Diastolic dysfunction in exercise and its role for exercise capacity

Survivors of Pediatric Hematopoietic Stem Cell Transplantation Exhibit Progressive Diastolic Dysfunction Over Years of Follow-Up

Patients who have undergone hematopoietic stem cell transplantation (HSCT) in childhood have a higher risk of diastolic heart failure (HF). The rate of progression of diastolic dysfunction in aging pediatric patients is unknown and is more difficult to assess in young patients secondary to changes in diastolic indices as they grow. HSCT recipients at our center were previously found to have decline in diastolic function indices at 1 year after HSCT. This study provides follow-up of this cohort, using age-normalized z-scores to assess whether the decline in diastolic function noted at 1-year post-HSCT persists, worsens, or improves over time. Patients age <21 years who underwent HSCT at Boston Children's Hospital/Dana-Farber Cancer Center between 2005 and 2008 with ≥3 surveillance echocardiograms, including 1 performed pre-HSCT, were included. Diastolic measures included mitral inflow (E/A ratio) and Doppler tissue imaging of left ventricular lateral wall (LV lateral e'), LV septal wall (septal e') and right ventricular free wall (RV e'). Systolic function was measured by LV ejection fraction (LVEF). Normalization by age was done using z-scores, and >±2 SD was defined as abnormal in linear modeling of diastolic dysfunction and systolic dysfunction over time. In a subset of patients with adequate post-HSCT images of the entire left atrium (LA), LA volume and LA strain analyses also were performed. The study cohort comprised 61 patients (41% female; median age at HSCT, 10.7 years; median follow-up, 7.4 years). Diastolic index z-scores declined by -.045/year for LV lateral e', -.06/year for LV septal e', and -.14/year for RV e' (P < .01). The E/A ratio z-score increased by .034/year (P = .028). Linear modeling demonstrated that LV lateral e' and LV septal e' would become abnormal at 25 and 20 years post-HSCT, respectively, whereas RV e' would become abnormal sooner, at 12.6 years. LVEF z-score declined by -.04/year (P < .01) and was estimated to become abnormal at 40 years post-HSCT. Exposure to total body irradiation (TBI) was associated with worsening diastolic indices, lower LVEF (P ≤ .002), and decreased LA reservoir strain (42.0% versus 45.0%; P = .016) and conduit strain (-31.5% versus -35.1%; P = .029), although there was significant overlap between TBI and anthracycline exposure. Treatment with anthracyclines even at low doses (median, 150 mg/m2) was associated with declining LVEF but not with changes in diastolic indices. Long-term survivors of childhood HSCT exhibit declines in both LV and RV diastolic function indices. These results inform the rate of progression of LV and RV diastolic dysfunction indices over time in long-term survivors of pediatric HSCT. A significant association was observed between TBI and diastolic dysfunction and a decline in LVEF. Treatment with anthracyclines even at low doses was associated with a mild decline in LVEF. Our results can inform a lifespan perspective on disease management in this population, encourage clinicians and patients to be vigilant in following guideline-directed surveillance echocardiography, and inform anticipatory responses by clinicians as patients transition from pediatric care to adult care.

Early Left Ventricular Diastolic Dysfunction in Females with Chronic Hyperprolactinemia: A Doppler Echocardiographic Study

Despite the myocardial prolactin (PRL) binding activity and the known effect of enhancing contractility in the isolated rat heart, little information is available concerning the cardiovascular consequences of hyperprolactinemia in humans. To elucidate the effects of chronic hyperprolactinemia on cardiac structure and function, twenty-four patients with isolated PRL-secreting adenoma and twenty-four controls underwent a complete mono- and two-dimensional Doppler-echocardiography. Blood pressure and heart rate were similar in the two groups, and no significant differences were observed as to left ventricular (LV) geometry between patients and controls. Resting LV systolic function was normal in patients with hyperprolactinemia, as shown by similar values of fractional shortening and cardiac output. Conversely, hyperprolactinemic patients exhibited a slight impairment of LV diastolic filling, as demonstrated by the prolongation of the isovolumetric relaxation time and the increase of the atrial filling wave of mitral Doppler velocimetry (58 ± 13 vs. 47 ± 8 cm/s, p < 0.05) with a subgroup of females (16%) having a clear diastolic dysfunction, and a worse exercise capacity (6 min walking test 452 ± 70 vs. 524 ± 56; p < 0.05). In conclusion, hyperprolactinemia in humans may be associated with a slight impairment of diastolic function, with an overt diastolic dysfunction in a subgroup of females which correlated with poorer exercise performance, in the absence of significant abnormalities of LV structure and systolic function.

