Increased mortality among patients taking digoxin--analysis from the AFFIRM study

Implications of Atrial Fibrillation for Guideline-Directed Therapy in Patients With Heart Failure: JACC State-of-the-Art Review

Atrial fibrillation (AF) and heart failure (HF) are common cardiovascular conditions that frequently coexist. Among patients with HF, more than one-half also have AF. Both are associated with significant morbidity and mortality. Moreover, the prevalence of each is increasing globally, and this trend is expected to continue owing to an aging population and increased life expectancy. Diagnosis of AF in a patient with HF is associated with greater symptom burden, more frequent hospitalizations, and a worse prognosis. Guideline-directed medical therapy (GDMT) for HF can affect the incidence of AF. Once present, AF can influence the efficacy of some components of GDMT for HF. In this review, we discuss the effect of GDMT for HF across the spectrum of ejection fraction on prevention of AF as well as the benefit of GDMT in patients with vs without AF.

Patterns of Digoxin Prescribing for Medicare Beneficiaries in the United States 2013-2019

Background

Studies show that digoxin use is declining but is still prevalent. Recent data on digoxin prescription and characteristics of digoxin prescribers are unknown, which can help understand its contemporary use.

Methods

Using Medicare Part D data from 2013 to 2019, we studied the change in number and proportion of digoxin prescriptions and digoxin prescribers, overall and by specialty. Using logistic regression, we identified prescriber characteristics associated with digoxin prescription.

Results

From 2013 to 2019, total digoxin prescriptions (4.6 to 1.8 million) and proportion of digoxin prescribers decreased (9.1% to 4.3% overall; 26.6% to 11.8% among General Medicine prescribers and 65.4% to 48.9% among Cardiology). Of digoxin prescribers from 2013 practicing in 2019 (91.2% remained active), 59.1% did not prescribe digoxin at all, 31.7% reduced, and 9.2% maintained or increased prescriptions. The proportion of all digoxin prescriptions that were prescribed by General Medicine prescribers declined from 59.7% to 48.2% and increased for Cardiology (29% to 38.5%). Among new prescribers in 2019 (N = 85,508), only 1.9% prescribed digoxin. Digoxin prescribers when compared to non-digoxin prescribers were more likely male, graduated from medical school earlier, were located in the Midwest or South, and belonged to Cardiology (all P < .001).

Conclusions

Digoxin prescriptions continue to decline with over half of 2013 prescribers no longer prescribing digoxin in 2019. This may be a result of the increasing availability of newer heart failure therapies. The decline in digoxin prescription was greater among general medicine physicians than cardiologists, suggesting a change in digoxin use to a medication prescribed increasingly by specialists.

Modelling anticoagulation and health-related quality of life in those with atrial fibrillation: a secondary analysis of AFFIRM

Associations of anticoagulation with primary endpoints in longitudinal studies are impacted by selection bias and time-varying covariates (e.g. comorbidities). We demonstrate how time-varying covariates and selection bias influence association estimates between anticoagulation and health-related quality of life (HRQoL) in patients with atrial fibrillation. We performed a secondary analysis of the Atrial Fibrillation Follow-up Investigation of Rhythm Management trial quality of life substudy. Dichotomized warfarin use was ascertained at the study baseline, 2 months later, and annually for up to 6 years. HRQoL was measured at every time point using a self-reported ordinal 5-point Likert-scale (lower score and lower odds ratio represents better health-related quality of life). Static and time-varying covariates were ascertained throughout the study period. Confounder-adjusted generalized mixed model and generalized estimating equation regressions were used to demonstrate traditional association estimates between anticoagulation and HRQoL. Inverse probability of treatment and censorship weights were used to ascertain the influence of time-varying confounding and selection bias. Age-stratified analysis (age ≥ 70 years) evaluated for effect modification. 656 individuals were included in the analysis, 601 on warfarin at baseline. The association of warfarin use with better HRQoL over time strengthened when accounting for time-varying confounding and selection bias (OR 0.30, 95% CI 0.14-0.55) compared to traditional analyses (OR 0.61, 95% CI 0.38-0.97), and was most pronounced in those ≥ 70 years upon stratified analysis. Anticoagulation is associated with higher HRQoL in patients with atrial fibrillation, with time-varying confounding and selection bias likely influencing longitudinal estimates in anticoagulation-HRQoL research.

Evaluation of Safety and Efficacy of Intravenous Digoxin Loading Doses Based on Ideal Body Weight

BACKGROUND

Intravenous digoxin loading dose recommendations differ between clinical guidelines and Food and Drug Administration packaging for acute rate control.

OBJECTIVE

The objective of this study was to assess the safety and efficacy of intravenous digoxin loading in patients who received ≤12 µg/kg and >12 µg/kg of digoxin using ideal body weight (IBW).

METHODS

This single center retrospective cohort study with exempt status from the local Institutional Review Board included patients who received intravenous digoxin and had a serum digoxin concentration (SDC) drawn. Digoxin doses >36 hours after the first dose were excluded. Patients who received a total of >12 µg/kg and ≤12 µg/kg IBW were compared. The primary endpoint was frequency of SDCs ≥1.2 ng/mL, which have been shown to be associated with increased mortality.

RESULTS

A total of 244 patients were included (144 receiving >12 µg/kg and 100 receiving ≤12 µg/kg). There were significantly more SDC ≥1.2 ng/mL in the >12 µg/kg group than the ≤12 µg/kg group (50.6% vs. 30.0%; adjusted odds ratio, 3.19; 95% confidence interval [CI]: 1.79-5.84), with no difference in rate control failure. Major limitations of the study include retrospective nature and possible selection bias.

CONCLUSION AND RELEVANCE

Compared to patients who received digoxin doses ≤12 µg/kg IBW, patients who received >12 µg/kg IBW had higher rates of SDC ≥1.2 ng/mL. This suggests that appropriate weight-based dosing with 8 to 12 µg/kg IBW has the potential to be a safer approach to digoxin loading, rather than frequently used dosing strategies that result in doses >12 µg/kg.

A stepwise external cardioversion protocol for atrial fibrillation to maximize acute success rate

AIMS

Cardioversion is a very commonly performed procedure for persistent atrial fibrillation (AF). However, there is no well-defined protocol to address failed external electrical direct current cardioversion. The aim of the study is to test the efficacy of a pre-defined stepwise cardioversion protocol for patients with persistent AF of ≤12 months. Success was the achievement of sinus rhythm.

METHODS AND RESULTS

The study population included patients with persistent AF of ≤12 months duration requiring rhythm management. Patients were offered cardioversion using a pre-defined stepwise protocol using different electrode placement locations, applying compression at end of expiration, and higher energy delivered simultaneously through two defibrillators. : A total of 414 patients were included in the study, of which 362 (87.4%) required a single successful cardioversion. The remaining 52 (12.5%) patients required additional cardioversion attempts using the stepwise cardioversion protocol with an overall success rate of 99.3%. Two simultaneous defibrillators were required in 14 patients (3.4%). Patients with multiple cardioversions (13.5%) experienced more local skin irritation and pain compared with patients with single cardioversion (13.5% vs. 3.5%, P = 0.004). The predictor for the need for multiple cardioversion attempts is high body mass index, while high transthoracic impedance is associated with failed cardioversion. No major complications were observed during the study.

