Predictor Of Exercise Capacity Research Articles

Does fear of activity predict exercise capacity in patients with coronary artery disease in both sexes? A cross-sectional multicenter study.

This study aimed to identify whether fear of activity predicts exercise capacity in patients with coronary artery disease (CAD) and whether there is a difference between sexes regarding this relationship. One hundred ninety-seven patients (145 males, 52 females; mean age: 56.3±10.8 years; range, 22 to 80 years) with a diagnosis of CAD or cardiac event in the previous one to 60 months were enrolled in this cross-sectional multicenter study between November 2015 and February 2017. Demographic and clinical features were recorded. Fear of activity was assessed by the fear of activity scale in patients with CAD (FactCAD). A 6-min walk test was used to assess exercise capacity. Female participants were older, less educated, and less employed (p=0.045, p=0.048, and p<0.001, respectively) than males. Prevalence of myocardial infarction was higher in males. Comorbidities were higher in females. Multiple linear regression predicted 6-min walk distance (6MWD) based on FactCAD, sex, and education level with an r-squared of 0.321 (p<0.001). Fear of activity had an effect on walking distance in males (each additional score of FactCAD predicts a decrease of 1.3 m in 6MWD), together with disease duration, presence of chronic pulmonary disease, and low back pain, whereas fear of activity was not a predicting factor on walking distance in females. Age, education, and presence of angina predicted 6MWD in females. This study emphasizes that fear of activity is one of the predictors of 6MWD in males with CAD, and its assessment is recommended as a possible barrier to rehabilitation.

Aortic arch shape after arch repair predicts exercise capacity: a multicentre analysis.

Coarctation of the aorta is associated with long-term morbidity including decreased exercise capacity, despite successful repair. In the absence of discrete recoarctation, the haemodynamic mechanism remains unknown. This multicentre study evaluated the relationship between aorta shape, flow, and exercise capacity in patients after arch repair, specifically through the lens of aortic size mismatch and descending aortic (DAo) flow and their association with exercise. Cardiac magnetic resonance, cardiopulmonary exercise test, and echocardiogram data within 1 year were analysed from 58 patients (age 28 ± 10 years, 48% male) across four centres with history of isolated arch repair. Aortic arch measurements were correlated with % predicted VO2max with subgroup analyses of those with residual arch obstruction, bicuspid aortic valve, and hypertension. Ascending aorta (AAo) to DAo diameter ratio (DAAo/DDAo) was negatively correlated with % predicted VO2max. %DAo flow positively correlated with VO2max. Sub-analyses demonstrated that the negative correlation of DAAo/DDAo with VO2max was maintained only in patients without arch obstruction and with a bicuspid aortic valve. Smaller aortic arch measurements were associated with both hypertension and exercise-induced hypertension. Aorta size mismatch, due to AAo dilation or small DAo, and associated decreased %DAo flow, correlated significantly with decreased exercise capacity after aortic arch repair. These correlations were stronger in patients without arch obstruction and with a bicuspid aortic valve. Aorta size mismatch and %DAo flow capture multiple mechanisms of altered haemodynamics beyond blood pressure gradient or discrete obstruction and can inform the definition of a successful repair.

Cardiac remodelling in male and female athletes: An MRI assessment of cardiac size and its impact on cardiorespiratory fitness

Abstract Background Cardiac remodelling occurs in response to endurance training in elite athletes. Previous small studies have shown relationships between cardiac size and cardiorespiratory fitness (CRF) using echocardiography, but few studies have assessed the relationship on a larger scale with female athletes and cardiac MRI. Aim To examine the relationship between CRF and MRI measures of cardiac size and function in male and female endurance athletes. Methods 183 male and 64 female elite endurance athletes aged &amp;gt; 16 years underwent assessment of biventricular size and function using cardiac MRI and CRF (as measured by VO2peak). The association between biventricular size, function and VO2peak was assessed using univariate linear regression and multivariate regression adjusting for age, BMI and systolic blood pressure. Results There was a strong correlation between VO2peak and LVEDV and RVEDV in both male and female athletes (females r = 0.81 and r = 0.82 respectively, males r = 0.76 and 0.67, p &amp;lt; 0.001). There was no significant correlation between VO2peak and LV or RV EF in female athletes, and there was a weak association in males (LVEF r= 0.15, p=0.04, RVEF r = 0.27, p&amp;lt; 0.001). On multivariate analysis, LVEDV and LV mass were independent predictors in males and explained 78% of the variance in VO2peak (b = 0.41 and 0.18 respectively, p= &amp;lt; 0.001) and only LVEDV was an independent predictor in females explaining 64% of VO2peak variance (b =0.67, p &amp;lt; 0.001). Conclusion CRF as measured by VO2peak is determined by cardiac size as opposed to function in both male and female elite endurance athletes. This study is the largest assessment of endurance athletes with cardiac MRI and emphasises the role of cardiac volumes in predicting exercise capacity in the population.

