Digitalis use in contemporary clinical practice: refitting the foxglove

Atrial fibrillation in patients with systolic heart failure: pathophysiology mechanisms and management

Heart failure (HF) and atrial fibrillation (AF) demonstrate a constantly increasing prevalence during the 21^st century worldwide, as a result of the aging population and the successful interventions of the clinical practice in the deterioration of adverse cardiovascular outcomes. HF and AF share common risk factors and pathophysiological mechanisms, creating the base of a constant interrelation. AF impairs systolic and diastolic function, resulting in the increasing incidence of HF, whereas the structural and neurohormonal changes in HF with preserved or reduced ejection fraction increase the possibility of the AF development. The temporal relationship of the development of either condition affects the diagnostic algorithms, the prognosis and the ideal therapeutic strategy that leads to euvolaemia, management of non-cardiovascular comorbidities, control of heart rate or restoration of sinus rate, ventricular synchronization, prevention of sudden death, stroke, embolism, or major bleeding and maintenance of a sustainable quality of life. The indicated treatment for the concomitant HF and AF includes rate or/and rhythm control as well as thromboembolism prophylaxis, while the progress in the understanding of their pathophysiological interdependence and the introduction of the genetic profiling, create new paths in the diagnosis, the prognosis and the prevention of these diseases.

Association Between Digoxin Use and Cancer Incidence: A Propensity Score-Matched Cohort Study With Competing Risk Analysis

Background: Previous studies neglected death as a critical competing risk while estimating the cancer risk for digoxin users. Therefore, the current study aims to assess the effectiveness of digoxin on cancer prevention by competing risk analysis. Methods: We performed a population-based retrospective cohort study using the Taiwan National Health Insurance Research database between 1998 and 2010. After one-to-one propensity score-matching from 36,160 patients with defined criteria, we enrolled 758 patients both in digoxin and β-blocker group for further analysis. Results: The results showed that the digoxin group had higher all-cause mortality than the β-blocker group in the 4- year (10.4 vs. 4.9%) and 8 years (13.6 vs. 7.0%) follow-up. The subdistribution HR of cancer incidence in the digoxin group compared to the β-blocker group was 1.99 (95% confidence interval [CI]: 1.22-3.01) and 1.46 (95% CI: 1.01-2.15) in the 4 years and 8 years follow-up, respectively. Conclusions: The result of our study showed the usage of digoxin has no benefit in cancer prevention compared with β-blocker. The possibility of β-blocker as a new drug candidate for cancer prevention needs further clinical evaluation. The current study also emphasized the necessity of competing risk analysis applying to similar clinical researches.

Current Drug Treatment Strategies for Atrial Fibrillation and TASK-1 Inhibition as an Emerging Novel Therapy Option

Atrial fibrillation (AF) is the most common sustained arrhythmia with a prevalence of up to 4% and an upwards trend due to demographic changes. It is associated with an increase in mortality and stroke incidences. While stroke risk can be significantly reduced through anticoagulant therapy, adequate treatment of other AF related symptoms remains an unmet medical need in many cases. Two main treatment strategies are available: rate control that modulates ventricular heart rate and prevents tachymyopathy as well as rhythm control that aims to restore and sustain sinus rhythm. Rate control can be achieved through drugs or ablation of the atrioventricular node, rendering the patient pacemaker-dependent. For rhythm control electrical cardioversion and pharmacological cardioversion can be used. While electrical cardioversion requires fasting and sedation of the patient, antiarrhythmic drugs have other limitations. Most antiarrhythmic drugs carry a risk for pro-arrhythmic effects and are contraindicated in patients with structural heart diseases. Furthermore, catheter ablation of pulmonary veins can be performed with its risk of intraprocedural complications and varying success. In recent years TASK-1 has been introduced as a new target for AF therapy. Upregulation of TASK-1 in AF patients contributes to prolongation of the action potential duration. In a porcine model of AF, TASK-1 inhibition by gene therapy or pharmacological compounds induced cardioversion to sinus rhythm. The DOxapram Conversion TO Sinus rhythm (DOCTOS)-Trial will reveal whether doxapram, a potent TASK-1 inhibitor, can be used for acute cardioversion of persistent and paroxysmal AF in patients, potentially leading to a new treatment option for AF.

Digoxin in Atrial Fibrillation: An Old Topic Revisited

Digoxin has been used for more than 50 years in patients with Atrial Fibrillation (AF), with the goal of Controlling Heart Rate (HR) and restoring sinus rhythm. In the last two decades, several studies have correlated therapeutic use of digoxin with increased mortality. However, such studies have potential biases that cannot be disregarded, mainly because they are cross-sectional experiments or post-hoc analyses of Randomized Controlled Trials (RCTs). Despite uncertainties regarding the safety of digoxin in this setting, it remains one of the most prescribed drugs for AF worldwide. On the other hand, the absence of any RCTs designed to evaluate mortality makes a definitive conclusion more difficult to reach; therefore, this medication must be used with care. In this review, we explored the therapeutic use of digoxin in the context of AF, discussed mortality data by means of critical analysis in the light of the best available evidence, and position ourselves in relation to more rigorous control of serum levels of this drug in daily practice.