CONCLUSION

The stepwise cardioversion protocol has a high success rate of >99% and can be safely performed in outpatient or inpatient settings.

Digitalis therapy in patients with ventricular tachyarrhythmias

Objective. The study sought to assess the prognostic value of treatment with digitalis on long-term prognosis in patients with ventricular tachyarrhythmias and atrial fibrillation (AF) and/or heart failure (HF). Background. Data regarding the outcome of digitalis therapy following ventricular tachyarrhythmias is limited. Methods. A large retrospective registry was used including consecutive patients with episodes of ventricular tachycardia (VT) or fibrillation (VF) from 2002 to 2015. Patients treated with digitalis were compared to patients without. The primary prognostic endpoint was all-cause mortality at 3 years, secondary endpoints comprised a composite arrhythmic endpoint (i.e. recurrences of ventricular tachyarrhythmias, appropriate implantable cardioverter defibrillator (ICD) therapies, sudden cardiac death) and cardiac rehospitalization. Kaplan Mayer survival curves, multivariable cox regression, and time trend analyses were applied for statistics. Results. Eight hundred and thirty-one patients were included (20% treated with digitalis and 80% without). At 3 years, digitalis treatment was not associated with all-cause mortality following ventricular tachyarrhythmias (24 vs. 21%, log-rank p = .736; HR = 1.063; 95% CI 0.746-1.515; p = .736). However, digitalis therapy was associated with an increased risk of the composite arrhythmic endpoint (38 vs. 23%; log-rank p = .001; HR = 1.719; 95% CI 1.279-2.311; p = .001) and cardiac rehospitalization (31 vs. 18%; log-rank p = .001; HR = 1.829; 95% CI 1.318-2.538; p = .001), which was still evident within multivariable Cox regression analyses. Finally, digitoxin may be associated with a worse prognosis than digoxin. Conclusion. Digitalis therapy was not associated with mortality in patients with ventricular tachyarrhythmias, but with increased risk of the composite arrhythmic endpoint and cardiac rehospitalization at 3 years.

Effectiveness of early rhythm control in improving clinical outcomes in patients with atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Current guidelines recommend rhythm control for improving symptoms and quality of life in symptomatic patients with atrial fibrillation (AF). However, the long-term prognostic outcomes of rhythm control compared with rate control are still inconclusive. In this meta-analysis, we aimed to assess the effects of early rhythm control compared with rate control on clinical outcomes in newly diagnosed AF patients.

METHODS

We systematically searched the PubMed and Embase databases up to August 2022 for randomized and observational studies reporting the associations of early rhythm control (defined as within 12 months of AF diagnosis) with effectiveness outcomes. The primary outcome was a composite of death, stroke, admission to hospital for heart failure (HF), or acute coronary syndrome (ACS). Hazard ratios (HRs) and 95% confidence intervals (CIs) from each study were pooled using a random-effects model, complemented with an inverse variance heterogeneity or quality effects model.

RESULTS

A total of 8 studies involving 447,202 AF patients were included, and 23.5% of participants underwent an early rhythm-control therapy. In the pooled analysis using the random-effects model, compared with rate control, the early rhythm-control strategy was significantly associated with reductions in the primary composite outcome (HR = 0.88, 95% CI: 0.86-0.89) and secondary outcomes, including stroke or systemic embolism (HR = 0.78, 95% CI: 0.71-0.85), ischemic stroke (HR = 0.81, 95% CI: 0.69-0.94), cardiovascular death (HR = 0.83, 95% CI: 0.70-0.99), HF hospitalization (HR = 0.90, 95% CI: 0.88-0.92), and ACS (HR = 0.86, 95% CI: 0.76-0.98). Reanalyses using the inverse variance heterogeneity or quality effects model yielded similar results.

CONCLUSIONS

Our current meta-analysis suggested that early initiation of rhythm control treatment was associated with improved adverse effectiveness outcomes in patients who had been diagnosed with AF within 1 year.

REGISTRATION

The study protocol was registered to PROSPERO (CRD42021295405).

Racial, ethnic, and sex disparities in atrial fibrillation management: rate and rhythm control

BACKGROUND

Atrial fibrillation (AF) affects around 6 million Americans. AF management involves pharmacologic therapy and/or interventional procedures to control rate and rhythm, as well as anticoagulation for stroke prevention. Different populations may respond differently to distinct management strategies. This review will describe disparities in rate and rhythm control and their impact on outcomes among women and historically underrepresented racial and/or ethnic groups.

METHODS

This is a narrative review exploring the topic of sex and racial and/or ethnic disparities in rate and rhythm management of AF. We describe basic terminology, summarize AF epidemiology, discuss diversity in clinical research, and review landmark clinical trials.

RESULTS

Despite having higher rates of traditional AF risk factors, Black and Hispanic adults have lower risk of AF than non-Hispanic White (NHW) patients, although those with AF experience more severe symptoms and report lower quality-of-life scores than NHW patients with AF. NHW patients receive antiarrhythmic drugs, cardioversions, and invasive therapies more frequently than Black and Hispanic patients. Women have lower rates of AF than men, but experience more severe symptoms, heart failure, stroke, and death after AF diagnosis. Women and people from diverse racial and ethnic backgrounds are inadequately represented in AF trials; prevalence findings may be a result of underdetection.

CONCLUSION

Race, ethnicity, and gender are social determinants of health that may impact the prevalence, evolution, and management of AF. This impact reflects differences in biology as well as disparities in treatment and representation in clinical trials.

Pharmacologic Rate versus Rhythm Control for Atrial Fibrillation in Heart Failure Patients

Atrial fibrillation (AF) and Heart failure (HF) constitute two frequently coexisting cardiovascular diseases, with a great volume of the scientific research referring to strategies and guidelines associated with the best management of patients suffering from either of the two or both of these entities. The common pathophysiological paths, the adverse outcomes, the hospitalization rates, and the mortality rates that occur from various reports and trials indicate that a targeted therapy to the common background of these cardiovascular conditions may reverse the progression of their interrelating development. Among other optimal treatments concerning the prevalence of both AF and HF, the introduction of rhythm and rate control strategies in the guidelines has underlined the importance of sinus rhythm and heart rate control in the prevention of deleterious complications. The use of these strategies in the clinical practice has led to a debate about the superiority of rhythm versus rate control. The current guidelines as well as the published randomized trials and studies have not proved that rhythm control is more beneficial than the rate control treatments in the terms of survival, all-cause mortality, hospitalization rates, and quality of life. Therefore, the current therapeutic strategy is based on the therapy guidelines and the clinical judgment and experience. The aim of this review was to elucidate the endpoints of pharmacologic randomized clinical trials and the clinical data of each antiarrhythmic or rate-limiting medication, so as to promote their effective, individualized, evidence-based clinical use.

