Digoxin in atrial fibrillation: report from the Stockholm Cohort study of Atrial Fibrillation (SCAF)

Digoxin and Standard-of-Care Therapy for Heart Failure Patients with COVID-19: Analysis of Data from the US Military Health System (MHS) Data Repository

BACKGROUND

Cardiac glycosides such as digoxin, digitoxin and ouabain are still used around the world to treat patients with chronic heart failure with reduced ejection fraction (HFrEF) and/or atrial fibrillation (AF). However, in the US, only digoxin is licensed for treating these illnesses, and the use of digoxin for this group of patients is increasingly being replaced in the US by a new standard of care with groups of more expensive drugs. However, ouabain and digitoxin, and less potently digoxin, have also recently been reported to inhibit SARS-CoV-2 virus penetration into human lung cells, thus blocking COVID-19 infection. COVID-19 is known to be a more aggressive disease in patients with cardiac comorbidities, including heart failure.

OBJECTIVE

We therefore considered the possibility that digoxin might provide at least a measure of relief from COVID-19 in digoxin-treated heart failure patients. To this end, we hypothesized that treatment with digoxin rather than standard of care might equivalently protect heart failure patients with regard to diagnosis of COVID-19, hospitalization and death.

METHODS

To test this hypothesis, we conducted a cross-sectional study by using the US Military Health System (MHS) Data Repository to identify all MHS TRICARE Prime and Plus beneficiaries aged 18-64 years with a heart failure (HF) diagnosis during the period April 2020 to August 2021. In the MHS, all patients receive equal, optimal care without regard to rank or ethnicity. Analyses included descriptive statistics on patient demographics and clinical characteristics, and logistic regressions to determine likelihood of digoxin use.

RESULTS

We identified 14,044 beneficiaries with heart failure in the MHS during the study period. Of these, 496 were treated with digoxin. However, we found that both digoxin-treated and standard-of-care groups were equivalently protected from COVID-19. We also noted that younger active duty service members and their dependents with HF were less likely to receive digoxin compared with older, retired beneficiaries with more comorbidities.

CONCLUSION

The hypothesis of equivalent protection by digoxin treatment of HF patients in terms of susceptibility to COVID-19 infection appears to be supported by the data.

Digoxin Impact on Heart Failure Patients with Atrial Fibrillation

BACKGROUND

Digoxin is a cardiac glycoside, derived from the plant Digitalis purpurea. For many years digitalis has been widely used in the treatment of heart failure (HF), owing to its cardiotonic and neurohormonal effects and atrial fibrillation (AF), due to its parasympathomimetic effect on the AV node.

OBJECTIVE

The aim of this paper is to evaluate the available evidence on the safety and efficacy of digoxin in patients with HF and AF, by reviewing the pertinent literature.

METHODS

We conducted a PubMed/MEDLINE and SCOPUS search to evaluate the currently available evidence on the administration of digoxin and its association with all-cause mortality risk in patients with AF and HF.

RESULTS

Several observational analyses of clinical trials and meta-analyses have shown conflicting results on the safety and efficacy of digoxin administration in patients with AF and HF. According to these results, digoxin should be avoided in patients without HF, as it is associated with worse outcomes. On the other hand, in patients with AF and HF digoxin should be used with caution.

CONCLUSION

The impact of digoxin on all-cause mortality and adverse effects in these patients remains unclear based on the current evidence. More trials at low risk of bias evaluating the effects of digoxin are needed.

Effect of Digoxin Therapy on Mortality in Patients With Atrial Fibrillation: An Updated Meta-Analysis

Background: Whether digoxin is associated with increased mortality in atrial fibrillation (AF) remains controversial. We aimed to assess the risk of mortality and clinical effects of digoxin use in patients with AF.

Methods: PubMed, Embase, and the Cochrane library were systematically searched to identify eligible studies comparing all-cause mortality of patients with AF taking digoxin with those not taking digoxin, and the length of follow-up was at least 6 months. Hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted and pooled.

Results: A total of 29 studies with 621,478 patients were included. Digoxin use was associated with an increased risk of all-cause mortality in all patients with AF (HR 1.17, 95% CI 1.13–1.22, P < 0.001), especially in patients without HF (HR 1.28, 95% CI 1.11–1.47, P < 0.001). There was no significant association between digoxin and mortality in patients with AF and HF (HR 1.06, 95% CI 0.99–1.14, P = 0.110). In all patients with AF, regardless of concomitant HF, digoxin use was associated with an increased risk of sudden cardiac death (SCD) (HR 1.40, 95% CI 1.23–1.60, P < 0.001) and cardiovascular (CV) mortality (HR 1.27, 95% CI 1.08–1.50, P < 0.001), and digoxin use had no significant association with all-cause hospitalization (HR 1.13, 95% CI 0.92–1.39, P = 0.230).

Conclusion: We conclude that digoxin use is associated with an increased risk of all-cause mortality, CV mortality, and SCD, and it does not reduce readmission for AF, regardless of concomitant HF. Digoxin may have a neutral effect on all-cause mortality in patients with AF with concomitant HF.

Systematic Review Registration:https://www.crd.york.ac.ukPROSPERO.

A Comparison of Rate Control Agents for the Treatment of Atrial Fibrillation: Follow-Up Investigation of the AFFIRM Study

There are limited data from randomized controlled trials comparing rate control agents in atrial fibrillation. Patient-level data from the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial was used to compare outcomes in patients randomized to the rate control arm who were treated with a single rate control agent at baseline. The rate control agents used were beta-blockers, non-dihydropyridine calcium channel blockers, and digoxin. The independent variable for this analysis was the initial study drug used and the dependent variables were time to first hospitalization and time to death from any cause. We analyzed 1,144 out of 2,027 participants assigned to the rate control group who were on a single rate control agent at the start of the trial. There were 485 (42.5%) participants in the beta-blocker group, 344 (30%) in the calcium channel blocker group, and 315 (27.5%) in the digoxin group. All hospitalization and all-cause mortality occurred in 55.9% and 12.5% of those in the beta-blocker group, 58.4% and 16.7% in the calcium channel blocker group, and 55.2% and 21.1% in the digoxin group, respectively. After adjustment for differences in baseline characteristics, there were no significant differences in time to hospitalization or death for any group. In the AFFIRM trial, the initial rate control drug used was not associated with statistically significant differences in time to hospitalization or death after controlling for differences in baseline characteristics. There is limited data at present to guide the selection of rate control agents in patients with atrial fibrillation.

