Effects of digoxin on morbidity and mortality in diastolic heart failure: the ancillary digitalis investigation group trial

Epidemiology and clinical course of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFPEF) is increasingly recognized as a major public health problem worldwide. Significant advances have been made in our understanding of the epidemiology of HFPEF over the past two decades, with the publication of numerous population-based epidemiological studies, large heart failure registries, and randomized clinical trials. These recent studies have provided detailed characterization of larger numbers of patients with HFPEF than ever before. This review summarizes the state of current knowledge with regards to the disease burden, patient characteristics, clinical course, and outcomes of HFPEF. Despite the wealth of available data, substantive gaps in knowledge were identified. These gaps represent opportunities for further research in HFPEF, a syndrome that is clearly a rising societal burden and that is associated with substantial morbidity and mortality.

Rationale and design of the 'aldosterone receptor blockade in diastolic heart failure' trial: a double-blind, randomized, placebo-controlled, parallel group study to determine the effects of spironolactone on exercise capacity and diastolic function in patients with symptomatic diastolic heart failure (Aldo-DHF)

AIMS

Increasing evidence suggests that enhanced aldosterone signalling plays a key role in the onset and progression of diastolic heart failure (DHF). Aldo-DHF will test the hypothesis that aldosterone receptor blockade by spironolactone will improve exercise capacity and diastolic function in patients with DHF.

METHODS

Aldo-DHF is a randomized, placebo-controlled, double-blinded, two-armed, multicentre, parallel group study. Four hundred and twenty patients with DHF will be randomly assigned to receive spironolactone 25 mg per day or placebo. The main inclusion criteria are: age > or = 50 years, New York Heart Association II/III, preserved left ventricular ejection fraction (> or =50%), and echocardiographic evidence of diastolic dysfunction. The two primary endpoints are changes in exercise capacity (peak VO(2), spiroergometry) and in diastolic function (E/é, echocardiography) after 12 months. Secondary endpoints include effects of spironolactone on additional parameters of exercise performance and diastolic as well as systolic function, neurohumoral activation, and quality of life. Morbidity and mortality as well as safety aspects will also be assessed.

CONCLUSION

Aldo-DHF is the first large-scale clinical trial to evaluate the effects of aldosterone receptor blockade on exercise capacity and diastolic function in patients with DHF. Aldo-DHF will provide important information about the clinical course of this condition and may have significant impact on treatment strategies and future trials in these patients.

Ouabain attenuates cardiotoxicity induced by other cardiac steroids

BACKGROUND AND PURPOSE

All cardiac steroids have a similar structure, bind to and inhibit the ubiquitous transmembrane protein Na(+), K(+)-ATPase and increase the force of contraction of heart muscle. However, there are diverse biological responses to different cardiac steroids both at the cellular and at the molecular level. Moreover, we have recently shown that ouabain inhibits digoxin- and bufalin-induced changes in membrane traffic. The present study was designed to test the hypothesis that ouabain also has an inhibitory effect on cardiotoxicity induced by other cardiac steroids.

EXPERIMENTAL APPROACH

The hypothesis was tested in isolated heart muscle preparations and in an in vivo model of cardiotoxicity in guinea pigs.

KEY RESULTS

Ouabain at a low dose attenuated the toxicity induced by bufalin and digoxin in heart muscle preparations. In addition, ouabain at the low dose (91 ng.kg(-1).h(-1)), but not at a higher dose (182 ng.kg(-1).h(-1)), delayed the development of digoxin-induced (500 microg.kg(-1).h(-1)) cardiotoxicity in anaesthetized guinea pigs, as manifested by delayed arrhythmia and terminal ventricular fibrillation, as well as a reduced heart rate. In addition, as observed with ouabain, the phosphoinositide 3-kinase inhibitor wortmannin (100 microg.kg(-1).h(-1)) delayed the digoxin-induced arrhythmia in anaesthetized guinea pigs.

CONCLUSIONS AND IMPLICATIONS

The present study demonstrates the inhibitory effect, probably through signal transduction pathways, of ouabain on digoxin- and bufalin-induced cardiotoxicity in guinea pigs. Further understanding of this phenomenon could be beneficial for increasing the therapeutic window for cardiac steroids in the treatment of chronic heart failure.

Digoxin treatment in heart failure--unveiling risk by cluster analysis of DIG data

BACKGROUND

Digoxin has been shown to reduce heart failure (HF) hospitalizations with no overall effect on mortality in HF patients. We used cluster analysis to delineate the clinical characteristics of HF patients in whom digoxin therapy was associated with improved or worsened clinical outcomes.

METHODS

The Digitalis Investigation Group (DIG) database was partitioned into 20 clusters. Multivariate Cox regression analyses was used, to identify clusters in which digoxin was associated with either an increase (Mortality(dig)HR>1), decrease (Mortality(dig)HR<1), or no association with all cause mortality (Mortality(dig)HR-NS); and separately, with an increase (HFA(dig)HR>1), decrease (HFA(dig)HR<1), or no association (HFA(dig)HR-NS) with HF admissions (HFA).

