American Society of Echocardiography recommendations for performance, interpretation, and application of stress echocardiography

Clinical impact of multimodality assessment of myocardial viability

Coronary artery disease (CAD) is a prevalent cause of left ventricular dysfunction. Nevertheless, effective elective revascularization, particularly surgical revascularization, can enhance long-term outcomes and, in selected cases, global left ventricular contractility. The assessment of myocardial viability and scars is still relevant in guiding treatment decisions and selecting patients who are likely to benefit most from blood flow restoration. Although the most recent randomized studies challenge the notion of "hibernating myocardium" and the clinical usefulness of assessing myocardial viability, the advancement of imaging techniques still renders this assessment valuable in specific situations. According to the guidelines of the European Society of Cardiology, non-invasive stress imaging may be employed to define myocardial ischemia and viability in patients with CAD and heart failure before revascularization. Currently, several non-invasive imaging techniques are available to evaluate the presence and extent of viable myocardium. The selection of the most suitable technique should be based on the patient, clinical context, and resource availability. This narrative review evaluates the characteristics of available imaging modalities for assessing myocardial viability to determine the most appropriate therapeutic strategy.

Impact of Stress Echocardiography on Aortic Valve Stenosis Management

Rest and stress echocardiography (SE) play a fundamental role in the evaluation of aortic valve stenosis (AS). According to the current guidelines for the echocardiographic evaluation of patients with aortic stenosis, four broad categories can be defined: high-gradient AS (mean gradient ≥ 40 mmHg, peak velocity ≥ 4 m/s, aortic valve area (AVA) ≤ 1 cm2 or indexed AVA ≤ 0.6 cm2/m2); low-flow, low-gradient AS with reduced ejection fraction (mean gradient < 40 mmHg, AVA ≤ 1 cm2, left ventricle ejection fraction (LVEF) < 50%, stroke volume index (Svi) ≤ 35 mL/m2); low-flow, low-gradient AS with preserved ejection fraction (mean gradient < 40 mmHg, AVA ≤ 1 cm2, LVEF ≥ 50%, SVi ≤ 35 mL/m2); and normal-flow, low-gradient AS with preserved ejection fraction (mean gradient < 40 mmHg, AVA ≤ 1 cm2, indexed AVA ≤ 0.6 cm2/m2, LVEF ≥ 50%, SVi > 35 mL/m2). Aortic valve replacement (AVR) is indicated with the onset of symptoms development or LVEF reduction. However, there is often mismatch between resting transthoracic echocardiography findings and patient's symptoms. In these discordant cases, SE and CT calcium scoring are among the indicated methods to guide the management decision making. Additionally, due to the increasing evidence that in asymptomatic severe aortic stenosis an early AVR instead of conservative treatment is associated with better outcomes, SE can help identify those that would benefit from an early AVR by revealing markers of poor prognosis. Low-flow, low-gradient AS represents a challenge both in diagnosis and in therapeutic management. Low-dose dobutamine SE is the recommended method to distinguish true-severe from pseudo-severe stenosis and assess the existence of flow (contractile) reserve to appropriately guide the need for intervention in these patients.

Lean body mass and the cardiorespiratory phenotype: An ethnic-specific relationship in Hans Chinese women and men

BACKGROUND

Lean body mass (LBM) and the functional capacity of cardiovascular (CV) and respiratory systems constitute a female-specific relationship in European-American individuals. Whether this recent finding be extrapolated to the world's largest ethnic group, that is, Hans Chinese (HC, a population characterized by low LBM), is unknown.

METHODS

Healthy HC adults (n = 144, 50% ♀) closely matched by sex, age and physical activity were included. Total and regional (leg, arm and trunk) LBM and body composition were measured via dual-energy X-ray absorptiometry. Cardiac structure, stiffness, central/peripheral haemodynamics and peak O2 consumption (VO2peak) were assessed via transthoracic echocardiography and pulmonary gas analyses at rest and during exercise up to peak effort. Regression analyses determined the sex-specific relationship of LBM with cardiac and aerobic phenotypes.

RESULTS

Total and regional LBM were lower and body fat percentage higher in women compared with men (P < 0.001). In both sexes, total LBM positively associated with left ventricular (LV) mass and peak volumes (r ≥ 0.33, P ≤ 0.005) and negatively with LV end-systolic and central arterial stiffness (r ≥ -0.34, P ≤ 0.004). Total LBM strongly associated with VO2peak (r ≥ 0.60, P < 0.001) and peak cardiac output (r ≥ 0.40, P < 0.001) in women and men. Among regional LBM, leg LBM prominently associated with the arterio-venous O2 difference at peak exercise in both sexes (r ≥ 0.43, P < 0.001). Adjustment by adiposity or CV risk factors did not modify the results.

CONCLUSIONS

LBM independently determines internal cardiac dimensions, ventricular mass, distensibility and the capacity to deliver and consume O2 in HC adults irrespective of sex.

Routine Functional Testing or Standard Care in High-Risk Patients after Percutaneous Coronary Intervention

PURPOSE OF REVIEW

This review aimed to collate the available evidence on outcomes following routine functional stress testing vs standard of care (i.e. symptom-guided stress testing) in high-risk patients following percutaneous coronary intervention (PCI).

RECENT FINDINGS

The most recent pragmatic POST-PCI trial provided randomized evidence showing that routine functional stress testing post-PCI did not lead to a reduction in 2-year ischemic cardiovascular events or all-cause mortality, as compared to a symptom-guided standard-of-care approach. This was also true for sub-analyses including multivessel or left main disease, diabetics, as well as following imaging or physiology guided PCI. In the absence of a change in their clinical or functional status suggestive of stent failure, post-PCI routine periodic stress testing in stable patients on guideline-directed medical therapy is currently not recommended by American clinical practice guidelines. While evidence on the cost-effectiveness of routine stress testing strategy is scarce, physician, payer, and policy-level interventions to reduce inappropriate use of routine functional testing need to be addressed.

Prognostic Significance of Elevated Left Ventricular Filling Pressures with Exercise: Insights from a Cohort of 14,338 Patients

BACKGROUND

Exercise echocardiography can assess for cardiovascular causes of dyspnea other than coronary artery disease. However, the prevalence and prognostic significance of elevated left ventricular (LV) filling pressures with exercise is understudied.

METHODS

We evaluated 14,338 patients referred for maximal symptom-limited treadmill echocardiography. In addition to assessment of LV regional wall motion abnormalities (RWMAs), we measured patients' early diastolic mitral inflow (E), septal mitral annulus relaxation (e'), and peak tricuspid regurgitation velocity before and immediately after exercise.

RESULTS

Over a mean follow-up of 3.3 ± 3.4 years, patients with E/e' ≥15 with exercise (n = 1,323; 9.2%) had lower exercise capacity (7.3 ± 2.1 vs 9.1 ± 2.4 metabolic equivalents, P < .0001) and were more likely to have resting or inducible RWMAs (38% vs 18%, P < .0001). Approximately 6% (n = 837) had elevated LV filling pressures without RWMAs. Patients with a poststress E/e' ≥15 had a 2.71-fold increased mortality rate (2.28-3.21, P < .0001) compared with those with poststress E/e' ≤ 8. Those with an E/e' of 9 to 14, while at lower risk than the E/e' ≥15 cohort (hazard ratio [HR] = 0.58 [0.48-0.69]; P < .0001), had higher risk than if E/e' ≤8 (HR = 1.56 [1.37-1.78], P < .0001). On multivariable analysis, adjusting for age, sex, exercise capacity, LV ejection fraction, and presence of pulmonary hypertension with stress, patients with E/e' ≥15 had a 1.39-fold (95% CI, 1.18-1.65, P < .0001) increased risk of all-cause mortality compared with patients without elevated LV filling pressures. Compared with patients with E/e' ≤ 15 after exercise, patients with E/e' ≤15 at rest but elevated after exercise had a higher risk of cardiovascular death (HR = 8.99 [4.7-17.3], P < .0001).

CONCLUSION

Patients with elevated LV filling pressures are at increased risk of death, irrespective of myocardial ischemia or LV systolic dysfunction. These findings support the routine incorporation of LV filling pressure assessment, both before and immediately following stress, into the evaluation of patients referred for exercise echocardiography.

Blood volume contributes to the mechanical synchrony of the myocardium during moderate and high intensity exercise in women

PURPOSE

Whether blood volume (BV) primarily determines the synchronous nature of the myocardium remains unknown. This study determined the impact of standard blood withdrawal on left ventricular mechanical dyssynchrony (LVMD) in women.

METHODS

Transthoracic speckle-tracking echocardiography and central hemodynamic measurements were performed at rest and during moderate- to high-intensity exercise in healthy women (n = 24, age = 53.6 ± 16.3 year). LVMD was determined via the time to peak standard deviation (TPSD) of longitudinal and transverse strain and strain rates (LSR, TSR). Measurements were repeated within a week period immediately after a 10% reduction of BV.

