercise time, and the secondary outcome was change in Seattle Angina Questionnaire summary score in response to anti-ischemic therapy. Analysis was on a per protocol basis according to the following classification: coronary microvascular disease (CMD group) if CFR<2.5 and reference group if CFR≥2.5. The study protocol was registered before the first patient was enrolled (International Standard Randomised Controlled Trial Number: ISRCTN94728379).

RESULTS

Eighty-seven patients (61±8 years of age; 62% women) underwent random assignment (57 CMD group and 30 reference group). Baseline exercise time and Seattle Angina Questionnaire summary scores were similar between groups. The CMD group had a greater increment (delta) in exercise time than the reference group in response to both amlodipine (difference in delta, 82 s [95% CI, 37-126 s]; P<0.001) and ranolazine (difference in delta, 68 s [95% CI, 21-115 s]; P=0.005). The CMD group reported a greater increment (delta) in Seattle Angina Questionnaire summary score than the reference group in response to ranolazine (difference in delta, 7 points [95% CI, 0-15]; P=0.048), but not to amlodipine (difference in delta, 2 points [95% CI, -5 to 8]; P=0.549).

CONCLUSIONS

Among phenotypically similar patients with angina with nonobstructive coronary arteries, only those with an impaired CFR derive benefit from anti-ischemic therapy. These findings support measurement of CFR to diagnose and guide management of this otherwise heterogeneous patient group.

Current status and perspectives of nuclear cardiology

Nuclear cardiology has long been used to identify myocardial ischemia for appropriate treatment strategies for stable coronary artery disease (CAD). After the Ischemia Trial, it is time to reevaluate the significance of ischemia assessment. Functional imaging continues to play pivotal role in detecting microcirculatory disturbances. PET provides a clear image of blood flow distribution and is useful for the quantitative evaluation of myocardial flow reserve (MFR), which plays an important role in predicting treatment strategies and improving prognosis in CAD. Heart failure has become a major area of focus in cardiovascular medicine. Radionuclide imaging has been widely applied in this field. FDG PET is useful in identifying cardiac sarcoidosis and active inflammation. Clinical values of I-123 MIBG and BMIPP SPECT have been reported worldwide from Japan. Additionally, clinical experiences of Tc-99m pyrophosphate imaging have recently gained attention for assessing cardiac amyloidosis. Cardiac PET/CT and PET/MR imaging permit combined assessment of metabolic/functional/structural analyses of various cardiac diseases. While other non-invasive imaging modalities have rapidly been developed, the roles of radionuclide imaging remain to be valuable for early and accurate diagnosis and patient management in most cases of chronic CAD and various cardiovascular diseases.

Symptom-limited exercise capacity is associated with long-term survival

The prognostic value of exercise capacity has been demonstrated in subjects with established cardiovascular diseases. We aim to evaluate the independence of exercise capacity measured by treadmill exercise test (TET) in predicting long-term outcomes among various comorbidities. This study was conducted from January 2003 to December 2012 in a tertiary medical center in Taiwan. Subjects referred for symptom-limited TET were recruited. Peak achieved metabolic equivalents (METs) were determined by treadmill grade and speed at peak exercise. The main outcomes were cardiovascular and all-cause mortality by linking to the National Death Registry. A total of 18,954 participants (57.8 ± 12.8 years, 62% men) achieved a mean peak METs of 9.2. Subjects in the lowest tertile of peak METs were older, had poorer renal function, lower hemoglobin, and more comorbidities. During a median follow-up of 4.3 years, there were 642 mortalities and 132 cardiovascular deaths. Peak METs significantly predicted cardiovascular death and all-cause mortality in the multivariable Cox regression models [hazard ratio (95% confidence intervals): 0.788 (0.660-0.940) and 0.835 (0.772-0.903), respectively]. The prognostic influence of peak METs consistently appeared in the subgroups, regardless of age, gender, body weight, comorbidities, use of beta-blockers, or the presence of exercise-induced ischemia. The fitness was more predictive of long-term outcomes in young or those with ischemic changes during TET (P for interaction: 0.035 and 0.018, respectively). The benefit of fitness was nonlinearly associated with long-term survival. The prognostic impacts of exercise capacity were universally observed in subjects with or without various comorbidities.

Review and Key Takeaways of the 2021 Percutaneous Coronary Intervention Guidelines

The 2021 Percutaneous Coronary Intervention guidelines completed by American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions provide a set of guidelines regarding revascularization strategies. With emphasis on equity of care, multidisciplinary heart team use, revascularization for acute coronary syndrome, and stable ischemic heart disease, the guidelines create a thorough framework with recommendations regarding therapeutic strategies. In this comprehensive review, our aim is to summarize the 2021 revascularization guidelines and analyze key points regarding each recommendation.

Management of Residual Risk in Chronic Coronary Syndromes. Clinical Pathways for a Quality-Based Secondary Prevention

Chronic coronary syndrome (CCS), which encompasses a broad spectrum of clinical presentations of coronary artery disease (CAD), is the leading cause of morbidity and mortality worldwide. Recent guidelines for the management of CCS emphasize the dynamic nature of the CAD process, replacing the term "stable" with "chronic", as this disease is never truly "stable". Despite significant advances in the treatment of CAD, patients with CCS remain at an elevated risk of major cardiovascular events (MACE) due to the so-called residual cardiovascular risk. Several pathogenetic pathways (thrombotic, inflammatory, metabolic, and procedural) may distinctly contribute to the residual risk in individual patients and represent a potential target for newer preventive treatments. Identifying the level and type of residual cardiovascular risk is essential for selecting the most appropriate diagnostic tests and follow-up procedures. In addition, new management strategies and healthcare models could further support available treatments and lead to important prognostic benefits. This review aims to provide an overview of the diagnostic and therapeutic challenges in the management of patients with CCS and to promote more effective multidisciplinary care.

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

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

Ten-year predictors of major adverse cardiovascular events in patients without angina

BACKGROUND

Longstanding cardiovascular risk factors cause major adverse cardiovascular events (MACE). Major adverse cardiovascular events prediction may improve outcomes. The aim was to evaluate the ten-year predictors of MACE in patients without angina.

METHODS

Patients referred to Inkosi Albert Luthuli Hospital, Durban, South Africa, without typical angina from 2002 to 2008 were collected and followed up for MACE from 2009 to 2019. Survival time was calculated in months. Independent variables were tested with Cox proportional hazard models to predict MACE morbidity and MACE mortality.