Digoxin-mortality: randomized vs. observational comparison in the DIG trial

AIMS

The Digitalis Investigation Group (DIG) trial, the only large randomized trial of digoxin in heart failure, reported a neutral effect on mortality and a significant reduction in heart failure hospitalizations. Recent observational studies reported increased mortality with digoxin treatment. We present further analyses of the DIG trial displaying the inability to control bias in observational treatment comparisons despite extensive statistical adjustments.

METHODS AND RESULTS

Forty-four percent of the 6800 patients in the DIG trial had been treated with digoxin before randomization, and half of them were randomly withdrawn from digoxin treatment. We contrast the main randomization-based result of the DIG trial with the observational non-randomized comparison of patients pre-treated or not pre-treated with digoxin. Mortality [hazard ratio (HR) 1.22, 95% confidence interval (CI) 1.12-1.34; P < 0.001] and heart failure hospitalizations (HR 1.47, 95% CI 1.33-1.61; P < 0.001) were significantly higher in patients pre-treated with digoxin even after adjustment for baseline population differences. The higher risks for both outcomes in those who had previously received digoxin persisted even if they received placebo during the trial (HR 1.24, 95% CI 1.10-1.40; P < 0.001). This sharply contradicts the neutral effect on mortality and the significant reduction in heart failure hospitalizations observed in the randomized comparison.

CONCLUSION

Prescription of digoxin is an indicator of disease severity and worse prognosis, which cannot be fully accounted for by covariate adjustments in the DIG trial where patients were well-characterized. It is unlikely that weaker research approaches (observational studies of administrative data or registries) can provide more reliable estimates of the effects of cardiac glycosides.

The impact of serum concentration-guided digoxin therapy on mortality of heart failure patients: A long-term follow-up, propensity-matched cohort study

BACKGROUND

Recently published studies suggested that digoxin may increase mortality in heart failure with reduced ejection fraction (HFrEF). However, in the vast majority of former trials serum digoxin concentration (SDC) was not measured and therapy was not SDC-guided.

AIM

To assess the impact of SDC-guided digoxin therapy on mortality in HFrEF patients.

METHODS

Data of 580 HFrEF patients were retrospectively analyzed. In patients on digoxin, SDC was measured every 3 months and digoxin dosage was SDC-guided (target SDC: 0.5-0.9 ng/mL). All-cause mortality of digoxin users and nonusers was compared after propensity score matching (PSM).

RESULTS

After 7.1 ± 4.7 years follow-up period (FUP) all-cause mortality of digoxin users (n = 180) was significantly higher than nonusers (n = 297) (propensity-adjusted HR = 1.430; 95% CI = 1.134-1.804; P = .003). Patients having SDC of 0.9 to 1.1 ng/mL (n = 60) or > 1.1 ng/mL (n = 44) at any time during the FUP had an increased risk of all-cause mortality (HR = 1.750; 95% CI = 1.257-2.436, P = .001 and HR = 1.687; 95% CI = 1.153-2.466, P = .007), while patients having a maximal SDC < 0.9 ng/mL (n = 76) had similar mortality risk (HR = 1.139; 95% CI = 0.827-1.570, P = .426), compared to digoxin nonusers.

CONCLUSIONS

According to our propensity-matched analysis, SDC-guided digoxin therapy was associated with increased all-cause mortality in optimally treated HFrEF patients, especially with SDC ≥0.9 ng/mL. These results reinforce the expert opinion that digoxin in HFrEF can only be used among carefully selected patients with close SDC monitoring.

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.

Deleterious cardiovascular effect of exosome in digitalis-treated decompensated congestive heart failure

Heart failure (HF) is a medical condition inability of the heart to pump sufficient blood to meet the metabolic demand of the body to take place. The number of hospitalized patients with cardiovascular diseases is estimated to be more than 1 million each year, of which 80% to 90% of patients ultimately progress to decompensated HF. Digitalis glycosides exert modest inotropic actions when administered to patients with decompensated HF. Although its efficacy in patients with HF and atrial fibrillation is clear, its value in patients with HF and sinus rhythm has often been questioned. A series of recent studies have cast serious doubt on the benefit of digoxin when added to contemporary HF treatment. We are hypothesizing the role and mechanism of exosome and its biological constituents responsible for worsening the disease state and mortality in decompensated HF patients on digitalis.

Current pharmacotherapeutic strategies for cardiac arrhythmias in heart failure

Introduction: Heart failure (HF) affects over 6 million Americans and is the most common cause of hospital readmissions in the United States. Cardiac arrhythmias are common comorbidities seen in patients with HF and are associated with an increase in morbidity and mortality. Pharmacotherapeutic agents along with device and ablation therapies are the mainstays of treatment for cardiac arrhythmias in HF.Areas covered: An extensive literature review of articles and clinical trials on PUBMED on the topic of pharmacotherapy for cardiac arrhythmias in heart failure was conducted. This review article summarizes the above literature to describe the prevalence of the various types of arrhythmias in HF, the recommended pharmacotherapies for the treatment of these arrhythmias in HF and the evidence that supports these recommendations.Expert opinion: Cardiac arrhythmias are common in HF and are the leading cause of death in this patient population. The management of cardiac arrhythmias in HF is challenging. Pharmacotherapy is the primary though increasingly adjunctive therapy for most cardiac arrhythmias. Further, antiarrhythmic drugs must be used with caution in this patient population due to their potential adverse effects.

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.

Impact of Digitalis Use on Mortality in Japanese Patients With Non-Valvular Atrial Fibrillation - A Subanalysis of the J-RHYTHM Registry

BACKGROUND

Because the influence of digitalis use on the death of patients with non-valvular atrial fibrillation (NVAF) remains controversial, a subanalysis of the J-RHYTHM Registry was performed.Methods and Results:A consecutive series of outpatients with AF from 158 institutions was enrolled and followed for 2 years or until the occurrence of an event. Among 7,406 patients with NVAF, 7,018 (age, 69.7±10.0 years; men, 71.1%) with information on antiarrhythmic drug and digitalis use at baseline were divided into 2 groups based on digitalis use. The influence of digitalis on death was investigated using a propensity score-matching model. In 802 patients treated with digitalis, all-cause death was significantly higher than in 6,216 patients with no digitalis use during the 2-year follow-up period (4.4% vs. 2.4%, unadjusted P<0.001). Digitalis use was significantly associated with all-cause death in the crude model (hazard ratio [HR] 1.85, 95% confidence interval [CI] 1.28-2.68, P=0.001). However, after propensity score-matching, the association was not significant (HR 1.31, 95% CI 0.70-2.46, P=0.405). Older age, male sex, heart failure, coronary artery disease, and lower body mass index were significantly associated with all-cause death in NVAF patients treated with digitalis.