RESULTS

With intact BV, all individuals presented cardiac structure and function variables within normative values of the study population. Blood withdrawal decreased BV (5.3 ± 0.7 L) by 0.5 ± 0.1 L. Resting left ventricular (LV) end-diastolic volume (- 8%, P = 0.040) and passive filling (- 16%, P = 0.001) were reduced after blood withdrawal. No effect of blood withdrawal was observed for any measure of LVMD at rest (P ≥ 0.225). During exercise at a fixed submaximal workload (100 W), LVMD of myocardial longitudinal strain (LS TPSD) was increased after blood withdrawal (36%, P = 0.047). At peak effort, blood withdrawal led to increased LVMD of myocardial transverse strain rate (TSR TPSD) (31%, P = 0.002). The effect of blood withdrawal on TSR TPSD at peak effort was associated with LV concentric remodeling (r = 0.59, P = 0.003).

CONCLUSION

Marked impairments in the mechanical synchrony of the myocardium are elicited by moderate blood withdrawal in healthy women during moderate and high intensity exercise.

Usefulness of cardiopulmonary exercise test combined with exercise stress echocardiography in mild chronic thromboembolic pulmonary disease

PURPOSE

Chronic thromboembolic pulmonary disease (CTEPD) can lead to exercise limitations even without right ventricular (RV) dysfunction or pulmonary hypertension at rest. Combining exercise stress echocardiography with cardiopulmonary exercise testing (ESE-CPET) for RV function and pressure changes combined measuring overall function may be useful for CTEPD evaluation. This study aims to investigate CPET and ESE results to elucidate the mechanisms of exercise limitation in mild CTEPD cases.

METHODS

Among our CTEPD registry, 50 patients who performed both right heart catheterization data of mild disease (less than 30 mm Hg of mean pulmonary arterial pressure (mPAP)) and ESE-CPET were enrolled. Echocardiography and CPET-derived parameters were compared with hemodynamic parameters measured through right heart catheterization.

RESULTS

Peak VO2 (maximal oxygen consumption) was decreased in overall population (71.3 ± 16.3% of predictive value). Peak VO2 during exercise was negatively correlate with mPAP and pulmonary vascular resistance at rest. A substantial increase in RV systolic pressure (RVSP) was observed during exercise (RVSP: pre-exercise 37.2 ± 11.8 mm Hg, postexercise 64.3 ± 24.9 mm Hg, p-value < .001). Furthermore, RV function deteriorated during exercise when compared to the baseline (RV fractional area change: 31.5 ± 10.0% to 37.8 ± 7.0%, p-value < .001; RV global longitudinal strain: -17.1 ± 4.2% to -17.7 ± 3.3%, p-value < .001) even though basal RV function was normal. While an excessive increase in RVSP during exercise was noticed in both groups, dilated RV and RV dysfunction during exercise were demonstrated only in the impaired exercise capacity group.

CONCLUSION

CTEPD patients with mild PH or without PH exhibited limited exercise capacity alongside an excessive increase in RVSP during exercise. Importantly, RV dysfunction during exercise was significantly associated with exercise capacity. ESE-CPET could aid in comprehending the primary cause of exercise limitation in these patients.

Predicting major adverse cardiovascular events after orthotopic liver transplantation using a supervised machine learning model: A cohort study

BACKGROUND

Liver transplant (LT) patients have become older and sicker. The rate of post-LT major adverse cardiovascular events (MACE) has increased, and this in turn raises 30-d post-LT mortality. Noninvasive cardiac stress testing loses accuracy when applied to pre-LT cirrhotic patients.

AIM

To assess the feasibility and accuracy of a machine learning model used to predict post-LT MACE in a regional cohort.

METHODS

This retrospective cohort study involved 575 LT patients from a Southern Brazilian academic center. We developed a predictive model for post-LT MACE (defined as a composite outcome of stroke, new-onset heart failure, severe arrhythmia, and myocardial infarction) using the extreme gradient boosting (XGBoost) machine learning model. We addressed missing data (below 20%) for relevant variables using the k-nearest neighbor imputation method, calculating the mean from the ten nearest neighbors for each case. The modeling dataset included 83 features, encompassing patient and laboratory data, cirrhosis complications, and pre-LT cardiac assessments. Model performance was assessed using the area under the receiver operating characteristic curve (AUROC). We also employed Shapley additive explanations (SHAP) to interpret feature impacts. The dataset was split into training (75%) and testing (25%) sets. Calibration was evaluated using the Brier score. We followed Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis guidelines for reporting. Scikit-learn and SHAP in Python 3 were used for all analyses. The supplementary material includes code for model development and a user-friendly online MACE prediction calculator.

RESULTS

Of the 537 included patients, 23 (4.46%) developed in-hospital MACE, with a mean age at transplantation of 52.9 years. The majority, 66.1%, were male. The XGBoost model achieved an impressive AUROC of 0.89 during the training stage. This model exhibited accuracy, precision, recall, and F1-score values of 0.84, 0.85, 0.80, and 0.79, respectively. Calibration, as assessed by the Brier score, indicated excellent model calibration with a score of 0.07. Furthermore, SHAP values highlighted the significance of certain variables in predicting postoperative MACE, with negative noninvasive cardiac stress testing, use of nonselective beta-blockers, direct bilirubin levels, blood type O, and dynamic alterations on myocardial perfusion scintigraphy being the most influential factors at the cohort-wide level. These results highlight the predictive capability of our XGBoost model in assessing the risk of post-LT MACE, making it a valuable tool for clinical practice.

CONCLUSION

Our study successfully assessed the feasibility and accuracy of the XGBoost machine learning model in predicting post-LT MACE, using both cardiovascular and hepatic variables. The model demonstrated impressive performance, aligning with literature findings, and exhibited excellent calibration. Notably, our cautious approach to prevent overfitting and data leakage suggests the stability of results when applied to prospective data, reinforcing the model's value as a reliable tool for predicting post-LT MACE in clinical practice.

The Chinese cardiorespiratory and circulatory system at work in women and men: a case-control study

Background

The physiology of prominent prognostic factors in the cardiorespiratory system remains unchartered in the world's largest ethnic group: Hans Chinese (HC). This study assessed and contrasted the fundamental variables in HC and European-American (EA) individuals.

Methods

Healthy HC and EA adults (n = 140, 43% ♀) closely matched by age, sex and physical activity were included. Body composition (DXA) and haematological variables (haemoglobin mass, blood volume (BV)) were measured at rest. Pulmonary O2 uptake (VO2) measurements along with cycle ergometry designed for accurate transthoracic echocardiography were implemented to assess cardiorespiratory structure/function up to peak effort.

Findings

HC presented with higher body fat and lower lean body mass (LBM) percentage than EA irrespective of sex (P ≤ 0.014). BV did not differ whereas blood haemoglobin concentration was lower in HC compared with EA, particularly in females (P = 0.009). Myocardial diastolic and overall function at rest was enhanced in HC versus EA (P < 0.001). During exercise, heart volumes and output per unit of body size did not differ between ethnicities, whereas larger heart volumes per unit of LBM were found in HC versus EA in females (P ≤ 0.003). At high exercise intensities, VO2 (-16%) and the arteriovenous O2 difference (-28%) were markedly reduced in HC compared with EA in females (P ≤ 0.024). In males, no physiological difference between HC and EA was observed during exercise.

Interpretation

Notwithstanding lower LBM, HC are characterised by similar BV and cardiac capacity but reduced peak VO2 than EA in females, partly explained by low ethnic-specific blood O2 carrying capacity.

Funding

Early Career Scheme (106210224, to D.M.) and Seed Fund (104006024, to D.M.).

Exercise Training on Anginal Threshold Does Not Improve Endothelial Function in Refractory Angina Patients

Refractory angina (RA) is a chronic condition of coronary artery disease (CAD). Endothelial function (EF) measured by flow-mediated dilation (FMD) is an important prognostic marker in CAD. Exercise training is a stimulus that improves EF in CAD. However, exercise training effects on EF in RA are unknown. Therefore, we aimed to verify the effects of exercise training on EF in RA. This was a longitudinal, non-randomized clinical study, involving patients with patients limited by angina, aged 45 to 75 years. Patients were prospectively allocated by convenience to either exercise trained (ET) or control group (C). Laboratory analysis, cardiopulmonary exercise test (CPET), and FMD were implemented at inclusion and after 12 weeks of exercise training or clinical treatment period. Exercise training included 60 minutes per session, 3 times a week, including 40 minutes of aerobic exercise on anginal threshold heart rate obtained on the CPET, 15 minutes of resistance training, and 5 minutes of stretching. A total of 38 patients were included (mean age 60 ± 9 years, 22 men); 21 were allocated to the ET and 17 to the C group. Baseline measures showed no differences between groups. After 12 weeks glycated hemoglobin and systolic blood pressure were lower in ET before than ET after (p = 0.004, and p = 0.05, respectively), and exercise time of the CPET was lower in ET before than ET after (p = 0.002). Exercise training did not change FMD. In conclusion, exercise training performed on anginal threshold increases exercise tolerance but causes no changes in EF in patients with RA.

