Supervised Exercise Training for Chronic Heart Failure With Preserved Ejection Fraction: A Scientific Statement From the American Heart Association and American College of Cardiology.

Heart failure with preserved ejection fraction (HFpEF) is one of the most common forms of heart failure; its prevalence is increasing, and outcomes are worsening. Affected patients often experience severe exertional dyspnea and debilitating fatigue, as well as poor quality of life, frequent hospitalizations, and a high mortality rate. Until recently, most pharmacological intervention trials for HFpEF yielded neutral primary outcomes. In contrast, trials of exercise-based interventions have consistently demonstrated large, significant, clinically meaningful improvements in symptoms, objectively determined exercise capacity, and usually quality of life. This success may be attributed, at least in part, to the pleiotropic effects of exercise, which may favorably affect the full range of abnormalities-peripheral vascular, skeletal muscle, and cardiovascular-that contribute to exercise intolerance in HFpEF. Accordingly, this scientific statement critically examines the currently available literature on the effects of exercise-based therapies for chronic stable HFpEF, potential mechanisms for improvement of exercise capacity and symptoms, and how these data compare with exercise therapy for other cardiovascular conditions. Specifically, data reviewed herein demonstrate a comparable or larger magnitude of improvement in exercise capacity from supervised exercise training in patients with chronic HFpEF compared with those with heart failure with reduced ejection fraction, although Medicare reimbursement is available only for the latter group. Finally, critical gaps in implementation of exercise-based therapies for patients with HFpEF, including exercise setting, training modalities, combinations with other strategies such as diet and medications, long-term adherence, incorporation of innovative and more accessible delivery methods, and management of recently hospitalized patients are highlighted to provide guidance for future research.

The autonomic nervous system and heart failure.

The pathophysiology of heart failure (HF) is characterized by hemodynamic abnormalities that result in neurohormonal activation and autonomic imbalance with increase in sympathetic activity and withdrawal of vagal activity. Alterations in receptor activation from this autonomic imbalance may have profound effects on cardiac function and structure. Inhibition of the sympathetic drive to the heart through ß-receptor blockade has become a standard component of therapy for HF with a dilated left ventricle because of its effectiveness in inhibiting the ventricular structural remodeling process and in prolonging life. Several devices for selective modulation of sympathetic and vagal activity have recently been developed in an attempt to alter the natural history of HF. The optimal counteraction of the excessive sympathetic activity is still unclear. A profound decrease in adrenergic support with excessive blockade of the sympathetic nervous system may result in adverse outcomes in clinical HF. In this review, we analyze the data supporting a contributory role of the autonomic functional alterations on the course of HF, the techniques used to assess autonomic nervous system activity, the evidence for clinical effectiveness of pharmacological and device interventions, and the potential future role of autonomic nervous system modifiers in the management of this syndrome.

Mechanisms for cachexia in heart failure.

The combination of profound muscle wasting and severe weight loss that occurs in heart failure is a complex phenomenon that involves the interplay of numerous factors. In this article, we describe processes that contribute to cachexia, as part of the clinical sequelae of heart failure, and their potential underlying mechanisms. While multiple mechanisms of cardiac cachexia have been described, we propose a multifactorial etiology for this condition that includes, but is not limited to, nutritional and gastrointestinal alterations, immunological and neurohormonal activation, and anabolic and catabolic imbalance.

Supervised Exercise Training for Chronic Heart Failure With Preserved Ejection Fraction: A Scientific Statement From the American Heart Association and American College of Cardiology.