CONCLUSIONS

Digitalis use was not independently associated with all-cause death, and several clinical confounding factors might contribute to increased mortality in NVAF patients treated with digitalis.

Is There Still a Role for Digoxin in the Management of Atrial Fibrillation?

PURPOSE OF REVIEW

A number of recent observational analyses have assessed clinical outcomes associated with digoxin use in patients with atrial fibrillation. In this review, we review these data and provide suggestions on the contemporary use of digoxin in patients with atrial fibrillation as supported by the recent evidence.

RECENT FINDINGS

Observational data from clinical trials and registries have provided variable results on the safety and efficacy of chronic digoxin use in patients with atrial fibrillation. In general, results have been consistent with an associated increase in adverse clinical outcomes with digoxin use in atrial fibrillation patients without heart failure. In atrial fibrillation patients with heart failure, while the weight of evidence suggested an associated risk with digoxin therapy, the results are inconsistent. In patients with atrial fibrillation without heart failure, digoxin should generally be avoided. In atrial fibrillation patients with heart failure, digoxin should generally be reserved for patients that do not achieve adequate rate control or are not tolerant of other rate control therapies.

Chronic digitalis therapy in patients before heart transplantation is an independent risk factor for increased posttransplant mortality

Objectives

Digitalis therapy (digoxin or digitoxin) in patients with heart failure is subject to an ongoing debate. Recent data suggest an increased mortality in patients receiving digitalis. This study investigated the effects of chronic digitalis therapy prior to heart transplantation (HTX) on posttransplant outcomes.

Patients and methods

This was a retrospective, observational, single-center study. It comprised 530 adult patients who were heart-transplanted at Heidelberg University Hospital between 1989 and 2012. Patients with digitalis prior to HTX (≥3 months) were compared to those without (no or <3 months of digitalis). Patients with digitalis were further subdivided into patients receiving digoxin or digitoxin. Primary outcomes were early posttransplant atrial fibrillation and mortality.

Results

A total of 347 patients (65.5%) had digitalis before HTX. Of these, 180 received digoxin (51.9%) and 167 received digitoxin (48.1%). Patients with digitalis before HTX had a significantly lower 30-day (P=0.0148) and 2-year (P=0.0473) survival. There was no significant difference between digoxin and digitoxin in 30-day (P=0.9466) or 2-year (P=0.0723) survival. Multivariate analysis for posttransplant 30-day mortality showed pretransplant digitalis therapy as an independent risk factor (hazard ratio =2.097, CI: 1.036–4.248, P=0.0397). Regarding atrial fibrillation in the early posttransplant period, there was neither a statistically significant difference between patients with and without digitalis (P=0.1327) nor between patients with digoxin or digitoxin (P=0.5867).

Conclusion

Digitalis in patients before HTX is an independent risk factor for increased posttransplant mortality.

Digoxin Use and Subsequent Clinical Outcomes in Patients With Atrial Fibrillation With or Without Heart Failure in the ENGAGE AF-TIMI 48 Trial

Background

Digoxin is widely used in patients with atrial fibrillation despite the lack of randomized controlled trials. Observational studies report conflicting results regarding its association with mortality, perhaps because of residual confounding by the presence of heart failure (HF).

Methods and Results

In the ENGAGE AF‐TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation‐Thrombolysis in Myocardial Infarction 48) trial, clinical outcomes of patients with atrial fibrillation with and without HF were examined by baseline digoxin use during a median follow‐up of 2.8 years. HF was defined at baseline as prior or current clinical stage C or D HF. Of 21 105 patients enrolled, 6327 (30%) were treated with digoxin at baseline. Among patients without HF (n=8981), digoxin use (20%) was independently associated with sudden cardiac death (adjusted hazard ratio, 1.51; 95% CI, 1.10–2.08), with no significant interaction by age, sex, left ventricular ejection fraction, renal function, or concomitant medications (P>0.05 for each). Consistent results were observed using propensity matching (adjusted hazard ratio for sudden cardiac death, 1.90; 95% CI, 1.36–2.65). Among patients with HF (n=12 124), digoxin use (37%) was associated with an increase in all‐cause death, cardiovascular death, sudden cardiac death, and death caused by HF/cardiogenic shock (P<0.01 for each), but not with noncardiovascular death, stroke/systemic embolism, or myocardial infarction.

Conclusions

In this observational analysis of patients with atrial fibrillation without investigator‐reported HF, digoxin use was significantly associated with sudden cardiac death. While residual confounding cannot be excluded, the association between digoxin use and worse clinical outcomes highlights the need to examine digoxin use, particularly when prescribed to control heart rate in patients with atrial fibrillation in a randomized trial.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00781391.

Effect of Chronic Kidney Diseases on Mortality among Digoxin Users Treated for Non-Valvular Atrial Fibrillation: A Nationwide Register-Based Retrospective Cohort Study

PURPOSE

This study investigated the impact of chronic kidney disease on all-causes and cardiovascular mortality in patients with atrial fibrillation treated with digoxin.

METHODS

All patients with non-valvular atrial fibrillation and/or atrial flutter as hospitalization diagnosis from January 1, 1997 to December 31, 2012 were identified in Danish nationwide administrative registries. Cox proportional hazard model was used to compare the adjusted risk of all-causes and cardiovascular mortality among patients with and without chronic kidney disease and among patients with different chronic kidney disease stages within 180 days and 2 years from the first digoxin prescription.