Downstream Imaging Studies Do Not Significantly Improve Outcome in Most Patients with Chest Pain Who Did Not Reach Their Target Heart Rate on a Stress ECHO Study

Echocardiographic stress tests are often used to evaluate patients who complain of chest pain. However, some patients fail to reach the target heart rate required for the test to be conclusive (usually defined as 85% of the predicted maximal heart rate based on the patient's age) and are often sent for additional imaging tests, such as myocardial perfusion imaging (MPI) or cardiac computed tomography angiography (CTA). Few studies have evaluated the effectiveness of these additional tests in patients who present with chest pain but did not meet the heart rate requirements for a stress test. The primary objective of the study was to evaluate the efficacy of additional imaging tests for patients who experience chest pain during daily activities but are unable to reach the target heart rate currently required for an echocardiographic stress test. The study group included 415 consecutive patients who underwent a stress echocardiogram, did not achieve their target heart rate, and did not demonstrate abnormal changes during the test. The control group consisted of 415 consecutive patients who did reach their target heart rate and demonstrated no signs of ischemia. Demographic and clinical data, medication use, imaging test results (MPI, CTA, and/or coronary catheterization) and documented cardiac events that occurred during 1 year of follow-up were obtained from the electronic medical records. Of the 415 patients in the study group, 73 (17.6%) were referred to another imaging test within 12 months. Of these 73 patients, 59 underwent MPI and 14 underwent cardiac CTA. In 12 of these patients (16.4%) the test was considered to be abnormal, but only 7 patients (1.7%) subsequently underwent a percutaneous intervention (PCI). In the control group, 28 (6.7%) patients were referred for another imaging test. Of these 28 patients, 14 underwent MPI and 14 underwent cardiac CTA. None of these tests were found to be abnormal, but two patients (0.5%) underwent a PCI (p = 0.2 between groups). There were no deaths during the study period and no patients underwent bypass surgery. The majority of the patients who underwent PCI had additional clinical risk factors (diabetes, hypertension, and/or known coronary artery disease), had taken a beta blocker within 24 h prior to the test, and/or did not reach a heart rate above 78% of their target heart rate. Our study suggests that in most patients with chest pain who do not show ischemic changes on a stress echocardiogram, additional imaging studies can be safely deferred, even if the required target heart rate was not reached. However, in patients with diabetes and/or known coronary disease, those who took a beta blocker 24 h prior to the test, or those who did not achieve a heart rate above 78% of the current target heart rate, additional imaging studies should be considered.

Evaluation of blood pressure response during dobutamine stress echocardiography in patients without cardiovascular diseases

Dobutamine stress echocardiography (DSE) is a diagnostic tool for determining coronary artery disease. Considering hypotension and hypertension as important complications of DSE, we aimed to evaluate the blood pressure (BP) responses during DSE. Patients without known cardiovascular diseases who underwent DSE were included. We excluded patients who had hypertension, diabetes mellitus, a known history of cardiovascular diseases, and those taking vasoactive medications. Systolic (SBP) and diastolic (DBP) blood pressure were recorded at baseline and peak stress. We included 688 patients with an age of 57.9 ± 12.01 years. During DSE, SBP (+19.72 ± 26.51 mm Hg, p < 0.001), DBP (+5.52 ± 17.35 mm Hg, p < 0.001), and HR (+54.05 ± 22.45 bpm, p < 0.001) significantly increased from baseline to peak stress. The normal cut-off value was measured between 101-210 mm Hg for SBP and 50-121 mm Hg for DBP. According to this normal cutoff, 11 (1.3%) and 30 (4.4%) patients had hypotensive and hypertensive SBP and 15 (2.2%) and 21 (3.1%) patients had hypotensive and hypertensive DBP, respectively. The hypotensive response was correlated with baseline SBP (r = 0.6, p = 0.001) and atropine (r = -2.18, p = 0.043), and the hypertensive response was correlated with baseline SBP (r = 0.048, p < 0.001). Baseline BP and atropine consumption were the independent variables associated with the outside-the-normal range of blood pressure responses.

Role of Imaging in Cardiomyopathies

Imaging has a central role in the diagnosis, classification, and clinical management of cardiomyopathies. While echocardiography is the first-line technique, given its wide availability and safety, advanced imaging, including cardiovascular magnetic resonance (CMR), nuclear medicine and CT, is increasingly needed to refine the diagnosis or guide therapeutic decision-making. In selected cases, such as in transthyretin-related cardiac amyloidosis or in arrhythmogenic cardiomyopathy, the demonstration of histological features of the disease can be avoided when typical findings are observed at bone-tracer scintigraphy or CMR, respectively. Findings from imaging techniques should always be integrated with data from the clinical, electrocardiographic, biomarker, genetic and functional evaluation to pursue an individualised approach to patients with cardiomyopathy.

Acute regulation of erythropoietin via lower body negative pressure: Influence of sex and age

The regulation of erythropoiesis via hemodynamic stimuli such as reduced central blood volume (CBV) remains uncertain in women and elderly individuals. This study assessed the acute effects of lower body negative pressure (LBNP) on key endocrine biomarkers regulating erythropoiesis, that is, erythropoietin (EPO) and copeptin, in young and older women and men (n = 87). Transthoracic echocardiography and hemodynamics were assessed throughout incremental LBNP levels for 1 hour, or until presyncope, with established methods. Venous blood samples were collected at baseline and immediately after termination of the orthostatic tolerance (OT) test for subsequent hormone analyses. The average age of young women and men (33.1 ± 6.0 vs. 29.5 ± 6.9 yr) and older women and men (63.8 ± 8.0 vs. 65.3 ± 8.9 yr) as well as their physical activity levels were matched within each age and sex group. CBV, as determined by right atrial volume, was reduced in all individuals at the end of the OT test (p < 0.001). The average OT time ranged from 50.1 to 58.1 min in all individuals. LBNP increased circulating EPO in young women (p = 0.023) but not in young men or older individuals. Copeptin was increased in all individuals with LBNP but was exclusively associated with EPO in men (r = 0.39, p = 0.013). The present study indicates that the acute hemodynamic regulation of EPO production is both sex- and age-dependent.

Prevalence and prognostic implications of hypertensive response to exercise in patients with hypertrophic cardiomyopathy

Objective

Hypertensive response to exercise (HRE) is observed in patients with hypertrophic cardiomyopathy (HCM) with normal resting blood pressure (BP). However, the prevalence or prognostic implications of HRE in HCM remain unclear.

Methods

In this study, normotensive HCM subjects were enrolled. HRE was defined as systolic BP > 210 mmHg in men or >190 mmHg in women, or diastolic BP > 90 mmHg, or an increase in diastolic BP > 10 mmHg during treadmill exercise. All participants were followed for subsequent development of hypertension, atrial fibrillation (AF), heart failure (HF), sustained ventricular tachycardia/fibrillation (VT/VF), and all-cause death. Six hundred and eighty HCM patients were screened.

Results

347 patients had baseline hypertension, and 333 patients were baseline normotensive. 132 (40%) of the 333 patients had HRE. HRE was associated with female sex, lower body mass index and milder left ventricular outflow tract obstruction. Exercise duration and metabolic equivalents were similar between patients with or without HRE, but the HRE group had higher peak heart rate (HR), better chronotropic response and more rapid HR recovery. Conversely, non-HRE patients were more likely to exhibit chronotropic incompetence and hypotensive response to exercise. After a mean follow-up of 3.4 years, patients with and without HRE had similar risks of progression to hypertension, AF, HF, sustained VT/VF or death.

Conclusion

HRE is common in normotensive HCM patients during exercise. HRE did not carry higher risks of future hypertension or cardiovascular adverse outcomes. Conversely, the absence of HRE was associated with chronotropic incompetence and hypotensive response to exercise.

Sex-specific improvement in cardiac phenotype in older females combining blood withdrawal and exercise training

This study determined whether an intervention combining hematological and exercise stimuli may overcome the prevailing limitations to improve the cardiac phenotype and orthostatic tolerance (OT) of females with advanced age. Healthy females (n = 15) and males (n = 14) matched by age (63.7 ± 7.0 vs. 63.6 ± 8.7 yr) and moderate physical activity were recruited. OT, transthoracic echocardiography, and central hemodynamics were assessed during incremental lower body negative pressure (LBNP) levels (up to -50 mmHg) for 1 h or until presyncope, prior to and after an intervention comprising standard (10%) blood withdrawal and an 8-wk exercise training program designed to maximize central hemodynamic adaptations. OT time was lower in females compared with males (48.1 ± 10.6 vs. 57.0 ± 4.8 min, P = 0.008) before the intervention. Improved OT time (+11%) in females (48.1 ± 10.6 vs. 53.5 ± 6.1 min, P = 0.021) but not in males (57.0 ± 4.8 vs. 56.7 ± 5.6 min, P = 0.868) was found following the intervention, resulting in similar OT time between females and males (P = 0.156). The intervention induced improvements in left ventricular (LV) diastolic function (+13% for myocardial e') along with increased LV mass (+13%) in females (P ≤ 0.039) but not in males (P ≥ 0.257). During the initial LBNP stages (0 to -20 mmHg), LV stroke volume and cardiac output were exclusively increased in females after the intervention (P ≤ 0.034). In conclusion, the cardiac phenotype of females with advanced age can be structurally and functionally modified in parallel to improved OT via short-term hematological and central hemodynamic stimuli.NEW & NOTEWORTHY Based on previous studies, main features of the cardiac phenotype in females with advanced age are generally unresponsive to lifestyle interventions. The present findings reveals that the cardiac phenotype of middle-age and older females is amenable to large modification in a short-term period when hematological stimuli are combined with those induced by exercise training. The same intervention only induced minor adaptations in males matched by age and potential confounding factors.