RESULTS

We identified 938 patients in the Mortality(dig)HR>1 group, 6818 patients in the Mortality(dig)HR-NS group, and none in Mortality(dig)HR<1 group. The Mortality(dig)HR>1 group had a higher prevalence of females, diabetes mellitus, hypertension, higher age, systolic blood pressure (SBP), heart rate and ejection fraction (EF), compared to the Mortality(dig)HR-NS group. Similarly, 6325 patients clustered in the HFA(dig)HR<1 group, 1431 patients in the HFA(dig)HR-NS group, and none in the HFA(dig)HR>1 group. The HFA(dig)HR-NS group had a higher prevalence of females and hypertension, higher SBP, body mass index and EF; and lower prevalence of peripheral edema and third heart sound, compared with the HFA(dig)HR<1 group.

CONCLUSION

Thus, the baseline characteristics of patients who did not have reduction in HF hospitalization or who had increased mortality were very similar and included females with hypertension, higher EF and higher SBP. Thus, use of digoxin in patients with this profile may need to be avoided.

Heart failure with preserved ejection fraction: pathophysiology and emerging therapies

Approximately half of patients with heart failure (HF) have a preserved ejection fraction (HFpEF). Morbidity and mortality are similar to HF with reduced EF (HFrEF), yet therapies with unequivocal benefit in HFrEF have not been shown to be effective in HFpEF. Recent studies have shown that the pathophysiology of HFpEF, initially believed to be due principally to diastolic dysfunction, is more complex. Appreciation of this complexity has shed new light into how HFpEF patients might respond to traditional HF treatments, while also suggesting new applications for novel therapies and strategies. In this review, we shall briefly review the pathophysiologic mechanisms in HFpEF, currently available clinical trial data, and finally explore new investigational therapies that are being developed and tested in ongoing and forthcoming trials.

Advances in diastolic heart failure

More than 50% of people living with congestive heart failure have diastolic heart failure (DHF). Most of them are older than 70 years, and female. The prevalence of DHF has increased with time. DHF is caused by left ventricular (LV) diastolic dysfunction (DD) which is induced by diastolic dyssynchrony. Cardiac and extracardiac factors play important roles in the development of heart failure (HF) symptoms. The diagnosis of DHF is generally based on typical symptoms and signs of HF, preserved or normal LV ejection fraction, DD and no valvular abnormalities on examination, using noninvasive and invasive methodologies. The outcomes with pharmacological therapy in patients with DHF are frequently neutral in clinical trials, and prognosis still remains poor with a 5-year mortality of 42.3% after hospitalization for HF. Further trials are necessary.

Treatment of heart failure with normal ejection fraction: an inconvenient truth!

Despite use of similar drugs, outcomes of recent heart failure (HF) trials were frequently neutral in heart failure with normal left ventricular ejection fraction (HFNEF) and positive in heart failure with reduced left ventricular ejection fraction (HFREF). The neutral outcomes of HFNEF trials were often attributed to deficient HFNEF patient recruitment with inclusion of many HFREF or noncardiac patients. Patient recruitment criteria of 21 HFNEF trials were therefore reviewed in reference to diagnostic guidelines for HFNEF. In the 4 published sets of guidelines, a definite diagnosis of HFNEF required the simultaneous and obligatory presence of signs and/or symptoms of HF and evidence of normal systolic left ventricular (LV) function and of diastolic LV dysfunction. In 3 of 4 sets of guidelines, normal systolic LV function comprised both a left ventricular ejection fraction (LVEF) >50% and an absence of LV dilation. Among the 21 HFNEF trials, LVEF cutoff values ranged from 35% to 50%, with only 8 trials adhering to an LVEF >50%. Furthermore, only 1 trial specified a normal LV end-diastolic dimension as an enrollment criterion and only 7 trials required evidence of diastolic LV dysfunction. Nonadherence to diagnostic guidelines induced excessive enrollment into HFNEF trials of HF patients with eccentric LV remodeling and ischemic heart disease compared with HF patients with concentric LV remodeling and arterial hypertension. Nonadherence to guidelines also led to underpowered HFNEF trials with a low incidence of outcome events such as death or HF hospitalizations. Future HFNEF trials should therefore adhere to diagnostic guidelines for HFNEF.

Mode of death in patients with heart failure and a preserved ejection fraction: results from the Irbesartan in Heart Failure With Preserved Ejection Fraction Study (I-Preserve) trial

BACKGROUND

The mode of death has been well characterized in patients with heart failure and a reduced ejection fraction; however, less is known about the mode of death in patients with heart failure and a preserved ejection fraction (HFPEF). The purpose of this study was to examine the mode of death in patients with HFPEF enrolled in the Irbesartan in Heart Failure With Preserved Ejection Fraction Study (I-Preserve) trial and to determine whether irbesartan altered the distribution of mode of death in HFPEF.

METHODS AND RESULTS

All deaths were reviewed by a clinical end-point committee, and the mode of death was assigned by consensus of the members. The annual mortality rate was 5.2% in the I-Preserve trial. There were no significant differences in mortality rate between the placebo and irbesartan groups. The mode of death was cardiovascular in 60% (including 26% sudden, 14% heart failure, 5% myocardial infarction, and 9% stroke), noncardiovascular in 30%, and unknown in 10%. There were no differences in the distribution of mode-specific mortality rates between placebo and irbesartan.

CONCLUSIONS

Sixty percent of the deaths in patients with HFPEF were cardiovascular, with sudden death and heart failure death being the most common. Treatment with irbesartan did not affect overall mortality or the distribution of mode-specific mortality rates.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00095238.