RESULTS

We identified 37,981 patients receiving digoxin; 1884 patients had the diagnosis of chronic kidney disease. Cox regression analysis showed no statistically significant differences in all-causes (Hazard Ratio, HR 0.89; 95% confident interval, CI 0.78-1.03) and cardiovascular mortality (HR 0.88; 95%CI 0.74-1.05) among patients with and without chronic kidney disease within 180 days of follow-up period. No statistically significant differences was found using a 2 years follow-up period neither for all causes mortality (HR 0.90; 95%CI 0.79-1.03), nor for cardiovascular mortality (HR 0.87; 95%CI 0.74-1.02). No statistically significant differences was found comparing patients with and without estimated Glomerular Filtration Rate <30ml/min/1.73m2 and patients with different stages of chronic kidney disease, for all-causes and cardiovascular mortality within 180 days and 2 years from the first digoxin prescription.

CONCLUSIONS

This study suggest no direct effect of chronic kidney disease and chronic kidney disease stages on all-causes and cardiovascular mortality within both 180 days and 2 years from the first digoxin prescription in patients treatment-naïve with digoxin for non-valvular atrial fibrillation.

Digoxin Is Associated With Increased All-cause Mortality in Patients With Atrial Fibrillation Regardless of Concomitant Heart Failure: A Meta-analysis

For decades, digoxin has been widely used to control ventricular rate in atrial fibrillation (AF). However, it remains controversial as to whether digoxin is associated with increased mortality in AF. In this study, we searched relevant studies that were published before December 1, 2014, in PubMed, EMBASE, and the Cochrane central databases. We systematically reviewed the references and performed a meta-analysis of 8 carefully selected studies with 302,738 patients who were included for the final analysis. It was shown that digoxin use was associated with increased risk of all-cause mortality in AF overall [hazard ratio (HR) = 1.375, 95% confidence intervals (CI), 1.201-1.574, P = 0.0001]. Subgroup analysis further revealed that digoxin was associated with increased all-cause mortality in patients with AF, which was complicated by heart failure (HF) (HR = 1.201, CI, 1.074- 1.344, P = 0.001), and in those subjects without HF (HR = 1.172, CI, 1.148-1.198, P = 0.0001). Sensitivity analyses found results to be robust. Our findings indicated that digoxin use was associated with significantly increased all-cause mortality in patients with AF regardless of concomitant HF. We suggest that digoxin should not be preferentially used over other rate control medications in AF.

Role of Digoxin in Atrial Fibrillation

Since its isolation in the 1930s, digoxin has played a pivotal role in the treatment of cardiac conditions including heart failure and supraventricular tachyarrhythmias. The parasympathomimetic activity makes digoxin a reasonable option for controlling ventricular rate in atrial fibrillation (AF). However, the unique pharmacokinetic properties, electrolyte-dependent effects, and P-glycoprotein drug interactions influence the clinical use of digoxin. In addition, the delayed onset and narrow therapeutic index can make digoxin utilization cumbersome and often necessitates serum drug monitoring. Despite digoxin's extensive history, recent literature has cast doubt on the efficacy and safety of this medication in the population with AF. Large amounts of data suggest digoxin offers no benefit on mortality and may increase the risk of mortality though this was not consistent in all evaluations. While robust, the majority of the available studies are not randomized which limits the ability to draw firm conclusions. The potential risk of mortality must be weighed against the expected benefits of digoxin use to make individualized patient care decisions. Clinicians should refrain from utilizing digoxin monotherapy for rate control in AF when other options are viable.

Atrial fibrillation management: evaluating rate vs rhythm control

Atrial fibrillation (AF) is an increasing global issue leading to increased hospitalizations, adverse health related events and mortality. This review focuses on the management of atrial fibrillation, in particular in the past decade, comparing two major strategies, rate or rhythm control. We evaluate the evidence for each strategy, pharmacological options and the increasing utilization of invasive techniques, in particular catheter ablation and use of implantable cardiac pacing devices. Pharmacological comparative trials evaluating both strategies have shown rate control being non-inferior to rhythm control for clinical outcomes of mortality and other cardiovascular events (including stroke). Catheter ablation techniques, involving radiofrequency ablation and recently cryoablation, have shown promising results in particular with paroxysmal AF. However, persistent AF provides ongoing challenges and will be a particular focus of continued research.

Beta-blockers or Digoxin for Atrial Fibrillation and Heart Failure?

In patients with atrial fibrillation (AF) and heart failure (HF) with or without systolic dysfunction, either rhythm control or rate control is an acceptable primary therapeutic option. If a rate control strategy is chosen, treatment with a beta-blocker is almost always required to achieve rate control. Adequate ventricular rate control is usually a resting rate of less than 100 beats per minute, but lower resting rates may be appropriate. Non-dihydropyridine calcium channel blockers are often contraindicated when AF is associated with HF with systolic dysfunction. There have been recent debates on a possible reduced efficacy of beta-blockers as well as safety issues with digoxin when treating HF patients with AF. The benefit of beta-blockers on survival may be lower in patients with HF with reduced ejection fraction when AF is present. Digoxin does not improve survival but may help to obtain satisfactory rate control in combination with a beta-blocker. Digoxin may be useful in the presence of hypotension or an absolute contraindication to beta-blocker treatment.

Digoxin Use to Control Ventricular Rate in Patients with Atrial Fibrillation and Heart Failure Is Not Associated with Increased Mortality

Introduction. Digoxin is used to control ventricular rate in atrial fibrillation (AF). There is conflicting evidence regarding safety of digoxin. We aimed to evaluate the risk of mortality with digoxin use in patients with AF using meta-analyses. Methods. PubMed was searched for studies comparing outcomes of patients with AF taking digoxin versus no digoxin, with or without heart failure (HF). Studies were excluded if they reported only a point estimate of mortality, duplicated patient populations, and/or did not report adjusted hazard ratios (HR). The primary endpoint was all-cause mortality. Adjusted HRs were combined using generic inverse variance and log hazard ratios. A multivariate metaregression model was used to explore heterogeneity in studies. Results. Twelve studies with 321,944 patients were included in the meta-analysis. In all AF patients, irrespective of heart failure status, digoxin is associated with increased all-cause mortality (HR [1.23], 95% confidence interval [CI] 1.16-1.31). However, digoxin is not associated with increased mortality in patients with AF and HF (HR [1.08], 95% CI 0.99-1.18). In AF patients without HF digoxin is associated with increased all-cause mortality (HR [1.38], 95% CI 1.12-1.71). Conclusion. In patients with AF and HF, digoxin use is not associated with an increased risk of all-cause mortality when used for rate control.