RESULTS

There were 525 patients; 401 (76.0%) were Indian, 167 (31.8%) had diabetes at baseline. At 10-year follow up 157/525 (29.9%) experienced MACE morbidity, of whom, 82/525 (15.6%) had MACE mortality. There were 368/525 (70.1%) patients censored, of whom 195/525 (37.1%) were lost to follow up. For MACE morbidity, mean and longest observation times were 102.2 and 201 months, respectively. Predictors for MACE morbidity were age (hazard ratio [HR] = 1.025), diabetes (HR = 1.436), Duke Risk category (HR = 1.562) and Ischaemic burden category (HR = 1.531). For MACE mortality, mean and longest observation times were 107.9 and 204 months, respectively. Predictors for MACE mortality were age (HR = 1.044), Duke Risk category (HR = 1.983), echocardiography risk category (HR = 2.537) and Ischaemic burden category (HR = 1.780).

CONCLUSION

Among patients without typical angina, early ischaemia on noninvasive tests indicated microvascular disease and hyperglycaemia, predicting long-term MACE morbidity and MACE mortality.Contribution: Diabetes was a predictor for MACE morbidity but not for MACE mortality; patients lost to follow-up were possibly diabetic patients with MACE mortality at district hospitals. Early screening for ischaemia and hyperglycaemia control may improve outcomes.

Clinical tools to assess functional capacity before elective non-cardiac surgery: a scoping review protocol

OBJECTIVE

The objective of this scoping review is to map the evidence on clinical tools to assess functional capacity prior to elective non-cardiac surgery.

INTRODUCTION

Functional capacity is a strong prognostic indicator before surgery, which can be used to identify patients at elevated risk of postoperative complications, yet, there is no consensus on which clinical tools should be used to assess functional capacity in patients prior to non-cardiac surgery.

INCLUSION CRITERIA

This review will consider any randomized or non-randomized studies that evaluate the performance of a functional capacity assessment tool in adults (≥18 years) prior to non-cardiac surgery. For studies to be included, the tool must be used clinically for risk stratification. We will exclude studies on lung and liver transplant surgery, as well as ambulatory procedures performed under local anesthesia.

METHODS

The review will be conducted in line with the JBI methodology for scoping reviews. A peer-reviewed search strategy will be used to query relevant databases (ie, MEDLINE, Embase, EBM Reviews). Additional sources of evidence will include databases of non-peer-reviewed literature and the reference lists of included studies. Two independent reviewers will identify eligible studies in 2 stages: stage 1, based on titles and abstracts; and stage 2, based on full texts. Information on study details, measurement properties, pragmatic qualities, and/or clinical utility metrics will be charted in duplicate onto standardized data collection forms. The results will be presented using descriptive summaries, frequency tables, and visual plots that highlight the extent of evidence and remaining gaps in the validation process of each tool.

REVIEW REGISTRATION

Open Science Framework https://osf.io/6nfht.

Evaluation of a new treadmill exercise protocol to unmask type 1 Brugada electrocardiographic pattern: can we improve diagnostic yield?

AIMS

High precordial leads (HPL) on the resting electrocardiogram (ECG) are widely used to improve diagnostic detection of type 1 Brugada ECG pattern (Br1ECGp). A parasympathetic activation marks the initial recovery phase of treadmill stress testing (TET), and this can be useful for detecting the typical ECG pattern. Our study aimed to evaluate the role of a new HPL-treadmill exercise testing (TET) protocol in detecting Br1ECGp fluctuation compared to resting HPL-ECG.

METHODS AND RESULTS

74 out of 163 patients of a Brugada syndrome (BrS) Brazilian cohort (GenBra Registry) underwent exercise testing with HPL-TET protocol. Precordial leads were displayed in strategic positions in the right and left parasternal spaces. The step-by-step analysis included ECG classification (as presence or absence of Br1ECGp) in standard vs. HPL leads placement in the following sequences: resting phase, maximal exercise, and the passive recovery phase (including 'quick lay down'). For heart rate recovery (HRR) measurements and comparisons, a Student's t-test was applied. McNemar tests compared the detection of Br1ECGp. The significance level was defined as P < 0.05. Fifty-seven patients (57/74; 77%) were male, the mean age was 49.0 ± 14, 78.4% had spontaneous BrS, and the mean Shanghai score was 4.5. The HPL-TET protocol increased Br1ECGp detection by 32.4% against resting HPL-ECG (52.7% vs. 20.3%, P = 0.001) alone.

CONCLUSION

Stress testing using HPL with the passive recovery phase in the supine position offers an opportunity to unmask the type 1 Br1ECGp, which could increase the diagnostic yield in this population.

Deployed Veterans exhibit distinct respiratory patterns and greater dyspnea during maximal cardiopulmonary exercise: A case-control study

BACKGROUND

Exertional dyspnea and exercise intolerance are frequently endorsed in Veterans of post 9/11 conflicts in Southwest Asia (SWA). Studying the dynamic behavior of ventilation during exercise may provide mechanistic insight into these symptoms. Using maximal cardiopulmonary exercise testing (CPET) to experimentally induce exertional symptoms, we aimed to identify potential physiological differences between deployed Veterans and non-deployed controls.

MATERIALS AND METHODS

Deployed (n = 31) and non-deployed (n = 17) participants performed a maximal effort CPET via the Bruce treadmill protocol. Indirect calorimetry and perceptual rating scales were used to measure rate of oxygen consumption ([Formula: see text]), rate of carbon dioxide production ([Formula: see text]), respiratory frequency (f R), tidal volume (VT), minute ventilation ([Formula: see text]), heart rate (HR), perceived exertion (RPE; 6-20 scale), and dyspnea (Borg Breathlessness Scale; 0-10 scale). A repeated measures analysis of variance (RM-ANOVA) model (2 groups: deployed vs non-deployed X 6 timepoints: 0%, 20%, 40%, 60%, 80%, and 100% [Formula: see text]) was conducted for participants meeting valid effort criteria (deployed = 25; non-deployed = 11).

RESULTS

Significant group (η2partial = 0.26) and interaction (η2partial = 0.10) effects were observed such that deployed Veterans exhibited reduced f R and a greater change over time relative to non-deployed controls. There was also a significant group effect for dyspnea ratings (η2partial = 0.18) showing higher values in deployed participants. Exploratory correlational analyses revealed significant associations between dyspnea ratings and fR at 80% (R2 = 0.34) and 100% (R2 = 0.17) of [Formula: see text], but only in deployed Veterans.

CONCLUSION

Relative to non-deployed controls, Veterans deployed to SWA exhibited reduced fR and greater dyspnea during maximal exercise. Further, associations between these parameters occurred only in deployed Veterans. These findings support an association between SWA deployment and affected respiratory health, and also highlight the utility of CPET in the clinical evaluation of deployment-related dyspnea in Veterans.

Evaluation of the relationship between left atrial strain and exercise tolerance in patients with hypertrophic cardiomyopathy by treadmill stress echocardiography

Objective

The aim of this study is to evaluate the left atrial strain (LAS) in patients with hypertrophic cardiomyopathy (HCM) by treadmill exercise stress echocardiography, combined with three-dimensional speckle tracking technology, for predicting exercise tolerance.

