Predictor Of Exercise Capacity Research Articles

Left atrial remodelling may predict exercise capacity in obstructive sleep apnoea patients

Background: Left atrial volume (LAV) and LA deformation has been proposed as a good marker of exercise performance in patients with diastolic dysfunction (DD). As DD is more prevalent in obstructive sleep apnoea (OSA) we aimed to evaluate the influence of LAV and LA deformation parameters on exercise performance in varying severity of OSA. Materials and methods: OSA was diagnosed after polysomnography. Fifty-five OSA patients were enrolled in the study. OSA patients were divided into two groups with apnoea-hypopna-index (AHI) > 30 and <30. LAV was calculated. LA strain and LA strain rates were assessed with speckle tracking echocardiography (STE). Exercise capacity was evaluated by treadmill exercise test. Results: MET values were lower in group II compared to group I (p < .05). Echocardiographic findings: Comparison within groups: In both groups E/E’, LA stain, LA strain rate S and LA strain rate E were higher after exercise than before (p < .05). In group I LA strain rate A was higher after exercise than before (p < .05). Comparison between groups: LA strain, LA strain rate S, LA strain rate E and LA strain rate A were lower and E/E’ and LAVI were higher in group II compared to group I before and after exercise (p < .05). Correlation with METs: AHI, LVEDV, E/E’ and LAVI were negatively and LA strain was positively correlated with METs (p < .05). Conclusions: Left ventricular diastolic dysfunction is more prevalent in severe OSA and is associated with impaired exercise performance. Additionally, LA remodelling may predict exercise capacity in this subgroup of patients.

Influence of resting lung diffusion on exercise capacity in patients with COPD

BackgroundLung diffusing capacity for carbon monoxide (DLCO) gives an overall assessment of functional lung surface area for gas exchange and can be assessed using various methods. DLCO is an important factor in exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). We investigated if the intra-breath (IBDLCO) method may give a more sensitive measure of available gas exchange surface area than the more typical single breath (SBDLCO) method and if COPD subjects with the largest resting DLCO relative to pulmonary blood flow (Qc) would have a more preserved exercise capacity.MethodsInformed consent, hemoglobin, spirometry, SBDLCO, IBDLCO, and Qc during IBDLCO were performed in moderate to severe COPD patients, followed by progressive cycle ergometry to exhaustion with measures of oxygen saturation (SaO2) and expired gases.ResultsThirty two subjects (47% female, age 66 ± 9 yrs., BMI 30.4 ± 6.3 kg/m2, smoking hx 35 ± 29 pkyrs, 2.3 ± 0.8 on the 0-4 GOLD classification scale) participated. The majority used multiple inhaled medications and 20% were on oral steroids. Averages were: FEV1/FVC 58 ± 10%Pred, peak VO2 11.4 ± 3.1 ml/kg/min, and IBDLCO 72% of the SBDLCO (r = 0.88, SB vs IB methods). Using univariate regression, both the SB and IBDLCO (% predicted but not absolute) were predictive of VO2peak in ml/kg/min; SBDLCO/Qc (r = 0.63, p < 0.001) was the best predictor of VO2peak; maximal expiratory flows over the mid to lower lung volumes were the most significantly predictive spirometric measure (r = 0.49, p < 0.01). However, in multivariate models only BMI added additional predictive value to the SBDLCO/Qc for predicting aerobic capacity (r = 0.73). Adjusting for current smoking status and gender did not significantly change the primary results.ConclusionIn patients with moderate to severe COPD, preservation of lung gas exchange surface area as assessed using the resting SBDLCO/Qc appears to be a better predictor of exercise capacity than more classic measures of lung mechanics.

Patient-Reported Dyspnea Correlates Poorly with Aerobic Exercise Capacity Measured During Cardiopulmonary Exercise Testing.