Heart failure

INTRODUCTION

Heart failure occurs in 3% to 4% of adults aged over 65 years, usually as a consequence of coronary artery disease or hypertension, and causes breathlessness, effort intolerance, fluid retention, and increased mortality. The 5-year mortality in people with systolic heart failure ranges from 25% to 75%, often owing to sudden death following ventricular arrhythmia. Risks of cardiovascular events are increased in people with left ventricular systolic dysfunction (LVSD) or heart failure.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of non-drug treatments, and of drug and invasive treatments, for heart failure? What are the effects of angiotensin-converting enzyme inhibitors in people at high risk of heart failure? What are the effects of treatments for diastolic heart failure? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2009 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 85 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: aldosterone receptor antagonists; amiodarone; angiotensin-converting enzyme inhibitors; angiotensin II receptor blockers; anticoagulation; antiplatelet agents; beta-blockers; calcium channel blockers; cardiac resynchronisation therapy; digoxin (in people already receiving diuretics and angiotensin-converting enzyme inhibitors); exercise; hydralazine plus isosorbide dinitrate; implantable cardiac defibrillators; multidisciplinary interventions; non-amiodarone antiarrhythmic drugs; and positive inotropes (other than digoxin).

Effects of diabetes mellitus in patients with heart failure and chronic kidney disease: a propensity-matched study of multimorbidity in chronic heart failure

BACKGROUND

Chronic kidney disease (CKD) and diabetes mellitus (DM) are common comorbidities in heart failure (HF) and each is associated with poor outcomes. However, the effects of multimorbidity related to having both CKD and DM compared to CKD alone have not been well studied in a propensity-matched population of chronic HF patients.

METHODS

Of the 7788 ambulatory chronic HF patients in the Digitalis Investigation Group trial, 3527 had CKD, of whom 1095 had DM. Based on the absence or presence of DM, patients were categorized CKD-only and CKD-DM, respectively. Propensity scores for CKD-DM were calculated for each patient and were used to match 987 pairs of CKD-only and CKD-DM patients. Hazard ratios (HR) and 95% confidence intervals (CI) comparing CKD-DM patients with CKD-only patients were estimated using matched Cox regression models.

RESULTS

All-cause mortality occurred in 47.0% (rate, 1783/10,000 person-years of follow-up) of CKD-DM patients and 39.6% (rate, 1414/10,000 person-years) of CKD-only patients (HR when CKD-DM is compared with CKD-only, 1.25; 95%-CI, 1.07-1.46; p=0.006). All-cause hospitalization occurred in 75.4% (rate, 5710/10,000 person-years) and 67.8% (rate, 4213/10,000 person-years) of CKD-DM and CKD-only patients respectively (HR, 1.32; 95%-CI, 1.15-1.52; p<0.0001). Respective HR and 95%-CI for other outcomes were: cardiovascular mortality (1.27; 1.06-1.52; p=0.009), HF mortality (1.34; 1.04-1.72; p=0.025); cardiovascular hospitalization (1.29; 1.12-1.49; p=0.001) and HF hospitalization (1.37; 1.16-1.63; p<0.0001).

CONCLUSIONS

Compared with comorbidity due to CKD alone, multimorbidity with CKD and DM was associated with poor outcomes in chronic HF patients.

Cardiac resynchronization therapy may benefit patients with left ventricular ejection fraction >35%: a PROSPECT trial substudy

AIMS

Cardiac resynchronization therapy (CRT) is currently limited to those with left ventricular ejection fraction (LVEF) < or =35%. To evaluate whether patients with LVEF >35% might benefit from CRT, we performed a retrospective analysis of the predictors of response to CRT (PROSPECT) database.

METHODS AND RESULTS

PROSPECT was a prospective, multicentre study that enrolled CRT patients based on enrolling centre-evaluated LVEF <35%, but all echocardiograms were subsequently analysed by a core laboratory. Patients with core laboratory-measured LVEF >35% (OVER35) were compared with those whose LVEF was <35% (UNDER35). Clinical composite score (CCS) and change in LV end systolic volume (LVESV) were analysed from baseline to 6-month follow-up. Of 361 patients, 86 (24%) had LVEF >35%. At entry, OVER35 had smaller LV volumes, shorter QRS duration, shorter 6-min walk distance, and were more likely to have ischaemic aetiology than UNDER35. Outcomes were comparable between the groups, with 62.8% of OVER35 improved in CCS (70.2% in UNDER35) and 50.8% of OVER35 improved in LVESV (57.8% in UNDER35).

CONCLUSION

Patients with LVEF >35%, New York heart association functional Class III-IV status, and QRS >130 ms appear to derive clinical and structural benefit from CRT. As CRT may offer a valuable option for these patients, this hypothesis should be formally tested in a prospective, randomized multicentre trial.

Chronic heart failure: contemporary diagnosis and management

Chronic heart failure (CHF) remains the only cardiovascular disease with an increasing hospitalization burden and an ongoing drain on health care expenditures. The prevalence of CHF increases with advancing life span, with diastolic heart failure predominating in the elderly population. Primary prevention of coronary artery disease and risk factor management via aggressive blood pressure control are central in preventing new occurrences of left ventricular dysfunction. Optimal therapy for CHF involves identification and correction of potentially reversible precipitants, target-dose titration of medical therapy, and management of hospitalizations for decompensation. The etiological phenotype, absolute decrease in left ventricular ejection fraction and a widening of QRS duration on electrocardiography, is commonly used to identify patients at increased risk of progression of heart failure and sudden death who may benefit from prophylactic implantable cardioverter-defibrillator placement with or without cardiac resynchronization therapy. Patients who transition to advanced stages of disease despite optimal traditional medical and device therapy may be candidates for hemodynamically directed approaches such as a left ventricular assist device; in selected cases, listing for cardiac transplant may be warranted.