Abstract 16196: E/e' Predicts Exercise Capacity in Participants Undergoing Exercise Stress Test

Introduction: The ratio of early transmitral flow velocity (E) to early diastolic mitral annular velocity (e’) is a surrogate for left ventricular (LV) filling pressure. Post-stress E/e’ has been shown to predict exercise capacity, but few studies have investigated this correlation with baseline E/e’. Our aim was to evaluate the relationship between baseline E/e’ and exercise capacity during stress test. Methods: All patients undergoing exercise stress testing at University of Virginia from 1/2015 through 9/2015 with the required echo data were included in this study. E/e’ was categorized into quartiles. ANOVA was used to evaluate the relationship between quartiles of E/e’ and exercise duration or METS. Multivariate linear regression was used to adjust for the variables: age, sex, ejection fraction, systolic blood pressure, heart rate, and regional wall motion abnormalities. Results: Baseline characteristics of the 312 participants based on E/e’ quartiles are shown in Table 1; those with higher E/e’, on average, had higher baseline SBP, were older, and had a higher percentage of females. There was a significant difference in exercise duration and METS between E/e’ quartiles (Table 2A) [p &lt; 0.001]. There was an inverse correlation between E/e’ and exercise capacity; the significance was more pronounced with increasing E/e’ (Table 2A) and was present even after adjusting for multiple covariates (Table 2B). Conclusions: Baseline E/e’ correlates with exercise capacity (both duration of exercise and total METS achieved). This suggests that elevated LV filling pressures at rest can predict exercise capacity and may be targeted in future studies to improve exercise tolerance.

Classification and Predictors of Right Ventricular Functional Recovery in Pulmonary Arterial Hypertension.

Normative changes in right ventricular (RV) structure and function have not been characterized in the context of treatment-associated functional recovery (RV functional recovery [RVFnRec]). The aim of this study is to assess the clinical relevance of a proposed RVFnRec definition. We evaluated 63 incident patients with pulmonary arterial hypertension by right heart catheterization and cardiac magnetic resonance imaging at diagnosis and cardiac magnetic resonance imaging and invasive cardiopulmonary exercise testing following treatment (≈11 months). Sex, age, ethnicity matched healthy control subjects (n=62) with 1-time cardiac magnetic resonance imaging and noninvasive cardiopulmonary exercise testing were recruited from the PVDOMICS (Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics) project. We examined therapeutic cardiac magnetic resonance imaging changes relative to the evidence-based peak oxygen consumption (VO2peak)>15 mL/(kg·min) to define RVFnRec by receiver operating curve analysis. Afterload was measured as mean pulmonary artery pressure, resistance, compliance, and elastance. A drop in RV end-diastolic volume of -15 mL best defined RVFnRec (area under the curve, 0.87; P=0.0001) and neared upper 95% CI RV end-diastolic volume of controls. This cutoff was met by 22 out of 63 (35%) patients which was reinforced by freedom from clinical worsening, RVFnRec 1 out of 21 (5%) versus no RVFnRec 17 out of 42, 40% (log-rank P=0.006). A therapy-associated increase of 0.8 mL/mm Hg in compliance had the best predictive value of RVFnRec (area under the curve, 0.76; [95% CI, 0.64-0.88]; P=0.001). RVFnRec patients had greater increases in stroke volume, and cardiac output at exercise. RVFnRec defined by RV end-diastolic volume therapeutic decrease of -15 mL predicts exercise capacity, freedom from clinical worsening, and nears normalization. A therapeutic improvement of compliance is superior to other measures of afterload in predicting RVFnRec. RVFnRec is also associated with increased RV output reserve at exercise.

Body Composition, Physical Function and Exercise Capacity in Chronic Obstructive Pulmonary Disease

Current literature yields unequivocal results regarding the effect of body composition on physical function in patients with chronic obstructive pulmonary disease and disproportionately includes a majority of males. The purpose of this study was to determine whether specific body composition measures are significantly associated with physical function and exercise capacity in patients with chronic obstructive pulmonary disease with equal representation of males and females. Independent variables included sex, total body mass, total body lean and fat mass, appendicular total mass, and appendicular lean and fat mass. Dependent variables included peak oxygen consumption, 6-minute walk distance and self-reported physical function. Patients (n = 170) with dual-energy X-ray absorptiometry data, 6-minute walk distance, and self-reported physical function were used for these analyses. A sub-set of 145 of these patients with peak oxygen consumption data were also analysed. Hierarchical multiple regression analysis was used to determine if sex and body composition measures correlated with physical function and exercise capacity and if they explained additional variance after controlling for disease severity. After controlling for disease severity, appendicular lean mass, total body fat mass, and sex explained an additional 16.5% of the variance in peak oxygen consumption (p < 0.001). Appendicular lean mass explained an additional 8.9% of the variance in 6-minute walk distance (p < 0.001) and an additional 2.5% of the variance in self-reported physical function (p = 0.057). Body composition measures may further predict exercise capacity, 6-minute walk distance, and self-reported physical function in patients with chronic obstructive pulmonary disease.

Aortic flow is associated with aging and exercise capacity.