Cardiovascular events in patients with coronary artery disease with and without myocardial ischemia: Long-term follow-up

BACKGROUND

After the results of the ISCHEMIA Trial, the role of myocardial ischemia in the prognosis of coronary artery disease (CAD) was under debate. We sought to comparatively evaluate the long-term prognosis of patients with multivessel CAD with or without documented myocardial ischemia.

METHODS

This is a single-center, retrospective, observational cohort study that included patients with CAD obtained from the research protocols database of "The Medicine, Angioplasty or Surgery Study," the MASS Study Group. Patients were stratified according to the presence or absence of myocardial ischemia. Cardiovascular events (overall mortality and myocardial infarction) were tracked from the registry entry up to a median follow-up of 8.7 years. Myocardial ischemia was assessed at baseline by a functional test with or without imaging.

RESULTS

From 1995 to 2018, 2015 patients with multivessel CAD were included. Of these, 1001 presented with conclusive tests at registry entry, 790 (79%) presenting with ischemia and 211 (21%) without ischemia. The median follow-up was 8.7 years (IQR 4.04 to 10.07). The primary outcome occurred in 228 (28.9%) patients with ischemia and in 64 (30.3%) patients without ischemia (p_log-rank=0.60). No significant interaction was observed with the presence of myocardial ischemia and treatment strategies in the occurrence of the combined primary outcome (p_interation=0.14).

CONCLUSIONS

In this sample, myocardial ischemia was not associated with a worse prognosis compared with no ischemia in patients with multivessel CAD. These results refer to debates about the role of myocardial ischemia in the occurrence of cardiovascular events.

Impaired cardiac mechanical synchrony revealed with increased myocardial work in women with advanced age

BACKGROUND

Whether the synchronous nature of the myocardium is sex-dependent or affected by the aging process remains unknown. This study aimed to determine the influence of sex and age on cardiac mechanical synchrony during controlled hemodynamic stress.

METHODS

Transthoracic speckle-tracking echocardiography analyses and central hemodynamics were assessed at rest and during moderate- to high-intensity exercise in healthy young (<45 yr) and older (≥45 yr) women (n = 32) and men (n = 34) matched by age, physical activity and exercise capacity. Left ventricular mechanical dyssynchrony (LVMD) was determined as the time to peak standard deviation (TPSD) of longitudinal and transverse strain and strain rates (LSR, TSR).

RESULTS

Physical activity, aerobic capacity, heart rate, blood pressure and LVMD at rest were similar between women and men in each age group (P > 0.05). The rate pressure product, an index of myocardial work, did not differ between sex and age groups at rest and during exercise at a given percentage of peak heart rate (P > 0.05). A consistent age effect was observed for transverse LVMD (P-for-age ≤ 0.011). Specifically, older women presented with marked increments (≥42 %) in TSR TPSD at all exercise levels compared with younger women (P ≤ 0.005). Sex per se did not generally affect LVMD.

CONCLUSION

A prevailing impairment of cardiac mechanical synchrony in the transverse axis of the left ventricle is revealed during conditions of elevated hemodynamic stress in women with advanced age.

Exercise-Induced Pulmonary Hypertension: A Valid Entity or Another Factor of Confusion?

Exercise-induced pulmonary hypertension EIPH has been defined as an increase in mean pulmonary arterial pressure (mPAP) during exercise in otherwise normal values at rest. EIPH reflects heart and/or lung dysfunction and may precede the development of manifest pulmonary hypertension (PH) in a proportion of patients. It is also associated with decreased life expectancy in patients with heart failure with reduced ejection fraction (HFrEF) or left ventricle (LV) valvular diseases. Diastolic dysfunction exacerbated during exercise relates to increased LV filling pressure and left atrial pressure (LAP). In this context backward, transmitted pressure alone or accompanied with backward blood flow promotes EIPH. The gold standard of EIPH assessment remains the right heart catheterization during exercise, which is an accurate but invasive method. Alternatively, non-invasive diagnostic modalities include exercise stress echocardiography (ESE) and cardiopulmonary exercise testing (CPET). Both diagnostic tests are performed under gradually increasing physical stress using treadmill and ergo-cycling protocols. Escalating workload during the exercise is analogous to the physiological response to real exercise. The results of the latter techniques show good correlation with invasive measurements, but they suffer from lack of validation and cut-off value determination. Although it is not officially recommended, there are accumulated data supporting the importance of EIPH diagnosis in the assessment of other mild/subclinical or probably fatal diseases in patients with latent PH or heart failure or LV valvular disease, respectively. Nevertheless, larger, prospective studies are required to ensure its role in clinical practice.

Standardizing submaximal exercise intensities for use of supine push-pull exercise during cardiovascular magnetic resonance

BACKGROUND

Cardiovascular magnetic resonance (CMR) imaging during supine exercise at (sub)maximal oxygen consumption (VO₂ ) offers unique diagnostic insights. However, maximal VO₂ is not achievable in the supine position and standardizing submaximal exercise intensities remains challenging. Using heart rate or workload could be a viable option to translate VO₂ -based submaximal exercise intensities.

AIM

To translate submaximal exercise intensities upright cycling exercise (UCE) to supine push-pull exercise (SPPE), by comparing heart rate or workload determined during UCE, with heart rate and workload during SPPE at similar exercise intensities.

METHODS AND RESULTS

Sixteen healthy young adults (20.4 ± 2.2 years; 8 female) underwent cardiopulmonary UCE and SPPE testing [mean ± standard deviation maximal VO₂ : 3.2 ± 0.6 vs. 5 ± 0.3 L min^-1 , p < 0.001 and median (interquartile range) of the maximum workload: 310 (244, 361) vs. 98 (98, 100), p < 0.001, respectively]. Heart rate at 40% and 60% of maximal VO₂ , as determined by UCE, showed low bias (-3 and 0 bpm, respectively) and wide limits of agreement (±26 and ±28 bpm, respectively), in Bland-Altman analysis. VO₂ /Workload relation was exponential and less efficient during SPPE compared to UCE. Generalized estimated equation analysis predicted model-based mean workload during SPPE, with acceptable 95% confidence interval.

CONCLUSION

Heart rate during UCE at submaximal exercise intensities can reasonably well be used to for SPPE in healthy subjects. Using workload, an ergometer specific, model-based mean can be used to determine exercise intensities during SPPE. Individual variations in response to posture and movement change are high. During clinical interpretation of exercise CMR, individual exercise intensity has to be considered.

NT-proBNP increase during stress echocardiography predicts significant changes in ischemic mitral regurgitation severity in patients qualified for surgical revascularization

BACKGROUND

In many patients, significant changes in ischemic mitral regurgitation (IMR) severity during exercise can be observed independent of the degree of IMR at rest. This study aimed to investigate the correlations between N-terminal fragment B-type natriuretic peptide (NT-proBNP) and echocardiography measurements at rest and at peak exercise in patients with moderate IMR who qualified for surgical revascularization.

METHODS

A total of 100 patients eligible for coronary artery bypass grafting, were included in this prospective study. All patients underwent exercise echocardiography. Additionally, the levels of NT-proBNP were measured at rest and after peak exercise.

RESULTS

A positive correlation of absolute NT-proBNP levels with effective regurgitant orifice area (EROA) were observed and with tricuspid regurgitant peak gradient (TRPG) at peak exercise. Absolute ΔNT-proBNP during exercise and the tenting area at rest were independent predictors of severe IMR at peak exercise. The level of absolute ΔNT-proBNP during exercise and coaptation height at rest were the most important predictors of significant increases in TRPG. The best cutoff value for ΔNT-proBNP as a predictor for increases in EROA at peak exercise was 68.9 pg/mL and to predict an increase in TRPG ≥ 50 mmHg at peak exercise was 68 pg/mL.

CONCLUSIONS

The level of ΔNT-proBNP during exercise was the most important parameter in predicting significant changes in IMR severity and pulmonary pressure. Based on the present data, it can be speculated that integration of the assessment of NT-proBNP at rest and at exercise might improve patient selection for valve surgery.

Prognostic implication of myocardial perfusion and contractile reserve in end-stage renal disease: A direct comparison of myocardial perfusion scintigraphy and dobutamine stress echocardiography

BACKGROUND

We aimed to compare the prognostic value of myocardial perfusion scintigraphy (MPS) and dobutamine stress echocardiography (DSE) in patients with end-stage renal disease (ESRD) without known coronary artery disease.

METHODS

Two-hundred twenty-nine ESRD patients who applied for kidney transplantation at our centre were prospectively evaluated by MPS and DSE. The primary endpoint was a composite of myocardial infarction (MI) or all-cause mortality. The secondary endpoint included MI or coronary revascularization (CR) not triggered by MPS or DSE at baseline.