Methods

A total of 97 patients with HCM who underwent treadmill exercise stress echocardiography were recruited in Sichuan Provincial People's Hospital between January 2018 and January 2021, and 30 control subjects were selected to be included in the normal group. HCM patients with their metabolic equivalents (METS) ≤ 6.0 were included in the HCM-1 group, while those with METS > 6.0 were included in the HCM-2 group. The LAS and exercise tolerance were analyzed. The ultrasound parameters that could predict a decrease in exercise tolerance were screened, and a predictive model was constructed.

Results

It was found that METS, Rest-LASr, Rest-LAScd, and Rest-LASct were significantly lower in HCM patients than those in normal controls. There was a significant difference in age, Target_HR, LVMI, LAVI, E/e'-Rest, E/e'-Peak, Rest-LASr, Rest-LAScd, and Rest-LASct between the HCM-1 and the HCM-2 groups. LASr is an independent resting echocardiographic predictor of METS ≤ 6.0. LASr remained significant for predicting different subtypes (AHCM, asymmetric HCM, and obstructive HCM). Rest-LASr (AUC 0.990) was better at predicting METS ≤ 6.0 than Peak-E/e' (AUC 0.753). A multivariate model (LASr + Age + Target_HR) was established for METS prediction.

Conclusion

Left atrial reservoir strain (LASr) has the strongest association with METS ≤ 6.0. The LASr is an independent resting predictor of METS ≤ 6.0 and has a good performance record in predicting different subtypes of HCM. Compared with the traditional parameters, Peak-E/e' and Rest-E/e', Rest-LASr is the best predictor. Rest-LASr can serve as a reliable method for HCM patients who are unable to undergo exercise testing but require an urgent evaluation of their METS, which provides a basis for clinical treatment decision-making and treatment effect evaluation.

The Role of MR Assessments of Cardiac Morphology, Function, and Tissue Characteristics on Exercise Capacity in Well-Functioning Older Adults

BACKGROUND

The relationship between resting cardiac indices and exercise capacity in older adults was still not well understood. New developments in cardiac magnetic resonance imaging (MRI) enable a much fuller assessment of cardiac characteristics.

PURPOSE/HYPOTHESIS

To assess the association between exercise capacity and specific aspects of resting cardiac structure, function, and tissue.

STUDY TYPE

Cross-sectional study.

POPULATION

A total of 112 well-functioning older adults (mean age 69 years, 52 men).

FIELD STRENGTH/SEQUENCE

All participants underwent 3.0 T MRI, using scan protocols including balanced steady-state free precession cine sequence, modified look-locker inversion recovery, and T2-prepared single-shot balanced steady-state free precession.

ASSESSMENT

Demographic and geriatric characteristics were collected. Blood samples were assayed for lipid and glucose related biomarkers. All participants performed a symptom-limited cardiopulmonary exercise test to achieve peakVO₂ . Cardiac MRI parameters were measured with semi-automatic software by S.Y., an 18-year experienced radiologist.

STATISTICAL TESTS

Demographic, geriatric characteristics and MR measurements were compared among quartiles of peakVO2, with different methods according to the data type. Spearman's partial correlation and least absolute shrinkage selection operator regression were performed to select significant MR features associated with peakVO₂ . Mediation effect analysis was conducted to test any indirect connection between age and peakVO₂ . A two-sided P value of <0.05 was defined statistical significance.

RESULTS

Epicardial fat volume, left atrial volume indexed to height, right ventricular end-systolic volume indexed to body surface area and global circumferential strain (GCS) were correlated with peakVO₂ (regression coefficients were -0.040, -0.093, 0.127, and 0.408, respectively). Mediation analysis showed that the total effect of peakVO₂ change was 43.6% from the change of age. The proportion of indirect effect from epicardial fat volume and GCS were 11.8% and 15.1% in total effect, respectively.

DATA CONCLUSION

PeakVO₂ was associated with epicardial fat volume, left atrial volume, right ventricular volume and GCS of left ventricle.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 5.

Functional testing, coronary artery calcifications, and outcomes in Hodgkin lymphoma survivors treated with chest radiation

BACKGROUND

Consensus guidelines recommend periodic screening for coronary artery disease (CAD) in Hodgkin lymphoma (HL) survivors treated with radiation therapy (RT) to the chest. However, the prognostic utility of screening strategies in this population remains unclear. We evaluated the association between functional testing, coronary artery calcifications (CAC), and guideline-based risk assessment and major adverse cardiovascular events (MACE) in HL survivors treated with RT.

METHODS

We retrospectively studied HL survivors treated with RT who underwent functional testing between 2003 and 2020 and chest computed tomography (CT) within 12 months of each other at our center. CAC was assessed semi-quantitatively from CT images. Cardiovascular risk was estimated using the 2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease. Diagnostic test characteristics were calculated using major adverse cardiac events (MACE) during follow-up as the gold standard.

RESULTS

The study included 159 patients (median age at functional testing 48 years, median age at HL diagnosis 27 years, 62.9% female). Abnormal functional testing had the highest specificity (94.2% (95% CI 88.4%-97.6%)) and positive likelihood ratio (4.55 (95% CI 1.86-11.13)) while CAC had the highest sensitivity (63.2% (95% CI 46.0%-78.2%)) and lowest negative likelihood ratio (0.52 (95% CI 0.34-0.80)). Specificity for ACC/AHA risk assessment was also high (88.5% (95% CI 81.1%-93.7%)). Over 3.3 years of follow-up, abnormal functional testing (adjusted subdistribution hazard ratio (SHR) 5.10, 95% CI 2.41 - 10.78, p < 0.001) and CAC (adjusted SHR 3.58, 95% CI 1.35 - 9.47, p = 0.010) were both significantly associated with MACE.

CONCLUSIONS

In HL survivors treated with RT, both abnormal functional testing and ACC/AHA risk assessment had high specificity for subsequent MACE, but CAC had higher sensitivity. Further research is needed to inform CAD screening and primary prevention strategies in this population.

Aspects of myocardial heterogeneity in assessment its remodeling

The influence of sports activity on the cardiovascular system is accompanied by physiological adaptation of the organism. Intense physical activity, far exceeding the body’s capabilities, can lead to structural changes or remodeling of the athlete’s myocardium. The review is devoted to the study of myocardial heterogeneity and is aimed at attracting attention of physicians, physiologists, biologists, researchers and developers of ECG computer analysis programs to prognostically significant indicators. Based on the mechanisms of electrical heterogeneity of the ventricular myocardium, the review considers the results of clinical studies by Russian and foreign specialists. The high predictive capabilities of indicators for the detection of fatal and non-fatal cardiovascular events and sudden cardiac death are discussed. It was found that the speed indicators of the electrical activity of the heart are the earliest marker of cardiac arrhythmias and conduction disorders. Risk factors - arterial hypertension, smoking, hypercholesterolemia and overweight - are associated with a decrease in the rate of electrical activity of the heart and an increase in myocardial heterogeneity. The data presented allow us to conclude that myocardial electrical heterogeneity is a prognostically significant indicator for the detection of fatal and non-fatal cardiovascular events; it is widely discussed in foreign literature, but is not used by domestic specialists.