Increased blood flow eccentricity in the aorta has been associated with aortic (AO) pathology, however, its association with exercise capacity has not been investigated. This study aimed to assess the relationships between flow eccentricity parameters derived from 2-dimensional (2D) phase-contrast (PC) cardiovascular magnetic resonance (CMR) imaging and aging and cardiopulmonary exercise test (CPET) in a cohort of healthy subjects. One hundred and sixty-nine healthy subjects (age 44 ± 13 years, M/F: 96/73) free of cardiovascular disease were recruited in a prospective study (NCT03217240) and underwent CMR, including 2D PC at an orthogonal plane just above the sinotubular junction, and CPET (cycle ergometer) within one week. The following AO flow parameters were derived: AO forward and backward flow indexed to body surface area (FFi, BFi), average flow displacement during systole (FDsavg), late systole (FDlsavg), diastole (FDdavg), systolic retrograde flow (SRF), systolic flow reversal ratio (sFRR), and pulse wave velocity (PWV). Exercise capacity was assessed by peak oxygen uptake (PVO2) from CPET. The mean values of FDsavg, FDlsavg, FDdavg, SRF, sFRR, and PWV were 17 ± 6%, 19 ± 8%, 29 ± 7%, 4.4 ± 4.2 mL, 5.9 ± 5.1%, and 4.3 ± 1.6 m/s, respectively. They all increased with age (r = 0.623, 0.628, 0.353, 0.590, 0.649, 0.598, all P < 0.0001), and decreased with PVO2 (r = -0.302, -0.270, -0.253, -0.149, -0.219, -0.161, all P < 0.05). A stepwise multivariable linear regression analysis using left ventricular ejection fraction (LVEF), FFi, and FDsavg showed an area under the curve of 0.769 in differentiating healthy subjects with high-risk exercise capacity (PVO2 ≤ 14 mL/kg/min). AO flow haemodynamics change with aging and predict exercise capacity. NCT03217240.

Impaired Exercise Capacity and Mortality Risk in Adults With Congenital Heart Disease

BackgroundAn association between impaired exercise capacity and risk of mortality has been reported among adults with congenital heart disease (CHD). Over the years, treatment methods have improved and may influence outcome. Hence, we report data from a national cohort reflecting a contemporary population. ObjectivesThe purpose of this study was to investigate the association between exercise capacity (workload) and mortality in a large registry-based cohort. MethodsData on exercise capacity using cycle ergometer were retrieved from the national registry of CHD. The association between predicted exercise capacity (%ECpred) and mortality was analyzed using Cox regression. ResultsIn total, 3,721 adults (>18 years, 44.6% women) with CHD were included. The median age was 27.0 years (IQR: 20.8-41.0 years) and mean %ECpred was 77% ± 20%. Over a mean follow-up of 9.4 ± 6.0 years, there were 214 (5.8%) deaths. The Multivariable Cox regression model showed that moderately and severely impaired exercise capacity (50-<70 %ECpred: HR: 2.1, 95% CI: 1.4-3.2, P < 0.001, and <50 %ECpred: HR: 3.5, 95% CI: 2.1-6.0, P < 0.001) and CHD complexity were associated with higher mortality (moderate complexity: HR: 1.9 95% CI: 1.2-3.0, P = 0.003, great complexity: HR: 2.3 95% CI: 1.3-4.2, P = 0.008) when adjusted for New York Heart Association class, physical activity, cardiovascular medication, sex, impaired systemic ventricular function, and age. ConclusionsImpaired exercise capacity and CHD complexity are independently associated with all-cause mortality in patients with CHD. Exercise capacity is an easily accessible variable that may be a useful tool for risk assessment in adult patients with CHD, but this needs confirmation in prospective studies.

Right Ventricle Myocardial Work in ToF-repair survivors: no longer behind the scenes

Abstract Funding Acknowledgements Type of funding sources: None. Background Tetralogy of Fallot is the most common cyanotic CHD and survivors after ToF repair are growing rapidly. Children and, more frequently, young adults spToF develop late complications: life-threatening ventricular arrhythmias and SCD remain a great concern in these patients. This study has the aim to analyse advanced Right Ventricle echocardiographic and CMR features sp-ToF in the long-term follow-up, finding non-invasive predictors of adverse prognosis. Methods This is a retrospective cohort study. 240 patients sp-ToF were included (mean age 13 ± 11 years). The electrocardiographic, echocardiographic, CMR and CPET data were reviewed retrospectively. Non-invasive RV Global myocardial Work Index (RVGWI) was calculated as the area of the RV pressure-strain loops. RV Global Constructive Work (RVGCW), RV Global Wasted Work (RVGWW) and RV Global Work Efficiency (RVGWE) were estimated. Patients were screened according to age at surgery, time since the radical repair at the follow-up, increased estimated RV systolic pressure, differences in instrumental findings after PVrep. A composite end-point of MACEs (syncope, sustained and non-sustained ventricular tachycardia, sudden cardiac death) was used. Results Older patients at surgery (≥12 months) have significantly reduced VO2 max at CPET, larger RA and LA areas and larger RV basal diameter. CPET values are not significantly different in patients with more than 25 years since the corrective surgery but echo and CMR-LVEF measured are slightly but significantly reduced and RVGWE is significantly lower. Patients with RVSP ≥ 60 mmHg have significantly higher RVGWW, worst RV FWLS, lower RVGCW and RVGWE. Patients who have undergone PVrep show improvement in RV GLS, RV FWLS and RVGWE and a RVGWW reduction. As reguards the CMR RV volume evaluation sp-ToF, patients with RVESVi ≥80ml/m2 have lower RVGWE and show an inverse correlation between RVEDVi and RVGWE. Sp-ToF patients with borderline/impaired predicted VO2 max at CPET have a reduced RV FWLS, higher RVGWW and an inverse correlation between METs and RVGWW. Patients who have suffered MACEs (2 NS-TV, 3 S-TV, 7 syncopes, 8 sudden deaths) hadsignificant impairment of RV systolic function (FAC, RV FWLS, CMR-RVFE), significantly higher RVGWW, lower RVGWE and RVGWI. Conclusion Long-term survival and clinical condition sp-ToF in infancy are generally good and late functional status in survivors could be excellent up to 25 years after radical correction. However, older patients at surgery have relative reduced functional status compared with those undergoing early repair. The advanced echocardiographic and CMR evaluation of RV function sp-ToF are usually related to worse prognosis, VT and reduced functional status. RV myocardial work evaluation is feasible in patients with repaired ToF, it may be a more sensitive indicator of RV fuctional impairment compared with standard echocardiographic parameters and is able to predict exercise capacity.

