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

New Management Strategies in Heart Failure

Despite >100 clinical trials, only 2 new drugs had been approved by the US Food and Drug Administration for the treatment of chronic heart failure in more than a decade: the aldosterone antagonist eplerenone in 2003 and a fixed dose combination of hydralazine-isosorbide dinitrate in 2005. In contrast, 2015 has witnessed the Food and Drug Administration approval of 2 new drugs, both for the treatment of chronic heart failure with reduced ejection fraction: ivabradine and another combination drug, sacubitril/valsartan or LCZ696. Seemingly overnight, a range of therapeutic possibilities, evoking new physiological mechanisms, promise great hope for a disease that often carries a prognosis worse than many forms of cancer. Importantly, the newly available therapies represent a culmination of basic and translational research that actually spans many decades. This review will summarize newer drugs currently being used in the treatment of heart failure, as well as newer strategies increasingly explored for their utility during the stages of the heart failure syndrome.

Falling Cardiovascular Mortality in Heart Failure With Reduced Ejection Fraction and Implications for Clinical Trials

OBJECTIVES

This study examined the trends in the relative contributions of cardiovascular and noncardiovascular mortality to total mortality according to use of beta-blockers in clinical trials of patients with heart failure with reduced ejection fraction (HF-REF).

BACKGROUND

With the increasingly widespread use of disease-modifying therapies, particularly beta-blockers, in HF-REF, the proportion of patients dying from cardiovascular causes is likely to be decreasing.

METHODS

In a systematic review, 2 investigators independently searched online databases to identify clinical trials including >400 patients with chronic heart failure published between 1986 and 2014 and that adjudicated cause of death. Trials were divided into 3 groups on the basis of the proportion of patients treated with a beta-blocker (<33% [low], 33% to 66% [medium], and >66% [high]). Percentages of total deaths adjudicated as cardiovascular or noncardiovascular were calculated by weighted means and weighted standard deviations. Weighted Student t tests were used to compare results between groups.

RESULTS

Sixty-six trials met the inclusion criteria with a total of 136,182 patients and 32,140 deaths. There was a sequential increase in the percentage of noncardiovascular deaths with increasing beta-blocker use from 11.4% of all deaths in trials with low beta-blocker use to 19.1% in those with high beta-blocker use (p < 0.001).

CONCLUSIONS

In trials of patients with HF-REF, the proportion of deaths adjudicated as cardiovascular has decreased. Cardiovascular mortality, and not all-cause mortality, should be used as an endpoint for trials of new treatments for HF-REF.

Team-Based Care for Outpatients with Heart Failure

Management of heart failure requires a multidisciplinary team-based approach that includes coordination of numerous team members to ensure guideline-directed optimization of medical therapy, frequent and regular assessment of volume status, frequent education, use of cardiac rehabilitation, continued assessment for the use of advanced therapies, and advance care planning. All of these are important aspects of the management of this complex condition.

Targeting heart failure with preserved ejection fraction: current status and future prospects

Heart failure with preserved ejection fraction (HFpEF) portrays a significant burden in terms of prevalence, morbidity, mortality, and health care costs. There is a lack of consensus on the basic pathophysiology, definition, and therapeutic targets for therapy for this syndrome. To date, there are no approved therapies available for reducing mortality or hospitalization for these patients. Several clinical trials have recently started to try and bridge this major gap. There is an urgent need to focus on drug and device development for HFpEF as well as to understand HFpEF pathophysiology.

After TOPCAT: What to do now in Heart Failure with Preserved Ejection Fraction

Although patients with heart failure and preserved ejection fraction (HF-PEF) represent nearly half of the population with chronic heart failure, few evidence-based medical therapies are available. The neutral overall results of the TOPCAT trial of spironolactone in HF-PEF leave clinicians who treat heart failure with an ongoing clinical dilemma. In this review, we outline an approach to the clinical management of the patient with HF-PEF synthesizing data from available clinical trials and expert consensus.

Is foxglove effective in heart failure?