Exercise oxygen desaturation is a predictor of cardiopulmonary complications after lung resection

BACKGROUND

To investigate whether oxygen desaturation during low technology tests was associated with complications after lung resection.

METHODS

A retrospective cohort study was conducted on 1097 candidates for pulmonary resection; seven metabolic equivalents in the Master's double two-step test were loaded. The predicted postoperative (PPO) forced expiratory volume in 1 s and PPO diffusing capacity of the lung for carbon monoxide were estimated. The patients were divided into three groups: those with both values ≥60% (≥60% group (n=298)), either value <30% (<30% group (n=112)) and others (30%-60% group (n=687)). The relationships between postoperative cardiopulmonary complications and exercise stress test based on availability, symptoms and percutaneous oxygen saturation values were investigated in each group.

RESULTS

Τhe cardiopulmonary morbidity rates in the ≥60%, 30%-60%, and <30% groups were 7.7%, 14.6%, and 47.3%, respectively. Multivariate analyses revealed that predictors of complications were age (OR 0.96; p<0.001), male sex (OR 1.74; p=0.016) and exercise oxygen desaturation (EOD) >4% (OR 2.39; p=0.001) in the 30%-60% group, and male sex (OR 3.76; p=0.042) and EOD >4% (OR 2.28; p=0.030) in the <30% group.The two-flight test (TFT) was performed in 181 patients (22.8%); desaturation >4% in the TFT was also a predictor of complications.

CONCLUSIONS

A low technology test is also valuable for high-risk patients. EOD >4% is a predictor of postoperative complications.

CLINICAL REGISTRATION

This study is a non-interventional observational study and has not been registered in a public database. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology reporting guidelines.This study was approved by the Ethics Committee of the Juntendo University School of Medicine (no. 2016085).

Clinical significance and prognostic value of ST segment depression on ECG during exercise treadmill test in asymptomatic patients with moderate or severe aortic stenosis

Objectives. In patients with asymptomatic moderate or severe aortic stenosis (AS), exercise testing is used for evaluating the need for aortic valve intervention. Expert opinions about the clinical significance and prognostic value of ST segment depression on electrocardiography (ECG) during exercise testing in AS is conflicting and there are no large studies exploring this issue. We aimed to explore the association of ST segment depression >5 mm during exercise treadmill test (ETT) with all-cause mortality, aortic valve replacement (AVR) or cardiac-related hospitalization. Design. We performed a retrospective analysis of prospectively collected data of a total of 315 patients (mean age 65 ± 12 years, 67% men) with asymptomatic moderate (n = 209; 66%) or severe (n = 106; 34%) AS. All patients underwent clinical evaluation, echocardiography and ETT. Results. During a mean follow-up of 34.9 ± 34.6 months, 29 (9%) patients died and 235 (74%) underwent AVR. The prevalence of ST segment depression (>5 mm) was 13% (n = 41) in the total study population and was comparable in patients with revealed symptoms (17.6%, n = 16) versus without revealed symptoms (11.3%, n = 25; p = .132). ST segment depression on ETT was strongly associated with aortic valve area. In univariate Cox regression analysis, ST segment depression was not associated with cardiac related hospitalizations (HR 1.65; 95% CI 0.89-3.10, p = .113), all-cause mortality (HR 1.37; 95% CI 0.47-3.98, p = .564) or AVR (HR 1.30; 95% CI 0.89-1.91, p = .170). Conclusion. In patients with moderate or severe AS, ST segment depression during ETT is non-specific, carries no prognostic risk and should be used with caution in the clinical interpretation of exercise test.

Exercise Stress Test Late after Arrhythmic versus Nonarrhythmic Presentation of Myocarditis

Background. Exercise stress test (EST) has been scarcely investigated in patients with arrhythmic myocarditis. Objectives. To report the results of EST late after myocarditis with arrhythmic vs. nonarrhythmic presentation. Methods. We enrolled consecutive adult patients with EST performed at least six months after acute myocarditis was diagnosed using gold-standard techniques. Patients with ventricular arrhythmia (VA) at presentation were compared with the nonarrhythmic group. Adverse events occurring during follow-up after EST included cardiac death, disease-related rehospitalization, malignant VA, and proven active myocarditis. Results. The study cohort was composed of 128 patients (age 41 ± 9 y, 70% males) undergoing EST after myocarditis. Of them, 64 (50%) had arrhythmic presentation. EST was performed after 15 ± 4 months from initial diagnosis, and was conducted on betablockers in 75 cases (59%). During EST, VA were more common in the arrhythmic group (43 vs. 4, p < 0.001), whereas signs and symptoms of ischemia were more prevalent in the nonarrhythmic one (6 vs. 1, p = 0.115). By 58-month mean follow-up, 52 patients (41%) experienced adverse events, with a greater prevalence among arrhythmic patients (39 vs. 13, p < 0.001). As documented both in the arrhythmic and nonarrhythmic subgroups, patients had greater prevalence of adverse events following a positive EST (40/54 vs. 12/74 with negative EST, p < 0.001). Electrocardiographic features of VA during EST correlated with the subsequent inflammatory restaging of myocarditis. Nonarrhythmic patients with uneventful EST both on- and off-treatment were free from subsequent adverse events. Conclusions. Late after the arrhythmic presentation of myocarditis, EST was frequently associated with recurrent VA. In both arrhythmic and nonarrhythmic myocarditis, EST abnormalities correlated with subsequent adverse outcomes.

Modified Haller index is inversely correlated with true positive exercise stress echocardiographic results

AIMS

The influence of chest wall shape on exercise stress echocardiography (ESE) results has been poorly investigated. We aimed at evaluating the main predictors of true positive (TP)-ESE in a population of subjects with suspected coronary artery disease (CAD), categorized according to chest wall conformation, assessed by modified Haller index (MHI, chest transverse diameter over the distance between sternum and spine).

METHODS

All consecutive patients with suspected CAD referred to our EchoLab for performing ESE between September 2011 and October 2021 were retrospectively enrolled. Preliminary assessment of both pretest probability (PTP) and MHI was performed. All patients with positive ESE underwent coronary angiography. Obstructive CAD was diagnosed by ≥70% stenosis in any epicardial coronary artery. Outcome was TP ESE result.