Comparison of patients with heart failure and preserved left ventricular ejection fraction among those with versus without diabetes mellitus

Heart failure (HF) with preserved left ventricular ejection fraction (LVEF) and diabetes commonly coexist, but the impact of diabetes on HF outcomes in patients with HF and preserved LVEF has not been well studied. We assessed the risk of HF death or hospitalization for worsening HF associated with diabetes by studying 987 patients with HF and preserved LVEF enrolled in the Digitalis Investigation Group (DIG) ancillary study. Diabetics (n = 285, 28.9%) were younger, had a larger body mass index, faster heart rate, and higher pulse pressure than nondiabetics. Diabetics were also more likely to be women, have a history of hypertension, ischemic cause for HF, and were more likely to be treated with diuretics. During the mean follow-up of 37 months, 88 (30.9%) diabetics and 133 (19.0%) nondiabetics developed the primary outcome of HF hospitalization or HF death. After adjustments for baseline differences, diabetes was associated with a 68% increased risk of HF hospitalization or HF death (adjusted hazard ratio 1.68, 95% confidence interval 1.26 to 2.25, p <0.001). In conclusion, in patients with HF and preserved LVEF, diabetes is associated with significantly increased risk of developing adverse HF outcomes.

Relation of beta-blocker use with frequency of hospitalization for heart failure in patients with left ventricular diastolic dysfunction (from the Heart and Soul Study)

Heart failure (HF) is a common public health problem, and many new cases are now recognized to occur in patients with preserved left ventricular ejection fraction. beta Blockers improve the outcomes of patients with known left ventricular systolic dysfunction, but whether beta blockers provide similar protection among patients with left ventricular diastolic dysfunction is unclear. We studied the association between use of beta blockers and subsequent hospitalization for HF in patients with diastolic dysfunction and stable coronary heart disease. We evaluated medication use and performed echocardiography at baseline in a prospective cohort of 911 outpatients with known coronary heart disease from the Heart and Soul Study. Hospitalizations for HF were assessed by blinded review of the medical records during an average follow-up of 5.2 years. Of the 911 participants, 118 (13%) had diastolic dysfunction, of whom 2 were lost to follow-up. Of the 116 remaining patients, 19 (25%) of the 77 using beta blockers were hospitalized for HF compared to 16 (41%) of the 39 not using beta blockers (age-adjusted hazard ratio 0.51, 95% confidence interval 0.26 to 1.00; p = 0.05). This association remained after additional adjustment for gender, smoking, history of myocardial infarction, diabetes, and creatinine (hazard ratio 0.46, 95% confidence interval 0.23 to 0.93; p = 0.03). The results were similar after excluding 31 participants with a history of self-reported HF (hazard ratio 0.33, 95% confidence interval 0.13 to 0.86; p = 0.02) and 24 participants with concurrent systolic dysfunction (hazard ratio 0.36, 95% confidence interval 0.14 to 0.89; p = 0.03). In conclusion, the use of beta blockers is associated with a decreased risk of hospitalization for HF in patients with diastolic dysfunction and stable coronary heart disease.

Current controversies in heart failure with a preserved ejection fraction

Heart failure with a preserved ejection fraction is a fascinating and multifaceted condition that has provoked enormous debate and a wealth of mechanistic studies. Controversies exist with regard to its nomenclature. If its nomenclature is questioned, one can be certain the pathogenesis is ill understood. If the pathogenesis is disputed, the diagnosis becomes difficult and inconsistent. These diagnostic challenges result in inappropriate recruitment to clinical trials. Therefore, the trials may be underpowered and difficult to interpret. This paper examines contemporary theories of heart failure with a preserved ejection fraction, clarifies the controversies and attempts to resolve the divergences of opinion.

Mortality in diastolic heart failure: an update

In 2003, the prevalence of heart failure in the United States was 5 million persons. Although historically at least one-third of these patients were considered to have diastolic heart failure (DHF) or "heart failure with preserved ejection fraction," contemporary cohort studies have shown that the prevalence of DHF in the community is not only higher than previously thought, but is actually rising. The increasing prevalence of this disorder has been attributed, in part, to the increasing mean age of the population and a progressive increase in the prevalence of associated risk factors, such as hypertension, obesity, and diabetes mellitus. New data suggest that mortality from DHF is high, if not equivalent, to that of systolic heart failure. For example, 2 recent retrospective studies found that the for 1 year all-cause mortality after an admission for DHF was 22% and 29%. Additional results from the Cardiovascular Health Study suggest that despite marginal differences in mortality rates, DHF has a greater attributable mortality rate because there are greater numbers of patients with HF with normal ejection fraction. Several important conclusions should be drawn from these data. One, the prevalence of DHF is high and is increasing. Second, the associated mortality is high, and comparable to systolic heart failure. Finally, efforts to reduce the prevalence of risk factors for DHF should be redoubled, and prospective clinical trials should be designed to help us better understand the pathophysiology and treatment of this disorder.