Heart failure with preserved ejection fraction (HFpEF) is one of the most common forms of heart failure; its prevalence is increasing, and outcomes are worsening. Affected patients often experience severe exertional dyspnea and debilitating fatigue, as well as poor quality of life, frequent hospitalizations, and a high mortality rate. Until recently, most pharmacological intervention trials for HFpEF yielded neutral primary outcomes. In contrast, trials of exercise-based interventions have consistently demonstrated large, significant, clinically meaningful improvements in symptoms, objectively determined exercise capacity, and usually quality of life. This success may be attributed, at least in part, to the pleiotropic effects of exercise, which may favorably affect the full range of abnormalities-peripheral vascular, skeletal muscle, and cardiovascular-that contribute to exercise intolerance in HFpEF. Accordingly, this scientific statement critically examines the currently available literature on the effects of exercise-based therapies for chronic stable HFpEF, potential mechanisms for improvement of exercise capacity and symptoms, and how these data compare with exercise therapy for other cardiovascular conditions. Specifically, data reviewed herein demonstrate a comparable or larger magnitude of improvement in exercise capacity from supervised exercise training in patients with chronic HFpEF compared with those with heart failure with reduced ejection fraction, although Medicare reimbursement is available only for the latter group. Finally, critical gaps in implementation of exercise-based therapies for patients with HFpEF, including exercise setting, training modalities, combinations with other strategies such as diet and medications, long-term adherence, incorporation of innovative and more accessible delivery methods, and management of recently hospitalized patients are highlighted to provide guidance for future research.

Biomarkers.

Epidemiologic, clinical, and basic research has identified several antecedent conditions that predispose individuals to heart failure and its predecessor, asymptomatic left ventricular remodeling and dysfunction (stage B heart failure). Many biochemical markers have been described that characterize the remodeling process and the development of cardiac dysfunction. Although natriuretic peptides and cardiac troponin are currently used in the context of diagnosis, risk stratification, and management of stage C and D heart failure, many other biomarkers provide insights into the underlying pathophysiology of left ventricular dysfunction, suggesting new directions for fundamental research or the development of new therapies.

Ventricular preexcitation modulates strain and attenuates cardiac remodeling in a swine model of myocardial infarction.

BACKGROUND: Myocardial infarction modifies the distribution of stress within the heart, increasing wall stress in ischemic and surrounding tissue, which often leads to adverse left ventricular remodeling. Electrical preexcitation pacing with appropriate timing of high-stress regions can reduce local strain and may attenuate global remodeling. METHODS AND RESULTS: Myocardial infarction was induced in 24 swine to study the short-term (n=12) and long-term (n=12) effects of therapy. Sonomicrometry and hemodynamic measurements were used to show the mechanistic effects of preexcitation and to determine the optimal stimulation site and atrioventricular delay. Lagrangian strain was used to assess regional loading characteristics. Long-term study animals were randomized to 8 weeks of preexcitation (therapy) or no pacing (control). Echocardiograms were performed 2 days after myocardial infarction and repeated at 60 days, when tissue weights and apoptosis were assessed. Preexcitation reduced regional strain in the short term, with the best results achieved when the border region was paced at an atrioventricular delay of 50% of the intrinsic PR interval. In the long term, the changes in left ventricular internal diameter and left atrial size were decreased in therapy animals versus control animals (0.9+/-0.3 versus 1.5+/-0.5 cm, P=0.03, and 1.06+/-0.78 versus 2.32+/-0.88 cm, P<0.04, respectively). Heart weight was significantly lower in the therapy animals than in the control animals (319.8+/-20.8 versus 359.6+/-29.3 g, P=0.02). Although not significant, cardiomyocyte apoptosis trended lower in the therapy group. CONCLUSIONS: Preexcitation of the left ventricle after myocardial infarction reduced strain and stroke work in the infarct and border regions in the short term and attenuated adverse ventricular remodeling in the long term.

Traditional and novel approaches to management of heart failure: successes and failures.

Although considerable progress has been made in the pharmacologic and device management of chronic heart failure in recent decades, heart failure patients continue to remain symptomatic, with high hospitalization and mortality rates. A number of novel agents, including endothelin antagonists and tumor-necrosis factor blockers, have recently failed to improve the clinical outcomes of patients with heart failure. Have we reached a ceiling in preventing the progression of the disease? This article reviews successes and late-stage clinical trial disappointments in the treatment of patients with heart failure. Furthermore, the article discusses how agents that have beneficial effects in heart failure also generally attenuate or reverse ventricular remodeling, whereas the newer agents that have failed to improve clinical outcomes either had no effect on remodeling or have been associated with adverse remodeling.

Effect of coronary artery bypass graft surgery on left ventricular systolic function.