Patient-reported dyspnea plays a central role in assessing cardiopulmonary disease. There is little evidence, however, that dyspnea correlates with objective exercise capacity measurements. If the correlation is poor, dyspnea as a proxy for objective assessment may be misleading. To compare patient's perception of dyspnea with maximum oxygen uptake (MaxVO2) during cardiopulmonary exercise testing (CPET). Fifty patients undergoing CPET for dyspnea evaluation were studied prospectively. Dyspnea assessment was measured by a metabolic equivalent of task (METs) table, Mahler Dyspnea Index, Borg Index, number of blocks walked, and flights of stairs climbed before stopping due to dyspnea. These descriptors were compared to MaxVO2. MaxVO2 showed low correlation with METs table (r=0.388, p=0.005) and no correlation with Mahler Index (r=0.24, p=0.093), Borg Index (r=-0.017, p=0.905), number of blocks walked (r=0.266, p=0.077) or flights of stairs climbed (r=0.188, p=0.217). When adjusted for weight (maxVO2/kg), there was significant correlation between MaxVO2 and METs table (r=0.711, p<0.001), moderate correlation with blocks walked (r=0.614, p<0.001), and low correlation with Mahler Index (r=0.488 p=0.001), Borg Index (r=-0.333 p=0.036), and flights of stairs (r=0.457 p=0.004). Subgroup analysis showed worse correlation when patients with normal CPET were excluded (12/50 excluded). Patients with BMI<30 had no correlation between Max VO2 and the assessment methods, while patients with BMI>30 had moderate correlation between MaxVO2 and METs table (r=0.568, p=0.002). Patient-reported dyspnea correlates poorly with MaxVO2 and fails to predict exercise capacity. Reliance on reported dyspnea may result in suboptimal categorization of cardiopulmonary disease severity.

Noninvasive Coronary Flow Reserve Predicts Response to Exercise in Asymptomatic Severe Aortic Stenosis

In patients with asymptomatic aortic stenosis (AS), exercise stress echocardiography (ESE) provides additional prognostic information beyond baseline. The coronary flow velocity reserve (CFVR) is impaired in AS, but its link with exertion is unknown in this setting. The aim of this study was to test the hypothesis that CFVR could predict exercise capacity and abnormal exercise test results in AS. Noninvasive CFVR and symptom-limited semisupine ESE were prospectively performed the same day in 43 patients with asymptomatic isolated severe AS (mean age, 68.5±11years; 26% women; mean aortic valve area, 0.8±0.16cm2; mean left ventricular ejection fraction, 70±7%). CFVR was performed in the distal part of the left anterior descending coronary artery using intravenous adenosine infusion (140μg/kg/min over 2min), and ESE was performed at an initial workload of 25W with a 20- to 25-W increase at 2-min intervals. An abnormal result on ESE was defined as onset of symptoms at <75% of maximum predicted workload, electrocardiographic ST-segment depression ≥2mm during exercise, increase of systolic blood pressure<20mmHg or decrease in blood pressure, and complex ventricular arrhythmia. Seventeen patients with isolated severe asymptomatic AS, unable to exercise because of extracardiac conditions, served as a comparative group. Resting, hyperemic left anterior descending coronary artery flow velocity and CFVR (2.45±0.8 vs 2.4±0.8) were similar between the group unable to perform ESE and the ESE group (P=NS for all). Compared with patients with normal results on ESE, those with abnormal results on ESE (n=22) were older, had higher E/e' ratios, had higher resting left anterior descending coronary artery flow velocities (39±12 vs 31±8cm/sec), and had lower CFVR (2.01±0.3 vs 2.85±0.7; P<.01 for all). Furthermore, CFVR was significantly correlated with age, changes in transvalvular pressure gradient and left ventricular ejection fraction with exercise, workload (in watts), and exercise duration (P<.05 for all). After adjusting for other variables, CFVR remained independently correlated with exercise duration, workload, and abnormal results on ESE (P<.01 for all). On receiver operating characteristic curve analysis, CFVR<2.3 was the best cutoff to predict abnormal results on ESE (area under the curve=0.88±0.06, P<.01). In patients with asymptomatic severe AS, noninvasive CFVR is correlated with exercise duration and workload, and low CFVR predicts abnormal results on ESE with good accuracy.