Death and dying in heart failure with normal ejection fraction

The overall mortality rate in patients with heart failure with normal ejection fraction (HFNEF) appears to be comparable to that in patients with heart failure with reduced ejection fraction. In contrast to the latter group of patients, randomized trials with neurohumoral blockade in patients with HFNEF have failed to demonstrate reduction in mortality. This is at least in part related to the lower proportion of heart failure-related death in the overall population of patients with HFNEF. In conclusion, better characterization of patients with HFNEF at greatest risk for heart failure-related death and understanding the risks of the different modes of death would allow more effective use of specific heart failure medical or device therapy in patients with HFNEF.

Understanding heart failure with preserved ejection fraction: clinical importance and future outlook

Heart failure (HF) with preserved ejection fraction (HF-PEF) accounts for approximately one half of all HF patients admitted with acute decompensated HF and carries a significant morbidity and mortality burden. This condition, however, has been largely understudied because it is difficult to diagnose, and management guidelines are still being discussed. This article provides an overview of HF-PEF and its pathophysiology, diagnosis, and treatment, with a focus on clinical trials using renin-angiotensin-aldosterone system (RAAS) blockers. Inhibitors of the RAAS have been studied in HF-PEF to determine whether their benefits extend beyond blood pressure control. However, the 3 trials conducted to date (CHARM-Preserved, PEP-CHF, and I-PRESERVE) with candesartan, perindopril, and irbesartan, have failed to demonstrate significant morbidity and mortality benefits. Although no agent has proven statistically significant benefits in morbidity and mortality in HF-PEF, recent studies have added to the breadth of clinical data and understanding of the demographics of these patients.

Prolonged electrocardiogram QRS duration independently predicts long-term mortality in patients hospitalized for heart failure with preserved systolic function

BACKGROUND

Prolonged electrocardiogram (ECG) QRS duration (>or=120 ms) is a risk factor for death in systolic heart failure, but its effects in heart failure with preserved systolic function (HFPSF) have not been extensively studied. We hypothesized that prolonged ECG QRS duration would independently predict long-term mortality in hospitalized HFPSF patients.

METHODS AND RESULTS

We analyzed 872 HFPSF patients (defined as left ventricular ejection fraction >or=50%) admitted to Michigan community hospitals between 2002 and 2004 and followed for a median of 660 days. We used Cox proportional hazards models to assess mortality hazard for prolonged QRS duration (>or=120 ms) on the last available predischarge ECG, first on a univariable basis and then after multivariable adjustment for other known risk factors. Prolonged QRS duration increased univariable all-cause mortality (HR 1.71; 95% CI 1.33-2.19, P < .001) and after multivariable adjustment (HR 1.31; 95% CI 1.01-1.71, P=.04). The univariable effect size was larger in younger patients. In multivariable models, there was no significant interaction between prolonged QRS and age, hypertension, or coronary artery disease status.

CONCLUSIONS

Prolonged QRS duration (>or=120 ms) on a predischarge ECG is an independent and consistent predictor of long-term mortality in hospitalized HFPSF patients.

Effect of aldosterone antagonism on exercise tolerance, Doppler diastolic function, and quality of life in older women with diastolic heart failure

Optimal therapy for diastolic heart failure (DHF), the most common form of heart failure in older persons, is unclear. To determine the effect of aldosterone antagonism in DHF, the authors conducted an open-label preliminary trial of spironolactone 25 mg/d in 11 women with DHF. Cardiopulmonary exercise testing, Doppler echocardiography, and a quality-of-life survey were administered at baseline and after 4 months. Peak exercise VO(2) increased by 8.3% (P=.001), the ratio of Doppler diastolic early filling velocity to mitral annulus velocity decreased by 25% (P=.02), quality-of-life score improved by 21% (P=.16 for trend), and median New York Heart Association class improved from class III to class II (P=.004). Findings from this preliminary study confirm the role of aldosterone in the pathophysiology of DHF and suggest that aldosterone antagonism may benefit such patients. These hypotheses are currently being tested in two separated National Institutes of Health-funded, randomized trials, the Spironolactone for Failure in the Elderly (SPIFFIE) and the Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist (TOPCAT) trials.

Heart failure with preserved ejection fraction in older adults

Age-associated physiologic changes predispose older adults to develop heart failure, even when left ventricular ejection fraction is normal or near normal. Heart failure with a preserved ejection fraction is particularly common in older hypertensive women, and hypertension plays a key role in its pathophysiology. In contrast with heart failure with a reduced ejection fraction, the treatment of heart failure with a preserved ejection fraction has a limited empiric basis, although some basic principles are useful. Ongoing studies provide hope of improving care of these patients.

The challenges associated with current clinical trials for diastolic heart failure

PURPOSE OF REVIEW

Diastolic heart failure (DHF) is the culmination of various cardiovascular insults, producing a proportionally greater alteration of diastolic performance, subtle reductions of systolic function and the clinical syndrome of heart failure. Over half of heart failure patients aged 65 years or older have DHF, which carries similar morbidity and mortality to systolic heart failure (SHF). The aging population and increased prevalence of hypertension, diabetes mellitus and obesity will result in disproportionately higher incidence of DHF.