BACKGROUND: Changes in left ventricular (LV) systolic function in response to coronary artery bypass grafting (CABG) have not been fully assessed. METHODS: Between January 2001 and December 2014, 2,838 consecutive patients underwent isolated CABG at the Minneapolis Veterans Affairs Health Care System. Of these, 375 had echocardiographic assessment of LV function before (within 6 months) and after (3 to 24 months) CABG and were included in this analysis. RESULTS: While the mean LV ejection fraction (LVEF) did not change following CABG [(49±13)% vs. (49±12)%, P=0.51], LVEF decreased in the subgroup with normal (≥50%) pre-operative LVEF [from (59±5)% to (56±9)%, P<0.001] and improved in those with decreased (<50%) pre-operative LVEF [from (36±9)% to (41±12)%, P<0.001]. There was a significant reduction in LV internal diameter during end-diastole (LVIDd) (5.4±0.8 vs. 5.3±0.9, P=0.002) and an increase in left atrial diameter (LAD) (4.4±0.7 vs. 4.6±0.7, P<0.001). There were no perioperative changes in LV internal diameter during end-systole, LV mass, posterior wall thickness, or septal wall thickness. LVEF improved by >5% in 24% of the study population, did not change (+/- 5%) in 55%, and worsened by >5% in 21%. Patients with improved EF were less often diabetic and had lower pre-operative LVEF, and greater LV dimensions at baseline. CONCLUSIONS: After CABG, there was a decrease in LVIDd and an increase in LAD. Also, a decrease in LV systolic function with CABG was observed in patients with normal pre-operative LVEF and an improvement in LV systolic function was observed in patients with decreased pre-operative LVEF.

C-reactive protein in heart failure: prognostic value and the effect of valsartan.

BACKGROUND: The role of C-reactive protein (CRP) in heart failure is not well studied. We assessed the prognostic value of CRP in patients randomized in Val-HeFT (Valsartan Heart Failure Trial) and studied changes in CRP that were associated with valsartan. METHODS AND RESULTS: Characteristics of patients with baseline CRP levels above and below the median value were compared. Univariable and multivariable Cox proportional hazards regression models were used to examine the relationship of CRP to mortality and morbidity. Interactions were tested to determine whether differences in CRP changes from baseline to 4 and 12 months between groups randomly assigned to valsartan or placebo depended on baseline ACE inhibitor use. Median plasma CRP was 3.23 mg/L (interquartile range 1.42 to 7.56 mg/L), which is higher than in the general population. Patients with CRP above the median had features of more severe heart failure than those with CRP levels below the median. The cumulative likelihood of death and first morbid event increased with increasing quartile of CRP. Relative to the lowest CRP quartile, the risk of mortality (hazard ratio 1.51, 95% CI 1.2 to 1.9) and first morbid event (hazard ratio 1.53, 95% CI 1.28 to 1.84) was increased in the highest CRP quartile in multivariable models. CRP added incremental prognostic information to that provided by brain natriuretic peptide alone. CRP did not change significantly over time in the placebo group; however, after 12 months, valsartan was associated with a decrease in CRP in patients not receiving ACE inhibitors but not in those receiving ACE inhibitors at 12 months. CONCLUSIONS: CRP is increased in heart failure. Higher levels are associated with features of more severe heart failure and are independently associated with mortality and morbidity. The ability of treatments to reduce CRP levels and the prognostic importance of reducing CRP require further study.

Anemia and change in hemoglobin over time related to mortality and morbidity in patients with chronic heart failure: results from Val-HeFT.

BACKGROUND: Anemia is known to be a prognostic marker for patients with heart failure. However, little is known about the prognostic value of changes in hemoglobin (Hgb) over time or about the causes of anemia. METHODS AND RESULTS: Retrospective analysis of Valsartan Heart Failure Trial data indicated that the quartile of patients with the biggest average decrease in Hgb over 12 months (from 14.2 to 12.6 g/dL) had significantly (P< or =0.01) increased risk of subsequent hospitalization (hazard ratio [HR], 1.47), morbid events (HR, 1.41), and death (HR, 1.6) compared with the quartile that exhibited little change in Hgb over 12 months (from 13.7 to 13.8 g/dL). Increasing Hgb was significantly associated with lower mortality in patients with (HR, 0.78) and without (HR, 0.79) anemia at baseline. Anemia at baseline and the changes in Hgb were independently associated with serum albumin, blood pressure, glomerular filtration rate, B-type natriuretic peptide, and C-reactive protein. Lack of anemia at baseline and increases in Hgb over 12 months were not associated with smaller left ventricular diameters or higher ejection fractions. CONCLUSIONS: Changes in Hgb over 12 months were inversely associated with subsequent risk of mortality and morbidity, independently of the effects of baseline anemia and other important predictors. Several factors were independently related to anemia at baseline and changes in Hgb, suggesting multiple causes of anemia in patients with heart failure. These findings raise important questions about the optimal level of Hgb in patients with moderate to severe heart failure and how to achieve them.