Comorbidity of atrial fibrillation and heart failure

Atrial fibrillation (AF) and heart failure (HF) are evolving epidemics, together responsible for substantial human suffering and health-care expenditure. Ageing, improved cardiovascular survival, and epidemiological transition form the basis for their increasing global prevalence. Although we now have a clear picture of how HF promotes AF, gaps remain in our knowledge of how AF exacerbates or even causes HF, and how the development of HF affects the outcome of patients with AF. New data regarding HF with preserved ejection fraction and its unique relationship with AF suggest a possible role for AF in its aetiology, possibly as a trigger for ventricular fibrosis. Deciding on optimal treatment strategies for patients with both AF and HF is increasingly difficult, given that results from trials of pharmacological rhythm control are arguably obsolete in the age of catheter ablation. Restoring sinus rhythm by catheter ablation seems successful in the medium term and improves HF symptoms, functional capacity, and left ventricular function. Long-term studies to examine the effect on rates of stroke and death are ongoing. Guidelines continue to evolve to keep pace with this rapidly changing field.

Increased All-Cause Mortality Associated With Digoxin Therapy in Patients With Atrial Fibrillation: An Updated Meta-Analysis

Digoxin is still commonly used in atrial fibrillation (AF) patients with and without heart failure (HF) for heart rate control. Studies concerning the detrimental effects of digoxin therapy in AF patients are inconsistent. This updated meta-analysis examined the association of digoxin therapy with all-cause mortality in AF patients, stratified by heart function status. We included observational studies with multivariate-adjusted data on digoxin and all-cause mortality in the analysis. The relative risks (RRs) of all-cause mortality were calculated and reported with 95% confidence intervals (95% CIs). Seventeen studies comprising 408,660 patients were included. Overall, in AF patients, digoxin treatment was associated with a significant increase in all-cause mortality after multivariate-adjustment (RR = 1.22; 95% CI 1.15-1.30). When stratified by heart function status, digoxin treatment was associated with a 14% increase in all-cause mortality in AF patients with HF (RR = 1.14, 95% CI 1.04-1.24), and a 36% increase in those without HF (RR = 1.36, 95% CI 1.18-1.56). The increased risk of all-cause mortality was significantly higher in AF patients without HF compared with those with HF (P for interaction = 0.04). This meta-analysis demonstrates that digoxin therapy was associated with a significant increase in all-cause mortality in AF patients, especially in those without HF. Given other available options, digoxin should be avoided as a first-line agent for heart rate control in AF patients.

Digoxin: A systematic review in atrial fibrillation, congestive heart failure and post myocardial infarction

AIM

To review digoxin use in systolic congestive heart failure, atrial fibrillation, and after myocardial infarction.

METHODS

A comprehensive PubMed search was performed using the key words "digoxin and congestive heart failure", "digoxin and atrial fibrillation", "digoxin, atrial fibrillation and systolic congestive heart failure", and "digoxin and myocardial infarction". Only articles written in English were included in this study. We retained studies originating from randomized controlled trials, registries and included at least 500 patients. The studies included patients with atrial fibrillation or heart failure or myocardial infarction and had a significant proportion of patients (at least 5%) on digoxin. A table reviewing the different hazard ratios was developed based on the articles selected. Our primary endpoint was the overall mortality in the patients on digoxin vs those without digoxin, among patients with atrial fibrillation and also among patients with atrial fibrillation and systolic heart failure. We reviewed the most recent international guidelines to discuss current recommendations.

RESULTS

A total of 18 studies were found that evaluated digoxin and overall mortality in different clinical settings including systolic congestive heart failure and normal sinus rhythm (n = 5), atrial fibrillation with and without systolic congestive heart failure (n = 9), and myocardial infarction (n = 4). Overall, patients with systolic congestive heart failure with normal sinus rhythm, digoxin appears to have a neutral effect on mortality especially if close digoxin level monitoring is employed. However, most of the observational studies evaluating digoxin use in atrial fibrillation without systolic congestive heart failure showed an increase in overall mortality when taking digoxin. In the studies evaluated in this systematic review, the data among patients with atrial fibrillation and systolic congestive heart failure, as well as post myocardial infarction were more controversial. The extent to which discrepancies among studies are based on statistical methods is currently unclear, as these studies' findings are generated by retrospective analyses that employed different techniques to address confounding.

CONCLUSION

Based on the potential risks and benefits, as well as the presence of alternative drugs, there is a limited role for digoxin in the management of patients with normal sinus rhythm and congestive heart failure. Based on the retrospective studies reviewed there is a growing volume of data showing increased mortality in those with only atrial fibrillation. The proper role of digoxin is, however, less certain in other subgroups of patients, such as those with both atrial fibrillation and systolic congestive heart failure or after a myocardial infarction. Further studies may provide helpful information for such subgroups of patients.

Impact of Digoxin on Mortality in Patients With Atrial Fibrillation Stratified by Heart Failure: Findings From Gulf Survey of Atrial Fibrillation Events in the Middle East

OBJECTIVE

The use of digoxin in patients having atrial fibrillation (AF) with or without heart failure (HF) is not without controversy. The aim of this study was to examine the impact of digoxin therapy on mortality stratified by HF.

METHODS

Gulf Survey of Atrial Fibrillation Events was a prospective, multinational, observational registry of consecutive patients with AF recruited from the emergency department of 23 hospitals in 6 countries in the Middle East. Patients were recruited between October 2009 and June 2010 and followed up for 1 year after enrollment. Analyses were performed using univariate and multivariate statistical techniques.

RESULTS

The study included a total of 1962 patients with AF, with an overall mean age of 56 ± 16 years, and 52% (n = 1026) were males. At hospital discharge, digoxin was prescribed in 36% (n = 709) of the patients, whereas HF was present in 27% (n = 528) of the cohort. A total of 225 (12.1%) patients died during the 12-month follow-up period after discharge (5.3% [n = 104] were lost to follow-up). Patients with HF were consistently associated with higher mortality at 1 month (5.1% vs 2.1%; P < .001), 6 months (17.2% vs 5.0%; P < 0.001), and 12 months (24.3% vs 7.6%; P < .001) when compared to those without HF. When stratified by HF, digoxin therapy was associated with significantly higher mortality in those without HF at 6 months (8.7% vs 3.7%; adjusted odds ratio (aOR), 5.07; P < .001) and 12 months (12.3% vs 6.0%; aOR, 4.22; P < .001) but not in those with HF (6 months: 18.6% vs 14.7%; aOR, 1.62; P = .177 and 12 months: 25.4% vs 22.4%; aOR, 1.37; P = .317).