BACKGROUND

Digoxin is the oldest known treatment for heart failure (HF) and has been demonstrated to reduce admissions for worsening heart failure in a large randomized trial recruiting patients in sinus rhythm with heart failure and ejection fraction <45%. This study forms the basis for current international guidelines recommending that digoxin should be considered in patients with symptomatic HF despite optimal doses of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, β-blockers, and mineralocorticoid receptor antagonists in addition to device therapy, if indicated. However, digoxin predates mortality reducing HF therapies, and this article reviews the historical and recent data.

METHODS

Multiple PubMed searches were performed including, but not limited to, the search terms "digoxin," "heart failure," "efficacy," "treatment," "side-effects," "morbidity," "mortality," and "arrythmia." Articles were excluded if not relevant, not in English or without abstract. Reference lists of relevant articles were manually searched for further references. Due to the large number of articles retrieved, a selection was reviewed based on the authors' best judgement.

RESULTS

Three randomized controlled trials and three large contemporary observational reports of digoxin therapy in heart failure and sinus rhythm were retrieved. Other studies were noted that included patients with heart failure and atrial fibrillation, which were also reviewed.

CONCLUSION

Definitive randomized evidence of digoxin efficacy as add-on therapy in HF is lacking because most landmark trials of modern HF disease modifying agents postdate the randomized studies of digoxin. Furthermore, questions remain regarding the optimum dose of digoxin and there are signals that digoxin may be harmful in some patients with HF. All contemporary data for digoxin in HF are derived from observational studies and the findings are conflicting. Despite two centuries of experience using cardiac glycosides to treat HF, fundamental questions regarding the efficacy and safety of digoxin in HF remain unanswered.

Digoxin in Heart Failure with a Reduced Ejection Fraction: A Risk Factor or a Risk Marker?

Digoxin is one of the oldest compounds used in cardiovascular medicine. Nevertheless, its mechanism of action and most importantly its clinical utility have been the subject of an endless dispute. Positive inotropic and neurohormonal modulation properties are attributed to digoxin, and it was the mainstay of heart failure therapeutics for decades. However, since the institution of β-blockers and aldosterone antagonists as part of modern heart failure medical therapy, digoxin prescription rates have been in free fall. The fact that digoxin is still listed as a valid therapeutic option in both American and European heart failure guidelines has not altered clinicians' attitude towards the drug. Since the publication of original Digitalis Investigation Group trial data, a series of reports based predominately on observational studies and post hoc analyses have raised concerns about the clinical efficacy and long-term safety of digoxin. In the present review, we will attempt a critical appraisal of the available clinical evidence regarding the efficacy and safety of digoxin in heart failure patients with a reduced ejection fraction. The methodological issues, strengths, and limitations of individual studies will be highlighted.

Time-Dependent Regional Myocardial Strains in Patients with Heart Failure with a Preserved Ejection Fraction

OBJECTIVES

To better understand the etiology of HFpEF in a controlled human population, regional time-varying strains were computed using echocardiography speckle tracking in patients with heart failure with a preserved ejection fraction and normal subjects.

METHODS

Eleven normal volunteers and ten patients with echo-graded diastolic dysfunction and symptoms of heart failure were imaged with echocardiography and longitudinal, circumferential, and rotational strains were determined using speckle-tracking. Diastolic strain rate was also determined. Patient demographics and echo-derived flows, volumes, and pressures were recorded.

RESULTS

Peak longitudinal and circumferential strain was globally reduced in patients (p < 0.001), when compared to controls. The patients attained peak longitudinal and circumferential strain at a consistently later point in systole than controls. Rotational strains were not different in most LV regions. Early diastolic strain rate was significantly reduced in the patients (p < 0.001). LV mass and wall thickness were significantly increased in the patients; however ejection fraction was preserved and stroke volume was diminished (p < 0.001).

CONCLUSIONS

This study shows that patients with HFpEF have reduced early diastolic strain rate and reduced peak strain that is regionally homogeneous and that they also utilize a longer fraction of systole to achieve peak axial strains.