RESULTS

MPS detected reversible ischemia in 31 patients (13.5%) and fixed perfusion defects in 13 (5.7%) patients. DSE discovered stress-induced wall motion abnormalities (WMAs) in 28 (12.2%) and at rest in 18 (7.9%) patients. MPS and DSE results agreed in 85.6% regarding reversible defects (κ = 0.358; P < .001) and in 90.8% regarding fixed defects (κ = 0.275; P < .001). Coronary angiography detected relevant stenosis > 50% in only 15 of 38 patients (39.5%) with pathological findings in MPS and/or DSE. At a median follow-up of 8 years and 10 months, the primary endpoint occurred in 70 patients (30.6%) and the secondary endpoint in 24 patients (10.5%). The adjusted Cox hazard ratios (HRs) for the primary endpoint were 1.77 (95% CI 1.02-3.08; P = .043) for perfusion defects in MPS and 1.36 (95% CI 0.78-2.37; P = ns) for WMA in DSE. The secondary endpoint was significantly correlated with the findings of both modalities, MPS (HR 3.21; 95% CI 1.35-7.61; P = .008) and DSE (HR 2.67; 95% CI 1.15-6.20; P = .022).

CONCLUSION

Perfusion defects in MPS are a stronger determinant of all-cause mortality, MI and the need for future CR compared with WMAs in DSE. Given the complementary functional information provided by MPS vs DSE, results are sometimes contradictory, which may indicate differences in the underlying pathophysiology.

Lean body mass and the cardiovascular system constitute a female-specific relationship

Recent evidence points toward a link between lean body mass (LBM) and cardiovascular capacity in women. This study aimed at determining the sex-specific relationship of LBM with central and peripheral circulatory variables in healthy women and men (n=70) matched by age (60±12 years versus 58±15 years), physical activity, and cardiovascular risk factors. Regional (legs, arms, and trunk) and whole-body (total) body composition were assessed via dual-energy x-ray absorptiometry. Cardiac structure, function, and central/peripheral hemodynamics were measured via transthoracic echocardiography and the volume-clamp method at rest and peak incremental exercise. Regression analyses determined sex-specific relationships between LBM and cardiovascular variables. Regional and total LBM were lower in women than men (P<0.001), with little overlap between sexes. Leg and arm LBM positively associated with left ventricular (LV) internal resting dimensions in women (r≥0.53, P≤0.002) but not men (P≥0.156). Leg, arm, and total LBM only associated with LV relaxation in women (r≥0.43, P≤0.013). All LBM variables strongly associated with LV volumes at peak exercise in women (r≥0.54, P≤0.001) but not men and negatively associated with total peripheral resistance at peak exercise in women (r≥0.43, P≤0.023). Adjustment by adiposity-related or cardiovascular risk factors did not alter results. In conclusion, leg and arm LBM independently associate with internal cardiac dimensions, ventricular relaxation, and systemic vascular resistance in a sex-specific manner, with these relationships exclusively present in women.

Worksite-based intensive lifestyle therapy has profound cardiometabolic benefits in people with obesity and type 2 diabetes

Lifestyle therapy (energy restriction and exercise) is the cornerstone of therapy for people with type 2 diabetes (T2D) but is difficult to implement. We conducted an 8-month randomized controlled trial in persons with obesity and T2D (17 women and 1 man) to determine the therapeutic effects and potential mechanisms of intensive lifestyle therapy on cardiometabolic function. Intensive lifestyle therapy was conducted at the worksite to enhance compliance and resulted in marked (17%) weight loss and beneficial changes in body fat mass, intrahepatic triglyceride content, cardiorespiratory fitness, muscle strength, glycemic control, β cell function, and multi-organ insulin sensitivity, which were associated with changes in muscle NAD+ biosynthesis, sirtuin signaling, and mitochondrial function and in adipose tissue remodeling. These findings demonstrate that intensive lifestyle therapy provided at the worksite has profound therapeutic clinical and physiological effects in people with T2D, which are likely mediated by specific alterations in skeletal muscle and adipose tissue biology.

Pulmonary Arterial Pressure Changes Under Dobutamine Stress Echocardiography in Non-Anemic Iron Deficient COPD Subjects

Purpose

Non-anemic iron deficiency (NAID) is common in COPD, and could induce functional/structural changes in the pulmonary vascular bed. Thus, we aimed to study, during resting and ambient oxygen conditions, the systolic pulmonary arterial pressure (sPAP) changes during dobutamine stress echocardiography (DSE) for NAID+ compared to NAID- subjects with COPD.

Patients and Methods

We analyzed 24 patients with COPD and evaluated their clinical parameters, including lung function and serum iron profile, followed by the changes in the sPAP under DSE.

Results

Ten subjects with NAID+ were compared with fourteen NAID- subjects for sPAP measurement. At baseline, only left atrial volume was significantly different between groups (30±4 vs 23±5 mL_*m²), respectively (p-value=0.002). For the right side, tricuspid annular plane systolic excursion (TAPSE) was similar between-groups (22±2 vs 20±4, p-value >0.05), at baseline. The sPAP (mmHg) changes were also not significantly different between groups (pre 32±14 vs peak 48±14 for NAID+ and pre 29±7 vs peak 43±10 for NAID-, Group p-value=0.400, Time p-value <0.0001, and Interaction p-value=0.606).

Conclusion

COPD subjects with NAID do not show increased sPAP responses during DSE, compared with iron-replete subjects.

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.

Prognostic Role of Cardiac Power in a Large Cohort of Patients with Normal Ejection Fraction Referred for Dobutamine Stress Echocardiography

BACKGROUND

Cardiac power reflects cardiac performance in terms of energy transferred by the left ventricle (LV) to the aorta per unit time. Peak stress cardiac power has been shown to predict outcome in patients with reduced LV ejection fraction (EF), and more recently, in patients with normal EF referred for exercise stress echocardiography. We sought to evaluate the prognostic significance of cardiac power in patients with normal EF referred for dobutamine stress test (DSE).

METHODS

We studied data from 15,576 patients with EF ≥50% and no significant valvular or right ventricular dysfunction, undergoing DSE. Cardiac power at rest and peak stress and power reserve (peak stress minus rest power) were calculated and normalized to LV mass. Outcome endpoints were all-cause mortality and new-onset heart failure (HF).

RESULTS

The mean age was 66±13 years and 49% patients were females. Resting and peak stress power/mass were 0.7±0.2 and 1.6±0.6 W/100 g of LV myocardium, respectively. During follow-up [median 3.3 (IQR 0.7-7.3) years], 2,278 patients died and 2,137 developed HF. After adjusting for age, sex, comorbidities, and stress test results, lower peak stress power/mass was independently associated with mortality [adjusted hazard ratio (HR), highest vs. lowest quartile, 0.84, 95% confidence intervals (CI) 0.74-0.95, P=0.004] and HF at follow-up [adjusted HR 0.67, 95% CI 0.59-0.76, P<0.0001]. Power reserve showed similar associations with outcomes.

CONCLUSION

Assessment of cardiac power during DSE in patients with normal EF provides valuable prognostic information regarding risk of mortality and future HF, in addition to stress test results. It is an important research tool to study cardiac performance and development of risk scores incorporating this novel index could be considered after further validation in prospective studies.

Marked improvements in cardiac function in postmenopausal women exposed to blood withdrawal plus endurance training

The cardiac phenotype of a substantial fraction of the population, i.e., mature women, is mainly unresponsive to endurance training (ET), the most effective intervention to improve cardiorespiratory fitness. This study assessed whether a novel intervention comprising additional haemodynamic stimuli may overcome the generalized limitations to modify the cardiac phenotype of middle-aged and older women. Fifteen healthy postmenopausal women (52-75 yr) were recruited. Transthoracic echocardiography and central haemodynamics were assessed during incremental cycle ergometry (i) in baseline conditions, (ii) after standard (10%) blood withdrawal and (iii) subsequent 8-week ET. Main outcomes such as left ventricular (LV) function and structure and blood volume (BV) were determined. Phlebotomy induced a 0.5 ± 0.1 l reduction of BV, which was re-established after ET. Decrements in LV end-systolic volume (-27%) and increments in LV ejection fraction (+8%) during exercise as well as improved E/A ratio were detected after ET compared with baseline. In parallel, ET induced a 10% increment in LV mass without a concomitant increase in LV size. In conclusion, postmenopausal women exhibit large improvements in cardiac systolic and diastolic functions along with LV concentric remodelling in response to the sequenced combination of blood withdrawal and ET.