Diagnostic performance of the non-invasive myocardial work indices in predicting subclinical myocardial work impairment in Fontan patients

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): public hospital sources. Background The Fontan procedure is an operation that has allowed many paediatric patients suffering from severe congenital heart disease to reach adulthood. More and more frequently we come to interface with the consequences of Fontan's circulation, such as cardiac function and exercise capacity deterioration. Recently the new non-invasive method for calculating myocardial work (MW) based on spackle tracking analysis with the estimation of left ventricular pressure and the measurement of non-invasive blood pressure has been introduced. Purpose Aim of this study was to evaluate the diagnostic performance of the non-invasive myocardial work indices in predicting subclinical myocardial work impairment in patients with Fontan circulation. Methods A total of 69 patients were included and compared with healthy age- and sex- matched controls (CTRL). Ventricular systolic function and global longitudinal strain (GLS) were assessed. Cardiopulmonary exercise test was performed. Global myocardial work index (MWI) was calculated as the area of the LV pressure strain loops. From MWI, global Constructive Work (MCW), Wasted Work (MWW) and Work Efficiency (MWE) were estimated. Results The two groups were comparable for blood pressure, weight end height. Mean age of Fontan patients was 21.0±9.2 years. MWI (1162 ± 364 mmHg% vs 1777 ± 240 mmHg%, p &amp;lt; 0.001), MCW (1554 ± 450 mmHg% vs 2102 ± 221 mmHg%, p = 0.001) and MWE (90 ± 6% vs 96 ± 2% p = 0.001) were significantly reduced in Fontan patients compared with healthy CTRL. Moreover, GLS (−13,9± 3,1 % vs −21,2 ± 1.5%, p &amp;lt; 0.001) and the ejection fraction (EF) (58,9 ± 4.5% vs 63.3 ± 3.9%, p &amp;lt; 0.002) were significantly lower in Fontan patients. Fontan patients with normal EF showed, however, significantly reduced values of MWI compared with CTRL (p&amp;lt;0.05). Fontan patients with functional right ventricle showed significantly reduced MWE compared with patients with functional left ventricle (p = 0.030).In univariate analysis, peak VO2 was significantly associated with age, SatO2, MWI. In multivariate regression, lower peak VO2 was associated with older age (p = 0.003) and lower MWI (p = 0.026). Conclusions Fontan's physiology is associated with impaired ventricular work. Estimation of myocardial work indices may be a more sensitive indicator of impaired myocardial work compared with ejection fraction and is able to predict exercise capacity.

Lower exercise capacity correlates with slower heart rate recovery in post-coronary artery bypass surgery patients

Abstract Funding Acknowledgements Type of funding sources: None. Background Heart rate recovery (HRR) describes the ability of the autonomic nervous system changes from the sympathetic to the parasympathetic nervous system. The slower heart rate recovery means there is an autonomic dysfunction of the nervous system. Heart rate recovery has been known to be a predictor of mortality in patients undergoing exercise stress test. Patients with slow heart rate recovery have a higher risk of cardiovascular death. Decreased exercise capacity is also known to increase the risk of cardiovascular death. Purpose This study aims to determine the relationship between low exercise capacity and slow heart rate recovery. Methods Patients who underwent post-coronary artery bypass (CABG) surgery cardiovascular rehabilitation program at our national cardiovascular center in 2022 were enrolled in this study. We assessed heart rate recovery during the maximal exercise stress test, by subtracting from maximal heart rate during the exercise stress test with heart rate at the first and second minute after exercise stress test. We used predicted METs from Bruce protocols treadmill test time to determine each patient’s exercise capacity. Results There were 238 patients (age 58±7 years old, 89.9% male). The mean exercise capacity was 6.42±2.21 METs and the mean first and second-minute heart rate recovery was 14±11 and 26±15 beats per minute. Predicted exercise capacity had a significant positive weak correlation with first-minute heart rate recovery/HRR1 (r=0.279; p=0.000) and a significant positive moderate correlation with second-minute heart rate recovery/HRR2 (r=0.409; p=0.000) in post-CABG patients. We performed receiver operating characteristic analysis that showed the area under the curve for exercise capacity was 0.69 for HRR1 and 0.71 for HRR2, and found the exercise capacity cut-off was 5.5 METs . Patients with exercise capacity less than 5.5 METs were likely to have slower HRR1 (OR=4.4 (95% CI, 2.7 – 7.2) p=0.000) and slower HRR2 (OR=3.8 (95% CI, 2.4 – 6.0) p=0.000). Conclusions There is a correlation between low exercise capacity and slow heart rate recovery. Patients with lower exercise capacity were likely to have slower heart rate recovery in post-CABG patients.