Chronic heart failure with preserved left ventricular ejection fraction: diagnostic and prognostic value of left atrial size.

BACKGROUND: Almost 40% of patients with heart failure (HF) have preserved left ventricular (LV) ejection fraction (EF) and prognosis similar to those with reduced EF. Data on prognostic markers in such patients are limited. We analyzed the prevalence and prognostic value of left atrial (LA) size in this condition. METHODS: 89 normal subjects (Group I), 38 asymptomatic hypertensive patients (Group II) and 183 HF patients with preserved EF (EF >45%) (Group III) were studied. LA diameter (LAD), LV diastolic (LVD) and systolic (LVS) dimensions and mass (LVmass) and EF were measured. E and A wave velocities and E/A were measured. The primary end point was all cause mortality in group III patients. RESULTS: Groups did not differ in age, gender or EF. Group III patients had larger LAD (4.6+-1.0 cm) compared with both Group I (3.7+/-0.6) and Group II (3.7+/-0.5 cm) (p<0.0001). A markedly enlarged (arbitrarily defined as LAD higher or equal 5 cm) had an odds ratio of 34 (95% CI 8-144) in distinguishing HF patients from normals. After a mean follow-up period of 29+/-27 months, 40 patients (21.9%) died. In Cox univariate analysis, NYHA class (HR 2.8 95% C.I. 1.8-4.3; p<0.0001), diastolic blood pressure (DBP) (HR 0.92 95% C.I. 0.88-0.96; p<0.0001), age (HR 1.059 95% C.I. 1.01-1.11; p=0.02) and LAD (HR 1.72 95% C.I. 1.27-2.3; p=0.0005) were predictors of mortality. LAD predicted survival independently of other variables. CONCLUSION: The left atrium is frequently dilated in HF patients compared with controls despite similar EF. LAD showed powerful prognostic value independent of clinical variables.

Heart Failure With Improved Ejection Fraction: Clinical Characteristics, Correlates of Recovery, and Survival: Results From the Valsartan Heart Failure Trial.

BACKGROUND: Heart failure with recovered or improved ejection fraction (HFiEF) has been proposed as a new category of HF. Whether HFiEF is clinically distinct from HF with persistently reduced ejection fraction remains to be validated. METHODS AND RESULTS: Of the 5010 subjects enrolled in the Valsartan Heart Failure Trial (Val-HeFT), 3519 had a baseline left ventricular EF of <35% and a follow-up echocardiographic assessment of EF at 12 months. Of these, 321 (9.1%) patients who had a 12-month EF of >40% constituted the subgroup with HFiEF. EF improved from 28.7±5.6% to 46.5±5.6% in the subgroup with HFiEF and remained reduced (25.2±6.2% and 27.5±7.1%) in the subgroup with HF with reduced ejection fraction. The group with HFiEF had a less severe hemodynamic, biomarker, and neurohormonal profile, and it was treated with a more intense HF medication regimen. Subjects who had higher blood pressure and those treated with a ß-blocker or randomized to valsartan had greater odds of being in the HFiEF group, whereas those with an ischemic pathogenesis, a more dilated left ventricle, and a detectable hs-troponin had lower odds of an improvement in EF. Recovery of the EF to >40% was associated with a better survival compared with persistently reduced EF. CONCLUSIONS: Our data support HFiEF as a stratum of HF with reduced ejection fraction with a more favorable outcome, which occurs in a minority of patients with HF with reduced ejection fraction who have a lower prevalence of ischemic heart disease, a less severe hemodynamic, biomarker, and neurohormonal profile, and who are treated with a more intense HF medication regimen. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00336336.

Surrogate end points in heart failure.