Recent advances in treatment of heart failure

With the total cases and economic burden of heart failure continuing to rise, there is an overwhelming need for novel therapies. Several drugs for heart failure have succeeded in preclinical and early-phase clinical trials, but most of them failed to show the real benefit in pivotal clinical trials. Meanwhile, the US Food and Drug Administration recently approved two promising new drugs to treat heart failure: ivabradine and sacubitril/valsartan. Furthermore, some of the newer agents in testing offer the potential for significant progress in addition to these drugs. Patiromer and zirconium cyclosilicate are attractive agents that are expected to prevent hyperkalemia during renin-angiotensin-aldosterone system inhibition, and serelaxin and urodilatin are promising drugs in the treatment of acute heart failure. Future clinical trials with more appropriate study designs, optimal clinical endpoints, and proper patient selection are mandatory to assess the true efficacy of these attractive compounds in clinical practice.

Na+/Ca2+ exchange and Na+/K+-ATPase in the heart

This paper is the third in a series of reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation–contraction coupling and arrhythmias: Na⁺ channel and Na⁺ transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on cardiac Na⁺/Ca²⁺ exchange (NCX) and Na⁺/K⁺-ATPase (NKA). While the relevance of Ca²⁺ homeostasis in cardiac function has been extensively investigated, the role of Na⁺ regulation in shaping heart function is often overlooked. Small changes in the cytoplasmic Na⁺ content have multiple effects on the heart by influencing intracellular Ca²⁺ and pH levels thereby modulating heart contractility. Therefore it is essential for heart cells to maintain Na⁺ homeostasis. Among the proteins that accomplish this task are the Na⁺/Ca²⁺ exchanger (NCX) and the Na⁺/K⁺ pump (NKA). By transporting three Na⁺ ions into the cytoplasm in exchange for one Ca²⁺ moved out, NCX is one of the main Na⁺ influx mechanisms in cardiomyocytes. Acting in the opposite direction, NKA moves Na⁺ ions from the cytoplasm to the extracellular space against their gradient by utilizing the energy released from ATP hydrolysis. A fine balance between these two processes controls the net amount of intracellular Na⁺ and aberrations in either of these two systems can have a large impact on cardiac contractility. Due to the relevant role of these two proteins in Na⁺ homeostasis, the emphasis of this review is on recent developments regarding the cardiac Na⁺/Ca²⁺ exchanger (NCX1) and Na⁺/K⁺ pump and the controversies that still persist in the field.

Challenging aspects of treatment strategies in heart failure with preserved ejection fraction: "Why did recent clinical trials fail?"

Heart failure (HF) is the leading cause of hospitalization among older adults and the prevalence is growing with the aging populations in the Western countries. Epidemiologic reports suggest that approximately 50% of patients who have signs or symptoms of HF have preserved left ventricular ejection fraction. This HF type predominantly affects women and the elderly with other co-morbidities, such as diabetes, hypertension, and overt volume status. Most of the current treatment strategies are based on morbidity benefits such as quality of life and reduction of clinical HF symptoms. Treatment of patients with HF with preserved ejection fraction displayed disappointing results from several large randomized controlled trials. The heterogeneity of HF with preserved ejection fraction, understood as complex syndrome, seems to be one of the primary reasons. Here, we present an overview of the current management strategies with available evidence and new therapeutic approach from drugs currently in clinical trials, which target diastolic dysfunction, chronotropic incompetence, and risk factor management. We provide an outline and interpretation of recent clinical trials that failed to improve outcome and survival in patients with HF with preserved ejection fraction.

Treating Heart Failure with Preserved Ejection Fraction: A Challenge for Clinicians

Despite a decline in many forms of cardiovascular disease, heart failure (HF) continues to increase. Heart failure with preserved ejection fraction (HFpEF) is common, especially among persons with multiple comorbidities. HFpEF presents many challenges for clinicians due to the incomplete understanding of the underlying mechanisms and lack of consensus on the most effective strategies for treatment. Angiotensin and beta receptor-blocking drugs, which form the cornerstone for the treatment of systolic HF, have failed to show similar benefits in patients with impaired diastolic function. This article provides an overview of drug therapy for HFpEF, including newer agents now under investigation.

Safety and efficacy of digoxin: systematic review and meta-analysis of observational and controlled trial data

OBJECTIVE

To clarify the impact of digoxin on death and clinical outcomes across all observational and randomised controlled trials, accounting for study designs and methods.