The need for increased pragmatism in cardiovascular clinical trials

The majority of cardiovascular randomized controlled trials (RCTs) test interventions in selected patient populations under explicitly protocol-defined settings. Although these ‘explanatory’ trial designs optimize conditions to test the efficacy and safety of an intervention, they limit the generalizability of trial findings in broader clinical settings. The concept of ‘pragmatism’ in RCTs addresses this concern by providing counterbalance to the more idealized situation underpinning explanatory RCTs and optimizing effectiveness over efficacy. The central tenets of pragmatism in RCTs are to test interventions in routine clinical settings, with patients who are representative of broad clinical practice, and to reduce the burden on investigators and participants by minimizing the number of trial visits and the intensity of trial-based testing. Pragmatic evaluation of interventions is particularly important in cardiovascular diseases, where the risk of death among patients has remained fairly stable over the past few decades despite the development of new therapeutic interventions. Pragmatic RCTs can help to reveal the ‘real-world’ effectiveness of therapeutic interventions and elucidate barriers to their implementation. In this Review, we discuss the attributes of pragmatism in RCT design, conduct and interpretation as well as the general need for increased pragmatism in cardiovascular RCTs. We also summarize current challenges and potential solutions to the implementation of pragmatism in RCTs and highlight selected ongoing and completed cardiovascular RCTs with pragmatic trial designs.

In this Review, Khan and colleagues discuss the benefits and challenges of including pragmatism in the design, conduct and interpretation of randomized controlled trials (RCTs) for cardiovascular disease and highlight selected ongoing and completed cardiovascular RCTs that incorporate a pragmatic design.

Most cardiovascular randomized controlled trials (RCTs) conducted to date have been ‘explanatory’, that is, designed to study the intervention in optimized conditions with selected patient populations and frequent protocolized assessments.

Although explanatory RCT designs increase validity, they limit the generalizability of trial findings, whereas a ‘pragmatic’ approach to RCTs yields findings more relevant to real-world practice.

In pragmatic RCTs, interventions are tested in patients who are broadly representative of the condition being studied, and the study is aligned with routine clinical care to reduce costs and organizational burden.

Although pragmatic RCTs tend to attenuate estimates of treatment effects, they do provide a more realistic understanding of population-level effectiveness and costs than explanatory trials.

Pragmatic trials can highlight barriers to the implementation of therapies and are better suited than explanatory RCTs to assessing the effects of implementation strategies and health-care policies at the population level.

Widespread implementation of pragmatic trials would require the development of technological infrastructure to collect and share data as well as regulatory guidelines amenable to findings derived from routinely collected data.

Digoxin Use in Atrial Fibrillation; Insights from National Ambulatory Medical Care Survey

OBJECTIVE

To evaluate the characteristics and trends of digoxin use during outpatient visits with atrial fibrillation in the US from 2006 to 2015.

METHODS

We conducted a retrospective analysis of adult (age ≥18) patient visits to office-based physicians from National Ambulatory Medical Care Survey (NAMCS) database between 2006-2015. The International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify patients with atrial fibrillation. Visits in which digoxin was listed as a medication were analyzed with descriptive statistics. Multivariable logistic regression analysis was used to identify the predictors of digoxin usage.

RESULTS

Of a weighted sample of 108,113,894 patient visits, 17,617,853 (16.3%) visits included use of digoxin. Patients who used digoxin had a mean age of 75 ± 0.7 years and were predominantly Caucasian (92.56%). Among the patients who used digoxin, 24% had a diagnosis of heart failure. Multivariate analysis showed that the increased likelihood of digoxin utilization was associated with female sex (adjusted odds ratio [aOR] 1.34, 95% CI 1.05-1.71, p = .019), heart failure (aOR 1.51, 95% CI 1.05-1.17, p = .025), and usage of ³5 medications (aOR 5.32, 95% CI 3.67-7.71, p = <0.001). Among the visits with atrial fibrillation, the percentage of visits with digoxin usage decreased from 23% in 2006 to 9% in 2013 and then again increased to 14% in 2015(P-trend <0.001).

CONCLUSION

This is the first study to examine the use of digoxin in atrial fibrillation patients in a large outpatient setting. During 2006-2015, the percentage of digoxin prescriptions in atrial fibrillation patients has declined. Predictors of digoxin use in atrial fibrillation patients are female sex, congestive heart failure, and higher number of concurrent medications.

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.

Digoxin use and clinical outcomes in elderly Chinese patients with atrial fibrillation: a report from the Optimal Thromboprophylaxis in Elderly Chinese Patients with Atrial Fibrillation (ChiOTEAF) registry

AIMS

Prior studies have reported conflicting results on digoxin's impact on clinical outcomes and quality of life, and there are limited data from Asia. The aim of this study is to evaluate the use of digoxin and its impact on clinical outcomes and quality of life in a high-risk cohort of elderly Chinese atrial fibrillation (AF) patients.

METHODS AND RESULTS

The Optimal Thromboprophylaxis in Elderly Chinese Patients with Atrial Fibrillation (ChiOTEAF) registry is a prospective, multicentre nationwide study conducted from October 2014 to December 2018. Endpoints of interest were the composite outcome of all-cause death/any thromboembolism (TE), all-cause death, cardiovascular death, sudden cardiac death, and TE events, as well as the quality of life. The eligible cohort for this analysis included 6391 individuals, of whom 751 (11.8%) patients were treated with digoxin. On multivariate analysis, the use of digoxin was associated with a higher odds ratio (OR) of composite outcome [OR: 1.71; 95% confidence interval (CI): 1.32-2.22], all-cause death (OR: 1.62; 95% CI: 1.23-2.14), and any TE (OR: 1.78; 95% CI: 1.08-2.95). Results were consistent in a subgroup of patients with diagnosed heart failure (HF) and patients with permanent AF. The use of digoxin was associated with worse health-related quality of life (mean EQ index: 0.76 ± 0.19 vs. 0.84 ± 0.18; P < 0.001).

CONCLUSIONS

In this nationwide cohort study, digoxin use was associated with an overall higher risk of the composite outcome of all-cause death/any TE, all-cause death, and any TE, regardless of HF diagnosis. Patients treated with digoxin had a worse health-related quality of life.

Utilization of Digoxin among Hospitalized Older Patients with Heart Failure and Atrial Fibrillation in Thailand: Prevalence, Associated Factors, and Clinical Outcomes

Background

Digoxin is used to control heart rate in patients with heart failure (HF) and atrial fibrillation (AF). However, its use is often limited in older patients, as they are prone to digoxin toxicity. This study aimed to determine the prevalence of digoxin use, investigate the factors associated with digoxin use, and explore the association between digoxin use and clinical outcomes in older Thai patients with HF and AF.

Methods

This cross-sectional study used data obtained from an electronic medical records database. We performed logistic regression analysis to determine the prevalence of digoxin use at index discharge and the factors associated with its use. The Cox proportional hazard model was used to determine the association of all-cause mortality and HF rehospitalization with digoxin use.

Results

Of the 640 patients assessed, 107 (16.72%) were prescribed digoxin before discharge. The factors negatively associated with digoxin use included high serum creatinine level (adjusted odds ratio [AOR]=0.38; 95% confidence interval [CI], 0.22–0.65) and ischemic heart disease (IHD) (AOR=0.52; 95% CI, 0.30–0.88). The factors positively associated with digoxin use were the use of diuretics (AOR=2.65; 95% CI, 1.60–4.38) and mineralocorticoid receptor antagonists (MRAs) (AOR=2.24; 95% CI, 1.18–4.27). We observed no significant association between digoxin use and clinical outcomes (adjusted hazard ratio=1.00; 95% CI, 0.77–1.30).