Because of the increasing number of pharmacologic strategies available for treatment of heart failure (HF), the time has come to reassess the adequacy of end points used to evaluate therapeutic efficacy. Interest in the use of surrogate end points in clinical studies is increasing. A surrogate end point is defined as a measurement that can substitute for a true end point for the purpose of comparing specific interventions or treatments in a clinical trial. A true end point is one that is of clinical importance to the patient (e.g., mortality or quality of life), whereas a surrogate end point is one biologically closer to the disease process (e.g., ejection fraction or left ventricular volume in HF). The prime motivation for the use of a surrogate end point concerns the possible reduction in sample size or trial duration. Such reductions have important cost implications and in some cases may influence trial feasibility. Another, perhaps more important, aspect of measuring surrogate end points is that they increase our understanding of the mechanism of action of drugs and thus may help physicians to take a more enlightened approach in managing their patients. In this article we have analyzed the possible potentials of the surrogate end points in clinical studies of patients with chronic HF. Other uses of possible surrogates are discussed, and the limitations in finding true surrogates are mentioned. At this time we conclude there is no well established surrogate in HF.

The cardiac component of cardiac cachexia.

BACKGROUND: Recent evidence suggests the importance of noncardiac mechanisms in the genesis of the syndrome of cardiac cachexia. This raises the question of the relative role of the heart itself in this syndrome. This study sought to assess the cardiac dimensions, mass, and function and changes in these parameters over time in patients with chronic heart failure with and without cachexia. METHODS: Doppler echocardiography was performed in 28 patients with nonedematous weight loss (>7.5% over a period of >6 months) compared with 56 matched patients without weight loss in a ratio of 1:2 (age 71 +/- 13 vs 67 +/- 8 years, P =.07; New York Heart Association class 2.9 +/- 0.7 vs 2.6 +/- 0.6, P =.08). In 18 cachectic and 35 noncachectic patients with previous echocardiographic recordings, we analyzed the changes in left ventricular (LV) dimensions and mass over time. RESULTS: Cardiac dimensions including LV diastolic (69 +/- 9 mm vs 67 +/- 13 mm) and systolic cavity diameter (58 +/- 11 mm vs 55 +/- 15 mm), LV mass (480 +/- 180 g vs 495 +/- 190 g), and LV systolic and diastolic function including fractional shortening (16% +/- 10% vs 18% +/- 10%), isovolumic relaxation time (29 +/- 22 ms vs 36 +/- 27 ms), and E/A ratio (2.7 +/- 1.6 vs 3.3 +/- 2.9) did not differ between cachectic and noncachectic patients (all P >.1). By analyzing changes in LV mass over time, we found an increase (>20%) in 2 (11%) cachectic and 14 (40%) noncachectic patients and a decrease in LV mass (>20%) in 9 (50%) cachectic and 8 (23%) noncachectic patients (chi2 test, P <.05). CONCLUSIONS: Although no specific cardiac abnormality could be detected echocardiographically in cachectic patients compared with patients with noncachectic chronic heart failure in a cross-sectional study, over time a significant loss of LV mass (>20%) occurs more frequently in patients with cardiac cachexia.

Insulin resistance in moderate chronic heart failure is related to hyperleptinaemia, but not to norepinephrine or TNF-alpha.