Comparing cardiac function and structure and their relationship with exercise capacity between patients with stable COPD and recent acute exacerbation: a cross-sectional study

OBJECTIVE

Patients with COPD are prone to cardiac remodeling; however, little is known about cardiac function in patients recovering from an acute exacerbation of COPD (AECOPD) and its association with exercise capacity. The aim of this study was to evaluate the cardiac function and structure and to compare their relationship with exercise capacity in patients with a recent AECOPD and patients with clinically stable COPD.

METHODS

This was a cross-sectional study including 40 COPD patients equally divided into two groups: recent AECOPD group (AEG) and clinically stable COPD group (STG). Echocardiography was performed to assess cardiac function and chamber structure. The six-minute walk distance (6MWD) and the Duke Activity Status Index (estimated Vo2) were used in order to assess exercise capacity.

RESULTS

No significant differences in cardiac function and structure were found between the groups. The 6MWD was associated with early/late diastolic mitral filling velocity ratio (r = 0.50; p < 0.01), left ventricular posterior wall thickness (r = -0.33; p = 0.03), and right atrium volume index (r = -0.34; p = 0.04), whereas Vo2 was associated with right atrium volume index (r = -0.40; p = 0.02).

CONCLUSIONS

Regardless of the clinical condition (recent AECOPD vs. stable COPD), the cardiac function and structure were similar between the groups, and exercise capacity (determined by the 6MWD and Vo2) was associated with cardiac features.

Left Ventricular Diastolic Indices and Their Impact on Outcomes in Patients with Recently Diagnosed Atrial Fibrillation

Background: Early identification of atrial fibrillation (AF) patients at risk for heart failure (HF) remains critical for improving their outcomes. We aimed to investigate whether indices of left ventricular diastolic dysfunction (LVDD) can stratify AF patients without clinical history of HF. Methods: We extracted 1775 patients’ data from a prospective cohort that consecutively recruited recently recognized AF patients with ejection fraction ≥50%. We categorized patients as LVDD grade 0 (none) to 3 (severe) based on mitral deceleration time and E/e’ per the American Society of Echocardiography recommendation. The primary outcome was a composite of all-cause death, stroke, and HF hospitalization during the 2-year follow-up. We also investigated the Atrial Fibrillation Effects on QualiTy-of-Life (AFEQT) scores. Results: Overall, 857 (48.3%) had mild or higher LVDD. Incidence of primary outcomes increased in parallel with LVDD grading (1.8%, 2.8%, 6.5%, and 8.1% for grades 0−3, respectively, p < 0.001), and the presence of grade 3 LVDD was an independent predictor of the primary outcome (adjusted HR 2.28 (vs. grade 0), 95%CI 1.13−4.60). Furthermore, patients with LVDD had lower AFEQT scores at the enrollment and 1-year follow-up. Conclusions: LVDD indices were associated with adverse clinical outcomes and patients’ perceived health status in a recently diagnosed AF cohort without HF.

Prolonged mean response time in older adults with cardiovascular risk compared to healthy older adults

BACKGROUND

During incremental exercise (Inc-Ex), the mean response time (MRT) of oxygen uptake (V̇O2) represents the time delay before changes in muscle V̇O2 reflect at the mouth level. MRT calculation by linear regression or monoexponential (τ') fitting of V̇O2 data are known to be highly variable, and a combination of incremental and constant load exercise (CL-Ex) is more reproducible.

METHODS

We evaluated MRT in older adults using linear regression and combination methods. We recruited 20 healthy adults (male: 9, 69.4 ± 6.8 years) and 10 cardiovascular risk subjects (male: 8, 73.0 ± 8.8 years). On day 1, they performed Inc-Ex using a 10W/min ramp protocol, for determination of the ventilatory anaerobic threshold (VAT) using the V-slope method. On day 2, they performed Inc-Ex to VAT exercise intensity and CL-Ex for 25min total. The MRT was calculated from the CL-Ex V̇O2 average and the time at equivalent V̇O2 in the Inc-Ex. We also assessed the amount of physical activity using the International Physical Activity Questionnaire short form (IPAQ-SF).