The Impact of Overweight on Flexibility and Functional Capacity

Obesity is a health problem worldwide, with a significant impact on the mortality of individuals. However, considering the importance of preventive management, few studies have addressed the predictors of functional impairment in overweight subjects. The present study aimed to verify the differences in functional variables in overweight volunteers compared to eutrophic subjects, to determine the independent predictors of functional capacity in overweight subjects and to provide a model that can predict exercise capacity in this population. Seventy-four physically active participants (both sexes, aged 18 to 60 years) were evaluated and stratified into two groups: eutrophic (n=45, 33 ± 11 years, 76% females) and overweight (n=29, 37 ± 12 years, 41% females), according to body mass index (BMI). All volunteers were submitted to clinical, anthropometric, flexibility, muscle strength and endurance evaluation and maximal exercise testing. Differences between groups were verified by Independent T test or Mann-Whitney. Uni and multivariate linear regressions were performed to verify the independent predictors of functional capacity in the overweight group. The overweight individuals were predominantly male (58.6%), with iliopsoas (p=0.009), pectoral (p<0.001) and piriformis (p=0.003) shortening, and with lower values of peak oxygen uptake (VO2peak) (p=0.012). In the final multivariate model, BMI and body fat percentage were the only independent predictors of functional capacity in overweight volunteers and VO2peak can be predicted by the model VO2peak=85.161 – (0.747 × BMI) – (0.925 × body fat percentage). Overweight individuals already show musculoskeletal and functional changes when compared to eutrophic ones. Preventive strategies should be adopted in this population, aiming to prevent musculoskeletal and functional dysfunctions that may compromise the functional capacity of these individuals.

Values of hemodynamic variation in response to passive leg raising in predicting exercise capacity of heart failure with preserved ejection fraction.

In heart failure patients with preserved ejection fraction, their hemodynamic parameters usually change when they are from recumbent to passive leg raising. The authors designed this study to investigate the relationship between hemodynamic parameters measured by impedance cardiography (ICG) and 6-minute walk distance (6MWD) of heart failure with preserved ejection fraction (HFPEF). We recruited 49 subjects with HFPEF in the study, and all the subjects were separated into 2 groups: the patients whose hemodynamic parameters rose after passive leg raising were in group 1 (n = 26) and the patients whose hemodynamic parameters did not rise after passive leg raising were in group 2 (n = 23). Our study then compared the 6MWD, left ventricular ejection fraction, and plasma NT-pro-brain natriuretic peptide between the 2 groups. Group 1 had significantly longer 6MWD than group 2 (515.38 ± 24.97 vs 306.39 ± 20.20 m; P = 0.043). Hemodynamic parameters measured by ICG significantly correlated with 6MWD in both groups. Patients whose hemodynamic parameters rose in response to passive leg raising were more likely to have better exercise capacity. Hemodynamic variation in response to passive leg raising measured by ICG may be more sensitive in predicting exercise capacity of patients with HFPEF.

Inspiratory capacity-to-total lung capacity ratio and dyspnoea predict exercise capacity decline in COPD.