RESULTS

One thousand two hundred and seventy-five consecutive patients (64.9 ± 13.0 years) entered the study. Subjects with concave-shaped chest wall (MHI > 2.5) (10.7%) and those with normal chest shape (MHI ≤ 2.5) (89.3%) were separately analyzed. PTP was similar in both groups (21.8 ± 13.2 vs. 23.5 ± 13.3%, P  = 0.15). One hundred and seventy patients were diagnosed with positive ESE: 129 (75.9%) had obstructive CAD (TP), whereas the remaining 41 (24.1%) had no CAD. Only 2.3% of TP ESE was detected in subjects with MHI >2.5. PTP [odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.04], dyslipidemia (OR 4.37, 95% CI 2.81-6.80), dyssynergy in the left anterior descending territory (OR 8.21, 95% CI 5.07-13.3) were linearly correlated with TP ESE, whereas MHI >2.5 (OR 0.25, 95% CI 0.14-0.67) was inversely associated with outcome.

CONCLUSIONS

Subjects with MHI >2.5 have low prevalence of TP ESE, regardless of PTP. Preliminary MHI assessment may reduce overestimation of PTP of CAD.

Evaluation of Exercise Tolerance in Non-obstructive Hypertrophic Cardiomyopathy With Myocardial Work and Peak Strain Dispersion by Speckle-Tracking Echocardiography

Background

The aim of this study was to evaluate exercise tolerance in non-obstructive hypertrophic cardiomyopathy (HCM) by investigating the value of myocardial work (MW) combined with strain peak dispersion.

Methods

A total of 65 patients with non-obstructive HCM and normal left ventricular ejection fraction were enrolled and 60 healthy subjects were selected as controls. The automated function imaging (AFI)-two-dimensional ultrasonic speckle-tracking technology was used to obtain the values for peak global longitudinal strain (GLS), longitudinal strain peak time dispersion (PSD), 18-segment systolic longitudinal peak strain (LPS), 18-segment longitudinal strain peak time (TTPLS), global waste work (GWW), global constructive work (GCW), global work index (GWI), global work efficiency (GWE), and exercise metabolic equivalents (METS).

Results

(1) Values for LV-GLS (−17.77 ± 0.20 vs. −21.66 ± 0.42%) were lower and PSD (95.10 ± 8.15 vs. 28.97 ± 1.50 ms) was prolonged in patients with HCM (p &lt; 0.01). (2) An increasing trend was shown in the basal segment &lt; intermediate segment &lt; apical segment for both patients with HCM and controls, although each segment had lower values in the HCM group. (3) TTPLS was prolonged in the HCM group (p &lt; 0.01). (4) GWE, GWI, and GCW were all lower (p &lt; 0.01) and GWW was higher in patients with HCM (p &lt; 0.01). (5) Values of GWE were less than 92.5%, GWI less than 1,200 mmHg, GCW less than 1,399 mmHg, these abnormal values are helpful for the diagnosis of impaired exercise tolerance and poor prognosis (6) The METS and LV-GLS of HCM in the asymmetric group were significantly lower than that in AHCM group, but the PSD was significantly greater than that in the AHCM group. Values of LPS-BL (−13.13% ± 2.51% vs −10.17% ± 2.20%) in the apical HCM group were better than in the asymmetric HCM group (p &lt; 0.05).

Conclusion

GCW, GWI, and GWE can be safely measured by resting echocardiography to evaluate exercise tolerance in patients with HCM who cannot perform an exercise-based examination. Such measurements provide a basis for clinical decisions regarding exercise and drug prescription.

Comparison Between Treadmill and Bicycle Ergometer Exercises in Terms of Safety of Cardiopulmonary Exercise Testing in Patients With Coronary Heart Disease

Background

Cardiopulmonary exercise testing (CPET) is used widely in the diagnosis, exercise therapy, and prognosis evaluation of patients with coronary heart disease (CHD). The current guideline for CPET does not provide any specific recommendations for cardiovascular (CV) safety on exercise stimulation mode, including bicycle ergometer, treadmill, and total body workout equipment.

Objective

The aim of this study was to explore the effects of different exercise stimulation modes on the occurrence of safety events during CPET in patients with CHD.

Methods

A total of 10,538 CPETs, including 5,674 performed using treadmill exercise and 4,864 performed using bicycle ergometer exercise at Peking University Third Hospital, were analyzed retrospectively. The incidences of CV events and serious adverse events during CPET were compared between the two exercise groups.

Results

Cardiovascular events in enrolled patients occurred during 355 CPETs (3.4%), including 2 cases of adverse events (0.019%), both in the treadmill group. The incidences of overall events [235 (4.1%) vs. 120 (2.5%), P &lt; 0.001], premature ventricular contractions (PVCs) [121 (2.1%) vs. 63 (1.3%), P = 0.001], angina pectoris [45 (0.8%) vs. 5 (0.1%), P &lt; 0.001], and ventricular tachycardia (VT) [32 (0.6%) vs. 14 (0.3%), P = 0.032] were significantly higher in the treadmill group compared with the bicycle ergometer group. No significant difference was observed in the incidence of bradyarrhythmia and atrial arrhythmia between the two groups. Logistic regression analysis showed that the occurrence of overall CV events (P &lt; 0.001), PVCs (P = 0.007), angina pectoris (P &lt; 0.001), and VT (P = 0.008) was independently associated with the stimulation method of treadmill exercise. In male subjects, the occurrence of overall CV events, PVCs, angina pectoris, and VT were independently associated with treadmill exercise, while only the overall CV events and angina pectoris were independently associated with treadmill exercise in female subjects.

Conclusion

In comparison with treadmill exercise, bicycle ergometer exercise appears to be a safer exercise stimulation mode for CPET in patients with CHD.

Validation of prognostic value of the hemodynamic gain index in different groups of patients undergoing exercise stress testing

Background:

Recently, the hemodynamic gain index (HGI) has shown to be a strong independent predictor of all-cause mortality and associated with metabolic equivalents (METs) in a cohort of male patients. However, the prognostic implications of the HGI have never been externally validated with subgroup analyses based on gender, body mass index (BMI) of 35 kg/m², history of heart failure (HF), coronary artery disease (CAD) and beta-blocker use.

Methods:

We identified 126,356 consecutive patients undergoing treadmill exercise testing between January 1st, 1991 and February 27th, 2015. HGI was calculated using the formula: [(SBP_peak × HR_peak) − (SBP_rest × HR_rest)] / (SBP_rest × HR_rest). Cox regression models were used to determine the associations between HGI quartiles and all-cause mortality with adjustment for cardiovascular risk factors and exercise testing parameters.