Prognostic Value of Exercise Capacity in Kidney Transplant Candidates

Background Exercise stress testing for cardiovascular assessment in kidney transplant candidates has been shown to be a feasible alternative to pharmacologic methods. Exercise stress testing allows the additional assessment of exercise capacity, which may have prognostic value for long-term cardiovascular outcomes in pre-transplant recipients. This study aimed to evaluate the prognostic value of exercise capacity on long-term cardiovascular outcomes in kidney transplant candidates. Methods and Results We retrospectively evaluated exercise capacity in 898 consecutive kidney transplant candidates between 2013 and 2020 who underwent symptom-limited exercise stress echocardiography for pre-transplant cardiovascular assessment. Exercise capacity was measured by age- and sex-predicted metabolic equivalents (METs). The primary outcome was incident major adverse cardiovascular events, defined as cardiac death, non-fatal myocardial infarction, and stroke. Cox proportional hazard multivariable modeling was performed to define major adverse cardiovascular events predictors with transplantation treated as a time-varying covariate. A total of 429 patients (48%) achieved predicted METs. During follow-up, 93 (10%) developed major adverse cardiovascular events and 525 (58%) underwent transplantation. Achievement of predicted METs was independently associated with reduced major adverse cardiovascular events (hazard ratio [HR] 0.49; [95% CI 0.29-0.82], P=0.007), as was transplantation (HR, 0.52; [95% CI 0.30-0.91], P=0.02). Patients achieving predicted METs on pre-transplant exercise stress echocardiography had favorable outcomes that were independent (HR, 0.78; [95% CI 0.32-1.92], P=0.59) and of similar magnitude to subsequent transplantation (HR, 0.97; [95% CI 0.42-2.25], P=0.95). Conclusions Achievement of predicted METs on pre-transplant exercise stress echocardiography confers excellent prognosis independent of and of similar magnitude to subsequent kidney transplantation. Future studies should assess the benefit on exercise training in this population.

Differences in Cardiac Output and Aerobic Capacity Between Sexes Are Explained by Blood Volume and Oxygen Carrying Capacity

Whether average sex differences in cardiorespiratory fitness can be mainly explained by blood inequalities in the healthy circulatory system remains unresolved. This study evaluated the contribution of blood volume (BV) and oxygen (O₂) carrying capacity to the sex gap in cardiac and aerobic capacities in healthy young individuals. Healthy young women and men (n = 28, age range = 20–43 years) were matched by age and physical activity. Echocardiography, blood pressures, and O₂ uptake were measured during incremental exercise. Left ventricular end-diastolic volume (LVEDV), stroke volume (SV), cardiac output (Q), peak O₂ uptake (VO_2peak), and BV were assessed with precise methods. The test was repeated in men after blood withdrawal and reduction of O₂ carrying capacity, reaching women’s levels. Before blood normalization, exercise cardiac volumes and output (LVEDV, SV, Q) adjusted by body size and VO_2peak (42 ± 9 vs. 50 ± 11 ml⋅min^–1⋅kg^–1, P < 0.05) were lower in women relative to men. Blood normalization abolished sex differences in cardiac volumes and output during exercise (P ≥ 0.100). Likewise, VO_2peak was similar between women and men after blood normalization (42 ± 9 vs. 40 ± 8 ml⋅min^–1⋅kg^–1, P = 0.416). In conclusion, sex differences in cardiac output and aerobic capacity are not present in experimental conditions matching BV and O₂ carrying capacity between healthy young women and men.

Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis: The AVATAR Trial

BACKGROUND

Surgical aortic valve replacement (SAVR) represents a class I indication in symptomatic patients with severe aortic stenosis (AS). However, indications for early SAVR in asymptomatic patients with severe AS and normal left ventricular function remain debated.

METHODS

The AVATAR trial (Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis) is an investigator-initiated international prospective randomized controlled trial that evaluated the safety and efficacy of early SAVR in the treatment of asymptomatic patients with severe AS, according to common criteria (valve area ≤1 cm² with aortic jet velocity >4 m/s or a mean transaortic gradient ≥40 mm Hg), and with normal left ventricular function. Negative exercise testing was mandatory for inclusion. The primary hypothesis was that early SAVR would reduce the primary composite end point of all-cause death, acute myocardial infarction, stroke, or unplanned hospitalization for heart failure compared with a conservative strategy according to guidelines. The trial was designed as event-driven to reach a minimum of 35 prespecified events. The study was performed in 9 centers in 7 European countries.

RESULTS

Between June 2015 and September 2020, 157 patients (mean age, 67 years; 57% men) were randomly allocated to early surgery (n=78) or conservative treatment (n=79). Follow-up was completed in May 2021. Overall median follow-up was 32 months: 28 months in the early surgery group and 35 months in the conservative treatment group. There was a total of 39 events, 13 in early surgery and 26 in the conservative treatment group. In the early surgery group, 72 patients (92.3%) underwent SAVR with operative mortality of 1.4%. In an intention-to-treat analysis, patients randomized to early surgery had a significantly lower incidence of primary composite end point than those in the conservative arm (hazard ratio, 0.46 [95% CI, 0.23-0.90]; P=0.02). There was no statistical difference in secondary end points, including all-cause mortality, first heart failure hospitalizations, major bleeding, or thromboembolic complications, but trends were consistent with the primary outcome.

CONCLUSIONS

In asymptomatic patients with severe AS, early surgery reduced a primary composite of all-cause death, acute myocardial infarction, stroke, or unplanned hospitalization for heart failure compared with conservative treatment. This randomized trial provides preliminary support for early SAVR once AS becomes severe, regardless of symptoms. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02436655.

The prospective randomized trial of the optimal evaluation of cardiac symptoms and revascularization: Rationale and design of the PRECISE trial

BACKGROUND

Clinicians vary widely in their preferred diagnostic approach to patients with non-acute chest pain. Such variation exposes patients to potentially avoidable risks, as well as inefficient care with increased costs and unresolved patient concerns.

METHODS

The Prospective Randomized Trial of the Optimal Evaluation of Cardiac Symptoms and Revascularization (PRECISE) trial (NCT03702244) compares an investigational "precision" diagnostic strategy to a usual care diagnostic strategy in participants with stable chest pain and suspected coronary artery disease (CAD).

RESULTS

PRECISE randomized 2103 participants with stable chest pain and a clinical recommendation for testing for suspected CAD at 68 outpatient international sites. The investigational precision evaluation strategy started with a pre-test risk assessment using the PROMISE Minimal Risk Tool. Those at lowest risk were assigned to deferred testing (no immediate testing), and the remainder received coronary computed tomographic angiography (cCTA) with selective fractional flow reserve (FFR_CT) for any stenosis meeting a threshold of ≥30% and <90%. For participants randomized to usual care, the clinical care team selected the initial noninvasive or invasive test (diagnostic angiography) according to customary practice. The use of cCTA as the initial diagnostic strategy was proscribed by protocol for the usual care strategy. The primary endpoint is time to a composite of major adverse cardiac events (MACE: all-cause death or non-fatal myocardial infarction) or invasive cardiac catheterization without obstructive CAD at 1 year. Secondary endpoints include health care costs and quality of life.

CONCLUSIONS

PRECISE will determine whether a precision approach comprising a strategically deployed combination of risk-based deferred testing and cCTA with selective FFR_CT improves the clinical outcomes and efficiency of the diagnostic evaluation of stable chest pain over usual care.

Diagnostic value of postsystolic shortening of the left ventricular myocardium assessed during speckle tracking stress echocardiography on the treadmill in patients with coronary artery disease

Aim      To evaluate the diagnostic capacity of left ventricular (LV) postsystolic shortening (PSS) values obtained by speckle-tracking stress-echocardiography (stress-EchoCG) using a treadmill test in determining the functional significance of the degree of coronary artery (CA) stenosis.Material and methods  The study included 132 patients (80 men aged 65.0±9.3 years) with suspected or previously verified diagnosis of ischemic heart disease. Stress-EchoCG with the treadmill test was performed for all patients. Strain parameters were determined by two-dimensional speckle-tracking on gray-scale images before and after the exercise. Values of LV postsystolic index (PSI) and LV mean postsystolic time (PST) were calculated. Coronary angiography was performed for all patients. Patients were divided into 3 groups based on the severity of CA stenosis according to the G. G. Gensini score.Results LV PSS values at rest did not significantly differ between the patient groups. After completion of the exercise, the mean LV PSI was significantly higher for patients with pronounced CA stenosis than in the group without CA stenosis or with moderate CA stenosis: 8.9 %  [3.8; 10.7 %] vs. 3.8 % [2.2; 6.8 %] (p=0.012) and 3.4 %  [2.2; 6.2 %] (p=0.012), respectively. The mean LV PSI after completion of the exercise indicated the presence of pronounced CA stenosis with a sensitivity of 75 % and a specificity of 61 % (area under the curve, AUC, 0.74±0.06; р&lt;0.001). After completion of the exercise, the mean LV PST was significantly greater for patients with pronounced CA stenosis than in the group without CA stenosis or with moderate CA stenosis: 27.4 [18.7; 34.7] ms vs. 18.4 [10.8; 26.5] ms (p=0.036) and 20.9 [14.2; 29.5] ms (p=0.036), respectively. The mean LV PST after completion of the exercise exceeding 23.5 ms suggests pronounced CA stenosis with a sensitivity of 71 % and a specificity of 65 % (AUC 0.69±0.06; p=0.004). A complex evaluation of the LV PSI, the LV local contractility disorder (LCD) index, the LV PST, and LV LCD index allows enhancement of the test sensitivity in diagnozing pronounced CA stenosis.Conclusion      Determination of LV PSS in speckle-tracking stress-EchoCG may be useful for evaluating the functional significance of the degree of CA stenosis to enhance the sensitivity of stress-EchoCG in patients with pronounced CA stenosis.