Exercise capacity decline is a predictor of mortality in patients with chronic obstructive pulmonary disease (COPD). Static pulmonary hyperinflation is a key determinant of exercise performance, but its effect on the longitudinal decline in exercise capacity remains unknown. We aimed to study the relationship between the inspiratory capacity-to-total lung capacity (IC/TLC) ratio and exercise capacity decline in COPD. We measured IC/TLC and other relevant clinical and functional variables in 342 clinically stable patients with COPD. The 6-min walk distance (6MWD) was determined at recruitment and after a mean ± SD of 1.7 ± 0.3 years. The annual rate of change in 6MWD was calculated. Multiple imputation to account for losses during follow up was implemented, and multivariate regression was used to analyze predictive factors of 6MWD decline. Mean decline rate in the 6MWD was 21.9 ± 34.1 m/year. In the bivariate analysis, patients with lower levels of IC/TLC had greater 6MWD decline (-27.4 ± 42.5, -24.9 ± 36.5 and -13.4 ± 39.9 m/year in the first, second and third tertile of IC/TLC, respectively; P-for-trend = 0.018). From other potential risk factors considered, dyspnoea, health status, serum C-reactive protein and Borg dyspnoea score at the end of the exercise test were related to exercise capacity decline. In the multivariate regression model, only IC/TLC (β = 0.7 m/year per each percentage unit of IC/TLC; P = 0.007) and dyspnoea (mMRC ≥ 2) (β = -14.6 m/year; P = 0.013) were associated with the annual rate of 6MWD change. IC/TLC and dyspnoea in clinically stable patients with COPD predict their exercise capacity decline and may help to guide early therapeutic interventions.

Coronary microvascular function, insulin sensitivity and body composition in predicting exercise capacity in overweight patients with coronary artery disease.

BackgroundCoronary artery disease (CAD) has a negative impact on exercise capacity. The aim of this study was to determine how coronary microvascular function, glucose metabolism and body composition contribute to exercise capacity in overweight patients with CAD and without diabetes.MethodsSixty-five non-diabetic, overweight patients with stable CAD, BMI 28–40 kg/m2 and left ventricular ejection fraction (LVEF) above 35 % were recruited. A 3-hour oral glucose tolerance test was used to evaluate glucose metabolism. Peak aerobic exercise capacity (VO2peak) was assessed by a cardiopulmonary exercise test. Body composition was determined by whole body dual-energy X-ray absorptiometry scan and magnetic resonance imaging. Coronary flow reserve (CFR) assessed by transthoracic Doppler echocardiography was used as a measure of microvascular function.ResultsMedian BMI was 31.3 and 72 % had impaired glucose tolerance or impaired fasting glucose. VO2peak adjusted for fat free mass was correlated with CFR (r = 0.41, p = 0.0007), LVEF (r = 0.33, p = 0.008) and left ventricular end-diastolic volume (EDV) (r = 0.32, p = 0.01) while it was only weakly linked to measures of glucose metabolism and body composition. CFR, EDV and LVEF remained independent predictors of VO2peak in multivariable regression analysis.ConclusionThe study established CFR, EDV and LVEF as independent predictors of VO2peak in overweight CAD patients with no or only mild functional symptoms and a LVEF > 35 %. Glucose metabolism and body composition had minor impact on VO2peak. The findings suggest that central hemodynamic factors are important in limiting exercise capacity in overweight non-diabetic CAD patients.

Aortic valve prosthesis–patient mismatch and exercise capacity in adult patients with congenital heart disease

ObjectivesTo report the prevalence of aortic valve prosthesis–patient mismatch (PPM) in an adult population with congenital heart disease (CHD) and its impact on exercise capacity. Adults with congenital heart disease...

Association between baseline cardiovascular mechanics and exercise capacity in patients with coronary artery disease.

Objective:Functional capacity is one of the cardinal determinants of morbidity and mortality in patients with coronary artery disease (CAD). We hypothesized that baseline cardiovascular mechanics, including cardiac systolic and diastolic functions, arterial mechanics, and ventriculo-arterial interaction, may play a role in predicting exercise capacity in patients with CAD.Methods:Fifty consecutive patients with CAD who were referred to cardiac rehabilitation were prospectively included in the study. Patients with non-sinus rhythms or severe valvular disease were excluded. Full left ventricular pressure–volume loops were constructed and arterial mechanics was evaluated using echocardiographic and tonometric measurements. Cardiopulmonary exercise tests were performed to measure exercise capacity.Results:Fifty patients were enrolled in the study. Ventriculo-arterial coupling showed a moderate correlation with peak oxygen consumption (VO2) (r=0.410, p=0.04) in patients with reduced left ventricular ejection fraction (LVEF). Only left ventricular volume at 15 mm Hg (r=0.514, p<0.01) in diastolic parameters (stiffness constant, p=0.75; ventricular compliance, p=0.17) and arterial compliance (r=0.467, p=0.01) in arterial parameters [arterial elastance, p=0.27; systemic vascular resistance, p=0.45; augmentation pressure, p=0.85; augmentation index (AIx), p=0.63; heart rate-corrected AIx, p=0.68] emerged as significant factors correlated with peak VO2 in patients with normal LVEF.Conclusion:Comprehensive evaluation of resting cardiovascular mechanics can give clues about exercise-recruited reserves of the cardiovascular system. Optimization of ventriculo-arterial coupling in patients with reduced LVEF and arterial compliance in patients with normal LVEF should be the main target in patients with CAD and limited functional capacity. (Anatol J Cardiol 2016; 16: 608-14)