RESULTS

The MRT of healthy participants and those at cardiovascular risk were 49.2 ± 36.3 vs. 83.6 ± 45.4s (p = 0.033). Total physical activity in the IPAQ-SF was inversely correlated with MRT.

CONCLUSION

The MRT was significantly prolonged in cardiovascular risk participants compared to healthy participants, possibly related to the amount of daily physical activity. Individual MRT may be useful for adjustment of exercise intensity, but this should also be based on daily physical activity and individual condition during exercise.

The microtubule cytoskeleton in cardiac mechanics and heart failure

The microtubule network of cardiac muscle cells has unique architectural and biophysical features to accommodate the demands of the working heart. Advances in live-cell imaging and in deciphering the 'tubulin code' have shone new light on this cytoskeletal network and its role in heart failure. Microtubule-based transport orchestrates the growth and maintenance of the contractile apparatus through spatiotemporal control of translation, while also organizing the specialized membrane systems required for excitation-contraction coupling. To withstand the high mechanical loads of the working heart, microtubules are post-translationally modified and physically reinforced. In response to stress to the myocardium, the microtubule network remodels, typically through densification, post-translational modification and stabilization. Under these conditions, physically reinforced microtubules resist the motion of the cardiomyocyte and increase myocardial stiffness. Accordingly, modified microtubules have emerged as a therapeutic target for reducing stiffness in heart failure. In this Review, we discuss the latest evidence on the contribution of microtubules to cardiac mechanics, the drivers of microtubule network remodelling in cardiac pathologies and the therapeutic potential of targeting cardiac microtubules in acquired heart diseases.

Need for Speed: The Importance of Physiological Strain Rates in Determining Myocardial Stiffness

The heart is viscoelastic, meaning its compliance is inversely proportional to the speed at which it stretches. During diastolic filling, the left ventricle rapidly expands at rates where viscoelastic forces impact ventricular compliance. In heart disease, myocardial viscoelasticity is often increased and can directly impede diastolic filling to reduce cardiac output. Thus, treatments that reduce myocardial viscoelasticity may provide benefit in heart failure, particularly for patients with diastolic heart failure. Yet, many experimental techniques either cannot or do not characterize myocardial viscoelasticity, and our understanding of the molecular regulators of viscoelasticity and its impact on cardiac performance is lacking. Much of this may stem from a reliance on techniques that either do not interrogate viscoelasticity (i.e., use non-physiological rates of strain) or techniques that compromise elements that contribute to viscoelasticity (i.e., skinned or permeabilized muscle preparations that compromise cytoskeletal integrity). Clinically, cardiac viscoelastic characterization is challenging, requiring the addition of strain-rate modulation during invasive hemodynamics. Despite these challenges, data continues to emerge demonstrating a meaningful contribution of viscoelasticity to cardiac physiology and pathology, and thus innovative approaches to characterize viscoelasticity stand to illuminate fundamental properties of myocardial mechanics and facilitate the development of novel therapeutic strategies.

Measures of Left Ventricular Diastolic Function and Cardiorespiratory Fitness According to Glucose Metabolism Status: The Maastricht Study

Background

This cross‐sectional study evaluated associations between structural and functional measures of left ventricular diastolic function and cardiorespiratory fitness (CRF) in a well‐characterized population‐based cohort stratified according to glucose metabolism status.

Methods and Results

Six hundred seventy‐two participants from The Maastricht Study (mean±SD age, 61±9 years; 17.4% prediabetes and 25.4% type 2 diabetes mellitus) underwent both echocardiography to determine left atrial volume index, left ventricular mass index, maximum tricuspid flow regurgitation, average e′ and E/e′ ratio; and submaximal cycle ergometer test to determine CRF as maximum power output per kilogram body mass. Associations were examined with linear regression adjusted for cardiovascular risk and lifestyle factors, and interaction terms. After adjustment, in normal glucose metabolism but not (pre)diabetes, higher left atrial volume index (per 1 mL/m²), left ventricular mass index (per 1 g/m^2.7), maximum tricuspid regurgitation flow (per 1 m/s) were associated with higher CRF (maximum power output per kilogram body mass; β in normal glucose metabolism 0.015 [0.008–0.023], P_interaction (pre)diabetes <0.10; 0.007 [−0.001 to 0.015], P_interaction type 2 diabetes mellitus <0.10; 0.129 [0.011–0.246], P_interaction >0.10; for left atrial volume index, left ventricular mass index, maximum tricuspid regurgitation flow, respectively). Furthermore, after adjustment, in all individuals, higher average E/e′ ratio (per unit), but not average e′, was associated with lower CRF (normal glucose metabolism −0.044 [−0.071 to −0.016]), P_interaction >0.10).