Results:

Mean age was 53.5 ± 12.6 years. There were 74,724 (59.1 %) male, 5940 (4.7 %) HF, 21,123 (16.7 %) CAD, and 30,568 (24.2 %) beta-blocker-using patients. During the median follow up of 7.1 years, 9929 (7.9 %) died. Median HGI was 1.93 (interquartile range [IQR] 1.40–2.54) bpm/mmHg. After adjustment for the covariates, lower HGI was independently associated with all-cause mortality in the entire cohort (quartile 1 vs 4, adjusted hazard ratio [95 % confidence interval] 1.33 [IQR 1.21–1.45], p < 0.001), and subgroups of men, women, patients with body mass index <35 kg/m², with and without HF, CAD, and beta-blocker use. The HGI also correlates well with METs in every subgroup.

Conclusions:

The HGI is a strong predictor of long-term mortality independently of traditional cardiovascular risk factors, and exercise performance across patient subgroups.

Cardiorespiratory Fitness and Mortality in Patients Aged 60 to 90 Years

Chronological age alone does not fully reflect a patient's prognosis. We sought to assess the association of cardiorespiratory fitness (quantified by METs) with all-cause mortality among patients aged 60 to 90 years. This retrospective study included patients who underwent exercise treadmill testing at an integrated healthcare system from 2011 to 2019. Patients were categorized into age groups: 60 to <70 years, 70 to <80 years, and 80 to 90 years; and cardiorespiratory fitness level: low (<5 METs), moderate (5 to 10 METs), and high fitness (>10 METs). Mean follow-up was 3.5 years. A total of 40,520 patients were included (mean age 67.7 ± 4.7 years, 48.6% women). Of whom, 27,021 were 60 to <70 years old (66.7%); 12,638 70 to <80 years old (31.2%); and 1,861 80 to 90 years old (4.6%). There were 3,494 patients categorized as low (8.6%), 21,863 as moderate (54%), and 15,163 as high fitness (37.4%). Low fitness level was independently associated with lower survival (hazard ratio [HR] 1.61, 95% confidence interval [CI] 1.15 to 2.24). Using age 60 to 70 group with high fitness level as reference, the age 80 to 90 group with high fitness level had better survival than their younger counterparts with low fitness level (age 80 to 90 years high fitness level: HR 2.9, 95% CI 1.2 to 7.2; age 60 to 70 years low fitness level: HR 4.3, 95% CI 3.1 to 5.9; age 70 to 80 years low fitness level: HR 6.8, 95% CI 5.2 to 8.9) on adjusted analysis. In conclusion, higher cardiorespiratory fitness is associated with better survival. Patients >80 years old with high fitness level have comparable or even better survival than their younger counterparts with submoderate fitness levels. Chronological age alone should not be the only factor when considering prognosis.

Predictors of Submaximal Exercise Test Attainment in Adults Reporting Long COVID Symptoms

Adults with long COVID often report intolerance to exercise. Cardiopulmonary exercise testing (CPET) has been used in many settings to measure exercise ability but has been conducted in a few long COVID cohorts. We conducted CPET in a sample of adults reporting long COVID symptoms using a submaximal cycle ergometer protocol. We studied pre-exercise predictors of achieving 85% of the age-predicted maximum heart rate (85%HRmax) using logistic regression. Eighty participants were included (mean age 46 years, range 25−78, 71% women). Forty participants (50%) did not reach 85%HRmax. On average, non-achievers reached 84% of their predicted 85%HRmax. No adverse events occurred. Participants who did not achieve 85%HRmax were older (p < 0.001), had more recent COVID-19 illness (p = 0.012) with higher frequency of hospitalization (p = 0.025), and had been more affected by dizziness (p = 0.041) and joint pain (p = 0.028). In the logistic regression model including age, body mass index, time since COVID-19, COVID-19-related hospitalization, dizziness, joint pain, pre-existing cardiopulmonary disease, and use of beta blockers, independent predictors of achieving 85%HRmax were younger age (p = 0.001) and longer time since COVID-19 (p = 0.008). Our cross-sectional findings suggest that exercise tolerance in adults with long COVID has potential to improve over time. Longitudinal research should assess the extent to which this may occur and its mechanisms. ClinicalTrials.gov identifier: NCT05027724 (TROPIC Study).

The acute, systemic effects of aerobic exercise in recently concussed adolescent student-athletes: preliminary findings

OBJECTIVES

Examine the acute effects (pre-, during, post-intervention) of two different intensities of aerobic exercise or rest on autonomic, oculomotor, and vestibular function and symptom burden in patients with a recent sport-related concussion (SRC) and compare their responses to sex-matched, age-stratified, non-concussed (HEALTHY) student-athletes.

METHODS

Student-athletes between the ages of 13 and 18 that presented to the sports medicine clinic within Day 3-7 post-SRC and from local schools were recruited for a randomized controlled trial (RCT). The participants were administered the Vestibular/Ocular Motor Screening (VOMS), King-Devick (K-D), and Post-Concussion Symptom Scale (PCSS) before and after the intervention. Heart rate variability (HRV) and mean arterial pressure (MAP) were collected before, during, and after the intervention. The intervention was either a single, 20-min session of treadmill walking at 40% (40HR) or 60% of age-predicted max heart rate (60HR), or seated, rest (NOEX).

RESULTS

30 participants completed the intervention with the SRC group treated 4.5 ± 1.3 days post-injury. Pre-exercise HRV and MAP were significantly different (p's < 0.001) during treatment but returned to pre-exercise values within 5 min of recovery in both the SRC and HEALTHY groups. Both the SRC and HEALTHY groups exhibited similar reductions pre- to post-intervention for symptom severity and count (p's < 0.05), three VOMS items (p's < 0.05) but not K-D time.

CONCLUSIONS

To date, this is the first adolescent RCT to report the acute, systemic effects of aerobic exercise on recently concussed adolescent athletes. The interventions appeared safe in SRC participants, were well-tolerated, and provided brief therapeutic benefit.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier NCT03575455.