Conclusion

Digoxin use was prevalent among older patients with HF and AF. Patients with high serum creatinine or IHD were less likely to be prescribed digoxin, whereas those using diuretics or MRAs were more likely to be prescribed digoxin. Although digoxin use was not uncommon among older patients, it was prescribed with caution among Thai patients hospitalized with HF and AF.

Rate control strategies for atrial fibrillation

Atrial fibrillation (AF) is one of the main cardiac arrhythmias associated with higher risk of cardiovascular morbidity and mortality. AF can cause adverse symptoms and reduced quality of life. One of the strategies for the management of AF is rate control, which can modulate ventricle rate, alleviate adverse associated symptoms and improve the quality of life. As primary management of AF through rate control or rhythm is a topic under debate, the purpose of this review is to explore the rationale for the rate control approach in managing AF by considering the guidelines, recommendations and determinants for the choice of rate control drugs, including beta blockers, digoxin and non- dihydropyridine calcium channel blockers for patients with AF and other comorbidities and atrioventricular nodal ablation and pacing. Despite the limitations of rate control treatment, which may not be effective in preventing disease progression or in reducing symptoms in highly symptomatic patients, it is widely used for almost all patients with atrial fibrillation. Although rate control is one of the first line management of all patient with atrial fibrillation, several issues remain debateable.

Digoxin use in contemporary heart failure with reduced ejection fraction: an analysis from the Swedish Heart Failure Registry

AIMS

Digoxin is included in some heart failure (HF) guidelines but controversy persists about the true role for and impact of treatment with this drug, particularly in the absence of atrial fibrillation (AF). The aim of this study was to assess the association between clinical characteristics and digoxin use and between digoxin use and mortality/morbidity in a large, contemporary cohort of patients with HF with reduced ejection fraction (HFrEF) stratified by history of AF.

METHODS AND RESULTS

Patients with HFrEF (EF < 40%) enrolled in the Swedish HF registry between 2005 and 2018 were analysed. The independent association between digoxin use and patient characteristics was assessed by logistic regression, and between digoxin use and outcomes [composite of all-cause mortality or HF hospitalization (HFH), all-cause mortality, and HFH] by Cox regressions in a 1:1 propensity score matched population. Digoxin use was analysed at baseline and as a time-dependent variable. Of 42 456 patients with HFrEF, 16% received digoxin, 29% in the AF group and 2.8% in the non-AF group. The main independent predictors of use were advanced HF, higher heart rate, history of AF, preserved renal function, and concomitant use of beta blockers. Digoxin use was associated with lower risk of all-cause death/HFH [hazard ratio (HR): 0.95; 95% confidence interval (CI): 0.91-0.99] in AF, but with higher risk in non-AF (HR: 1.24; 95% CI: 1.09-1.43). Consistent results were observed when digoxin use was analysed as a time-dependent variable.

CONCLUSION

The great majority of digoxin users had a history of AF. Digoxin use was associated with lower mortality/morbidity in patients with AF, but with higher mortality/morbidity in patients without AF.

Safety of digoxin in nonagenarian patients with atrial fibrillation: lessons from the Spanish Multicenter Registry

BACKGROUND

The association between digoxin and mortality is an unclear issue. In older patients with atrial fibrillation (AF), where use of digoxin is frequent, the evidence of its safety is scarce. Our aim is to assess the safety of digoxin in nonagenarian patients with AF.

METHODS

We evaluated data from 795 nonagenarian patients with non-valvular AF from the Spanish Multicenter Registry. We analyzed the relationship between digoxin and all-cause mortality with the Cox proportional-hazards model.

RESULTS

Follow-up was 27.7 ± 18.3 months. Mean age was 92.5 ± 3.8 years, and 71% of nonagenarian patients were female. Digoxin was not associated with increased risk of mortality [adjusted hazard ratio (aHR) = 1.16, 95% CI: 0.96−1.41,P = 0.130]. However, we found a significant increase in mortality in the subgroup with estimated glomerular filtration rate (eGFR) < 30 mL/min per 1.73 m ² (aHR = 2.01, 95% CI: 1.13−3.57,P = 0.018), but not in the other subgroups of eGFR (30−59 mL/min per 1.73 m² and ≥ 60 mL/min per 1.73 m²). When exploring the risk of mortality according to sex, male subgroup was associated with an increase in mortality (aHR = 1.48, 95% CI: 1.02−2.14,P = 0.041). This was not observed in females subgroup (aHR = 1.03, 95% CI: 0.81−1.29,P = 0.829). Based on the presence or absence of heart failure, we did not find significant differences (aHR = 1.20, 95% CI: 0.87−1.65,P = 0.268 vs. aHR = 1.15, 95% CI: 0.90−1.47,P = 0.273, respectively).

CONCLUSIONS

In our large registry of nonagenarian patients with AF, we did not find an association between digoxin and mortality in the total sample. However, in the subgroup analyses, we found an increase in mortality with the use of digoxin in men and in patients with an eGFR < 30 mL/min per 1.73 m ².

Outcomes of digoxin vs. beta-blocker in AF: report from ESC-EHRA EORP-AF Long-Term General Registry

BACKGROUND

The safety of digoxin therapy in atrial fibrillation (AF) remains ill-defined. We aimed to evaluate the effects of digoxin over beta-blocker therapy in AF.

METHODS

Patients with AF who were treated with either digoxin or beta-blocker from the ESC-EHRA EORP-AF General Long-Term Registry were included. Outcomes of interest were all-cause mortality, cardiovascular (CV) mortality, non-CV mortality, quality of life and number of patients with unplanned hospitalisations.

RESULTS

Of 6377 patients, 549(8.6%) were treated with digoxin. Over 24 months, there were 550(8.6%) all-cause mortality events and 1304(23.6%) patients with unplanned emergency hospitalisations. Compared to beta-blocker, digoxin therapy was associated with increased all-cause mortality (HR 1.90 [95%CI,1.48-2.44], CV mortality (HR 2.18 [95%CI,1.47-3.21] and non-CV mortality (HR 1.68 [95%CI,1.02-2.75] with reduced quality of life (Health Utility Score 0.555[±0.406] vs. 0.705[±0.346], P<0.001) but no differences in emergency hospitalisations (HR 1.00 [95%CI,0.56-1.80]) or AF-related hospitalisations (HR 0.95 [95%CI,0.60-1.52]).On multivariable analysis, there were no differences in any of the outcomes between both groups, after accounting for potential confounders. Similar results were obtained in the subgroups of patients with permanent AF and coexisting heart failure. There was no differences in outcomes between AF patients receiving digoxin with and without chronic kidney disease.

CONCLUSION

Poor outcomes related to the use of digoxin over beta-blocker therapy in terms of excess mortality and reduced quality of life are associated with the presence of other risk factors rather than digoxin per se. The choice of digoxin or beta-blocker therapy had no influence on the incidence of unplanned hospitalisations.

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.