Conclusions

In this population‐based study, structural and functional measures of left ventricular diastolic function were independently differentially associated with CRF over the strata of glucose metabolism status. This suggests that deteriorating left ventricular diastolic function, although of small effect, may contribute to the pathophysiological process of impaired CRF in the general population. Moreover, the differential effects in these structural measures may be the consequence of cardiac structural adaptation to effectively increase CRF in normal glucose metabolism, which is absent in (pre)diabetes.

Prevalence of fibrinous pericarditis in heavy pigs (170 kg) and its association with other pluck lesions at slaughter inspection

This study determined the prevalence of fibrinous pericarditis and its correlation with other pluck lesions in 658 batches of pigs from 236 intensive farms located in Northern Italy over a 12-month period. All pigs were slaughtered at 170 kg, and a total 57,943 plucks (approximately 90 pigs/batch) were individually assessed for the presence of fibrinous pericarditis, pneumonia, pleuritis, and liver milk spots. There was no seasonal variation in the prevalence of plucks with fibrinous pericarditis and annual mean prevalence was 5.6% (range, 0-26.3% at batch level; median, 4.71%). Farm of origin, evaluated as a random effect, accounted for 17.7% batch variation. Batches with a high prevalence of fibrinous pericarditis (≥7.7%) had higher prevalences of pleural, pulmonary, and liver lesions than those with low-middle prevalence of pericarditis; high prevalence of pericarditis was predictive of pluck lesions (P < 0.001). There was a highly significant association between fibrinous pericarditis and severe pleuritis, and 55% of plucks with the highest score for pleuritis also had ongoing fibrinous pericarditis, with a positive correlation at batch level (r² = 0.52; P < 0.001). The co-existence of pericarditis and pleuritis (73.5% of all pericarditis cases) suggests that pleuritis plays a role in the pathogenesis of pericarditis. Based on the prevalence fibrinous pericarditis, and the role of pleuritis as a potential comorbidity, abattoir data on pluck lesions with accompanying farm history, could aid the interpretation and management of on-farm health problems, and inform diagnostic protocols.

Determinants of Cardiorespiratory Fitness in Patients with Heart Failure Across a Wide Range of Ejection Fractions

Impaired cardiorespiratory fitness (CRF) in heart failure (HF) is influenced by a complex array of cardiac and extracardiac factors. The study aimed to identify clinical determinants of CRF measured as peak oxygen consumption (peak VO₂) in HF patients, and to determine a peak VO₂ prediction model using regression equations. Retrospective analysis of 200 HF patients who completed treadmill cardiopulmonary exercise testing and underwent Doppler echocardiography and/or biomarker analysis on the same day was performed. After univariate linear regression analysis, a multivariate peak VO₂ prediction model was developed using significant variables in a stepwise linear regression analysis. In subjects with repeated testing, Pearson's correlation was used to assess correlations between measured and predicted change in peak VO₂ (Δpeak VO₂) over time. Mean age was 57 years, with 55% being male. Stepwise linear regression was used to generate a weighted model for peak VO₂: 30.895 + (-0.112•age[years]) + (0.296•hemoglobin [g/dl]) + (-0.101•E/e'[unit change]) + (-0.202• body mass index [kg/m²]) + (-0.593• N-terminal pro-brain natriuretic peptide [log_N pg/ml])) + (-1.349•CRP [log mg/L]). Predicted peak VO₂ correlated strongly with measured peak VO₂ in HF with reduced ejection fraction and HF with preserved ejection fraction patients (r = +0.63, p <0.001; r = +0.64, p <0.001, respectively). Predicted Δpeak VO₂ correlated with measured Δpeak VO₂ (r = +0.23, p <0.001). In conclusion, in patients with HF across a wide range of left ventricular ejection fraction, age, systemic inflammation, oxygen carrying capacity, obesity, and elevated filling pressures are the strongest predictors of impaired CRF. The proposed CRF model allows prediction of peak VO₂ in HF patients and may be used to estimate peak VO₂ changes over time.