DATA SOURCES AND STUDY SELECTION

Comprehensive literature search of Medline, Embase, the Cochrane Library, reference lists, and ongoing studies according to a prospectively registered design (

PROSPERO

CRD42014010783), including all studies published from 1960 to July 2014 that examined treatment with digoxin compared with control (placebo or no treatment).

DATA EXTRACTION AND SYNTHESIS

Unadjusted and adjusted data pooled according to study design, analysis method, and risk of bias.

MAIN OUTCOME MEASURES

Primary outcome (all cause mortality) and secondary outcomes (including admission to hospital) were meta-analysed with random effects modelling.

RESULTS

52 studies were systematically reviewed, comprising 621,845 patients. Digoxin users were 2.4 years older than control (weighted difference 95% confidence interval 1.3 to 3.6), with lower ejection fraction (33% v 42%), more diabetes, and greater use of diuretics and anti-arrhythmic drugs. Meta-analysis included 75 study analyses, with a combined total of 4,006,210 patient years of follow-up. Compared with control, the pooled risk ratio for death with digoxin was 1.76 in unadjusted analyses (1.57 to 1.97), 1.61 in adjusted analyses (1.31 to 1.97), 1.18 in propensity matched studies (1.09 to 1.26), and 0.99 in randomised controlled trials (0.93 to 1.05). Meta-regression confirmed that baseline differences between treatment groups had a significant impact on mortality associated with digoxin, including markers of heart failure severity such as use of diuretics (P=0.004). Studies with better methods and lower risk of bias were more likely to report a neutral association of digoxin with mortality (P<0.001). Across all study types, digoxin led to a small but significant reduction in all cause hospital admission (risk ratio 0.92, 0.89 to 0.95; P<0.001; n=29,525).

CONCLUSIONS

Digoxin is associated with a neutral effect on mortality in randomised trials and a lower rate of admissions to hospital across all study types. Regardless of statistical analysis, prescription biases limit the value of observational data.

Patient selection in heart failure with preserved ejection fraction clinical trials

Recent clinical trials in patients with heart failure with preserved ejection fraction (HFpEF) have provided important insights into participant selection strategies. Historically, HFpEF trials have included patients with relatively preserved left ventricular ejection fraction ranging from 40% to 55% and a clinical history of heart failure. Contemporary HFpEF trials have also incorporated inclusion criteria such as hospitalization for HFpEF, altered functional capacity, cardiac structural and functional abnormalities, and abnormalities in neurohormonal status (e.g., elevated natriuretic peptide levels). Careful analyses of the effect of these patient selection criteria on outcomes in prior trials provide valuable lessons for future trial design. We review recent and ongoing HFpEF clinical trials from a patient selection perspective and appraise trial patient selection methodologies in relation to outcomes. This review reflects discussions between clinicians, scientists, trialists, regulators, and regulatory representatives at the 10th Global CardioVascular Clinical Trialists Forum in Paris, France, on December 6, 2013.

Epidemiology of heart failure with preserved ejection fraction

The prevalence of heart failure (HF) and its subtype, HF with preserved ejection fraction (HFpEF), is on the rise due to aging of the population. HFpEF is convergence of several pathophysiological processes, which are not yet clearly identified. HFpEF is usually seen in association with systemic diseases, such as diabetes, hypertension, atrial fibrillation, sleep apnea, renal and pulmonary disease. The proportion of HF patients with HFpEF varies by patient demographics, study settings (cohort vs. clinical trial, outpatient clinics vs. hospitalised patients) and cut points used to define preserved function. There is an expanding body of literature about prevalence and prognostic significance of both cardiovascular and non-cardiovascular comorbidities in HFpEF patients. Current therapeutic approaches are targeted towards alleviating the symptoms, treating the associated comorbid conditions, and reducing recurrent hospital admissions. There is lack of evidence-based therapies that show a reduction in the mortality amongst HFpEF patients; however, an improvement in exercise tolerance and quality of life is seen with few interventions. In this review, we highlight the epidemiology and current treatment options for HFpEF.