Review of the 2020 ESC Guidelines for the Diagnosis and Management of Atrial Fibrillation-What Has Changed and How Does This Affect Daily Practice

The high prevalence of atrial fibrillation (AF) in the overall population and its association with substantial morbidity, increased mortality and health care cost has instigated significant basic and clinical research efforts over recent years. The publication of multiple new high-quality randomized multi-center trials in the area of AF management and the rapidly evolving technological progress in terms of diagnostic possibilities and catheter ablation in recent years demanded a revision of the previous ESC AF Guidelines from 2016. The 2020 guidelines provide up-to-date, evidence-based guidance for the management of AF. One of the most important innovations is the presentation of a new concept for structural characterization of AF (the “4S AF scheme”) replacing the traditional classification based on its temporal pattern alone (paroxysmal-persistent-permanent). The 4S-AF-scheme highlights the importance of systematic assessment of stroke risk, severity of symptoms, total AF burden and underlying substrate as the foundation for effective and individualized AF treatment for each and every patient. Further novelties relate to the presentation of an easy and intuitive management pathway (“ABC pathway”) and strengthening the recommendations for early rhythm control, in particular the role of first line catheter ablation in heart failure. Another core component of the guidelines is the focus on patient involvement to achieve optimal outcomes. Patient education, shared decision making and incorporation of patient values and patient reported outcome of treatment interventions as well as integrated care by a multidisciplinary team all have a central role in the proposed management pathway for AF.

Eisen und Digitalis bei Herzinsuffizienz

Neben der medikamentösen Standardtherapie der Herzinsuffizienz (HI) gilt es, Patienten zu identifizieren, die von einer Eisensupplementation oder Therapie mit Digitalis profitieren können. Wir haben die aktuelle Evidenz für diese Therapien zusammengestellt und beschreiben, wie die HI-Therapie mit Eisen und Digitalis individualisiert werden kann. Eine Eisensupplementation verbessert Leistungsfähigkeit, Symptome und Lebensqualität bei Patienten mit symptomatischer Herzinsuffizienz und Eisenmangel. Die Daten aus der unlängst publizierten AFFIRM-AHF-Studie zeigen, dass eine Eisentherapie mit Eisencarboxymaltose zudem HI-Hospitalisationen verhindert. Die Therapie mit Digitalis sollte bei fortgeschrittenen Stadien der Herzinsuffizienz mit reduzierter systolischer Funktion trotz leitliniengerechter Pharmako- und Devicetherapie in Erwägung gezogen werden, insbesondere, wenn diese aufgrund von Komorbiditäten nur eingeschränkt möglich ist. Auch bei koexistentem Vorhofflimmern ist Digitalis zur Herzfrequenzkontrolle von großem Wert. Serumkonzentrationen von Digitalis im niedrigen therapeutischen Bereich sind anzustreben.

Heart failure with preserved ejection fraction based on aging and comorbidities

Heart failure (HF) with preserved ejection fraction (HFpEF) is a leading cause of hospitalizations and mortality when diagnosed at the age of ≥ 65 years. HFpEF represents multifactorial and multisystemic syndrome and has different pathophysiology and phenotypes. Its diagnosis is difficult to be established based on left ventricular ejection fraction and may benefit from individually tailored approaches, underlying age-related changes and frequent comorbidities. Compared with the rapid development in the treatment of heart failure with reduced ejection fraction, HFpEF presents a great challenge and needs to be addressed considering the failure of HF drugs to improve its outcomes. Further extensive studies on the relationships between HFpEF, aging, and comorbidities in carefully phenotyped HFpEF subgroups may help understand the biology, diagnosis, and treatment of HFpEF. The current review summarized the diagnostic and therapeutic development of HFpEF based on the complex relationships between aging, comorbidities, and HFpEF.

Cardiac glycosides are not associated with increased mortality or hospitalization rates in ICD and CRT-ICD patients after adjustment for baseline-characteristics at one-year follow-up: Results from the German DEVICE registry

AIMS

Despite lacking supporting randomized trials, cardiac glycosides (CGs) are widely used in heart failure and/or atrial fibrillation. Moreover, several pro- and retrospective studies and registry-data have recently raised serious concerns in terms of efficacy and safety of CGs in this field. We have therefore examined the association between CGs and clinical outcome of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization (CRT-ICD) patients of the large German DEVICE registry.

METHODS AND RESULTS

Between 2007 and 2014, 3782 ICD and 1529 CRT-ICD patients were enrolled in the German DEVICE registry. Those two groups were analyzed independently according to medication with or without CGs. After adjustment for patient characteristics, CGs were not significantly associated with increased one-year mortality (HR 1.27, 95%-CI 0.91-1.76, p = 0.162), major adverse cardiac and cerebrovascular events (OR 1.36, 95%-CI 0.98-1.89, p = 0.063), ICD-shocks (OR 1.29, 95%-CI 0.95-1.74, p = 0.104) or the need for rehospitalization in ICD patients at one-year-follow-up. Similar findings were obtained in CRT-ICD patients. Regarding possible determinants for glycoside treatment, atrial fibrillation at enrollment was found to be most strongly associated with the prescription of glycosides in ICD (adjusted OR 3.25, 95%-CI 2.63-4.02) and CRT-ICD patients (adjusted OR 3.17, 95%-CI 2.39-4.19).

CONCLUSION

Overall harmful effects of CGs in ICD- and CRT-ICD patients could not be confirmed in DEVICE. Further large and randomized-controlled trials that investigate dose-dependent effects of CGs in addition to contemporary therapy of heart failure and atrial fibrillation are needed.

Characteristics and Treatment of Atrial Fibrillation with Respect to the Presence or Absence of Heart Failure. Insights from the Multicenter Polish Atrial Fibrillation (POL-AF) Registry

Background: We aimed to assess characteristics and treatment of AF patients with and without heart failure (HF). Methods: The prospective, observational Polish Atrial Fibrillation (POL-AF) Registry included consecutive patients with AF hospitalized in 10 Polish cardiology centers in 2019–2020. Results: Among 3999 AF patients, 2822 (71%) had HF (AF/HF group). Half of AF/HF patients had preserved ejection fraction (HFpEF). Compared to patients without HF (AF/non–HF), AF/HF patients were older, more often male, more often had permanent AF, and had more comorbidities. Of AF/HF patients, 98% had class I indications to oral anticoagulation (OAC). Still, 16% of patients were not treated with OAC at hospital admission, and 9%—at discharge (regardless of the presence of HF and its subtypes). Of patients not receiving OAC upon admission, 61% were prescribed OAC (most often apixaban) at discharge. AF/non–HF patients more often converted from AF at admission to sinus rhythm at discharge compared to AF/HF patients (55% vs. 30%), despite cardioversion performed as often in both groups. Class I antiarrhythmics were more often prescribed in AF/non–HF than in AF/HF group (13% vs. 8%), but still as many as 15% of HFpEF patients received them. Conclusions: Over 70% of hospitalized AF patients have coexisting HF. A significant number of AF patients does not receive the recommended OAC.

Atrial Fibrillation in Congenital Heart Disease

The increasing prevalence of AF in a growing population of adults with congenital heart disease (CHD) poses new challenges to clinicians involved in the management of these patients. Distinctive underlying anatomies, unique physiological aspects, a high diversity of corrective surgeries and associated comorbidities can complicate clinical decision-making. In this review, the authors provide an overview of the current knowledge on epidemiology and pathophysiology, with a special focus on the differences to the non-CHD population and the clinical impact of AF in adults with CHD. Acute and long-term management strategies are summarised, including the use of antiarrhythmic drugs, catheter or surgical ablation and prophylaxis of thromboembolism. Finally, gaps of knowledge and potential areas of future research are highlighted.

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.