Abstract 16896: Exercise Pulmonary Capillary Wedge Pressure Patterns in Patients With Normal Resting Left-sided Filling Pressures Predict Heart Failure Outcomes

Introduction: Serial measurements of pulmonary capillary wedge pressure (PCWP) during exercise testing may help to improve hemodynamic (HD) classification of heart failure with preserved ejection fraction (HFpEF). However, the physiologic and prognostic significance of exercise PCWP patterns is largely unknown. Hypothesis: An elevated PCWP increment relative to cardiac output (CO) augmentation during exercise will independently predict exercise capacity and outcomes in patients with dyspnea on exertion and normal resting PCWP (DOE-nlrW). Methods: In a single center cohort of 175 patients referred for cardiopulmonary exercise testing (CPET) with invasive HD monitoring (n = 33 normal controls, n = 32 HFpEF with resting PCWP ≥ 15, and n = 110 consecutive patients with DOE-nlrW and LVEF &gt; 0.45) 1,929 PCWP-CO points during exercise were measured. Median follow-up was 3.2 years and events consisted of HF hospitalization, CV death, or future RHC with resting PCWP ≥ 15 mmHg. Results: PCWP-CO slope of 1.2±0.4 mmHg/L/min in controls was used to establish the upper limit (mean + 2SDev) of normal of 2mmHg/L/min. HFpEF patients had a PCWP-CO slope of 3.6±1.8 mmHg/L/min. In the DOE-nlrW cohort, patients achieved a mean peak VO2 of 17±6 ml/kg/min (74±19 % predicted), mean PCWP-CO was 2.1±1.3 mmHg/L/min (Figure) with 45 of 110 patients having elevated PCWP-CO. PCWP-CO but not resting PCWP was related to peak VO2 in univariable (rho = -0.51, p &lt; 0.01) and multi-variable linear regression adjusted for age, sex, hypertension, beta blocker use, diabetes, and resting PCWP (ß = -0.17, p = 0.03). Increased PCWP-CO also predicted worse event-free survival in univariable Cox regression (HR 1.67, p &lt; 0.01) and after adjustment for age, sex, BMI, and resting PCWP (HR 1.56, p = 0.03). Conclusions: Elevated PCWP-CO during exercise ( &gt; 2mmHg/L/min) is common in DOE-nlrW and predicts exercise capacity as well as outcomes, suggesting that assessment of exercise HD may help to refine early HFpEF diagnosis.

Left ventricular volume predicts exercise capacity in hypertrophic cardiomyopathy

a Unit for Inherited Cardiac Diseases, Department of Cardiology, The Heart Center, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark b Department of Cardiology, Copenhagen University Hospital Herlev hospital, Herlev, Denmark c Cardiovascular Division, Brigham and Women's Hospital, Boston, USA d Department of Cardiology, Copenhagen University Hospital Roskilde Hospital, Roskilde, Denmark

MR-proADM Predicts Exercise Capacity and Survival Superior to Other Biomarkers in PH.