Exercise intolerance in heart failure with preserved ejection fraction: more than a heart problem

Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF in older adults, and is increasing in prevalence as the population ages. Furthermore, HFpEF is increasing out of proportion to HF with reduced EF (HFrEF), and its prognosis is worsening while that of HFrEF is improving. Despite the importance of HFpEF, our understanding of its pathophysiology is incomplete, and optimal treatment remains largely undefined. A cardinal feature of HFpEF is reduced exercise tolerance, which correlates with symptoms as well as reduced quality of life. The traditional concepts of exercise limitations have focused on central dysfunction related to poor cardiac pump function. However, the mechanisms are not exclusive to the heart and lungs, and the understanding of the pathophysiology of this disease has evolved. Substantial attention has focused on defining the central versus peripheral mechanisms underlying the reduced functional capacity and exercise tolerance among patients with HF. In fact, physical training can improve exercise tolerance via peripheral adaptive mechanisms even in the absence of favorable central hemodynamic function. In addition, the drug trials performed to date in HFpEF that have focused on influencing cardiovascular function have not improved exercise capacity. This suggests that peripheral limitations may play a significant role in HF limiting exercise tolerance, a hallmark feature of HFpEF.

Causes and predictors of hospital readmissions in patients older than 65 years hospitalized for heart failure with preserved left ventricular ejection fraction in western Romania

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is more frequent in the elderly and is associated with important economic implications because of repetitive and prolonged hospitalizations, due to both cardiovascular and noncardiovascular causes.

PURPOSE

To identify the causes, as well as the clinical and biological markers, that could be used as predictors of hospital readmissions in HFpEF patients aged ≥65 years.

PATIENTS AND METHODS

Consecutive eligible patients hospitalized for a first heart failure (HF) episode were prospectively included and divided into one of two age groups (elderly: ≥65 years; and nonelderly: <65 years). The clinical features, therapeutic approaches, and clinical outcomes during the 1-year follow-up period were analyzed.

RESULTS

A total of 178 patients were included, with a mean age of 64.6±8.6 years; 80 (45%) were women. A total of 98 patients (55%) were aged ≥65 years, and 80 (45%) were aged <65 years. In the group aged ≥65 years, 58 patients (59%) were women, while in the group aged <65 years, 22 patients (28%) were women (P=0.0001). During the 1-year follow-up, no patients died or were lost to follow-up. Moreover, 116 (65%) of the HFpEF patients experienced hospital readmissions. The elderly patients had a significantly higher readmission rate (73% vs 55%, respectively; P<0.02); readmissions due to aggravated HF were significantly more frequent in this age group (41% vs 18%, respectively; P<0.002). Multivariate logistic regression analysis indicated that the independent predictors of readmission due to HF aggravation included plasma levels of brain natriuretic peptide >450 pg/mL (P<0.01) and N-terminal-pro-brain natriuretic peptide >477 pg/mL (P<0.02) in the elderly group, while in the nonelderly group, the independent predictors of this outcome were a New York Heart Association functional class of IV at initial hospitalization (P<0.04), as well as plasma levels of brain natriuretic peptide >390 pg/mL (P=0.03) and tumor necrosis factor (TNF)-α >7.1 pg/mL (P<0.001). Readmissions due to noncardiovascular causes were independently predicted by plasma levels of TNF-α >10 pg/mL in the elderly (P=0.003) and of interleukin (IL)-6 >1.9 pg/mL in the nonelderly (P<0.04).

CONCLUSION

We conclude that in HFpEF patients aged ≥65 years, the main cause of rehospitalization during the 1-year follow-up was HF aggravation. The risk of this outcome was independently predicted by increased levels of cardiac peptides, while the risk of noncardiovascular readmissions was predicted by increased levels of inflammatory biomarkers. Increased TNF-α levels predicted both cardiovascular and noncardiovascular readmissions, while increased levels of high-sensitivity C-reactive protein did not predict any of these outcomes in our study.