Surface Electromyography Thresholds as a Measure for Performance Fatigability During Incremental Cycling in Patients With Neuromuscular Disorders

In healthy persons, there is an excellent relation between the timing of the (two) surface electromyography (sEMG) thresholds and the (two) ventilatory thresholds during exercise. The primary aim of this study was to determine the relative timing of both sEMG and ventilatory thresholds in patients with neuromuscular disorders compared with healthy subjects during a maximal ergospirometry cycling test. We hypothesized that in patients with neuromuscular disorders, the sEMG thresholds would occur relatively earlier in time than the ventilatory thresholds, compared to healthy subjects, because performance fatigability occurs more rapidly. In total, 24 healthy controls and 32 patients with a neuromuscular disorder performed a cardiopulmonary exercise test on a bicycle using a 10-min ramp protocol, during which we collected ergospirometry data: power at both ventilatory and sEMG thresholds, and sEMG data of lower leg muscles. In line with our hypothesis, normalized values for all thresholds were lower for patients than healthy subjects. These differences were significant for the first ventilatory (p = 0.008) and sEMG threshold (p &lt; 0.001) but not for the second sEMG (p = 0.053) and ventilatory threshold (p = 0.238). Most parameters for test–retest reliability of all thresholds did not show any fixed bias, except for the second ventilatory threshold. The feasibility of the sEMG thresholds was lower than the ventilatory thresholds, particularly of the first sEMG threshold. As expected, the sEMG thresholds, particularly the first threshold, occurred relatively earlier in time than the ventilatory thresholds in patients compared with healthy subjects. A possible explanation could be (a combination of) a difference in fiber type composition, disuse, and limited muscle-specific force in patients with neuromuscular disorders. sEMG measurements during submaximal dynamic exercises are needed to generalize the measurements to daily life activities for future use in prescribing and evaluating rehabilitation interventions.

Influence of cardiopulmonary exercise test on platelet function in patients with coronary artery diseases on antiplatelet therapy

Background

Cardiac rehabilitation reduces mortality and morbidity rate of patients with coronary artery diseases (CAD); however, acute exercise stimulation may also increase the thrombotic risk through platelet activation. Studies on the effects of cardiac rehabilitation on platelet function have been sparse.

Methods

A total of 28 patients (24 men and 4 women; average age = 54.6 ± 8 years old) with stable CAD were enrolled in this study and divided into Aspirin-treated (n = 11; Aspirin group) and dual-antiplatelet-treated group (DAPT group; n = 17). Symptom-limited cardiopulmonary exercise test (CPET) with a cycle ergometer was performed on all the patients. Before and after CPET, platelet function was evaluated using light transmission aggregometry and whole blood flow cytometry.

Results

All patients completed the CPET without provoked cardiac events, and the mean value of peak oxygen uptake (Peak Vo₂) was 19.3 ± 3 ml/(kg min). Prior to CPET, platelet aggregation was significantly suppressed in DAPT group compared to Aspirin group (43.0 ± 21.5 vs. 72.9 ± 7.5, p < 0.001). CPET promoted platelet aggregation in Aspirin group (72.9 ± 7.5 vs. 80.9 ± 7.6, p = 0.005) and DAPT group (43.0 ± 21.5 vs. 50.1 ± 20.9, p = 0.010), and platelet count was increased in Aspirin (210.9 ± 54.6 vs. 227.5 ± 58.1, p = 0.001) and DAPT group (217.5 ± 63.8 vs. 229.7 ± 63.7, p = 0.001). However, the expression levels of CD62p and PAC-1 were not affected by CPET in both groups.

Conclusion

Symptom-limited CPET enhanced platelet aggregation in patients with CAD despite treatment with antiplatelet, mainly via platelet count augmentation, but not through single platelet activation.

Trial registration: Effects of high intensity interval training versus moderate intensity continue training in cardiac rehabilitation on platelet function of patients with coronary heart diseases: a exploratory randomized controlled trial.

ChiCTR-INR-17010717. Registered 23 February 2017, https://www.chictr.org.cn/edit.aspx?pid=18206&htm=4.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Changing Paradigms in the Diagnosis of Ischemic Heart Disease by Multimodality Imaging

Coronary artery disease (CAD) represents the most common cardiovascular disease, with high morbidity and mortality. Historically patients with chest pain of suspected coronary origin have been assessed with functional tests, capable to detect haemodynamic consequences of coronary obstructions through depiction of electrocardiographic changes, myocardial perfusion defects or regional wall motion abnormalities under stress condition. Stress echocardiography (SE), single-photon emission computed tomography (SPECT), positron emission tomography (PET) and cardiovascular magnetic resonance (CMR) represent the functional techniques currently available, and technical developments contributed to increased diagnostic performance of these techniques. More recently, cardiac computed tomography angiography (cCTA) has been developed as a non-invasive anatomical test for a direct visualisation of coronary vessels and detailed description of atherosclerotic burden. Cardiovascular imaging techniques have dramatically enhanced our knowledge regarding physiological aspects and myocardial implications of CAD. Recently, after the publication of important trials, international guidelines recognised these changes, updating indications and level of recommendations. This review aims to summarise current standards with main novelties and specific limitations, and a diagnostic algorithm for up-to-date clinical management is also proposed.

Does chest shape influence exercise stress echocardiographic results in patients with suspected coronary artery disease?

Despite the good specificity of exercise stress echocardiography (ESE) for the detection of coronary artery disease (CAD), false positive (FP) results may occur. We have previously reported that chest abnormalities may affect parameters of cardiac contractility. The influence of chest shape on ESE results has never been previously investigated. We retrospectively analyzed 160 consecutive patients (64.4 ± 13.0-year old, 91 women) who had undergone coronary angiography at our Institution because of positive ESE, between June 2014 and May 2020. Modified Haller index (MHI; chest transverse diameter over the distance between sternum and spine) was assessed in all patients. Obstructive CAD was diagnosed by ≥ 70% stenosis in any epicardial coronary artery. Outcome was false-positivity at ESE. 80.6% of patients were diagnosed with obstructive CAD, while 19.4% had no CAD (FP). We separately analyzed patients with normal chest shape (MHI ≤ 2.5) and those with concave-shaped chest wall (MHI > 2.5). These latter were mostly women with small cardiac chambers, mitral valve prolapse (MVP) and exercise-induced ST-segment changes. Likelihood of false-positivity was significantly higher in subjects with MHI > 2.5 than those with MHI ≤ 2.5 (30.7% vs 9.4%, p = 0.001). By multivariate logistic regression analysis, MHI > 2.5 (OR 4.04, 95%CI 1.45-11.2, p = 0.007), MVP (OR 3.47, 95%CI 1.32-9-12, p = 0.01) and dyssynergy in the left circumflex territory (OR = 3.35, 95%CI 1.26-8.93, p = 0.01) were independently associated with false-positivity. Concave-shaped chest wall (MHI > 2.5) may be associated with false-positive stress echocardiographic result. Mechanisms underpinning this finding need to be further explored.

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'.