Influence of digoxin on mortality in patients with atrial fibrillation: Overview of systematic reviews

Once a routine part of atrial fibrillation (AF) management, digoxin use has declined. Likely hastening this decline are findings from several studies and systematic reviews identifying a potential association between digoxin use and all-cause mortality in AF populations. However, inconsistency exists within some of these studies potentially leading to confusion among clinicians. To critically evaluate the current literature to contextualize the associations between digoxin and mortality risk in patients with AF by performing an overview of systematic reviews. We searched MEDLINE, Cochrane Central Database of Systematic Reviews, and SCOPUS from their earliest date through October 12, 2020, to identify systematic reviews (SRs) that included studies enrolling patients with AF or atrial flutter and evaluated the association between digoxin use and all-cause mortality. We used the AMSTAR 2 tool to assess the risk of bias for each included SR. Results from reviews are qualitatively synthesized. Our search identified 10 SRs that met our inclusion criteria. Of the 41 unique AF studies included in these SRs, 41% were cohort studies, 29% were post hoc analyses of randomized controlled trials (RCTs), 15% were RCTs, and 15% were registry studies. Based on our AMSTAR 2 assessment, the overall confidence in the results of the 10 reviews was rated as "moderate" in three SRs, "low" in three SRs, and "critically low" in the rest. Except for one review, each included SR shows that digoxin use in AF is associated with a 15 to 38% higher risk of all-cause mortality. This association may be greater when AF-only populations are considered compared with a mix of AF and heart failure populations. Serum digoxin concentration (SDC) data were infrequently considered, but available data suggested a greater association between increasing SDC and all-cause mortality. This overview of reviews found general consistency regarding the association between digoxin use and higher all-cause mortality in AF populations. However, heterogeneity exists among and between SRs and an unmet need exists for additional study in a RCT setting with close monitoring and reporting of SDC to better inform clinical practice.

Population Pharmacokinetic Studies of Digoxin in Adult Patients: A Systematic Review

BACKGROUND

Digoxin is a cardiac glycoside that was introduced to cardiovascular medicine more than 200 years ago. Its use is associated with large variability, which complicates achieving the desired therapeutic outcomes.

OBJECTIVES

To present a synthesis of the available literature on the population pharmacokinetics of digoxin in adults and to identify the sources of variability in its pharmacokinetics.

METHODS

This is a PROSPERO registered systematic review (CRD42018105300). A literature search was conducted using the ISI Web of Science, Science Direct, PubMed, and SCOPUS databases to identify digoxin population pharmacokinetic studies of adults that utilized the nonlinear mixed-effect modeling approach.

RESULTS

Sixteen articles were included in the present analysis. Only two studies were conducted in elderly subjects as a separate population. Both the pharmacokinetics and pharmacodynamics of digoxin were investigated in one study. Furthermore, the reviewed studies were mostly conducted in East Asian populations (68.8%). Digoxin's pharmacokinetics were usually described by a one-compartment model because of the nature of the collected data. Weight, age, kidney function, presence of heart failure, and co-administered medications such as calcium channel blockers were the most commonly identified predictors of digoxin clearance. The value of apparent clearance in a typical study individual ranged from 0.005 to 0.2 l/h/kg, while the value of the apparent volume of distribution ranged from 3.14 to 15.2 l/kg. The quality of model evaluation was deemed excellent only in 31.3% of the studies.

CONCLUSION

This review provides information about variables that need to be considered when prescribing digoxin. The results highlight the need for prospective studies that allow two-compartment pharmacokinetic/pharmacodynamic models to be established, with a special focus on the elderly subpopulation.

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.

Atrial fibrillation and stroke prevention: state of the art-epidemiology and pathophysiology: new risk factors, concepts and controversies

Atrial fibrillation (AF) increases the risk of thromboembolism, and risk assessment for thromboembolism is necessary for the management of AF patients. CHADS2 and CHA2DS2-VASc scores have been adopted in international guidelines for AF management, but the significance of each risk factor included in these risk scores are sometimes controversial, and the performance of these scores is only modest. There are several other risk factors not included in the scores such as renal dysfunction, low body weight, type of AF (paroxysmal or non-paroxysmal) as well as echocardiographic parameters and blood biomarkers, and physicians should assess patients risk in an integrated manner.

Safety and efficacy of dronedarone from clinical trials to real-world evidence: implications for its use in atrial fibrillation

Efficacy and safety of dronedarone was shown in the ATHENA trial for paroxysmal or persistent atrial fibrillation (AF) patients. Further trials revealed safety concerns in patients with heart failure and permanent AF. This review summarizes insights from recent real-world studies and meta-analyses, including reports on efficacy, with focus on liver safety, mortality risk in patients with paroxysmal/persistent AF, and interactions of dronedarone with direct oral anticoagulants. Reports of rapidly progressing liver failure in dronedarone-prescribed patients in 2011 led to regulatory cautions about potential liver toxicity. Recent real-world evidence suggests dronedarone liver safety profile is similar to other antiarrhythmics and liver toxicity could be equally common with many Class III antiarrhythmics. Dronedarone safety concerns (increased mortality in patients with permanent AF) were raised based on randomized controlled trials (RCT) (ANDROMEDA and PALLAS), but comedication with digoxin may have increased the mortality rates in PALLAS, considering the dronedarone-digoxin pharmacokinetic (PK) interaction. Real-world data on apixaban-dronedarone interactions and edoxaban RCT observations suggest no significant safety risks for these drug combinations. Median trough plasma concentrations of dabigatran 110 mg during concomitant use with dronedarone are at acceptable levels, while PK data on the rivaroxaban-dronedarone interaction are unavailable. In RCTs and real-world studies, dronedarone significantly reduces AF burden and cardiovascular hospitalizations, and demonstrates a low risk for proarrhythmia in patients with paroxysmal or persistent AF. The concerns on liver safety must be balanced against the significant reduction in hospitalizations in patients with non-permanent AF and low risk for proarrhythmias following dronedarone treatment.

Association of digoxin therapy with case fatality rate in acute pulmonary embolism

OBJECTIVE

Despite wide usage of digoxin for various diseases in cardiology practice, its benefit is controversial and moreover it had been associated with unfavorable outcomes in some previous studies. The aim of this present study was to demonstrate whether digoxin usage was related with worse outcomes or not in patients with acute pulmonary embolisms.

METHODS

A total number of 1215 patients retrospectively enrolled for the study. Basic demographic features, pulmonary embolism severity index (PESI) scores, laboratory parameters and medications of patients who had been diagnosed with acute pulmonary embolism were recorded. Short (30 days) and long-term mortality were reported as the clinical outcomes.

RESULTS

Total mortality was 15.4% in the study population and 78 of these subjects died within the first 30 days. The frequency of digoxin treatment was 8% and most of these patients were prior users. According to the binary logistic regression analyses the PESI score, right ventricle (RV) diastolic diameter, systolic pulmonary arterial pressure (sPAP), brain natriuretic peptide (BNP), troponin and digoxin therapy (odds ratio, OR: 2.82 95% confidence interval, CI: 1.39-8.31, P = 0.03) were found as independent predictors of short-term mortality. Beside these findings; sPAP, PESI score, RV diastolic diameter and digoxin therapy (hazard ratio, HR: 2.11 95%CI: 1.22-7.31, P = 0.03) were determined as independent predictors of long-term mortality in Cox regression analyses. In subgroup analysis, we determined significantly greater increase in short-term mortality with use of digoxin among patients who had chronic renal disease, among patients under thrombolytic therapy and under high dosage of digoxin therapy and among female patients.