Is there a role for digitalis in chronic heart failure?--First update

This Living FRISBEE (Living FRIendly Summary of the Body of Evidence using Epistemonikos) is an update of the summary published in April 2015, based on a new systematic review published in May 2015. The main clinical guidelines recommend the use of digitalis for chronic heart failure when moderate to severe symptoms persist after standard therapy, even though there is controversy about its efficacy and security. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified four systematic reviews including 13 randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded the use of digitalis for chronic heart failure probably leads to little or no decrease in mortality, but they might reduce hospitalizations and clinical deterioration. However, the certainty of the evidence is low.

Can emergency physicians diagnose and correctly classify diastolic dysfunction using bedside echocardiography?

OBJECTIVES

The goal of this study was to determine if emergency physicians (EPs) can correctly perform a bedside diastology examination (DE) and correctly grade the level of diastolic function with minimal additional training in echocardiography beyond what is learned in residency. We hypothesize that EPs will be accurate at detecting and grading diastolic dysfunction (DD) when compared to a criterion standard interpretation by a cardiologist.

METHODS

We conducted a prospective, observational study on a convenience sample of adult patients who presented to an urban emergency department with a chief concern of dyspnea. All patients had a bedside echocardiogram, including a DE, performed by an EP-sonographer who had 3 hours of didactic and hands-on echocardiography training with a cardiologist. The DE was interpreted as normal, grade 1 to 3 if DD was present, or indeterminate, all based on predefined criteria. This interpretation was compared to that of a cardiologist who was blinded to the EPs' interpretations.

RESULTS

We enrolled 62 patients; 52% had DD. Using the cardiology interpretation as the criterion standard, the sensitivity and specificity of the EP-performed DE to identify clinically significant diastolic function were 92% (95% confidence interval [CI], 60-100) and 69% (95% CI, 50-83), respectively. Agreement between EPs and cardiology on grade of DD was assessed using κ and weighted κ: κ = 0.44 (95% CI, 0.29-0.59) and weighted κ = 0.52 (95% CI, 0.38-0.67). Overall, EPs rated 27% of DEs as indeterminate, compared with only 15% by cardiology. For DEs where both EPs and cardiology attempted an interpretation (indeterminates excluded) κ = 0.45 (95% CI, 0.26 to 0.65) and weighted κ = 0.54 (95% CI, 0.36-0.72).

CONCLUSION

After limited diastology-specific training, EPs are able to accurately identify clinically significant DD. However, correct grading of DD, when compared to a cardiologist, was only moderate, at best. Our results suggest that further training is necessary for EPs to achieve expertise in grading DD.

The Hospitalization Burden and Post-Hospitalization Mortality Risk in Heart Failure With Preserved Ejection Fraction: Results From the I-PRESERVE Trial (Irbesartan in Heart Failure and Preserved Ejection Fraction)

OBJECTIVES

The aim of this study was to investigate prognosis in patients with heart failure (HF) with preserved ejection fraction and the causes of hospitalization and post-hospitalization mortality.

BACKGROUND

Although hospitalizations in patients with HF with preserved ejection fraction are common, there are limited data from clinical trials on the causes of admission and the influence of hospitalizations on subsequent mortality risk.

METHODS

Patients (n = 4,128) with New York Heart Association functional class II to IV HF and left ventricular ejection fractions >45% were enrolled in I-PRESERVE (Irbesartan in Heart Failure and Preserved Ejection Fraction). A blinded events committee adjudicated cardiovascular hospitalizations and all deaths using predefined and standardized definitions. The risk for death after HF, any-cause, or non-HF hospitalization was assessed using time-dependent Cox proportional hazard models.

RESULTS

A total of 2,278 patients had 5,863 hospitalizations during the 49 months of follow-up, of which 3,585 (61%) were recurrent hospitalizations. For any-cause hospitalizations, 26.5% of patients died during follow-up, with an incident mortality rate of 11.1 deaths per 100 patient-years (PYs) and an adjusted hazard ratio of 5.32 (95% confidence interval: 4.21 to 6.23). Overall, 53.6% of hospitalizations were classified as cardiovascular and 43.7% as noncardiovascular, with 2.7% not classifiable. HF was the largest single cause of initial (17.6%) and overall (21.1%) hospitalizations, although, after HF hospitalization, a substantially higher proportion of readmissions were due to primary HF causes (40%). HF hospitalization occurred in 685 patients, with 41% deaths during follow-up, an incident mortality rate of 19.3 deaths per 100 PYs. The adjusted hazard ratio was 2.93 (95% confidence interval: 2.40 to 3.57) relative to patients who were not hospitalized for HF and was greater in those with longer durations of hospitalization. There were 1,593 patients with only non-HF hospitalizations, 21% of whom died during follow-up, with an incident mortality rate of 8.7 deaths per 100 PYs and an adjusted hazard ratio of 4.25 (95% confidence interval: 3.27 to 5.32). The risk for death was highest in the first 30 days and declined over time for all hospitalization categories. Patients not hospitalized for HF or for any cause had observed incident mortality rates of 3.8 and 1.3 deaths per 100 PYs, respectively.