Cardiopulmonary and Muscular Interactions: Potential Implications for Exercise (In)tolerance in Symptomatic Smokers Without Chronic Obstructive Pulmonary Disease

Smoking and physical inactivity are important preventable causes of disability and early death worldwide. Reduced exercise tolerance has been described in smokers, even in those who do not fulfill the extant physiological criteria for chronic obstructive pulmonary disease (COPD) and are not particularly sedentary. In this context, it is widely accepted that exercise capacity depends on complex cardio-pulmonary interactions which support oxygen (O₂) delivery to muscle mitochondria. Although peripheral muscular factors, O₂ transport disturbances (including the effects of increased carboxyhemoglobin) and autonomic nervous system unbalance have been emphasized, other derangements have been more recently described, including early microscopic emphysema, pulmonary microvascular disease, ventilatory and gas exchange inefficiency, and left ventricular diastolic dysfunction. Using an integrative physiological approach, the present review summarizes the recent advances in knowledge on the effects of smoking on the lung-heart-muscle axis under the stress of exercise. Special attention is given to the mechanisms connecting physiological abnormalities such as early cardio-pulmonary derangements, inadequate oxygen delivery and utilization, and generalized bioenergetic disturbances at the muscular level with the negative sensations (sense of heightened muscle effort and breathlessness) that may decrease the tolerance of smokers to physical exercise. A deeper understanding of the systemic effects of smoking in subjects who did not (yet) show evidences of COPD and ischemic heart disease - two devastating smoking related diseases - might prove instrumental to fight their ever-growing burden.

C-Reactive Protein and N-Terminal Pro-brain Natriuretic Peptide Levels Correlate With Impaired Cardiorespiratory Fitness in Patients With Heart Failure Across a Wide Range of Ejection Fraction

Background: Impaired cardiorespiratory fitness (CRF) is a hallmark of heart failure (HF). Serum levels of C-reactive protein (CRP), a systemic inflammatory marker, and of N-terminal pro-brain natriuretic peptide (NT-proBNP), a biomarker of myocardial strain, independently predict adverse outcomes in HF patients. Whether CRP and/or NT-proBNP also predict the degree of CRF impairment in HF patients across a wide range of ejection fraction is not yet established.

Methods: Using retrospective analysis, 200 patients with symptomatic HF who completed one or more treadmill cardiopulmonary exercise tests (CPX) using a symptom-limited ramp protocol and had paired measurements of serum high-sensitivity CRP and NT-proBNP on the same day were evaluated. Univariate and multivariate correlations were evaluated with linear regression after logarithmic transformation of CRP (log₁₀) and NT-proBNP (log_N).

Results: Mean age of patients was 57 ± 10 years and 55% were male. Median CRP levels were 3.7 [1.5–9.0] mg/L, and NT-proBNP levels were 377 [106–1,464] pg/ml, respectively. Mean peak oxygen consumption (peak VO₂) was 16 ± 4 mlO₂•kg⁻¹•min⁻¹. CRP levels significantly correlated with peakVO₂ in all patients (R = −0.350, p < 0.001) and also separately in the subgroup of patients with reduced left ventricular ejection fraction (LVEF) (HFrEF, N = 109) (R = −0.282, p < 0.001) and in those with preserved EF (HFpEF, N = 57) (R = −0.459, p < 0.001). NT-proBNP levels also significantly correlated with peak VO₂ in all patients (R = −0.330, p < 0.001) and separately in patients with HFrEF (R = −0.342, p < 0.001) and HFpEF (R = −0.275, p = 0.032). CRP and NT-proBNP did not correlate with each other (R = 0.05, p = 0.426), but independently predicted peak VO₂ (R = 0.421, p < 0.001 and p < 0.001, respectively).

Conclusions: Biomarkers of inflammation and myocardial strain independently predict peak VO₂ in HF patients. Anti-inflammatory therapies and therapies alleviating myocardial strain may independently improve CRF in HF patients across a large spectrum of LVEF.