Besides the established biomarker NT-proBNP, the new cardiovascular biomarkers MR-proANP, MR-proADM, Copeptin, and CT-proET-1 are promising to evaluate hemodynamics, exercise parameters, and prognosis in patients with pulmonary hypertension (PH). 125 consecutive patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) were prospectively enrolled at five German PH centers. Blood samples were taken during right heart catheterization. The primary study endpoint was the correlation between biomarkers and hemodynamic and exercise parameters. As secondary endpoint, prediction of 1-year mortality was evaluated. MR-proADM showed the strongest correlations with 6MWD and VO2peak, whereas NT-proBNP showed the strongest correlations with PVR, PAPm, and CI. In multivariate analysis, only MR-proADM was independently associated with exercise variables, whereas only NT-proBNP independently predicted hemodynamic parameters. All biomarkers were associated with 1-year survival, with MR-proADM showing the highest C index of 0.78. In multivariate analysis, MR-proADM predicted survival independent of age, 6-MWD, CI, RAP, and NT-proBNP. The cut-off of 1.08nmol/l provided a sensitivity of 83% and specificity of 66%. Different biomarkers reflect distinctive disease aspects in PH. NT-proBNP best predicts hemodynamic impairment while MR-proADM strongly correlates with exercise capacity. Additionally, MR-proADM represents a promising new marker to evaluate prognosis in patients with PAH and CTEPH. Multi-marker strategies should further be evaluated.

Predictors of exercise capacity following exercise-based rehabilitation in patients with coronary heart disease and heart failure: A meta-regression analysis

The aim of this study was to undertake a comprehensive assessment of the patient, intervention and trial-level factors that may predict exercise capacity following exercise-based rehabilitation in patients with coronary heart disease and heart failure. Meta-analysis and meta-regression analysis. Randomized controlled trials of exercise-based rehabilitation were identified from three published systematic reviews. Exercise capacity was pooled across trials using random effects meta-analysis, and meta-regression used to examine the association between exercise capacity and a range of patient (e.g. age), intervention (e.g. exercise frequency) and trial (e.g. risk of bias) factors. 55 trials (61 exercise-control comparisons, 7553 patients) were included. Following exercise-based rehabilitation compared to control, overall exercise capacity was on average 0.95 (95% CI: 0.76-1.41) standard deviation units higher, and in trials reporting maximum oxygen uptake (VO2max) was 3.3 ml/kg.min(-1) (95% CI: 2.6-4.0) higher. There was evidence of a high level of statistical heterogeneity across trials (I(2) statistic > 50%). In multivariable meta-regression analysis, only exercise intervention intensity was found to be significantly associated with VO2max (P = 0.04); those trials with the highest average exercise intensity had the largest mean post-rehabilitation VO2max compared to control. We found considerable heterogeneity across randomized controlled trials in the magnitude of improvement in exercise capacity following exercise-based rehabilitation compared to control among patients with coronary heart disease or heart failure. Whilst higher exercise intensities were associated with a greater level of post-rehabilitation exercise capacity, there was no strong evidence to support other intervention, patient or trial factors to be predictive.

Exercise Capacity And Blood Pressure Response In Mild-to-moderate Renal Dysfunction