RECENT FINDINGS

To date, seven large placebo-controlled trials have been conducted in DHF and none have convincingly demonstrated substantial morbidity or mortality reductions. This review will highlight DHF clinical trial efforts and provide explanations for the discordance between clinical trial patients and clinical practice patients.

SUMMARY

Greater parity between clinical trial and clinical practice can be achieved by selecting DHF patients in the context of a few general principles: trials should enroll patients on the basis of the diagnostic criteria set forth by the European Study Group on Diastolic Heart Failure. A history of (<6 months) or current hospitalization for heart failure along with prespecified higher grades of diastolic dysfunction insures that a sufficiently at-risk population is studied. Patients with DHF are older, with multiple noncardiovascular comorbidities, and longer trial duration (>3 years) may be plagued with competing risks.

Heart failure with normal ejection fraction: consideration of mechanisms other than diastolic dysfunction

More than half of patients with heart failure (HF) have a normal ejection fraction (EF). These patients are typically elderly, are predominantly female, and have a high incidence of multiple comorbid conditions associated with development of ventricular hypertrophy and/or interstitial fibrosis. Thus, the cause of HF has been attributed to diastolic dysfunction. However, the same comorbidities may also impact myocardial systolic, ventricular, vascular, renal, and extracardiovascular properties in ways that can also contribute to symptoms of HF by way of mechanisms not related to diastolic dysfunction. Accordingly, the descriptive term HF with normal EF has been suggested as an alternative to the mechanistic term diastolic HF. In this article, we review the current understanding of nondiastolic mechanisms that may contribute to the HF with normal EF syndrome to highlight potential pathways for research that may lead to new targets for therapy.

Heart failure with normal ejection fraction. Pathophysiology, diagnosis, and treatment

Symptoms of heart failure are documented in patients, in a manner independent of their current ejection fraction (EF). Today, about 50% of all heart failure patients have a normal EF (HFNEF) and their outcome regarding mortality and morbidity is as severe as in patients with reduced EF. Nevertheless, the awareness of this disease is still limited. Furthermore, the diagnostic criteria are still a challenge in the daily clinical setting. Here, the recent recommendations of the European Society of Cardiology (ESC) on how to diagnose HFNEF will be reviewed. Moreover, the recent pathologic understanding will be discussed as well, because alongside noncardiac reasons for HFNEF, diastolic as well as nondiastolic abnormalities are known to be important for the development of HFNEF. Treatment options will be reviewed including the recent clinical trials for this group of patients.

Beta-blockade with nebivolol in elderly heart failure patients with impaired and preserved left ventricular ejection fraction: Data From SENIORS (Study of Effects of Nebivolol Intervention on Outcomes and Rehospitalization in Seniors With Heart Failure)

OBJECTIVES

In this pre-specified subanalysis of the SENIORS (Study of Effects of Nebivolol Intervention on Outcomes and Rehospitalization in Seniors With Heart Failure) trial, which examined the effects of nebivolol in elderly heart failure (HF) patients, we explored the effects of left ventricular ejection fraction (EF) on outcomes, including the subgroups impaired EF (< or =35%) and preserved EF (>35%).

BACKGROUND

Beta-blockers are established drugs in patients with HF and impaired EF, but their value in preserved EF is unclear.

METHODS

We studied 2,111 patients; 1,359 (64%) had impaired (< or =35%) EF (mean 28.7%) and 752 (36%) had preserved (>35%) EF (mean 49.2%). The effect of nebivolol was investigated in these 2 groups, and it was compared to explore the interaction of EF with outcome. Follow-up was 21 months; the primary end point was all-cause mortality or cardiovascular hospitalizations.

RESULTS

Patients with preserved EF were more often women (49.9% vs. 29.8%) and had less advanced HF, more hypertension, and fewer prior myocardial infarctions (all p < 0.001). During follow-up, the primary end point occurred in 465 patients (34.2%) with impaired EF and in 235 patients (31.2%) with preserved EF. The effect of nebivolol on the primary end point (hazard ratio [HR] of nebivolol vs. placebo) was 0.86 (95% confidence interval: 0.72 to 1.04) in patients with impaired EF and 0.81 (95% confidence interval: 0.63 to 1.04) in preserved EF (p = 0.720 for subgroup interaction). Effects on all secondary end points were similar between groups (HR for all-cause mortality 0.84 and 0.91, respectively), and no p value for interaction was <0.48.

CONCLUSIONS

The effect of beta-blockade with nebivolol in elderly patients with HF in this study was similar in those with preserved and impaired EF.

Heart failure with normal left ventricular ejection fraction: what is the evidence?

Heart failure with a normal ejection fraction (HFNEF) is a common clinical problem with many unsolved questions regarding pathophysiology, diagnosis, and therapy. Although the term diastolic heart failure has been abandoned, diastolic left ventricular (LV) dysfunction together with combined systolic ventricular and arterial stiffening are considered to be the main pathophysiologic mechanisms in HFNEF. Current guidelines define HFNEF by symptoms or signs of heart failure in the presence of LV ejection fraction of more than 50%, but with additional evidence of LV diastolic dysfunction. Definite diagnosis of HFNEF requires exclusion of valvular heart disease, constrictive pericarditis, and several noncardiac diseases. Echocardiographic assessment of the tissue Doppler-derived filling index E/E', which is the ratio of the peak early mitral valve flow velocity to the peak early diastolic mitral annular velocity, should improve the noninvasive estimation of filling pressures in suspected HFNEF. Elevated plasma levels of natriuretic peptides may confirm HFNEF if tissue Doppler echocardiography is inconclusive. Treatment of HFNEF is symptom oriented and mainly based on pathophysiologic assumptions such as heart rate reduction, blood pressure control, and maintenance of sinus rhythm. In contrast to heart failure with reduced ejection fraction, large-scale randomized controlled drug trials for HFNEF are scarce and could not demonstrate mortality reduction so far.