Effect of exercise on diastolic function in heart failure patients: a systematic review and meta-analysis

Diastolic dysfunction contributes to the development and progression of heart failure. Conventional echocardiography and tissue Doppler imaging are widely utilised in clinical research providing a number of indices of diastolic function valuable in the diagnosis and prognosis of heart failure patients. The aim of this meta-analysis was to quantify the effect of exercise training on diastolic function in patients with heart failure. Exercise training studies that investigate different indices of diastolic function in patients with heart failure have reported that exercise training improves diastolic function in these patients. We sought to add to the current literature by quantifying, where possible, the effect of exercise training on diastolic function. We conducted database searches (PubMed, EBSCO, EMBASE, and Cochrane Trials Register to 31 July 2016) for exercise based rehabilitation trials in heart failure, using the search terms 'exercise training, diastolic function and diastolic dysfunction'. Data from six studies, with a total of 266 heart failure with reduced ejection fraction (HFrEF) participants, 144 in intervention groups and 122 in control groups, indicated a significant reduction in the ratio of early diastolic transmitral velocity (E) to early diastolic tissue velocity (E') (E/E' ratio) with exercise training, exercise vs. control mean difference (MD) of -2.85 (95% CI -3.66 to -2.04, p < 0.00001). Data from five studies in heart failure with preserved ejection fraction (HFpEF) patients, with a total of 204 participants, 115 in intervention groups and 89 in control groups, also demonstrated a significant improvement in E/E' in exercise vs. control MD of -2.38 (95% CI -3.47 to -1.28, p < 0.0001).

Cardiac Adaptations to High-Intensity Aerobic Training in Premenopausal and Recent Postmenopausal Women: The Copenhagen Women Study

BACKGROUND

We examined the role of menopause on cardiac dimensions and function and assessed the efficacy of exercise training before and after menopause.

METHODS AND RESULTS

Two groups of healthy premenopausal (n=36, 49.4±0.3 years) and postmenopausal (n=37, 53.5±0.5 years) women with no history of cardiovascular disease and with a mean age difference between groups of only 4 years were studied. Cardiac dimensions and systolic and diastolic function were determined by transthoracic echocardiography with tissue Doppler imaging and 2-dimensional speckle tracking. Measurements were performed at baseline and after a 12-week period of high-intensity aerobic cycle training. LV internal diastolic diameter and LV mass were similar in the 2 groups at baseline and increased by ≈2% to 8% (P=0.04-0.0007) with training in both groups. Left atrial end-diastolic and end-systolic volumes were similar for both groups and increased by 23% to 36% (P=0.0006-0.0001) with training. Systolic function assessed by mean global strain was similar in both groups at baseline and increased by ≈8% (P=0.0004) with training in the postmenopausal group. LV displacement increased by ≈3% (P=0.04) in the premenopausal women only. Diastolic function assessed by E/A ratio was similar at baseline and increased by ≈7% (P=0.01) in the premenopausal group and 11% (P=0.0001) in the postmenopausal group with training.

CONCLUSIONS

These results suggest that training-induced cardiac adaptations are preserved in the early postmenopausal phase. Furthermore, the hormonal changes associated with the menopausal transition do not appear to affect cardiac dimensions and function.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02135575.

METformin in DIastolic Dysfunction of MEtabolic syndrome (MET-DIME) trial: rationale and study design : MET-DIME trial

PURPOSE

Insulin resistance plays a central role in the pathophysiology of metabolic syndrome (MS). Its cardiac deleterious effects are characterized by an increase in fibrous tissue that increases myocardial stiffness and contributes to subclinical left ventricular diastolic dysfunction (LVDD) and heart failure with preserved ejection fraction in patients with MS. In addition to lifestyle counseling (LC), metformin treatment may attenuate or even reverse diastolic dysfunction in these patients. This trial aims to evaluate if treating non-diabetic patients with MS and LVDD with metformin in addition to LC improves diastolic function and assess its impact in functional capacity and health-related quality of life (HRQoL).

DESIGN

MET-DIME is a phase II prospective, randomized, open-label, blinded-endpoint trial with a scheduled follow-up of 24 months. Fifty-four patients (adults 40-65 years old with AHA/NHLBI criteria of MS and rest LVDD) will be randomized by minimization to LC only or LC plus metformin (target dose of 1,000 mg twice daily). The primary endpoint will be change in mean of early diastolic mitral annular velocity, an echocardiographic parameter highly correlated with myocardial fibrosis (serial measurements will be performed at 6, 12 and 24 months). The secondary endpoints will include change in diastolic parameters at rest; metabolic, inflammatory and remodeling biomarkers; functional capacity; adipose tissue volumes and HRQoL.

CONCLUSION

MET-DIME is a pragmatic trial designed to evaluate if adding metformin to the standard treatment of patients with MS improves diastolic dysfunction, assessing its impact in metabolic homeostasis, proinflammatory state, functional capacity and HRQoL.