Mechanical dispersion is a superior echocardiographic feature to predict exercise capacity in preclinical and overt heart failure with preserved ejection fraction.

Heart Failure with Preserved Ejection Fraction (HFpEF) is a syndrome characterized by different degrees of exercise intolerance, which leads to poor quality of life and prognosis. Recently, the European score (HFA-PEFF) was proposed to standardize the diagnosis of HFpEF. Even though Global Longitudinal Strain (GLS) is a component of HFA-PEFF, the role of other strain parameters, such as Mechanical Dispersion (MD), has yet to be studied. In this study, we aimed to compare MD and other features from the HFA-PEFF according to their association with exercise capacity in an outpatient population of subjects at risk or suspected HFpEF. This is a single-center cross-sectional study performed in an outpatient population of 144 subjects with a median age of 57 years, 58% females, referred to the Echocardiography and Cardiopulmonary Exercise Test to investigate HFpEF. MD had a higher correlation to Peak VO2 (r=-0.43) when compared to GLS (r=-0.26), MD presented a significant correlation to Ventilatory Anaerobic Threshold (VAT) (r=-0.20; p = 0.04), while GLS showed no correlation (r=-0.14; p = 0.15). Neither MD nor GLS showed a correlation with the time to recover VO2 after exercise (T1/2). In Receiver Operator Characteristic (ROC) analysis, MD presented superior performance to GLS to predict Peak VO2 (AUC: 0.77 vs. 0.62), VAT (AUC: 0.61 vs. 0.57), and T1/2 (AUC: 0.64 vs. 0.57). Adding MD to HFA-PEFF improved the model performance (AUC from 0.77 to 0.81). MD presented a higher association with Peak VO2 when compared to GLS and most features from the HFA-PEFF. Adding MD to the HFA-PEFF improved the model performance.

Hemodynamic parameters at rest predicting exercise capacity in patients supported with left ventricular assist device.

Left ventricular assist devices improve prognosis and quality of life, but exercise capacity remains limited in most patients after device implantation. Left ventricular assist device optimization through right heart catheterization reduces device-related complications. However, hemodynamic parameters associated with exercise capacity under optimized conditions. The aim of this study was to elucidate the predictors of exercise capacity from hemodynamic parameters at rest after left ventricular assist device optimization. We retrospectively reviewed 24 patients who underwent a ramp test with right heart catheterization, echocardiography and cardiopulmonary exercise testing more than 6months after left ventricular assist device implantation. Pump speed was optimized to a lower setting that achieved right atrial pressure < 12mmHg, pulmonary capillary wedge pressure < 18mmHg, and cardiac index > 2.2L/min/m2, then exercise capacity was assessed by cardiopulmonary exercise testing. After left ventricular assist device optimization, the mean right atrial pressure, pulmonary capillary wedge pressure, cardiac index, and peak oxygen consumption were 7 ± 5mmHg, 10 ± 7mmHg, 2.7 ± 0.5L/min/m2, and 13.2 ± 3.0mL/min/kg, respectively. Pulse pressure, stroke volume, right atrial pressure, mean pulmonary artery pressure, and pulmonary capillary wedge pressure were significantly associated with peak oxygen consumption. Multivariate linear regression analysis of factors predicting peak oxygen consumption revealed that pulse pressure, right atrial pressure, and aortic insufficiency remained independent predictors (β = 0.401, p = 0.007; β = -0.558, p < 0.001; β = -0.369, p = 0.010, respectively). Our findings suggests that cardiac reserve, volume status, right ventricular function, and aortic insufficiency predict exercise capacity in patients with a left ventricular assist device.

Left atrial dysfunction can independently predict exercise capacity in patients with chronic heart failure who use beta-blockers