Comparison of ventricular structure and function in Chinese patients with heart failure and ejection fractions >55% versus 40% to 55% versus <40%

Subjects with heart failure (HF) and a preserved ejection fraction (EF) are heterogenous and the EF used to define this syndrome varies considerably among studies. We sought to determine if physiologic differences exist between subjects with a normal EF (>55%) or mildly decreased EF (40% to 55%). 357 consecutive Chinese patients who were healthy (n = 93) or had HF (n = 264) underwent comprehensive echocardiography, Doppler analysis, and measurement of neurohormones. Subjects with HF were stratified by EF into those with normal EF (>55%, n = 128), mildly decreased EF (40% to 55%, n = 38), or moderate to severely decreased EF (<40%, n = 100). Employing noninvasive pressure-volume analysis, estimated end-systolic and end-diastolic pressure-volume relations were calculated. Subjects with HF and an EF 40% to 55% more often had a previous myocardial infarction and diabetes than those with HF and an EF >55%. Physiologically, the cohort with a mildly decreased EF had eccentrically enlarged ventricles with evidence of remodeling (rightward shifted end-diastolic pressure-volume relation) and decreased chamber contractility (downward shifted end-systolic pressure-volume relation) most comparable to subjects with overt systolic HF. In conclusion, in subjects with HF and a preserved EF, there are distinct physiologic differences between those with a normal (>55%) and a mildly decreased (40% to 55%) EF.

Heart failure

Despite advances in management of heart failure, the condition remains a major public-health issue, with high prevalence, poor clinical outcomes, and large health-care costs. Risk factors are well known and, thus, preventive strategies should have a positive effect on disease burden. Treatment of established systolic chronic heart failure includes use of agents that block the renin-angiotensin-aldosterone and sympathetic nervous systems to prevent adverse remodelling, to reduce symptoms and prolong survival. Diuretics are used to achieve and maintain euvolaemia. Devices have a key role in management of advanced heart failure and include cardiac resynchronisation in patients with evidence of cardiac dyssynchrony and implantation of a cardioverter defibrillator in individuals with low ejection fraction. Approaches for treatment of acute heart failure and heart failure with preserved ejection fraction are supported by little clinical evidence. Emerging strategies for heart failure management include individualisation of treatment, novel approaches to diagnosis and tracking of therapeutic response, pharmacological agents aimed at new targets, and cell-based and gene-based methods for cardiac regeneration.

DEFEAT - Heart Failure: a guide to management of geriatric heart failure by generalist physicians

Over 80% of all heart failure patients are 65 years and older. The diagnosis and management of heart failure in older adults can be challenging. However, with the correct clinical skill and experience, most geriatric heart failure can be properly diagnosed and managed. Management of geriatric heart failure can be simplified by following this useful mnemonic: DEFEAT Heart Failure. This covers the essential aspects of geriatric heart failure management: Diagnosis, Etiology, Fluid, Ejection fraAction, and Treatment. The process begins with a clinical Diagnosis, which must be established, before ordering an echocardiogram, as nearly half of all geriatric heart failure patients have normal left ventricular ejection fraction. Because heart failure is a syndrome and not a disease, an underlying Etiology must be sought and determined. Determination of the Fluid volume status by careful examination of the external jugular veins in the neck is vital to achieve euvolemia. An echocardiography should be ordered to obtain left ventricular Ejection frAction to assess prognosis and guide Therapy. However, if left ventricular ejection fraction cannot be determined, as in many developing nations, all geriatric heart failure patients should be treated as if they have low ejection fraction, and should be prescribed an angiotensin-converting enzyme inhibitor and a beta-blocker. Diuretic and digoxin should be prescribed for all symptomatic patients with heart failure. An aldosterone antagonist may be used in select patients with advanced systolic heart failure, carefully avoiding hyperkalemia.

Diastolic heart failure: state of the science on best treatment practices

PURPOSE

The purpose of this article is to increase awareness among nurse practitioners (NPs) of the current state of the science on diastolic heart failure (DHF), the American College of Cardiology (ACC) and the American Heart Association (AHA) guidelines for DHF, and pathophysiology, diagnosis, and nonpharmacological and pharmacological management of DHF.

DATA SOURCES

The articles included in the review of the state of the science were retrieved by a search of PUBMED literature using the following key search terms: heart failure, diastolic heart failure, preserved systolic function, heart failure management, treatment of diastolic heart failure, treatment of diastolic dysfunction, and treatment of preserved systolic function. Current published guidelines from the ACC and AHA were reviewed to establish clinical recommendations for patients with DHF.

CONCLUSIONS

The state of the science and clinical recommendations for DHF are in the early stages compared to those for systolic heart failure (SHF). The need for more randomized clinical trials on nonpharmacological and pharmacological management and the development of standardized guidelines for DHF patients are clearly apparent.