Cardiac Imaging for the Assessment of Left Atrial Mechanics Across Heart Failure Stages

The left atrium (LA) is emerging as a key element in the pathophysiology of several cardiac diseases due to having an active role in contrasting heart failure (HF) progression. Its morphological and functional remodeling occurs progressively according to pressure or volume overload generated by the underlying disease, and its ability of adaptation contributes to avoid pulmonary circulation congestion and to postpone HF symptoms. Moreover, early signs of LA dysfunction can anticipate and predict the clinical course of HF diseases before the symptom onset which, particularly, also applies to patients with increased risk of HF with still normal cardiac structure (stage A HF). The study of LA mechanics (chamber morphology and function) is moving from a research interest to a clinical application thanks to a great clinical, prognostic, and pathophysiological significance. This process is promoted by the technological progress of cardiac imaging which increases the availability of easy-to-use tools for clinicians and HF specialists. Two-dimensional (2D) speckle tracking echocardiography and feature tracking cardiac magnetic resonance are becoming essential for daily practice. In this context, a deep understanding of LA mechanics, its prognostic significance, and the available approaches are essential to improve clinical practice. The present review will focus on LA mechanics, discussing atrial physiology and pathophysiology of main cardiac diseases across the HF stages with specific attention to the prognostic significance. Imaging techniques for LA mechanics assessment will be discussed with an overlook on the dynamic (under stress) evaluation of the chamber.

Sex and age interaction in fundamental circulatory volumetric variables at peak working capacity

Background

Whether the fundamental hematological and cardiac variables determining cardiorespiratory fitness and their intrinsic relationships are modulated by major constitutional factors, such as sex and age remains unresolved.

Methods

Transthoracic echocardiography, central hemodynamics and pulmonary oxygen (O₂) uptake were assessed in controlled conditions during submaximal and peak exercise (cycle ergometry) in 85 healthy young (20–44 year) and older (50–77) women and men matched by age-status and moderate-to-vigorous physical activity (MVPA) levels. Main outcomes such as peak left ventricular end-diastolic volume (LVEDV_peak), stroke volume (SV_peak), cardiac output (Q_peak) and O₂ uptake (VO_2peak), as well as blood volume (BV), BV–LVEDV_peak and LVEDV_peak–SV_peak relationships were determined with established methods.

Results

All individuals were non-smokers and non-obese, and MVPA levels were similar between sex and age groups (P ≥ 0.140). BV per kg of body weight did not differ between sexes (P ≥ 0.118), but was reduced with older age in men (P = 0.018). Key cardiac parameters normalized by body size (LVEDV_peak, SV_peak, Q_peak) were decreased in women compared with men irrespective of age (P ≤ 0.046). Older age per se curtailed Q_peak (P ≤ 0.022) due to lower heart rate (P < 0.001). In parallel, VO_2peak was reduced with older age in both sexes (P < 0.001). The analysis of fundamental circulatory relationships revealed that older women require a higher BV for a given LVEDV_peak than older men (P = 0.024).

Conclusions

Sex and age interact on the crucial circulatory relationship between total circulating BV and peak cardiac filling, with older women necessitating more BV to fill the exercising heart than age- and physical activity-matched men.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-021-00409-9.

The fundamental role of stress echo in evaluating coronary artery disease in specific patient populations

Stress echocardiography (SE) was initially used for assessing patients with known or suspected coronary heart disease by detecting and evaluating myocardial ischemia and viability. The implementation of SE has gradually been extended to several cardiovascular diseases beyond coronary artery disease, and SE protocols have been modified and adapted for the detection of coronary artery disease (CAD) or other cardiovascular diseases in specific patient populations. This review attempts to summarize current data concerning SE implementation and clinical value in these specific and diverse populations: patients with an intramural course of a coronary artery - known as a myocardial bridge, chronic severe or end-stage hepatic disease, chronic severe or end-stage kidney disease, cardiac allograft vasculopathy, patients scheduled for solid-organ transplantation and other intermediate and high-risk surgery and, finally, patients treated with anticancer drugs or radiotherapy.

Blood withdrawal acutely impairs cardiac filling, output and aerobic capacity in proportion to induced hypovolemia in middle-aged and older women

Blood donation entails acute reductions of cardiorespiratory fitness in healthy men. Whether these effects can be extrapolated to blood donor populations comprising women remains uncertain. The purpose of this study was to comprehensively assess the acute impact of blood withdrawal on cardiac function, central hemodynamics and aerobic capacity in women throughout the mature adult lifespan. Transthoracic echocardiography and O2 uptake were assessed at rest and throughout incremental exercise (cycle ergometry) in healthy women (n = 30, age: 47-77 yr). Left ventricular end-diastolic volume (LVEDV), stroke volume (SV), cardiac output (Q̇) and peak O2 uptake (V̇O2peak), and blood volume (BV) were determined with established methods. Measurements were repeated following a 10% reduction of BV within a week period. Individuals were non-smokers, non-obese and moderately fit (V̇O2peak = 31.4 ± 7.3 mL·min-1·kg-1). Hematocrit and BV ranged from 38.0 to 44.8% and from 3.8 to 6.6 L, respectively. The standard 10% reduction in BV resulted in 0.5 ± 0.1 L withdrawal of blood, which did not alter hematocrit (P = 0.953). Blood withdrawal substantially reduced cardiac LVEDV and SV at rest as well as during incremental exercise (≥10% decrements, P ≤ 0.009). Peak Q̇ was proportionally decreased after blood withdrawal (P < 0.001). Blood withdrawal induced a 10% decrement in V̇O2peak (P < 0.001). In conclusion, blood withdrawal impairs cardiac filling, Q̇ and aerobic capacity in proportion to the magnitude of hypovolemia in healthy mature women. Novelty: The filling of the heart and therefore cardiac output are impaired by blood withdrawal in women. Oxygen delivery and aerobic capacity are reduced in proportion to blood withdrawal.

Automated Echocardiographic Detection of Severe Coronary Artery Disease Using Artificial Intelligence

OBJECTIVES

The purpose of this study was to establish whether an artificially intelligent (AI) system can be developed to automate stress echocardiography analysis and support clinician interpretation.

BACKGROUND

Coronary artery disease is the leading global cause of mortality and morbidity and stress echocardiography remains one of the most commonly used diagnostic imaging tests.

METHODS

An automated image processing pipeline was developed to extract novel geometric and kinematic features from stress echocardiograms collected as part of a large, United Kingdom-based prospective, multicenter, multivendor study. An ensemble machine learning classifier was trained, using the extracted features, to identify patients with severe coronary artery disease on invasive coronary angiography. The model was tested in an independent U.S.

STUDY

How availability of an AI classification might impact clinical interpretation of stress echocardiograms was evaluated in a randomized crossover reader study.

RESULTS

Acceptable classification accuracy for identification of patients with severe coronary artery disease in the training data set was achieved on cross-fold validation based on 31 unique geometric and kinematic features, with a specificity of 92.7% and a sensitivity of 84.4%. This accuracy was maintained in the independent validation data set. The use of the AI classification tool by clinicians increased inter-reader agreement and confidence as well as sensitivity for detection of disease by 10% to achieve an area under the receiver-operating characteristic curve of 0.93.

CONCLUSION

Automated analysis of stress echocardiograms is possible using AI and provision of automated classifications to clinicians when reading stress echocardiograms could improve accuracy, inter-reader agreement, and reader confidence.

Blood Oxygen Carrying Capacity Determines Cardiorespiratory Fitness in Middle-Age and Older Women and Men

PURPOSE

Whether blood oxygen (O2)-carrying capacity plays a substantial role in determining cardiorespiratory fitness, a strong predictor of mortality, remains uncertain in women and elderly individuals because of the scarcity of experimental investigations. This study experimentally assessed the role of blood O2-carrying capacity on cardiorespiratory fitness in middle-age and older individuals.

METHODS

Healthy women and men (n = 31, 35-76 yr) matched by age and fitness were recruited. Transthoracic echocardiography, central hemodynamics, and O2 uptake were assessed throughout incremental exercise in (i) control conditions and (ii) after a 10% reduction of blood O2-carrying capacity via carbon monoxide administration, in a blinded manner. Effects on cardiac function, blood pressure, peak O2 uptake, and effective hemoglobin (Hb) were determined with established methods.

RESULTS

Blood O2-carrying capacity, represented by effective Hb, was similarly reduced in women (11.8 ± 0.6 vs 10.7 ± 0.6 g·dL-1, P < 0.001) and men (13.0 ± 0.9 vs 11.7 ± 0.6 g·dL-1, P < 0.001) (P for sex effect = 0.580). Reduced O2-carrying capacity did not induce major effects on cardiac function and hemodynamics during exercise, except for a 10%-15% decrement in peak systolic blood pressure in both sexes (P ≤ 0.034). Peak O2 uptake decreased from 35 ± 6 to 31 ± 6 mL·min-1·kg-1, P < 0.001) in women and from 35 ± 9 to 32 ± 9 mL·min-1·kg-1 (P = 0.024) in men in approximate proportion to the reduction of O2-carrying capacity, an effect that did not differ between sexes (P = 0.778).