BackgroundBeta-blockers are first-line clinical drugs for the treatment of chronic heart failure (CHF). In the guidelines for cardiac rehabilitation, patients with heart failure who do or do not receive beta-blocker therapy have different reference thresholds for maximal oxygen uptake (VO2max). It has been reported that left atrial (LA) strain can be used to predict VO2max in patients with heart failure, which can be used to assess exercise capacity. However, most existing studies included patients who did not receive beta-blocker therapy, which could have a heterogeneous influence on the conclusions. For the vast majority of CHF patients receiving beta-blockers, the exact relationship between LA strain parameters and exercise capacity is unclear.MethodsThis cross-sectional study enrolled 73 patients with CHF who received beta-blockers. All patients underwent a thorough resting echocardiogram and a cardiopulmonary exercise test to obtain VO2max, which was used to reflect exercise capacity.ResultsLA reservoir strain, LA maximum volume index (LAVImax), LA minimum volume index (LAVImin) (P < 0.0001) and LA booster strain (P < 0.01) were all significantly correlated with VO2max, and LA conduit strain was significantly correlated with VO2max (P < 0.05) after adjusting for sex, age, and body mass index. LA reservoir strain, LAVImax, LAVImin (P < 0.001), and LA booster strain (P < 0.05) were significantly correlated with VO2max after adjusting for left ventricular ejection fraction, the ratio of transmitral E velocity to tissue Doppler mitral annulus e′ velocity (E/e′), and tricuspid annular plane systolic excursion. LA reservoir strain with a cutoff value of 24.9% had a sensitivity of 74% and specificity of 63% for the identification of patients with VO2max < 16 mL/kg/min.ConclusionAmong CHF patients receiving beta-blocker therapy, resting LA strain is linearly correlated with exercise capacity. LA reservoir strain is a robust independent predictor of reduced exercise capacity among all resting echocardiography parameters.Clinical Trial registration: This study is a part of the Baduanjin-Eight-Silken-Movement with Self-efficacy Building for Patients with Chronic Heart Failure (BESMILE-HF) trial NCT03180320 (ClinicalTrials.gov, registration date: 08/06/2017).

Cardiac MRI-based right-to-left ventricular blood pool T2 relaxation times ratio correlates with exercise capacity in patients with chronic heart failure

BackgroundMRI T2 mapping has been proven to be sensitive to the level of blood oxygenation. We hypothesized that impaired exercise capacity in chronic heart failure is associated with a greater difference between right (RV) to left ventricular (LV) blood pool T2 relaxation times due to a higher level of peripheral blood desaturation, compared to patients with preserved exercise capacity and to healthy controls. MethodsPatients with chronic heart failure (n = 70) who had undergone both cardiac MRI (CMR) and a 6-min walk test (6MWT) were retrospectively identified. Propensity score matched healthy individuals (n = 35) served as control group. CMR analyses included cine acquisitions and T2 mapping to obtain blood pool T2 relaxation times of the RV and LV. Following common practice, age- and gender-adjusted nominal distances and respective percentiles were calculated for the 6MWT. The relationship between the RV/LV T2 blood pool ratio and the results from 6MWT were evaluated by Spearman's correlation coefficients and regression analyses. Inter-group differences were assessed by independent t-tests and univariate analysis of variance. ResultsThe RV/LV T2 ratio moderately correlated with the percentiles of nominal distances in the 6MWT (r = 0.66) while ejection fraction, end-diastolic and end-systolic volumes showed no correlation (r = 0.09, 0.07 and − 0.01, respectively). In addition, there were significant differences in the RV/LV T2 ratio between patients with and without significant post-exercise dyspnea (p = 0.001). Regression analyses showed that RV/LV T2 ratio was an independent predictor of the distance walked and the presence of post-exercise dyspnea (p < 0.001). ConclusionThe proposed RV/LV T2 ratio, obtained by two simple measurements on a routinely acquired four-chamber T2 map, was superior to established parameters of cardiac function to predict exercise capacity and the presence of post-exercise dyspnea in patients with chronic heart failure.

Korean vs. Western Exercise Capacity Nomograms for Korean Patients With Cardiovascular Disease.

Exercise capacity is known to be an independent predictor of cardiovascular events and mortality. However, most previous studies were based on Western populations. Further study is warranted for Asian patients according to ethnic or national standards. We aimed to compare prognostic values of Korean and Western nomograms for exercise capacity in Korean patients with cardiovascular disease (CVD). In this retrospective cohort study, we enrolled 1,178 patients (62 ± 11 years; 78% male) between June 2015 and May 2020, who were referred for cardiopulmonary exercise testing in our cardiac rehabilitation program. The median follow-up period was 1.6 years. Exercise capacity was measured in metabolic equivalents by direct gas exchange method during the treadmill test. The nomogram for exercise capacity from healthy Korean individuals and a previous landmark Western study was used to determine the percentage of predicted exercise capacity. The primary endpoint was the composite of major adverse cardiovascular events (MACE; all-cause death, myocardial infarction, repeat revascularization, stroke and hospitalization for heart failure). A multivariate analysis showed that the risk of primary endpoint was more than double (hazard ratio [HR], 2.20; 95% confidence interval [CI], 1.10-4.40) in the patients with lower exercise capacity (< 85% of predicted) by Korean nomogram. The lower exercise capacity was one of the strong independent predictors along with left ventricular ejection fraction, age, and level of hemoglobin. However, the lower exercise capacity by Western nomogram could not predict the primary endpoint (HR, 1.33; 95% CI, 0.85-2.10). Korean patients with CVD with lower exercise capacity have higher risk of MACE. Considering inter-ethnic differences in cardiorespiratory fitness, the Korean nomogram provides more suitable reference values than the Western nomogram to determine lower exercise capacity and predict cardiovascular events in Korean patients with CVD.