OBJECTIVES: Chronic heart failure (CHF) has emerged as an insulin-resistant state, independently of ischaemic aetiology. The underlying mechanisms of this finding are not known. Catecholamines, tumor necrosis factor alpha (TNFalpha) and leptin, the adipocyte specific hormone, have all been implicated as mediators of impaired insulin sensitivity. The purpose of this study was to examine in patients with CHF and in comparison to healthy controls subjects whether norepinephrine, TNFalpha or leptin relate to insulin sensitivity. DESIGN: 41 patients with CHF (age 60+/-2 years, NYHA I/II/III/IV 4/12/22/3, peak oxygen consumption 17.6+/-1.0 ml/kg per min) and 21 healthy controls of similar age and total and regional fat distribution were studied in a cross-sectional study. Insulin sensitivity was assessed by intravenous glucose tolerance testing using the minimal model approach; catecholamines, TNFalpha and soluble TNF receptors 1 and 2 were also measured. Total and regional body fat mass was assessed by dual energy X-ray absorptiometry. RESULTS: Insulin sensitivity was reduced in CHF patients compared to controls by 31% (P<0.01) and fasting insulin was higher in patients than in controls (79.1+/-9.7 vs. 41.4+/-6.0 pmol/l, P<0.01). Patients had, compared to healthy controls, elevated serum leptin levels (8.28+/-0.84 vs. 4.83+/-0.68 ng/ml), norepinephrine (3.45+/-0.34 vs. 1.87+/-0.16 nmol/l, both P<0.01) and soluble TNF-receptors 1 (1280+/-141 vs. 639+/-52 pg/ml) and 2 (2605+/-184 vs. 1758+/-221 pg/ml, both P<0.01). Leptin levels corrected for total body fat mass were higher in CHF patients than in controls (41.3+/-3 vs. 24.3+/-2 pg/ml per 100 g, P<0.001). TNFalpha was not significantly different between the groups. In both groups there was an inverse correlation between insulin sensitivity and serum leptin (r=-0.65, P<0.0001 for pooled subjects); in contrast, no significant relation was found between insulin sensitivity and norepinephrine or TNFalpha. In multivariate regression analysis, leptin emerged as the only significant predictor of insulin sensitivity (standardised coefficient=-0.59, P<0.001), independent of body fat mass, age and peak VO2. CONCLUSION: In moderate CHF, elevated leptin levels directly and independently predict insulin resistance. Elevated serum leptin levels could play a role in the impaired regulation of energy metabolism in CHF. In contrast to observations in other conditions, TNFalpha and norepinephrine are not related to insulin resistance in moderate CHF.

Wasting of the left ventricle in patients with cardiac cachexia: a cardiovascular magnetic resonance study.

BACKGROUND: The "cachectic heart" has been described as a pathologic decrease in the size and mass of the heart, but no in vivo studies have shown changes in cardiac dimensions or left ventricular (LV) mass over time in chronic heart failure (CHF) associated with body wasting (cardiac cachexia). Cardiovascular magnetic resonance (CMR) has high reproducibility and is more sensitive than other techniques. METHODS: CMR studies of LV volumes and mass were performed at baseline and a mean of 15 months later in nine CHF patients with cardiac cachexia and 28 matched CHF controls without cachexia (mass index 23 +/- 1 vs. 29 +/- 5 kg/m2, P=0.0005). RESULTS: At baseline, LV end-diastolic volume (197 +/- 78 vs. 203 +/- 65 ml), end-systolic volume (131 +/- 75 vs. 126 +/- 63 ml), LV mass (213 +/- 44 vs. 222 +/- 62 g), and LV ejection fraction (38 +/- 19% vs. 40 +/- 16%) did not differ between cachectic patients and controls (all P>0.10). During follow-up, there was a significant decrease in LV mass in patients with cachexia (-16 g, P<0.05) and a trend to increase in LV mass in patients without cachexia (+7 g, P=0.12, comparison between groups: P=0.010). CONCLUSIONS: The direction of changes over time in LV mass differs in CHF patients with cachexia as compared with non-cachectic controls. A significant decrease in LV mass occurs in patients with cardiac cachexia. This study documents in vivo the occurrence of wasting of the left ventricle in patients with CHF who demonstrate general body wasting.

Left Atrial Appendage Thrombus Despite Anticoagulation.

The American College of Cardiology Foundation/American Heart Association task force on practice guidelines recommend therapeutic anticoagulation for at least 3 weeks prior to cardioversion in patients with atrial fibrillation of 48-hour duration or longer, or when the duration of atrial fibrillation is unknown. This case report demonstrates the presence of thrombi in the left atrial appendage despite adequate anticoagulation, challenging the current guidelines. Therapeutic anticoagulation for at least 3 weeks followed by transesophageal echocardiography in search of thrombus may enhance thromboembolic safety of elective cardioversion. Atrial fibrillation (AF) and heart failure (HF) have emerged as major cardiovascular epidemics in developed nations over the past decade. They share similar risk factors, seem to mutually accelerate progression and are associated with increased morbidity and mortality. Their relationship involves complex hemodynamic, neuro-hormonal, inflammatory and electrophysiologic mechanisms, which go beyond just mutual risk factors. This review focuses on updates in AF and HF with a hope of better understanding this relationship and the management of this complex duo.