CONCLUSIONS

In I-PRESERVE, HFpEF patients hospitalized for any reason, and especially for HF, were at high risk for subsequent death, particularly early. The findings support the need for careful attention in the post-discharge time period including attention to comorbid conditions. Among those hospitalized for HF, the high mortality rate and increased proportion of readmissions due to HF (highest during the first 30 days), suggest that this group would be an appropriate target for investigation of new interventions.

Facts and numbers on epidemiology and pharmacological treatment of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a major and growing public health problem. Epidemiologic studies demonstrated that heart failure (HF) can be clinically diagnosed in patients with normal or preserved left ventricular ejection fraction. These patients are therefore termed as having HFpEF. In the past, this was often called diastolic HF. Because of the permanent increase of the prevalence of HFpEF during the past decades, HFpEF now accounts for more than 50% of the total HF population. There are uncertainties and debates regarding the definition, diagnosis, and pathophysiology with the consequence that all outcome trials performed so far used criteria for inclusion and exclusion that were not consistent. These trials also failed to document improved prognosis. Recent smaller proof‐of‐concept or Phase II clinical trials investigating different pathophysiological approaches with substances such as the neprilysin inhibitor–angiotensin receptor blocker− combination (LCZ 696), ranolazine, or ivabradine were successful to improve biomarkers, haemodynamics, or functional capacity. Future trials will need to document whether also prognosis can be improved.

Digoxin-associated mortality: a systematic review and meta-analysis of the literature

There are conflicting data regarding the effect of digoxin use on mortality in patients with atrial fibrillation (AF) or with congestive heart failure (CHF). The aim of this meta-analysis was to provide detailed analysis of the currently available study reports. We performed a MEDLINE and a COCHRANE search (1993-2014) of the English literature dealing with the effects of digoxin on all-cause-mortality in subjects with AF or CHF. Only full-sized articles published in peer-reviewed journals were considered for this meta-analysis. A total of 19 reports were identified. Nine reports dealt with AF patients, seven with patients suffering from CHF, and three with both clinical conditions. Based on the analysis of adjusted mortality results of all 19 studies comprising 326 426 patients, digoxin use was associated with an increased relative risk of all-cause mortality [Hazard ratio (HR) 1.21, 95% confidence interval (CI), 1.07 to 1.38, P < 0.01]. Compared with subjects not receiving glycosides, digoxin was associated with a 29% increased mortality risk (HR 1.29; 95% CI, 1.21 to 1.39) in the subgroup of publications comprising 235 047 AF patients. Among 91.379 heart failure patients, digoxin-associated mortality risk increased by 14% (HR 1.14, 95% CI, 1.06 to 1.22). The present systematic review and meta-analysis of all available data sources suggest that digoxin use is associated with an increased mortality risk, particularly among patients suffering from AF.

Comorbidities and differential diagnosis in heart failure with preserved ejection fraction

Careful consideration must be given when diagnosing heart failure with preserved ejection fraction (HF-PEF). HF-PEF diagnosis is challenging and essentially a diagnosis of exclusion, with comorbidities potentially making the diagnosis more difficult. This article describes the comorbidities commonly associated with HF-PEF, the potential influence of these comorbidities on morbidity and mortality, and the differential diagnosis.