966 ADVANCED ECHOCARDIOGRAPHIC AND CMR FEATURES OF PATIENTS WITH REPAIRED TETRALOGY OF FALLOT IN THE LONG-TERM FOLLOW-UP

Abstract Advanced echocardiographic and CMR features of patients with repaired Tetralogy of Fallot in the long-term follow-up. Anna Gozzi1, Jolanda Sabatino1, Elena Cuppini1, Irene Cattapan1, Alessia Basso1, Jennifer Fumanelli1, Angela Di Candia1, Martina Avesani1, Domenico Sirico1, Biagio Castaldi1, Elena Reffo1, Alessia Cerutti1, Roberta Biffanti1, Giovanni Di Salvo1 1Department for Women's and Children's Health, University Hospital of Padova, Pediatric and Congenital Cardiology Unit, Via Nicolo` Giustiniani, 2, 35128 Padova, Italy Background Tetralogy of Fallot (ToF) is the most common cyanotic congenital heart disease and the population of ToF repair survivors is growing rapidly. Children and, more frequently young adults, with repaired ToF develop late complications. Sudden cardiac death and life-threatening ventricular arrhythmia remain a concern in patients with repaired tetralogy of Fallot. The aim of this study was to describe and analyse advanced echocardiographic and CMR features of patients with repaired ToF in the long-term follow-up and to find non-invasive predictors of adverse prognosis. Methods This is a retrospective cohort study. Consecutive 200 patients with repaired ToF who did not undergo pulmonary valve replacement were included. Mean age of all patients was 19 ± 8. The electrocardiographic (ECG), cardiopulmonary exercise testing (CPET), echocardiographic and cardiac magnetic resonance (CMR) data were reviewed retrospectively. Right myocardial work index (RWI) was calculated as the area of the right ventricular pressure strain loops. From RWI, Right Constructive Work (RCW), Wasted Work (RWW) and Work Efficiency (RWE) were estimated. Patients were screened according the age at surgery (&amp;lt;12 months and &amp;gt;12 months) and the time since the repair (&amp;lt; 25 years and ≥ 25 years). A composite end-point of major adverse cardiovascular events (sudden cardiac death, sustained and non-sustained ventricular tachycardia, resuscitated sudden cardiac death, or syncope) was used. Results CPET values were not significantly different in patients with more than 25 years since the corrective surgery. Left ventricular ejection fraction measured either by CMR or echocardiography were slightly but significantly reduced in patients with more than 25 years since the corrective surgery. Patients with older age at surgery (&amp;gt;12 months) have significantly reduced V02max at CPET, larger RA and LA areas and larger RV basal diameter. During a median follow-up of 2.9 years, 1 patient died suddenly, 5 had documented ventricular tachycardia, and other 4 had syncope. On univariate analysis, echocardiographic left atrial area/BSA (P=0.044) and right ventricular longitudinal strain (P=0.010) were significantly related to the combined end point. Patients with reported VT at Holter ECG presented significantly reduced right ventricular function in terms of CMR-EF, echocardiographic FAC and RWI. Finally, TOF patients with borderline/impaired predicted VO2 max at CPET presented with significantly reduced RV freewall longitudinal strain and right ventricular myocardial work index. Conclusion Long-term survival and clinical condition after surgical correction of ToF in infancy is generally good and the late functional status in ToF - operated patients could be excellent up to 25 years after the repair. However, patients with older age at surgery have relative reduced functional status compared with those undergoing early repair. The echocardiographic and CMR evaluation of RV function are usually related to worse prognosis, recurrency of VT and reduced functional status in patients with repaired TOF. Right ventricular myocardial work index is feasible in patients with repaired TOF; disadvantageous right ventricular work may be a more sensitive indicator of right ventricular impairment compared with standard echocardiographic parameters, and is able to predict exercise capacity.

1115 NON-INVASIVE MYOCARDIAL WORK INDICES IN PATIENTS WITH FONTAN CIRCULATION

Abstract Background Although the Fontan operation has contributed greatly to the improvement of survival in patients with a single ventricle, cardiac function and exercise capacity may deteriorate over time. However, there have been no quantitative analyses of the effects of Fontan circulation on myocardial work (MW). Recently, a novel non-invasive method for calculating MW has been introduced on the basis of speckle tracking analysis with the estimation of left ventricular (LV) pressure from brachial artery cuff pressure. Purpose Aim of this study was to evaluate the diagnostic performance of the non-invasive myocardial work indices in predicting subclinical myocardial work impairment in Fontan patients. Methods A total of 69 patients were included and compared with healthy age- and sex- matched controls (CTRL). Ventricular systolic function and global longitudinal strain (GLS) were assessed. Cardiopulmonary exercise test was performed. Global myocardial work index (MWI) was calculated as the area of the LV pressure strain loops. From MWI, global constructive work (MCW), wasted work (MWW) and work efficiency (MWE) were estimated. Results The two groups were comparable for blood pressure, weight and height. Mean age of Fontan patients was 21.0±9.2 years. MWI (1162 ± 364 mmHg% vs 1777 ± 240 mmHg%, p &amp;lt; 0.001), MCW (1554 ± 450 mmHg% vs 2102 ± 221 mmHg%, p = 0.001) and MWE (90 ± 6% vs 96 ± 2% p = 0.001) were significantly reduced in Fontan patients compared with healthy CTRL. Moreover, GLS (-13,9 ± 3,1% vs -21,2 ± 1.5%, p &amp;lt; 0.001) and the ejection fraction (EF) (58,9 ± 4.5% vs 63.3 ± 3.9%, p &amp;lt; 0.002) were significantly lower in Fontan patients. Fontan patients with normal EF showed, however, significantly reduced values of MWI compared with CTRL (p&amp;lt;0.05). Fontan patients with functional right ventricle showed significantly reduced MWE compared with patients with functional left ventricle (p=0.030). In univariate analysis, peak VO2 was significantly associated with age, SatO2, MWI. In multivariate regression, lower peak VO2 was associated with older age (p = 0.003) and lower MWI (p = 0.026). Conclusions Fontan physiology is associated with disadvantageous ventricular work. In Fontan patients, estimation of MWI may be a more sensitive indicator of myocardial work impairment compared with EF and is able to predict exercise capacity.