Association Between Digoxin Use and Adverse Outcomes Among Patients in the Chinese Atrial Fibrillation Registry

INTRODUCTION

Digoxin is widely used in patients with atrial fibrillation (AF), but its association with adverse outcomes remains controversial.

OBJECTIVE

We aimed to assess the association between digoxin and adverse outcomes in Chinese patients with AF.

METHODS

We used data from the Chinese Atrial Fibrillation Registry, a prospective, multicenter, hospital-based registry study involving 31 hospitals. In total, 10,472 eligible patients with AF, enrolled from August 2011 to December 2016, were included in this study. The association between digoxin use and all-cause mortality, cardiovascular death, and cardiovascular hospitalization were investigated using Cox proportional hazards models.

RESULTS

In total, 1152 (11%) patients were treated with digoxin at baseline. Patients receiving digoxin were older (mean age 69.7 vs. 66.5 years) and had a higher heart rate (92.4 vs. 79.7 beats/min). A higher proportion of patients receiving digoxin therapy had a history of heart failure (62.5 vs. 15.6%), diabetes mellitus (34.4 vs. 24.4%), and persistent AF (67.9 vs. 38.4%). Digoxin use was independently associated with increased all-cause mortality (adjusted hazard ratio (aHR) 1.21; 95% confidence interval (CI) 1.02-1.43; p = 0.031), cardiovascular death (aHR 1.25; 95% CI 1.01-1.55; p = 0.043), and cardiovascular hospitalization (aHR 1.21; 95% CI 1.05-1.39; p = 0.007). The associations were also homogeneous across various subgroups except in patients with and without renal dysfunction (p value for interaction = 0.029).

DISCUSSION

In this Chinese AF cohort, for patients who had not undergone ablation, digoxin use was associated with a significant increase in adverse outcomes. Although residual confounders may exist, and serum concentrations of digoxin were unavailable, digoxin should be used with caution in clinical practice, and its effects need to be critically evaluated in randomized trials.

CLINICAL TRIAL REGISTRATION

URL: http://www.chictr.org.cn/showproj.aspx?proj=5831. Unique identifier: ChiCTR-OCH-13003729.

Atrial Fibrillation Ablation Should Be First-Line Therapy in Heart Failure Patients: CON

Heart failure (HF) and atrial fibrillation (AF) are the epidemics of the twenty-first century. These often coexist and are the cause of major morbidity and mortality. Management of these patients has posed a significant challenge to the medical community. Guideline-directed pharmacologic therapy for heart failure is important; however, there is no clear consensus on how best to treat AF with concomitant HF. In this article, we provide an in-depth review of the management of AF in patients with HF and provide insight as to why catheter ablation should not be the first line of therapy in this population.

Effect of digitalis level on readmission and mortality rate among heart failure reduced ejection fraction patients

INTRODUCTION

Digitalis has been used for over 200 years to treat patients with heart failure, and evidence supports its use to improve clinical symptoms and quality of life, but not survival. The objective of this retrospective study was to evaluate the effects of digitalis on readmission and mortality in patients with heart failure with reduced ejection fraction (HFrEF) who were receiving current guideline recommended medical therapy.

METHODS

We reviewed medical record data from a retrospective cohort study of 1047 patients admitted to the hospital from 2005 to 2014 with decompensated HFrEF. 244 received digitalis, at some point during patient trajectory, and 803 never received digitalis. The primary outcomes of interest were the length of stay in hospital, readmission rates after discharge at 1, 6, 12, and 24 months and the overall mortality rate, at the same time points.

RESULTS

We studied the effects of digitalis after adjusting for age, sex, race, potentially confounding comorbidities, and prescription medications. Digitalis treatment is associated with decreases in EF in patients with HFrEF (OR = -2.83, P < 0.001) and was associated with an increased readmission rate for any reason after discharge from the hospital at 6, 12, and 24 months, 53%, 34%, and 35%, respectively. No statistically significant difference was found between patients who received digitalis and those who did not (referent group) for the length of hospital stay and overall mortality rate.

CONCLUSION

Digitalis use is associated with increased re-admission rates for any reason following discharge from the hospital at 6, 12, and 24 months.