Effects of long-term endurance and resistance training on diastolic function, exercise capacity, and quality of life in asymptomatic diastolic dysfunction vs. heart failure with preserved ejection fraction

BACKGROUND

The long-term effects of exercise training (ET) in diastolic dysfunction (DD) and heart failure with preserved ejection fraction (HFpEF) are unknown. The present study compared the long-term effects of ET on exercise capacity, diastolic function, and quality of life (QoL) in patients with DD vs. HFpEF.

METHODS

A total of n = 43 patients with asymptomatic DD (n = 19) or HFpEF [DD and New York Heart Association (NYHA) ≥II, n = 24] and left ventricular ejection fraction ≥50% performed a combined endurance/resistance training over 6 months (2-3/week) on top of usual care. Cardiopulmonary exercise testing, echocardiography, and QoL were obtained at baseline and follow-up.

RESULTS

Patients were 62 ± 8 years old (37% female). In the HFpEF group, 67% of patients were in NYHA class II (33% in NYHA III). Exercise capacity (peak oxygen consumption, peak VO₂ ) differed at baseline (DD 29.2 ± 8.7 mL/min/kg vs. HFpEF 17.8 ± 4.6 mL/min/kg; P = 0.004). After 6 months, peak VO₂ increased significantly (P < 0.044) to 19.7 ± 5.8 mL/min/kg in the HFpEF group and also in the DD group (to 32.8 ± 8.5 mL/min/kg; P < 0.002) with no overall difference between the groups (P = 0.217). E/e' ratio (left ventricular filling index) decreased from 12.2 ± 3.5 to 10.1 ± 3.0 (P < 0.002) in patients with HFpEF and also in patients with DD (10.7 ± 3.1 vs. 9.5 ± 2.3; P = 0.03; difference between groups P = 0.210). In contrast, left atrial volume index decreased in the HFpEF group (P < 0.001) but remained stable within the DD group (difference between groups P = 0.015). After 6 months, physical QoL (Minnesota living with heart failure Questionnaire, 36-item short form health survey), general health perception, and 9-item patient health questionnaire score only improved in HFpEF (P < 0.05). In contrast, vitality improved in both groups (difference between groups P = 0.708).

CONCLUSION

A structured 6 months ET programme effectively improves exercise capacity and diastolic function in patients with DD and overt HFpEF. Therefore, controlled lifestyle modification with physical activity is effective both in DD and HFpEF.

Left ventricular diastolic performance at rest is essential for exercise capacity in patients with non-complicated myocardial infarction

INTRODUCTION

In patients with recent myocardial infarction (MI) limited exercise capacity during physical activity is an important symptom and the base for future treatment. The myocardial injury after MI leads to both systolic and diastolic left ventricular (LV) dysfunction.

OBJECTIVE

The aim of this study was to assess the relevance of systolic and diastolic LV function for cardiopulmonary exercise capacity in patients with prior MI.

METHODS

Sixty-five consecutive patients after first MI without signs and symptoms of heart failure, aged 52 ± 6 years, were included in the study. The following echo parameters were evaluated: LV ejection fraction (LVEF), peak early and late diastolic velocities (E, A), deceleration time of E wave (dec t E), ratio of early trans-mitral to early annular diastolic velocities (E/e'), velocity propagation of early filling (Vp), and diameters and volumes of LV and left atrium (LA). CPET variables included: oxygen uptake at peak exercise (peak VO2), oxygen pulse (VO2 HR), VE/VCO2 slope, circulatory power (CP) and recovery half time (T1/2).

RESULTS

Significant correlations were demonstrated between peak VO2 and E/e' (p < 0.001), peak VO2 and dec t E (p < 0.001), VO2 HR and E/e' (p = 0.002) and between VE/VCO2 and E/e' (p < 0.001). Twenty patients with elevated LV filling pressure achieved significantly lower peak VO2 (1624 vs. 1932 ml, p = 0.027) VO2 HR (11.70 vs. 14.05, p = 0.011) and CP (287,073 vs. 361,719, p = 0.014). By using multivariate regression model we found that only E/e' (p = 0.001) and dec t E (p = 0.008) significantly contributed to peak VO2.

CONCLUSIONS

Diastolic dysfunction, particularly LV filling pressure, determine exercise capacity, despite differences in LV ejection fraction in patients with prior MI.