CONCLUSION

Digoxin has been used extensively for decades in the treatment of heart failure and arrhythmias despite some controversies over its benefit. For the first time in the literature, we have demonstrated independent association of digoxin therapy with short-term and long-term mortality in patients with acute pulmonary embolism.

Digoxin Initiation and Outcomes in Patients with Heart Failure (HFrEF and HFpEF) and Atrial Fibrillation

BACKGROUND

Digoxin reduces the risk of heart failure hospitalization but has no effect on mortality in patients with heart failure without atrial fibrillation in the randomized controlled trial setting. Observational studies of digoxin use in patients with atrial fibrillation have suggested a higher risk for poor outcomes. Less is known about this association in patients with heart failure and atrial fibrillation, the examination of which was the objective of the current study.

METHODS

We conducted an observational propensity score-matched study of predischarge digoxin initiation in 1768 hospitalized patients with heart failure and atrial fibrillation in the Medicare-linked Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF) registry, balanced on 56 baseline characteristics (mean age, 79 years; 55% women; 7% African American). Hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes were estimated for the 884 patients initiated on digoxin compared with 884 not initiated on digoxin.

RESULTS

HRs (95% CIs) for 30-day, 2-year, and 4-year all-cause mortality were 0.80 (0.55-1.18; P = .261), 0.94 (0.87-1.16; P = .936), and 1.01 (0.90-1.14; P = .729), respectively. Respective HRs (95% CIs) for heart failure readmission were 0.67 (0.49-0.92; P = .014), 0.81 (0.69-0.94; P = .005), and 0.85 (0.74-0.97; P = .022), and those for all-cause readmission were 0.78 (0.64-0.96; P = .016), 0.90 (0.81-1.00; P = .057), and 0.91 (0.83-1.01; P = .603). These associations were homogeneous between patients with left ventricular ejection fraction ≤45% vs >45%.

CONCLUSIONS

Among hospitalized older patients with heart failure (HFrEF and HFpEF) and atrial fibrillation, initiation of digoxin was associated with a lower risk of heart failure readmission but had no association with mortality.

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, mortality, and cardiac hospitalizations in patients with atrial fibrillation and heart failure with reduced ejection fraction and atrial fibrillation: An AF-CHF analysis

BACKGROUND

Recent publications have raised serious concerns regarding the safety of digoxin for atrial fibrillation (AF). However, the subgroup of patients with reduced ejection fraction and AF have been speculated to derive clinical benefit from digoxin. We aimed to assess the impact of digoxin on mortality and cardiovascular hospitalizations in the Atrial Fibrillation and Congestive Heart Failure (AF-CHF) trial since all AF-CHF patients had an ejection fraction ≤35% and AF.

METHODS AND RESULTS

Using marginal structural modeling, a contemporary statistical method that overcomes limitations of traditional modeling techniques and reduces bias, we assessed the impact of digoxin on the pre-specified primary and secondary outcomes of the AF-CHF trial, i.e., all-cause, cardiac and arrhythmic death as well as cardiovascular hospitalization. Among 1376 patients, 869 (65%) were on digoxin at one-year follow-up. Over a mean (SD) follow-up of 37 (19) months (maximum 74 months), 445 (32%) patients died, 357 (26%) from cardiovascular causes and 159 (12%) from arrhythmic death. Digoxin was significantly associated with all-cause, cardiac, and arrhythmic death, with estimated hazard ratios (HR) of 1.39 (95% confidence interval [CI] 1.11-1.73, P = 0.004), 1.44 (95% CI 1.13-1.82, P = 0.003), and 2.03 (95% CI 1.63-2.54, P < 0.0001), respectively. Digoxin was not associated with cardiovascular hospitalizations [HR 1.12 (95% CI 0.91-1.37), P = 0.29].

CONCLUSION

Digoxin is associated with increased all-cause mortality among patients with combined heart failure with reduced ejection fraction and AF, which is predominantly driven by arrhythmic deaths. In contrast, cardiovascular hospitalizations were not impacted by digoxin.

Matching with time-dependent treatments: A review and look forward

Observational studies of treatment effects attempt to mimic a randomized experiment by balancing the covariate distribution in treated and control groups, thus removing biases related to measured confounders. Methods such as weighting, matching, and stratification, with or without a propensity score, are common in cross‐sectional data. When treatments are initiated over longitudinal follow‐up, a target pragmatic trial can be emulated using appropriate matching methods. The ideal experiment of interest is simple; patients would be enrolled sequentially, randomized to one or more treatments and followed subsequently. This tutorial defines a class of longitudinal matching methods that emulate this experiment and provides a review of existing variations, with guidance regarding study design, execution, and analysis. These principles are illustrated in application to the study of statins on cardiovascular outcomes in the Framingham Offspring cohort. We identify avenues for future research and highlight the relevance of this methodology to high‐quality comparative effectiveness studies in the era of big data.

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.

Increased mortality in patients with secondary diagnosis of atrial fibrillation: Report from Chinese AF registry

Background

The relationship between mortality and the primary diagnosis in AF patients is poorly recognized. The purpose of the study is to compare the differences on mortality in patients with a primary or secondary diagnosis of AF and to identify risk factors amenable to treatment.

Methods

This was a prospective cohort study using data from the Chinese AF registry. For admitted patients, a follow‐up was completed to obtain the outcomes during 1 year.

Results

A total of 2015 patients with confirmed AF were included. AF was the primary diagnosis in 40.9% (n = 825) of them. 78.9% (n = 939) of the secondary AF diagnosis patients and 55.5% (n = 458) of the primary AF diagnosis patients were sustained AF. Compared with primary AF diagnosis group, the secondary AF diagnosis group was older with more comorbidities. At 1 year, the unadjusted mortality was much higher in the secondary AF diagnosis groups compared with the primary AF diagnosis groups. In Cox regression analysis with adjustment for confounding factors, patients with secondary AF diagnosis were associated with an increased mortality (relative risk 1.723; 95% CI: 1.283 to 2.315, p < .001). On multivariate analysis, age ≥ 75, LVSD, COPD, and diabetes were independent predictors of mortality in patients with primary AF diagnosis, while for the secondary AF diagnosis group, the risk factors were age ≥ 75, heart failure, and previous history of stroke.

Conclusions

Patients presenting to ED with secondary diagnosis of AF were suffering from higher mortality risks compared with primary AF diagnosis patients. Physicians should distinguish these two groups in clinical practice.

Modified SAMe-TT2R2 score for predicting the therapeutic range of digoxin

BACKGROUND

Digoxin treatment has come under scrutiny in recent years after reports from several studies that it is associated with increased mortality in patients with atrial fibrillation (AF). The clinical effects of digoxin on mortality were closely related to serum digoxin concentrations (SDC) in these studies. In the present work, we evaluated the role of the SAMe-TT₂R₂ and modified SAMe-TT₂R₂ scores in predicting the therapeutic range of digoxin therapy.

METHODS

Medical records from our institution were screened for patients who were under digoxin treatment between 2008 and 2018. A total of 2418 patients for whom SDC were recorded were included in the study. An SDC of <0.5 or >1.2 ng/ml was defined as being out of the therapeutic range (oTR).