IMPLICATIONS FOR PRACTICE

Both nonpharmacologic and pharmacologic management are effective and necessary to control the clinical signs and symptoms of DHF and improve overall quality of life. Successful tailoring of a treatment plan to suit each individual patient's needs and including the family are important for the NP to consider.

The effect of cardiovascular drugs on pro-inflammatory cytokine secretion and natural killer activity of peripheral blood mononuclear cells of patients with chronic heart failure in vitro

Recent studies have shown that patients with heart failure over-express pro-inflammatory cytokines which enhance natural killer (NK) activity and negatively influence contractility and contribute to the remodeling of myocardium. The question is that how cardiovascular drugs influence on the cytokines of Peripheral Blood Mononuclear Cells (PBMCs) in Chronic Heart Failure (CHF). To study the effect of cardiovascular drugs on PBMCs-cytokines and NK activity of CHF patients. PBMCs of CHF patients/normal controls collected by Ficoll-paque density centrifugation. NK activity against K562 target cell was measured with MTT colorimetric assay. PBMCs were cultivated in RPMI/FCS, stimulated with phytohaemaglutinin (PHA). Tumor necrosis factor (TNF)-alpha interleukin (IL)-6, IL-2 and IL-1beta of culture supernatants after 24 h incubation with/without furosemide, captopril and digoxin were measured with sandwitch ELISA. Patients had higher NK activity than controls (56.9% +/- 1.6 vs 50.9% +/- 1.2, p < 0.05). NK activity of patients who already consumed Captopril/Furosemide didn't show difference with controls. Captopril (3, 1, 0.3 microg mL(-1)) and Furosemide (5, 2.5, 1.25 microg mL(-1)) caused a dose dependent inhibition in TNF-alpha compared with control (329 +/- 23, 427 +/- 15, 519 +/- 19 and 343 +/- 19, 430 +/- 14, respectively vs. 562 +/- 24 pg mL(-1) p < 0.05). Furosemide caused a dose dependent decrease in IL-6 (421 +/- 31, 534 +/- 33 vs. 662 +/- 41 pg mL(-1) p < 0.05). Captopril and Furosemide didn't show any significant effect on IL-1beta/IL-2. Digoxin had no significant effect on PBMCs-cytokines. These data suggest that the immunomodulatory effects of Captopril and Furosemide may contribute to their beneficial and no long-term adverse effects on PBMCs.

Effectiveness of digoxin in reducing one-year mortality in chronic heart failure in the Digitalis Investigation Group trial

Post hoc analyses of the Digitalis Investigation Group (DIG) trial indicate that digoxin at low (0.5 to 0.9 ng/ml) serum digoxin concentration (SDC) reduces mortality, which is eliminated at higher (>or=1 ng/ml) SDC, and that low-dose digoxin ( Collapse

Key Words

• digoxin
• low dose
• heart failure
• one-year
• morbidity
• mortality

Collapse

MESH Headings

• Aged
• Canada/epidemiology
• Cardiotonic Agents/administration & dosage
• Cause of Death/trends
• Chronic Disease
• Digoxin/administration & dosage
• Dose-Response Relationship, Drug
• Female
• Follow-Up Studies
• Heart Failure/drug therapy
• Heart Failure/mortality
• Humans
• Male
• Middle Aged
• Survival Rate/trends
• Time Factors
• Treatment Outcome
• United States/epidemiology

Collapse

Grants

• P50-HL077100 NHLBI NIH HHS
• R01 HL085561 NHLBI NIH HHS
• 5-R01-HL085561-02 NHLBI NIH HHS
• P50 HL077100 NHLBI NIH HHS
• R01 HL085561-02 NHLBI NIH HHS

Collapse

Affiliation(s) Collapse

Digoxin and reduction of heart failure hospitalization in chronic systolic and diastolic heart failure

In the Digitalis Investigation Group trial, digoxin-associated decrease in the combined end point of heart failure (HF) hospitalization or HF mortality was significant in systolic but not in diastolic HF. To assess whether this apparent disparity could be explained by differences in baseline characteristics and sample size, we used propensity score matching to assemble a cohort of 916 pairs of patients with systolic and diastolic HF who were balanced in all measured baseline covariates. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) of the effect of digoxin on outcomes separately in systolic and diastolic HF, at 2 years (protocol prespecified), and at the end of 3.2 years of median follow-up. HF hospitalization or HF mortality occurred in 28% and 32% of patients with systolic HF (HR digoxin vs placebo 0.85, 95% CI 0.67 to 1.08, p = 0.188) and 20% and 25% in those with diastolic HF (HR 0.79, 95% CI 0.60 to 1.03, p = 0.085) receiving digoxin and placebo, respectively. At 2 years, HRs for this combined end point were similar for systolic HF (0.72, 95% CI 0.55 to 0.95, p = 0.022) and diastolic HF (0.69, 95% CI 0.50 to 0.95, p = 0.025). Digoxin also decreased 2-year HF hospitalization in systolic HF (HR 0.73, 95% CI 0.54 to 0.97, p = 0.033) and diastolic HF (HR 0.64, 95% CI 0.45 to 0.90, p = 0.010). In conclusion, as in patients with systolic HF, digoxin was equally effective in those with diastolic HF, who constitute half of all patients with HF, yet have few evidence-based therapeutic options.