A Comparison among Different Machine Learning Pretest Approaches to Predict Stress-Induced Ischemia at PET/CT Myocardial Perfusion Imaging

Traditional approach for predicting coronary artery disease (CAD) is based on demographic data, symptoms such as chest pain and dyspnea, and comorbidity related to cardiovascular diseases. Usually, these variables are analyzed by logistic regression to quantifying their relationship with the outcome; nevertheless, their predictive value is limited. In the present study, we aimed to investigate the value of different machine learning (ML) techniques for the evaluation of suspected CAD; having as gold standard, the presence of stress-induced ischemia by ⁸²Rb positron emission tomography/computed tomography (PET/CT) myocardial perfusion imaging (MPI) ML was chosen on their clinical use and on the fact that they are representative of different classes of algorithms, such as deterministic (Support vector machine and Naïve Bayes), adaptive (ADA and AdaBoost), and decision tree (Random Forest, rpart, and XGBoost). The study population included 2503 consecutive patients, who underwent MPI for suspected CAD. To testing ML performances, data were split randomly into two parts: training/test (80%) and validation (20%). For training/test, we applied a 5-fold cross-validation, repeated 2 times. With this subset, we performed the tuning of free parameters for each algorithm. For all metrics, the best performance in training/test was observed for AdaBoost. The Naïve Bayes ML resulted to be more efficient in validation approach. The logistic and rpart algorithms showed similar metric values for the training/test and validation approaches. These results are encouraging and indicate that the ML algorithms can improve the evaluation of pretest probability of stress-induced myocardial ischemia.

The prognostic role of heart rate recovery after exercise and metabolic syndrome in IgA nephropathy

Background

Cardiovascular (CV) morbidity and mortality are higher in chronic kidney disease (CKD) than in the general population. Reduced heart rate recovery (HRR) is an independent risk factor for CV disease. The aim of the study was to determine the prognostic role of HRR in a homogenous group of CKD patients.

Methods

One hundred and twenty-five IgA nephropathy patients (82 male, 43 female, age 54.7 ± 13 years) with CKD stage 1–4 were investigated and followed for average 70 months. We performed a graded exercise treadmill stress test. HRR was derived from the difference of the peak heart rate and the heart rate at 1 min after exercise. Patients were divided into two groups by the mean HRR value (22.9 beats/min). The composite (CV and renal) endpoints included all-cause mortality and any CV event such as stroke, myocardial infarction, revascularisation (CV) and end-stage renal disease, renal replacement therapy (renal).

Results

Patients with reduced HRR (< 23 bpm) had significantly more end point events (22/62 patients vs. 9/53 patients, p = 0.013) compared to the higher HRR (≥23 bpm). Of the secondary the endpoints (CV or renal separately) rate of the renal endpoint was significantly higher in the lower HRR group (p = 0.029), while there was no significant difference in the CV endpoint between the two HRR groups (p = 0.285). Independent predictors of survival were eGFR and diabetes mellitus by using Cox regression analysis. Kaplan-Meier curves showed significant differences in metabolic syndrome and non-metabolic syndrome when examined at the combined endpoints (cardiovascular and renal) or at each endpoint separately. The primary endpoint rate was increased significantly with the increased number of metabolic syndrome component (Met.sy. comp. 0 vs. Met. sy. comp. 2+, primary endpoints, p = 0.012).

Conclusion

Our results showed that reduced HRR measured by treadmill exercise test has a predictive value for the prognosis of IgA nephropathy. The presence of metabolic syndrome may worsen the prognosis of IgA nephropathy.

Cardiovascular Disease in Older Women

Cardiovascular disease is the major cause of death in women. Older women remain at risk for coronary artery disease/cardiovascular disease, but risk-modifying behavior can improve outcomes. Women have a different symptom profile and have been underdiagnosed and undertreated as compared with men. Although older women are underrepresented in trials, clinicians should be more attuned to the prevention, diagnosis, and treatment of cardiovascular disease in older women.

Exercise Stress Test-Induced Atrioventricular Dissociation With Syncope

Background: The exercise stress test is widely used as a diagnostic test for evaluating coronary artery disease in symptomatic patients or those with underlying cardiovascular disorders. Although exercise stress test risk is minimal with a <1% chance of causing heart block, physician awareness of potential complications is paramount for prompt recognition and treatment. Case Report: A 65-year-old-female with angina-like chest pain underwent an exercise stress test for ischemic heart disease evaluation. She performed the exercise stress test up to stage 2 (exercise Bruce protocol) with an exercise duration of 5 minutes and maximum metabolic equivalents of 7. During her recovery phase, the patient developed atrioventricular dissociation with junctional rhythm followed by syncope. Immediate treatment was administered, including intravenous normal saline, and she recovered without any complications. Conclusion: This case reminds clinicians to be aware of the unpredictable effects of the exercise stress test even though atrioventricular dissociation after an exercise stress test is rare. Providing immediate treatment to prevent any untoward effects is essential.

Outcomes in the ISCHEMIA Trial Based on Coronary Artery Disease and Ischemia Severity

BACKGROUND

The ISCHEMIA trial (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) postulated that patients with stable coronary artery disease (CAD) and moderate or severe ischemia would benefit from revascularization. We investigated the relationship between severity of CAD and ischemia and trial outcomes, overall and by management strategy.

METHODS

In total, 5179 patients with moderate or severe ischemia were randomized to an initial invasive or conservative management strategy. Blinded, core laboratory-interpreted coronary computed tomographic angiography was used to assess anatomic eligibility for randomization. Extent and severity of CAD were classified with the modified Duke Prognostic Index (n=2475, 48%). Ischemia severity was interpreted by independent core laboratories (nuclear, echocardiography, magnetic resonance imaging, exercise tolerance testing, n=5105, 99%). We compared 4-year event rates across subgroups defined by severity of ischemia and CAD. The primary end point for this analysis was all-cause mortality. Secondary end points were myocardial infarction (MI), cardiovascular death or MI, and the trial primary end point (cardiovascular death, MI, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest).

RESULTS

Relative to mild/no ischemia, neither moderate ischemia nor severe ischemia was associated with increased mortality (moderate ischemia hazard ratio [HR], 0.89 [95% CI, 0.61-1.30]; severe ischemia HR, 0.83 [95% CI, 0.57-1.21]; P=0.33). Nonfatal MI rates increased with worsening ischemia severity (HR for moderate ischemia, 1.20 [95% CI, 0.86-1.69] versus mild/no ischemia; HR for severe ischemia, 1.37 [95% CI, 0.98-1.91]; P=0.04 for trend, P=NS after adjustment for CAD). Increasing CAD severity was associated with death (HR, 2.72 [95% CI, 1.06-6.98]) and MI (HR, 3.78 [95% CI, 1.63-8.78]) for the most versus least severe CAD subgroup. Ischemia severity did not identify a subgroup with treatment benefit on mortality, MI, the trial primary end point, or cardiovascular death or MI. In the most severe CAD subgroup (n=659), the 4-year rate of cardiovascular death or MI was lower in the invasive strategy group (difference, 6.3% [95% CI, 0.2%-12.4%]), but 4-year all-cause mortality was similar.

CONCLUSIONS

Ischemia severity was not associated with increased risk after adjustment for CAD severity. More severe CAD was associated with increased risk. Invasive management did not lower all-cause mortality at 4 years in any ischemia or CAD subgroup. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01471522.