Outcomes of Rate-Control Treatment in Patients With Atrial Fibrillation and Heart Failure - A Nationwide Cohort Study

BACKGROUND

Rate control is now a front-line therapy in the management of atrial fibrillation (AF). However, the survival benefits of different rate-control medications remain controversial, so we assessed the efficacy of rate-control medications in AF patients with concomitant heart failure (HF).Methods and Results:From January 2002 to December 2008, a total of 7,034 AF patients with a single type of rate-control drug or without rate-control treatment were enrolled from the Korea National Health Insurance Service database. The death rates over a mean follow-up of 4.5±1.2 years were 12.6% (580 of 4,593) and 29.0% (709 of 2,441) in non-HF and HF patients, respectively. Among the total subjects, the risk of death was lower in patients receiving β-blockers (adjusted hazard ratio (HR) 0.75, 95% confidence interval (CI) 0.64-0.88) and calcium-channel blockers (adjusted HR 0.74, 95% CI 0.55-0.98) compared with those who did not receive rate-control medications. In patients without HF, use of rate-control medications did not affect the risk of death. In patients with HF, β-blockers significantly decreased the mortality risk (adjusted HR 0.63, 95% CI 0.50-0.79), whereas use of calcium-channel blockers or digoxin was not associated with death. The results were observed consistently among the cohorts after propensity matching.

CONCLUSIONS

Use of β-blockers was associated with a reduced mortality rate for AF patient with HF but not for those without HF. These findings should be examined in a large randomized trial.

Digoxin versus placebo, no intervention, or other medical interventions for atrial fibrillation and atrial flutter: a protocol for a systematic review with meta-analysis and Trial Sequential Analysis

BACKGROUND

Atrial fibrillation is the most common arrhythmia of the heart with a prevalence of approximately 2% in the western world. Atrial flutter, another arrhythmia, occurs less often with an incidence of approximately 200,000 new patients per year in the USA. Patients with atrial fibrillation and atrial flutter have an increased risk of death and morbidities. In the management of atrial fibrillation and atrial flutter, it is often necessary to use medical interventions to lower the heart rate. Lowering the heart rate may theoretically prevent the development of heart failure and tachycardia-mediated cardiomyopathy. The evidence on the benefits and harms of digoxin compared with placebo or with other medical interventions is unclear. This protocol for a systematic review aims at identifying the beneficial and harmful effects of digoxin compared with placebo, no intervention, or with other medical interventions for atrial fibrillation and atrial flutter.

METHODS

This protocol for a systematic review was conducted following the recommendations of Cochrane and the eight-step assessment procedure suggested by Jakobsen and colleagues. We plan to include all relevant randomised clinical trials comparing digoxin with placebo, no intervention, or with other medical interventions. We plan to search the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, Science Citation Index Expanded on Web of Science, and BIOSIS to identify relevant trials. Any eligible trial will be assessed and classified as either at high risk of bias or low risk of bias, and our primary conclusions will be based on trials with low risk of bias. We will perform our meta-analyses of the extracted data using Review Manager 5.3 and Trial Sequential Analysis ver. 0.9.5.5 beta. For both our primary and secondary outcomes, we will create a 'Summary of Findings' table based on GRADE assessments of the quality of the evidence.

DISCUSSION

The results of this systematic review have the potential to benefit millions of patients worldwide as well as healthcare economy.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016052935.

Atrial fibrillation in heart failure: what should we do?

Heart failure (HF) and atrial fibrillation (AF) are two conditions that are likely to dominate the next 50 years of cardiovascular (CV) care. Both are increasingly prevalent and associated with high morbidity, mortality, and healthcare cost. They are closely inter-related with similar risk factors and shared pathophysiology. Patients with concomitant HF and AF suffer from even worse symptoms and poorer prognosis, yet evidence-based evaluation and management of this group of patients is lacking. In this review, we evaluate the common mechanisms for the development of AF in HF patients and vice versa, focusing on the evidence for potential treatment strategies. Recent data have suggested that these patients may respond differently than those with HF or AF alone. These results highlight the clear clinical need to identify and treat according to best evidence, in order to prevent adverse outcomes and reduce the huge burden that HF and AF are expected to have on global healthcare systems in the future. We propose an easy-to-use clinical mnemonic to aid the initial management of newly discovered concomitant HF and AF, the CAN-TREAT HFrEF + AF algorithm (Cardioversion if compromised; Anticoagulation unless contraindication; Normalize fluid balance; Target initial heart rate <110 b.p.m.; Renin-angiotensin-aldosterone modification; Early consideration of rhythm control; Advanced HF therapies; Treatment of other CV disease).

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.

Digoxin: its role in contemporary medicine

Digoxin has been a key therapeutic for heart failure and atrial tachyarrhythmias for over 200 years following Withering's groundbreaking work depicting the therapeutic benefit of the common botanical foxglove in his 1785 monograph. The use of digoxin preceded any randomised evidence or even basic understanding of its mechanism of action. Over the past two decades, there has been mounting evidence further challenging the safety and efficacy of digoxin, while multiple other therapies for both heart failure and atrial tachyarrhythmias have proven to be more effective and safe. Altogether, digoxin still has an important role in contemporary pharmacotherapeutics, though its role remains controversial and should be reserved for selective patients and clinical situations, with careful attention to serum concentrations.