CONCLUSIONS

In patients with AF and HF, digoxin did not offer any survival advantages. However, in those without HF, digoxin therapy was, in fact, associated with significantly higher long-term mortality.

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 use in patients with atrial fibrillation and adverse cardiovascular outcomes: a retrospective analysis of the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF)

BACKGROUND

Digoxin is a widely used drug for ventricular rate control in patients with atrial fibrillation (AF), despite a scarcity of randomised trial data. We studied the use and outcomes of digoxin in patients in the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF).

METHODS

For this retrospective analysis, we included and classified patients from ROCKET AF on the basis of digoxin use at baseline and during the study. Patients in ROCKET AF were recruited from 45 countries and had AF and risk factors putting them at moderate-to-high risk of stroke, with or without heart failure. We used Cox proportional hazards regression models adjusted for baseline characteristics and drugs to investigate the association of digoxin with all-cause mortality, vascular death, and sudden death. ROCKET AF was registered with ClinicalTrials.gov, number NCT00403767.

FINDINGS

In 14,171 randomly assigned patients, digoxin was used at baseline in 5239 (37%). Patients given digoxin were more likely to be female (42% vs 38%) and have a history of heart failure (73% vs 56%), diabetes (43% vs 38%), and persistent AF (88% vs 77%; p<0·0001 for each comparison). After adjustment, digoxin was associated with increased all-cause mortality (5·41 vs 4·30 events per 100 patients-years; hazard ratio 1·17; 95% CI 1·04-1·32; p=0·0093), vascular death (3·55 vs 2·69 per 100 patient-years; 1·19; 1·03-1·39, p=0·0201), and sudden death (1·68 vs 1·12 events per 100 patient-years; 1·36; 1·08-1·70, p=0·0076).

INTERPRETATION

Digoxin treatment was associated with a significant increase in all-cause mortality, vascular death, and sudden death in patients with AF. This association was independent of other measured prognostic factors, and although residual confounding could account for these results, these data show the possibility of digoxin having these effects. A randomised trial of digoxin in treatment of AF patients with and without heart failure is needed.

FUNDING

Janssen Research & Development and Bayer HealthCare AG.

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.

Meta-analysis of digoxin use and risk of mortality in patients with atrial fibrillation

There is an ongoing debate on the safety of digoxin use in patients with atrial fibrillation (AF). To address this issue, the investigators assembled a synthesis of the available evidence on the relation between digoxin and all-cause mortality in patients with AF. PubMed and the Embase database were systematically searched to identify all eligible studies examining the association between digoxin use and the mortality risk in AF. Overall hazard ratios and 95% confidence intervals were calculated using the random-effects model. Eleven observational studies were identified that met the inclusion criteria, 5 of which additionally used propensity score matching for statistical adjustment. In total, 318,191 patients were followed up for a mean of 2.8 years. Overall, digoxin use was associated with a 21% increased risk for mortality (hazard ratio 1.21, 95% confidence interval 1.12 to 1.30). Sensitivity analyses found the results to be robust. In the propensity score-matched AF patients, digoxin use was associated with a 17% greater risk for mortality (hazard ratio 1.17, 95% confidence interval 1.13 to 1.22). When the AF cohort was grouped into patients with and without heart failure, the use of digoxin was associated with an increase in mortality in patients with and those without heart failure, and no significant heterogeneity was seen between the groups (p >0.10). In conclusion, the results suggest that digoxin use was associated with a greater risk for mortality in patients with AF, regardless of concomitant heart failure. A well-powered randomized trial is necessary to reveal the true effect of digoxin.

Digoxin and risk of death in adults with atrial fibrillation: the ATRIA-CVRN study

BACKGROUND

Digoxin remains commonly used for rate control in atrial fibrillation, but limited data exist supporting this practice and some studies have shown an association with adverse outcomes. We examined the independent association between digoxin and risks of death and hospitalization in adults with incident atrial fibrillation and no heart failure.

METHODS AND RESULTS

We performed a retrospective cohort study of 14,787 age, sex, and high-dimensional propensity score-matched adults with incident atrial fibrillation and no previous heart failure or digoxin use in the AnTicoagulation and Risk factors In Atrial fibrillation-Cardiovascular Research Network (ATRIA-CVRN) study within Kaiser Permanente Northern and Southern California. We examined the independent association between newly initiated digoxin and the risks of death and hospitalization using extended Cox regression. During a median 1.17 (interquartile range, 0.49-1.97) years of follow-up among matched patients with atrial fibrillation, incident digoxin use was associated with higher rates of death (8.3 versus 4.9 per 100 person-years; P<0.001) and hospitalization (60.1 versus 37.2 per 100 person-years; P<0.001). Incident digoxin use was independently associated with a 71% higher risk of death (hazard ratio, 1.71; 95% confidence interval, 1.52-1.93) and a 63% higher risk of hospitalization (hazard ratio, 1.63; 95% confidence interval, 1.56-1.71). Results were consistent in subgroups of age and sex and when using intent-to-treat or on-treatment analytic approaches.

CONCLUSIONS

In adults with atrial fibrillation, digoxin use was independently associated with higher risks of death and hospitalization. Given other available rate control options, digoxin should be used with caution in the management of atrial fibrillation.

Digoxin treatment is associated with increased total and cardiovascular mortality in anticoagulated patients with atrial fibrillation

BACKGROUND

Some evidences suggest that the use of digoxin may be harmful inatrial fibrillation (AF) patients. The aim of the study was to investigate in a "real world" of AF patients receiving vitamin K antagonists (VKAs), the relationship between digoxin use and mortality.

METHODS

Prospective single-center observational study including 815 consecutive non-valvular AF patients treated with VKAs. Total mortality was the primary outcome of the study. We also performed a sub-analysis considering only cardiovascular (CV) deaths. Time in therapeutic range (TTR) was used for anticoagulation quality.