Clinical trials in patients with heart failure and preserved left ventricular ejection fraction

There is no robust evidence that any treatment can modify the natural history of patients with heart failure and preserved left ventricular ejection fraction (HFpEF), although most agree that diuretics can control congestion and improve symptoms. HFpEF is often complicated by systemic and pulmonary hypertension, atrial fibrillation, obesity, chronic lung and kidney disease, lack of physical fitness, and old age that can complicate both diagnosis and management. Further trials should phenotype patients precisely and create better definitions of HFpEF based on biomarkers.

Patients with left ventricular ejection fraction greater than 58 % have fewer incidences of future acute decompensated heart failure admission and all-cause mortality

Based on our previous observation, inertia stress (IS) of late systolic aortic flow was often observed in left ventricles with relatively higher left ventricular (LV) ejection fraction (EF). Most left ventricles with relatively lower LVEF did not have IS. Accordingly, lack of IS may correlate with LV diastolic dysfunction through the loss of LV elastic recoil and may contribute to the pathogenesis of heart failure (HF) and reduced survival. We enrolled 144 consecutive patients that underwent cardiac catheterization for the diagnosis of coronary artery disease. Left ventricular ejection fraction (LVEF) was obtained from left ventriculography. The IS was calculated from the LV pressure (P)-dP/dt relation. The study endpoint of this retrospective outcome-observational study was combined subsequent acute decompensated heart failure (ADHF) and all-cause mortality. During the follow-up period (median 6.1 years), seven unscheduled hospitalizations for ADHF and nine all-cause deaths were observed. The event-free survival rate was significantly higher among patients with IS than among patients without IS (log-rank, p = 0.001). On a multivariate Cox regression analysis, lack of IS was a prime predictor of the endpoint during follow-up (hazard ratio: 6.98; 95 % confidence interval: 1.48-33.03; p = 0.01). An LVEF ≥ 58 % was a surrogate indicator for the presence of IS, and patients with LVEF ≥ 58 % had fewer incidences of the endpoint than patients with LVEF < 58 %. In conclusion, lack of IS or LVEF < 58 % should be a predictor of future ADHF and all-cause mortality.

Heart failure with preserved ejection fraction in the elderly: scope of the problem

Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure (HF) in older adults, particularly women, and is increasing in prevalence as the population ages. With morbidity and mortality on par with HF with reduced ejection fraction, it remains a most challenging clinical syndrome for the practicing clinician and basic research scientist. Originally considered to be predominantly caused by diastolic dysfunction, more recent insights indicate that HFpEF in older persons is typified by a broad range of cardiac and non-cardiac abnormalities and reduced reserve capacity in multiple organ systems. The globally reduced reserve capacity is driven by: 1) inherent age-related changes; 2) multiple, concomitant co-morbidities; 3) HFpEF itself, which is likely a systemic disorder. These insights help explain why: 1) co-morbidities are among the strongest predictors of outcomes; 2) approximately 50% of clinical events in HFpEF patients are non-cardiovascular; 3) clinical drug trials in HFpEF have been negative on their primary outcomes. Embracing HFpEF as a true geriatric syndrome, with complex, multi-factorial pathophysiology and clinical heterogeneity could provide new mechanistic insights and opportunities for progress in management. This article is part of a Special Issue entitled CV Aging.

[New therapy concepts for heart failure with preserved ejection fraction]

The management of patients with heart failure and preserved ejection fraction (HFpEF) remains challenging and requires an accurate diagnosis. Although currently no convincing therapy that can prolong survival in patients with HFpEF has been established, treatment of fluid retention, heart rate and control of comorbidities are important cornerstones to improve the quality of life and symptoms. In recent years many new therapy targets have been tested for development of successful interventional strategies for HFpEF. Insights into new mechanisms of HFpEF have shown that heart failure is associated with dysregulation of the nitric oxide-cyclic guanosine monophosphate-protein kinase (NO-cGMP-PK) pathway. Two new drugs are currently under investigation to test whether this pathway can be significantly improved by either the neprilysin inhibitor LCZ 696 due to an increase in natriuretic peptides or by the soluble guanylate cyclase stimulator vericiguat, which is also able to increase cGMP. In addition, several preclinical or early phase studies which are currently investigating new mechanisms for matrix, intracellular calcium and energy regulation including the role of microRNAs and new devices are presented and discussed.