CONCLUSIONS

Blood O2-carrying capacity stands out as a major determinant of cardiorespiratory fitness in healthy mature women and men, with no differential effect of sex.

Stress Echocardiography Protocol for Deciding Type of Surgery in Ischemic Mitral Regurgitation: Predictors of Mitral Regurgitation Recurrence following CABG Alone

Purpose: Although coronary artery bypass grafting alone (CABGa), or, with mitral annuloplasty (CABGmp), is considered the best therapeutic strategy for patients with ischemic mitral regurgitation (IMR), some recurrences are still reported. The aim of this study was to evaluate the use of the mitral deformation indices (MDI) as a predictor of recurrence of mitral regurgitation in a 12-month follow-up after CABG alone. Methods: A total of 145 patients after myocardial infarction with significant IMR, eligible for CABG, were prospectively enrolled in the study. Mitral valve morphology, left ventricle function, IMR degree as assessed by effective regurgitation orifice area (ERO), myocardial viability, and MDI were assessed prior to surgery. Patients were referred for CABGa (gr.1; n = 90) or CABGmp (gr.2; n = 55) based on clinical assessment, and the results of rest and stress echocardiography (exercise echocardiography and low dose dobutamine echocardiography-DBX). One year after surgery, each patient underwent the evaluation of cardiovascular events. Univariable logistic regression analysis was used to identify the factors of recurrence of IMR in 1 year follow-up. Serial echo examinations were performed in all patients at discharge, and at 1 and 12 months after surgery. Results: Logistic regression analysis revealed that in CABGa, group preoperative changes of tenting area (TA) and coaptation high (CH) during DBX remained the predictors of the recurrence of IMR in 12 months follow-up. TAdbx > 1 cm² provided a sensitivity of 90% and specificity of 29%, (AUC 0.6436). The best cut-off value for CHdbx was 0.4 cm (sensitivity 90%, specificity 34%; AUC 0.6432). In both groups (CABGa vs. CABGmp) no significant differences were observed in 12-month mortality (1.2% vs. 0%; p = 1.0), hospitalizations due to the heart failure (HF) exacerbation (5.9% vs. 8.5%; p = 0.72), and in the incidence of the composite endpoint (deaths/CV hosp/stroke) (7% vs. 8.5%; p = 0.742). Conclusions: The preoperative assessment of MDI changes during dbx can be used to identify patients with IMR qualified to CABG alone at increased risk of recurrence of IMR in 1 year follow-up. Mitral deformation analysis should be used for a better qualification of patients with IMR to the exact surgical approach.

A Reminder That Stress Echocardiography Is Useful in Diagnosing Myocardial Ischemia in Nonobstructive Coronary Artery Disease: Case Series

Identification of ischemia remains critical when assessing individuals presenting with atypical symptoms or in patients with known coronary artery disease (CAD). Several imaging modalities are currently available to attain this diagnostic goal. Unfortunately, not all case presentations are straightforward, particularly when microvascular dysfunction (MVD) is the cause of symptoms in the absence of identifiable epicardial luminal stenosis. Specifically, in such cases, current imaging guidelines do not include stress echocardiography (SE) as a recommended tool when assessing these patients. We present three cases that highlight the utility of SE for identifying MVD and provide mechanistic explanations. We believe that SE should not be completely discarded as an inadequate testing modality; we highlight the potential utility of this imaging modality not only in diagnosing CAD and pre-surgical evaluation of patients but also in identifying patients with MVD.

Safety of SF6(SonoVue®) Contrast Agent on Pharmacological Stress Echocardiogram

Fundamento

Em 2007, a Food and Drug Administration (FDA) determinou revisões sobre segurança dos agentes de contraste ecocardiográfico (ACE) disponíveis no mercado após relatos de mortes. Ao longo desses anos, diversos estudos comprovaram a segurança dos ACE, porém com poucos estudos relacionados ao SonoVue^®.

Objetivos

Avaliar a segurança do SonoVue^® durante o ecocardiograma sob estresse farmacológico (EEF) por meio da análise da incidência de reações alérgicas e da comparação entre os grupos quanto ao surgimento de arritmia, efeitos colaterais menores e eventos adversos.

Métodos

Estudo observacional, prospectivo, no qual 2.346 pacientes foram submetidos ao EEF e divididos em dois grupos: grupo 1 com ACE (n=1.099) e grupo 2 sem ACE (n=1.247). Os pacientes foram avaliados durante o EEF – 24 horas e 30 dias. Foi definido p significativo quando <0,05.

Resultados

O grupo 1 apresentou efeitos colaterais mais leves, como cefaleia (5/0,5% vs. 19/1,5%, p=0,012) e hipertensão reativa (3/0,3% vs . 19/1,5%, p=0,002), menos arritmias como extrassístoles ventriculares (180/16,4% vs . 247/19,8%, p=0,032) e taquicardia paroxística supraventricular (2/0,2% vs . 15/1,2%, p=0,003), assim como nenhum evento adverso como infarto agudo do miocárdio (IAM) e óbito. No grupo 2, um paciente apresentou IAM <24h (1/01%) e dois óbitos <30 dias (2/0,1%). Urticária relacionada ao SonoVue^® foi observada em 3 (0,3%) pacientes sem reação anafilática.

Conclusão

SonoVue^® demonstrou segurança durante o EEF, não sendo observados morte, IAM ou reação anafilática. Observou-se menor incidência de efeitos colaterais mais leves e arritmias no grupo que utilizou o ACE, assim como baixa incidência de reações alérgicas leves.

Effects of Copaiba Oil in Peripheral Markers of Oxidative Stress in a Model of Cor Pulmonale in Rats

Fundamento

Até o presente momento, os efeitos sistêmicos do óleo de copaíba jamais foram documentados no Cor pulmonale induzido por monocrotalina.

Objetivos

Investigar os efeitos do óleo de copaíba nos marcadores periféricos de stress oxidativo em ratos com Cor pulmonale.

Métodos

Ratos Wistar machos (170±20g, n=7/grupo) foram divididos em quatro grupos: controle (CO), monocrotalina (MCT), óleo de copaíba (O), e monocrotalina + óleo de copaíba (MCT-O). Foi administrada a MCT (60 mg/kg i.p.) e, depois de uma semana, foi iniciado o tratamento com óleo de copaíba (400 mg/kg/day-gavagem-14 dias). Foi realizado o ecocardiograma e, depois disso, foi coletado sangue do tronco para a realização de avaliações de stress oxidativo. Análise estatística: ANOVA de duas vias com teste Student-Newman-Keuls post hoc. P-valores <0,05 foram considerados significativos.

Resultados

O óleo de copaíba reduziu a resistência vascular pulmonar e a hipertrofia do ventrículo direito (VD) hipertrofia (Índice de Fulton (mg/mg)): MCT-O= 0,39±0,03; MCT= 0,49±0,01), e função sistólica melhorada (fração de encurtamento do VD, %) no grupo MCT-O (17,8±8,2) em comparação com o grupo de MCT (9,4±3,1; p<0,05). Além disso, no grupo MCT-O, espécies reativas do oxigênio e os níveis de carbonila foram reduzidos, e os parâmetros antioxidantes aumentaram no sangue periférico (p <0,05).

Conclusões

Os resultados deste estudo sugerem que o óleo de copaíba tem um efeito antioxidante sistêmico interessante, que se reflete na melhoria da função e na morfometria do VD nesse modelo de Cor pulmonale . A atenuação do Cor pulmonale promovida pelo óleo de copaíba coincidiu com uma redução no stress oxidativo sistêmico.

Predicting premature termination of exercise during Bruce protocol stress echocardiography

AIMS

Clinical guidelines recommend that the exercise protocol of a stress echocardiogram is selected to induce volitional exhaustion after a target duration of at least 8 minutes. While the Bruce protocol is very commonly used for clinical stress tests, it is known to be "steep", and many patients therefore fail to reach 8 minutes. We studied predictors of failure and developed a method for identifying patients not suitable for Bruce protocol which was accurate and yet simple enough to be used as a point-of-care decision support tool.

METHODS AND RESULTS

We studied data out-patients undergoing Bruce protocol stress echocardiograms (n = 11 086) and analyzed predictors of inappropriate early termination (defined as test duration < 8 min as per current practice guidelines) using logistic regression. A prediction model was constructed as follows: .5 points were given for each of hypertension, diabetes, smoking, and E/e' > 7.9 in the resting echocardiogram; .1 point was added for each 1-unit increment in body mass index; 1 point was added for patient age by decade; 2.0 points were subtracted for male sex (p for all < 0.001). In tests on held-out validation data, the model was well calibrated (in plots of predicted vs actual risk) and discriminated failure versus non-failure well (C-statistic .86 for a score of 6.0 points; p < 0.001).

CONCLUSION

These data may help to standardize protocol selection in stress echocardiography, by identifying patients pre-hoc where Bruce protocol will be inappropriately steep.