RESULTS

Median follow-up was 33.2months (2460 person-years); 171 (21.0%) patients were taking digoxin. Compared to those without, patients on digoxin were older (p=0.007), with a clinical history of HF (p<0.001) and at higher risk of thromboembolic events (p<0.001). No difference in TTR between the two groups was registered (p=0.598). During the follow-up, 85 deaths occurred: 47 CV and 38 non-CV deaths; 35 deaths occurred in digoxin users (20.6%). A significant increased rate of total mortality was observed in digoxin-treated patients (p<0.001). Multivariable analysis showed that digoxin was associated with total mortality (hazard ratio [HR]: 2.224, p<0.001) and CV death (HR: 4.686, p<0.001). A propensity score-matched analysis confirmed that digoxin was associated with total mortality (HR: 2.073, p=0.0263) and CV death (HR: 4.043, p=0.004).

CONCLUSIONS

In AF patients on good anticoagulation control with VKAs, digoxin use was associated with a higher rate of total and CV mortality.

Interaction between digoxin and dronedarone in the PALLAS trial

BACKGROUND

Elevated serum digoxin concentration can cause toxicity, including death. Dronedarone increases digoxin concentration by P-glycoprotein interaction. In Permanent Atrial Fibrillation Outcome Study Using Dronedarone On Top Of Standard Therapy Trial (PALLAS), dronedarone was associated with both increased cardiovascular death and heart failure in patients with permanent atrial fibrillation. The present analysis examines whether the dronedarone-digoxin interaction might explain these adverse outcomes.

METHODS AND RESULTS

Subgroup analysis was performed to compare outcomes of patients on digoxin at baseline or not. In PALLAS, 1619 patients were randomized to dronedarone and 1617 to placebo, of whom 544 (33.6%) and 526 (32.5%) were receiving digoxin, respectively. Median (Q1,Q3) digoxin serum concentration on day 7 was 1.1 (0.7,1.5) ng/mL on dronedarone and 0.7 (0.5,1.1) ng/mL on placebo (P<0.001). Among patients on digoxin, there were 15 (8.6%/year) cardiovascular deaths on dronedarone and 2 (1.2%/year) on placebo (adjusted hazard ratio, 7.31; 95% confidence interval, 1.66-32.20; P=0.009). Among patients not on digoxin, there were 6 cardiovascular deaths on dronedarone (1.7%/year) and 8 on placebo (2.2%/year; adjusted hazard ratio, 0.67; 95% confidence interval, 0.23-1.95; P=0.46; interaction P value 0.01). In patients on digoxin, there were 11 arrhythmic deaths on dronedarone and none on placebo; and in patients not on digoxin, there were 2 arrhythmic deaths on dronedarone and 4 on placebo (P value for interaction 0.002). There was no interaction between baseline digoxin use and the adverse effect of dronedarone on heart failure events.

CONCLUSIONS

In PALLAS, there was a strong effect of concurrent digoxin use on the adverse effect of dronedarone on cardiovascular death, but not on occurrence of heart failure.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT01151137.

Increased mortality associated with digoxin in contemporary patients with atrial fibrillation: findings from the TREAT-AF study

BACKGROUND

Despite endorsement of digoxin in clinical practice guidelines, there exist limited data on its safety in atrial fibrillation/flutter (AF).

OBJECTIVES

The goal of this study was to evaluate the association of digoxin with mortality in AF.

METHODS

Using complete data of the TREAT-AF (The Retrospective Evaluation and Assessment of Therapies in AF) study from the U.S. Department of Veterans Affairs (VA) healthcare system, we identified patients with newly diagnosed, nonvalvular AF seen within 90 days in an outpatient setting between VA fiscal years 2004 and 2008. We used multivariate and propensity-matched Cox proportional hazards to evaluate the association of digoxin use with death. Residual confounding was assessed by sensitivity analysis.

RESULTS

Of 122,465 patients with 353,168 person-years of follow-up (age 72.1 ± 10.3 years, 98.4% male), 28,679 (23.4%) patients received digoxin. Cumulative mortality rates were higher for digoxin-treated patients than for untreated patients (95 vs. 67 per 1,000 person-years; p < 0.001). Digoxin use was independently associated with mortality after multivariate adjustment (hazard ratio [HR]: 1.26, 95% confidence interval [CI]: 1.23 to 1.29, p < 0.001) and propensity matching (HR: 1.21, 95% CI: 1.17 to 1.25, p < 0.001), even after adjustment for drug adherence. The risk of death was not modified by age, sex, heart failure, kidney function, or concomitant use of beta-blockers, amiodarone, or warfarin.

CONCLUSIONS

Digoxin was associated with increased risk of death in patients with newly diagnosed AF, independent of drug adherence, kidney function, cardiovascular comorbidities, and concomitant therapies. These findings challenge current cardiovascular society recommendations on use of digoxin in AF.

Digoxin in patients with permanent atrial fibrillation: data from the RACE II study

BACKGROUND

The Atrial Fibrillation Follow-up Investigation of Rhythm Management trial showed that digoxin was associated with increased mortality in patients with atrial fibrillation.

OBJECTIVES

To assess the association of digoxin with cardiovascular (CV) morbidity and mortality in patients with permanent atrial fibrillation enrolled in the Dutch Rate Control Efficacy in Permanent AF: A Comparison Between Lenient Versus Strict Rate Control II trial as well as to assess the role of digoxin to achieve heart rate targets.

METHODS

The primary outcome was a composite of CV morbidity and mortality. Secondary outcomes included CV hospitalization and all-cause mortality or heart failure (HF) hospitalization. Of the 614 patients, 608 (99%) completed the dose-adjustment phase. Outcome events were analyzed from the end of the dose-adjustment phase until the end of follow-up. The median follow-up period was 2.9 years (interquartile range 2.7-3.0 years).

RESULTS

In total, 284 patients (46.7%) used digoxin after the dose-adjustment phase (median dosage 0.250 mg; interquartile range 0.0625-0.750 mg). These patients were more often women, previously admitted for HF, had an increased left ventricular end-systolic diameter, and more often randomized to strict rate control. By using Cox proportional hazards regression analysis, the use of digoxin was not associated with an increased risk for the primary and secondary outcomes. For the primary outcome, the 3-year estimated cumulative incidence was 12.9% vs 13.4% in the digoxin group vs the no-digoxin group (unadjusted hazard ratio [HR] 0.97; 95% confidence interval [CI] 0.62-1.52). Incidence was 19.4% vs. 19.5% for CV hospitalization (unadjusted HR 1.00; 95% CI 0.69-1.45) and 6.6% vs. 9.9% for all-cause mortality or HF hospitalization (unadjusted HR 0.62; 95% CI 0.34-1.13) in the digoxin group vs the no-digoxin group.