RESULTS

In multivariable regression analyses, abnormal body mass index (odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.29-1.95, p < 0.01), white blood cell count (OR: 1.12, 95% CI: 1.01-1.27, p < 0.01), and the modified SAMe-TT₂R₂ score (OR: 4.19 95% CI: 3.71-4.72, p < 0.01) were determined to be independent predictors of oTR. A modified SAMe-TT₂R₂ score greater than 3 predicted oTR with a sensitivity of 86% and a specificity of 65% (AUC: 0.825, p < 0.01).

CONCLUSION

Digoxin is still widely used in the treatment of heart failure and AF despite concerns about the increased risk of mortality when levels are oTR. In the present study, the modified SAMe-TT₂R₂ score was found to be an independent predictor of oTR. This score may aid clinicians in identifying patients who are more likely to benefit from digoxin therapy.

Combined amiodarone and digitalis therapy before heart transplantation is associated with increased post-transplant mortality

Aims

Amiodarone and digitalis are frequently used drugs in patients with heart failure. Both have separately been linked to reduced post‐transplant survival, but their combined impact on mortality after HTX remains uncertain. This study investigated the effects of combined amiodarone and digitalis use before HTX on post‐transplant outcomes.

Methods and results

This registry study analysed 600 patients receiving HTX at Heidelberg Heart Center between 1989 and 2016. Patients were stratified by amiodarone and digitalis use before HTX. Analysis included patient characteristics, medication, echocardiographic features, heart rates, permanent pacemaker implantation, atrial fibrillation, and post‐transplant survival including causes of death. One hundred eighteen patients received amiodarone before HTX (19.7%), hereof 67 patients with digitalis (56.8%) and 51 patients without digitalis before HTX (43.2%). Patients with and without amiodarone before HTX showed a similar 1 year post‐transplant survival (72.0% vs. 78.4%, P = 0.11), but patients with combined amiodarone and digitalis before HTX had a worse 1 year post‐transplant survival (64.2%, P = 0.01), along with a higher percentage of death due to transplant failure (P = 0.03). Echocardiographic analysis of these patients showed a higher percentage of an enlarged right ventricle (P = 0.02), left atrium (P = 0.02), left ventricle (P = 0.03), and a higher rate of reduced left ventricular ejection fraction (P = 0.03). Multivariate analysis indicated combined amiodarone and digitalis use before HTX as a significant risk factor for 1 year mortality after HTX (hazard ratio: 1.69; 95% confidence interval: 1.02–2.77; P = 0.04).

Conclusions

Combined pre‐transplant amiodarone and digitalis therapy is associated with increased post‐transplant mortality.

Stroke prevention in elderly patients with non-valvular atrial fibrillation in the BALKAN-AF survey

BACKGROUND

Atrial fibrillation (AF) is common amongst the elderly, but this group tends to be suboptimally treated. Limited data are available on the stroke prevention strategies in the elderly, especially in the Balkan region.

AIM

We investigated the use of oral anticoagulant therapy (OAC) amongst elderly AF patients in clinical practice in the Balkan region.

METHOD

A 12-week prospective snapshot survey (2014-2015) of consecutive non-valvular AF patients was conducted in Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Montenegro, Romania and Serbia. Data were collected via an electronic case report form.

RESULTS

Of 2671 patients, 418 (15.6%) were ≥80 years old. Overall, OAC was used in 1965 patients (73.6%). Compared with younger patients, the elderly (age ≥ 80) had a higher mean CHA₂ DS₂ -VASc score (3.22 ± 1.71 vs 4.89 ± 1.35, P < .001) and more often a HAS-BLED score of ≥3 (n = 198 [47.0%] vs n = 625 [27.3%], P < .001), but were less likely to receive OAC (n = 269 [64.4%] vs n = 1696 [75.3%], odds ratio [OR] 0.91; 95%CI 0.86-0.97, P = .003). There was no significant association between OAC use and mean CHA₂ DS₂ -VASc (OR 0.86; 95%CI 0.75-1.00, P = .053) or HAS-BLED score (OR 1.21; 95%CI 0.81-1.81, P = .349) in the elderly.

CONCLUSION

In the BALKAN-AF Survey, elderly AF patients were less likely to receive the guideline-adherent treatment despite their less favourable risk profile. Since OAC nonuse among the elderly was not associated with increased HAS-BLED score, factors other than patients' risk profile could influence the implementation of guideline-adherent treatment for thromboprophylaxis in the elderly AF patients.

Pharmacological management of atrial fibrillation in patients with heart failure with reduced ejection fraction: review of current knowledge and future directions

Introduction: Both heart failure with reduced ejection fraction (HFrEF) and atrial fibrillation (AF) independently cause significant morbidity and mortality. The two conditions commonly coexist and AF in the setting of HFrEF is associated with worse mortality, hospitalizations, and quality of life compared to HFrEF without AF. Despite the large burden of these conditions, there is no clear optimal management strategy for when they occur together.Areas covered: This review focuses on the pharmacological management of AF in HFrEF. Studies were identified through PubMed search of relevant keywords. The authors review key clinical trials that have influenced management strategies and guidelines. The authors focus on the classes of drugs used to treat AF for both rate and rhythm control strategies including beta-blockers, digoxin, amiodarone, and dofetilide. Additionally, the authors discuss select non-antiarrhythmic medications that affect AF in HFrEF. The authors highlight the strengths and weakness of the data supporting the use of these medications and suggest future directions.Expert opinion: The pharmacological treatment of AF in HFrEF will need further refinement alongside the emerging role of catheter ablation. Novel HF medications and antiarrhythmics offer new tools to prevent the development of AF, as well as for rate and rhythm control strategies.

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.

Do most patients with obesity or type 2 diabetes, and atrial fibrillation, also have undiagnosed heart failure? A critical conceptual framework for understanding mechanisms and improving diagnosis and treatment

Obesity and diabetes can lead to heart failure with preserved ejection fraction (HFpEF), potentially because they both cause expansion and inflammation of epicardial adipose tissue and thus lead to microvascular dysfunction and fibrosis of the underlying left ventricle. The same process also causes an atrial myopathy, which is clinically evident as atrial fibrillation (AF); thus, AF may be the first manifestation of HFpEF. Many patients with apparently isolated AF have latent HFpEF or subsequently develop HFpEF. Most patients with obesity or diabetes who have AF and exercise intolerance have increased left atrial pressures at rest or during exercise, even in the absence of diagnosed HFpEF. Among patients with AF, those who also have latent HFpEF have increased risk for systemic thromboembolism and death. The identification of HFpEF in patients with obesity or diabetes alters the risk-to-benefit relationship of commonly prescribed treatments. Bariatric surgery and statins can ameliorate AF and reduce the risk for HFpEF. Conversely, antihyperglycaemic drugs that promote adipogenesis or cause sodium retention (insulin and thiazolidinediones) may increase the risk for heart failure in patients with an underlying ventricular myopathy. Patients with obesity and diabetes who undergo catheter ablation for AF are at increased risk for AF recurrence and for post-ablation increases in pulmonary venous pressures and worsening heart failure, especially if HFpEF coexists. Therefore, AF may be the earliest indicator of HFpEF in patients with obesity or type 2 diabetes, and recognition of HFpEF alters the management of these patients.