PURPOSE: Low exercise capacity is associated with poor prognosis in patients with chronic kidney disease (CDK). A previous study on this material has showed that cardiac involvement including left ventricular hypertrophy can be seen at early stages of CDK. The aim of this study was to investigate weather mild-to-moderate CDK is associated with diminished exercise capacity and increased blood pressure response compared to healthy controls, and to to what extent this correlates to glomerular filtration rate (GFR). METHODS: Exercise tests were performed in 51 Patients with CDK at stages 2-3 (mild- to -moderate renal dysfunction) and 38 patients in CDK 4-5 (severe renal dysfunction), and in 49 healthy controls (CTR). Tests were performed on ergometer bikes with exercise capacity expressed in Watts and systolic blood pressure was measured before and during the exercise test until maximal exhaustion. GFR was measured by iohexol clearance. The groups did not differ significantly regarding to age, sex or body size. Inclusion criteria for the controls were absence of kidney disease, cardiovascular disease and diabetes and no ongoing medication. RESULTS: Comparisons between groups were made using independent sample T-test and one-way ANOVA where applicaple. Patients with CDK 2-3 had significant lower exercise capacity compared to healthy controls (193W+/- 64, vs 238W +/- 60, t=-3,56, df=98, p< 0,001 ). The CDK 2-3 group also hade higher exercise capacity than the CDK 4-5 group (163W +/- 63 for CDK 45, =2,2, df p=87, p<0,05). Exercise capacity was not significantly correlated to GFR in any of the groups (using Pearsons´s r) and there was no significant difference in maximal systolic blood pressure during exercise between patients with CDK (200 mmHg +/- 33 in CDK 2-3 and 190 mmHg +/-27 in CDK 4-5) and CTR (194 mmHg +/- 25). CONCLUSIONS: Exercise capacity is significantly lower in patients with mild- to-moderate renal dysfunction compared to healthy controls but exercise capacity in the CDK groups did not correlate well to GFR, suggesting that other variables are more important in predicting exercise capacity. CDK patients did not have an increased blood pressure response to exercise. Antihypertensive medications among CDK patients could perhaps contribute to this.

(946) - The Reliability of 6-Minute Walk Test to Predict Exercise Capacity in Patients With Pulmonary Hypertension

(946) - The Reliability of 6-Minute Walk Test to Predict Exercise Capacity in Patients With Pulmonary Hypertension

Predictors of exercise capacity in heart failure

&lt;p&gt;Background and Aim: Compromised exercise capacity is a major symptom in patients with heart failure (HF) and reduced left ventricular (LV) ejection fraction (EF). Six-minute walk test (6-MWT) is popular for the objective assessment of exercise capacity in these patients but is largely confined to major heart centres. The aim of this study was to prospectively examine functional parameters that predict 6-MWT in patients with HF and reduced LVEF.&lt;/p&gt;&lt;p&gt;&lt;span&gt;Methods: &lt;/span&gt;In 111 HF patients (mean age 60Å}12 years, 56% male), a 6-MWT and an echo-Doppler study were performed in the same day. In addition to conventional ventricular function measurements, global LV dyssynchrony was indirectly assessed by total isovolumic time - t-IVT [in s/min; calculated as: 60 – (total ejection time – total filling time)], and Tei index (t-IVT/ejection time). Also, LV and right ventricular function were assessed by mitral and tricuspid annular plane systolic excursion (MAPSE and TAPSE, respectively). Based on the 6-MWT distance, patients were divided into 2 groups: Group I: ≤300m and Group II: &amp;gt;300m.&lt;/p&gt;&lt;p&gt;&lt;span&gt;Results: &lt;/span&gt;The 6-MWT distance correlated with t-IVT and Tei index (r=-0.37, p&amp;lt;0.001, for both), lateral and septal e’ velocities (r=0.41, p&amp;lt;0.001, and r=0.46, p&amp;lt;0.001, respectively), E/e’ ratio (r=-0.37, p&amp;lt;0.001) and TAPSE (r=0.45, p&amp;lt;0.001), but not with the other clinical or echo parameters. Group I patients had longer t-IVT, lower E/e’ratio, TAPSE and lateral e’ (p&amp;lt;0.001 for all) compared with Group II. In multivariate analysis, TAPSE [0.076 (0.017-0.335), p=0.001], E/e’ [1.165 (1.017-1.334), p=0.027], t-IVT [1.178 (1.014-1.370), p=0.033] independently predicted poor 6-MWT performance (&amp;lt;300m). Sensitivity and specificity for TAPSE ≤1.9 cm were 66% and 77%, (AUC 0.78, p&amp;lt;0.001); E/e’ ≥10.7 were 66% and 62% (AUC 0.67, p=0.002) and t-IVT ≥13 s/min were 64% and 60% (AUC 0.68, p=0.002) in predicting poor 6-MWT. Combined TAPSE and E/e’ had a sensitivity of 68% but specificity of 92% in predicting 6-MWT. Respective values for combined TAPSE and t-IVT were 71% and 85%.&lt;/p&gt;&lt;p&gt;&lt;span&gt;Conclusion: &lt;/span&gt;In patients with HF, the limited exercise capacity assessed by 6-MWT, is multifactorial being related both to the severity of right ventricular systolic dysfunction as well as to raised LV filling pressures and global dyssynchrony.&lt;/p&gt;