Abstract 14064: Utility of Tricuspid Annular Plane Systolic Excursion Normalized by Right Ventricular Size in Pulmonary Hypertension to Predict Exercise Capacity, Pulmonary Compliance, and Clinical Outcomes

1. Introduction: While tricuspid annular plane systolic excursion (TAPSE) captures the predominant longitudinal motion of right ventricle (RV), it may not accurately predict ventricular function as the RV dilates. Hence, normalizing TAPSE to ventricular area (in systole: TAPSE/RV-area-S, and diastole: TAPSE/RV-area-D) may lead to improved assessment of right heart function. In this study, we aim to determine the utility of RV size-indexed-TAPSE metrics in predicting exercise capacity and clinical outcomes. 2. Methods: We perform a retrospective analysis of 71 consecutive subjects undergoing invasive exercise hemodynamics with cardiopulmonary exercise test for evaluation of dyspnea. Patients were classified into four groups: pulmonary arterial hypertension, isolated post-capillary, combined pre-/post-capillary PH, and control (no PH) based on hemodynamic analysis. Transthoracic echocardiogram data included: TAPSE (mm), TAPSE-index-D (RV end-diastole area in cm), and TAPSE-index-S (RV end-systole area in cm). Subjects were followed for 12 months after hemodynamic study for adverse events (death, heart failure hospitalization). 3. Results: On ROC analysis of indexed-TAPSE to predict pulmonary compliance (&gt;3.0 ml/mmHg), we identified optimal cutoff of 1.1 for TAPSE-index-D (AUC=0.792, p&lt;0.001), 1.5 for TAPSE-index-S (AUC=0.827, p&lt;0.001), and 17 mm for TAPSE (AUC=0.672, p=0.005). Similar results were obtained for predicting %predicted VO 2 max (&gt;50%). We dichotomized indexed-TAPSE based on ROC analysis. As shown in the Figure, compared to the current recommended TAPSE cut-off of 17 mm, RV size-indexed TAPSE metrics were both superior in predicting adverse outcome (p&lt;0.01). 4. Discussion/Conclusion: Normalizing TAPSE to RV size can capture longitudinal and radial motion of the RV as the ventricle dilates and have better ability to predict clinical outcomes (death and HF hospitalization).

Abstract 11479: Adolescents Have Reduced Exercise Capacity After Heart Transplant

Introduction: There are limited data on exercise capacity and its determinants in pediatric heart transplant patients (HT). Methods: This single-center, retrospective cohort study of patients (&lt;18yo) includes subjects who received their index HT from 1990-2016 and completed a maximal effort cardiopulmonary exercise test (CPET) during adolescence (12-18yo). The primary outcome was maximum oxygen consumption (VO2). Secondary outcomes included anaerobic threshold (AT) and power consumption (PC). Outcomes were evaluated as percent predicted by sex and age. Wilcoxon rank-sum tests were used to test deviation from predicted exercise capacity. Linear regression models were used to assess association of clinical variables with CPET outcomes. Results: Our sample of 86 patients was 53% male (n=46), 68% White (n=53), with a median age at transplant of 10y (IQR [3-14]). The majority had a diagnosis of congenital heart disease (59%, n=51) and 21% (n=18) were supported with VAD prior to HT. The median age at EST was 17y (IQR 14.7, 17.6), mean time from OHT 7.1y (SD 5.3), and most patients were tested using cycle ergometry (87%, n=75). Max VO2 (median=26.3 ml/kg/min, 65% predicted), AT (median=17.5 ml/kg/min, 66% predicted) PC (median 1.8 w/kg, 56% predicted) were significantly lower than 100% predicted (p&lt;0.001 for all, Fig 1). After adjustment for age at transplant and time since transplant, increased BMI (b= -1.32 95% CI [-1.85, -0.79]) and decreased peak heart rate (HR) (b= 0.32 95% CI [0.19, 0.45]) predicted reduced max VO2. Ejection fraction, cardiac index, and pulmonary capillary wedge pressure measured on cardiac catheterization were not associated with max V02. Conclusions: Adolescents after HT demonstrate markedly reduced exercise capacity. While impaired chronotropy has been implicated in impaired exercise capacity in HT, the association of BMI is novel. The identification of this modifiable factor has important clinical implications for future interventions.