Exercise attenuates the premature cardiovascular aging effects of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2D) is an example of a disease process that results in decrements in function additional to those imposed by the inexorable 'primary aging' process. These decrements due to disease, rather than primary aging, can be termed 'secondary aging', and include the premature development (as early as adolescence) of asymptomatic preclinical cardiovascular abnormalities (e.g. endothelial dysfunction, arterial stiffness, diastolic dysfunction), as well as impaired exercise performance. These abnormalities are important, as they are associated with greater cardiovascular morbidity and mortality in people with and without T2D. A better understanding of the pathophysiology of secondary cardiovascular aging in people with T2D is warranted, and an evaluation of the benefits of existing treatments for these abnormalities is useful (e.g. exercise training). The focus of this review is to discuss the data relevant to the following key postulates: (a) T2D causes premature cardiovascular aging; (b) in contrast to primary cardiovascular aging, the premature cardiovascular aging of T2D may be modifiable with exercise. The exercise-focused perspective for this review is appropriate because impairments in exercise performance are markers of premature cardiovascular aging in T2D, and also because exercise training shows promise to attenuate some aspects of cardiovascular aging during the preclinical stage.

Increased left ventricular stiffness impairs exercise capacity in patients with heart failure symptoms despite normal left ventricular ejection fraction

Aims. Several mechanisms can be involved in the development of exercise intolerance in patients with heart failure despite normal left ventricular ejection fraction (HFNEF) and may include impairment of left ventricular (LV) stiffness. We therefore investigated the influence of LV stiffness, determined by pressure-volume loop analysis obtained by conductance catheterization, on exercise capacity in HFNEF. Methods and Results. 27 HFNEF patients who showed LV diastolic dysfunction in pressure-volume (PV) loop analysis performed symptom-limited cardiopulmonary exercise testing (CPET) and were compared with 12 patients who did not show diastolic dysfunction in PV loop analysis. HFNEF patients revealed a lower peak performance (P = .046), breathing reserve (P = .006), and ventilation equivalent for carbon dioxide production at rest (P = .002). LV stiffness correlated with peak oxygen uptake (r = -0.636, P < .001), peak oxygen uptake at ventilatory threshold (r = -0.500, P = .009), and ventilation equivalent for carbon dioxide production at ventilatory threshold (r = 0.529, P = .005). Conclusions. CPET parameters such as peak oxygen uptake, peak oxygen uptake at ventilatory threshold, and ventilation equivalent for carbon dioxide production at ventilatory threshold correlate with LV stiffness. Increased LV stiffness impairs exercise capacity in HFNEF.

Exercise training inhibits inflammatory cytokines and more than prevents myocardial dysfunction in rats with sustained beta-adrenergic hyperactivity

Myocardial hypertrophy and dysfunction occur in response to excessive catecholaminergic drive. Adverse cardiac remodelling is associated with activation of proinflammatory cytokines in the myocardium. To test the hypothesis that exercise training can prevent myocardial dysfunction and production of proinflammatory cytokines induced by beta-adrenergic hyperactivity, male Wistar rats were assigned to one of the following four groups: sedentary non-treated (Con); sedentary isoprenaline treated (Iso); exercised non-treated (Ex); and exercised plus isoprenaline (Iso+Ex). Echocardiography, haemodynamic measurements and isolated papillary muscle were used for functional evaluations. Real-time RT-PCR and Western blot were used to quantify tumour necrosis factor alpha, interleukin-6, interleukin-10 and transforming growth factor beta(1) (TGF-beta(1)) in the tissue. NF-B expression in the nucleus was evaluated by immunohistochemical staining. The Iso rats showed a concentric hypertrophy of the left ventricle (LV). These animals exhibited marked increases in LV end-diastolic pressure and impaired myocardial performance in vitro, with a reduction in the developed tension and maximal rate of tension increase and decrease, as well as worsened recruitment of the Frank-Starling mechanism. Both gene and protein levels of tumour necrosis factor alpha and interleukin-6, as well as TGF-beta(1) mRNA, were increased. In addition, the NF-B expression in the Iso group was significantly raised. In the Iso+Ex group, the exercise training had the following effects: (1) it prevented LV hypertrophy; (ii) it improved myocardial contractility; (3) it avoided the increase of proinflammatory cytokines and improved interleukin-10 levels; and (4) it attenuated the increase of TGF-beta(1) mRNA. Thus, exercise training in a model of beta-adrenergic hyperactivity can avoid the adverse remodelling of the LV and inhibit inflammatory cytokines. Moreover, the cardioprotection is related to beneficial effects on myocardial performance.