The presence and impact of diastolic dysfunction on physical function and body composition in hemodialysis patients.

Cardiovascular (CV) diseases are the main cause of death in maintenance hemodialysis (MHD) patients. Muscle wasting and physical function decline are common in MHD patients, and significantly impair their quality of life. These can result from abnormalities in cardiac function, which can be further worsened by physical deconditioning. Left ventricular diastolic function parameters were recently shown to be a better predictor of exercise capacity than systolic measures in patients with CV complications. But little is known about the relationship between cardiac function and physical function in MHD patients. In 82 MHD patients, left ventricular systolic dysfunction (LVSD) was assessed by ejection fraction and fractional shortening with echocardiography, and left ventricular diastolic dysfunction (LVDD) was assessed by pulse wave and tissue Doppler indices. Physical function was assessed by gait speed, performance on a shuttle walk test, and leg muscle strength. Dual-emission X-ray absorptiometry (DXA) was used to measure whole body lean mass (WBLM). The prevalence of LVDD and LVSD was 48.8 and 12.2%, respectively. Gait speed, shuttle walk time, leg strength, and WBLM% were significantly higher in the group without LVDD than with LVDD (p < 0.05 for all). However, there was no significant difference in any measure of physical function or body composition between patients with and without LVSD. These data suggest that LVDD is more closely related to physical function and body composition than LVSD in MHD patients, and hence that LVDD may be an important therapeutic target.

CARDIAC OUTPUT RESERVE: A NOVEL MARKER OF SYMPTOMS AND EXERCISE CAPACITY IN AORTIC STENOSIS

Traditional measures of AS severity neglect the effect of dynamic left ventricular function and the systemic vasculature. We hypothesized that cardiac output reserve (COR), the ratio of cardiac output at maximal exercise and cardiac output at rest, would be the best predictor of exercise capacity

TWEAK and NT-proBNP levels predict exercise capacity in hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is characterized by inappropriate hypertrophy, myocyte disarray and increased interstitial fibrosis. The tumour necrosis factor-like weak inducer of apoptosis (TWEAK) is a cell surface cytokine with biological activities including stimulation of cell growth, induction of inflammatory cytokines and stimulation of apoptosis. There are controversial data about the potential role of TWEAK in different cardiovascular pathologies. NT-proBNP is an established biomarker of myocardial wall stress, associated with poor functional class in HCM. We hypothesized that effort capacity in patients with HCM could be related to serum levels of these biomarkers. We included 40 haemodynamic stable HCM patients and 53 healthy controls with similar sex and age. We studied exercise capacity by maximal oxygen consumption in a limited treadmill exercise test. TWEAK and NT-proBNP were assayed by ELISA method and automated Elecsys® platform, respectively. We obtained 46 samples of myocardial tissues by septal myectomy in patients with HCM and evaluated myocardial fibrosis, immunoreaction with TWEAK antibody and apoptosis with TUNEL assay. We found raised TWEAK and NT-proBNP serum levels in patients when compared with control levels (both P < 0.001). In a multivariate analysis, TWEAK and NT-proBNP levels, as well as sex, remained independently associated with the effort capacity (all P < 0.05). We found an association between immunoreaction degree and the degree of myocardial fibrosis (P = 0.021), as well as apoptosis (P = 0.002) in the tissue samples from patients undergoing septal myectomy. TWEAK and NT-proBNP levels are biomarkers of disease severity independently associated with the effort capacity in patients with HCM.