CONCLUSION

The use of digoxin was not associated with increased morbidity and mortality.

Outcomes of a contemporary sample of patients with atrial fibrillation taking digoxin: results from the AFBAR study

INTRODUCTION AND OBJECTIVES

We aimed to assess and compare the effect of digoxin on clinical outcomes in patients with atrial fibrillation vs those under beta-blockers or none of these drugs.

METHODS

AFBAR is a prospective registry study carried out by a team of primary care physicians (n=777 patients). Primary endpoints were survival, survival free of admission due to any cause, and survival free of admission due to cardiovascular causes. The mean follow up was 2.9 years. Four groups were analyzed: patients receiving digoxin, beta-blockers, or digoxin plus beta-blockers, and patients receiving none of these drugs.

RESULTS

Overall, 212 patients (27.28%) received digoxin as the only heart control strategy, 184 received beta-blockers (23.68%), 58 (7.46%) were administered both, and 323 (41.57%) received none of these drugs. Digoxin was not associated with all-cause mortality (estimated hazard ratio=1.42; 95% confidence interval, 0.77-2.60; P=.2), admission due to any cause (estimated hazard ratio=1.03; 95% confidence interval, 0.710-1.498; P=.8), or admission due to cardiovascular causes (estimated hazard ratio=1.193; 95% confidence interval, 0.725-1.965; P=.4). No association was found between digoxin use and all-cause mortality, admission due to any cause, or admission due to cardiovascular causes in patients without heart failure. There was no interaction between digoxin use and sex in all-cause mortality or in survival free of admission due to any cause. However, an association was found between sex and admission due to cardiovascular causes.

CONCLUSIONS

Digoxin was not associated with increased all-cause mortality, survival free of admission due to any cause, or admission due to cardiovascular causes, regardless of underlying heart failure.

Does digoxin increase the risk of ischemic stroke and mortality in atrial fibrillation? A nationwide population-based cohort study

BACKGROUND

Digoxin and related cardiac glycosides have been used for almost 100 years in atrial fibrillation (AF). However, 2 recent analyses of the Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) trial showed inconsistent results regarding the risk of mortality associated with digoxin use. The goal of the present study was to investigate the relationship between digoxin and the risk of ischemic stroke and mortality in Asians.

METHODS

This study used the National Health Insurance Research Database (NHIRD) in Taiwan. A total of 4781 patients with AF who did not receive any antithrombotic therapy were selected as the study population. Among the study population, 829 participants (17.3%) received the digoxin treatment. The risk of ischemic stroke and mortality in patients who received digoxin and those who did not was compared.

RESULTS

The use of digoxin was associated with an increased risk of clinical events, with an adjusted hazard ratio of 1.41 (95% confidence interval [CI], 1.17-1.70) for ischemic stroke and 1.21 (95% CI, 1.01-1.44) for all-cause mortality. In the subgroup analysis based on coexistence with heart failure or not, digoxin was a risk factor for adverse events in patients without heart failure but not in those with heart failure (interaction P < 0.001 for either end point). Among patients with AF without heart failure, the use of β-blockers was associated with better survival, with an adjusted hazard ratio of 0.48 (95% CI, 0.34-0.68).

CONCLUSIONS

Digoxin should be avoided for patients with AF without heart failure because it was associated with an increased risk of clinical events. β-Blockers may be a better choice for controlling ventricular rate in these patients.

Comparative effectiveness of antiarrhythmic drugs on cardiovascular hospitalization and mortality in atrial fibrillation

AIM

To assess, through a systematic review, evidence for the effects of antiarrhythmic drugs (AADs) on cardiovascular (CV) hospitalization and mortality.

MATERIALS & METHODS

English language articles were identified using MEDLINE, EMBASE and the Cochrane Clinical Trial Registry and were screened for study applicability and methodological quality.

RESULTS

Out of 3526 identified studies, 38 were selected for analysis (19 evaluated individual AADs, 13 compared rate- versus rhythm-control strategies, and 6 evaluated multiple AADs but did not report outcomes for individual agents). None of the studies examining individual AADs employed the CV hospitalization end point used in ATHENA (the reference trial). There were no head-to-head comparisons of individual AADs on CV hospitalization. Most high-quality studies used multidrug rate- versus rhythm-control strategies.

CONCLUSION

Assessment of the comparative effectiveness of individual AADs on CV hospitalization and mortality end points is not possible with the current evidence.

Ventricular rate control of atrial fibrillation in heart failure

In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the indications; the optimal ventricular rate-control target, including detailed results of the Rate Control Efficacy in Permanent Atrial Fibrillation: a Comparison Between Lenient versus Strict Rate Control II (RACE II) study; and the pharmacologic and nonpharmacologic options to control the ventricular rate during AF in the setting of HF.

Digoxin - time to take the gloves off?

Digoxin has been used for hundreds of years to aid rate control in atrial fibrillation and as a positive inotrope in heart failure. Our familiarity with digoxin has allowed it to become easily prescribed even though there are data suggesting that use of digoxin may in fact result in increased mortality and pro-arrhythmia. Within this review we explain some of the outcome data associated with digoxin use to determine if it is time to take the gloves off and examine if we should still be using this drug in the 21st century.

Genetics of atrial fibrillation and possible implications for ischemic stroke

Atrial fibrillation is the most common cardiac arrhythmia mainly caused by valvular, ischemic, hypertensive, and myopathic heart disease. Atrial fibrillation can occur in families suggesting a genetic background especially in younger subjects. Additionally recent studies have identified common genetic variants to be associated with atrial fibrillation in the general population. This cardiac arrhythmia has important public health implications because of its main complications: congestive heart failure and ischemic stroke. Since atrial fibrillation can result in ischemic stroke, one might assume that genetic determinants of this cardiac arrhythmia are also implicated in cerebrovascular disease. Ischemic stroke is a multifactorial, complex disease where multiple environmental and genetic factors interact. Whether genetic variants associated with a risk factor for ischemic stroke also increase the risk of a particular vascular endpoint still needs to be confirmed in many cases. Here we review the current knowledge on the genetic background of atrial fibrillation and the consequences for cerebrovascular disease.