Digoxin Use and Adverse Outcomes in Patients With Atrial Fibrillation

Effect of digoxin on all-cause and cardiovascular mortality in patients with atrial fibrillation with and without heart failure: an umbrella review of systematic reviews and 12 meta-analyses

PURPOSE

To perform a systematic umbrella review with meta-analysis to evaluate the certainty of evidence on mortality risk associated with digoxin use in patients with atrial fibrillation (AF) with or without heart failure (HF).

METHODS

We systematically searched MEDLINE, Embase, and Web of Science databases from inception to 19 October 2021. We included systematic reviews and meta-analyses of observational studies investigating digoxin effects on mortality of adult patients with AF and/or HF. The primary outcome was all-cause mortality; secondary outcome was cardiovascular mortality. Certainty of evidence was evaluated by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool and the quality of systematic reviews/meta-analyses by the A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR2) tool.

RESULTS

Eleven studies accounting for 12 meta-analyses were included with a total of 4,586,515 patients. AMSTAR2 analysis showed a high quality in 1, moderate in 5, low in 2, and critically low in 3 studies. Digoxin was associated with an increased all-cause mortality (hazard ratio [HR] 1.19, 95% confidence interval [95%CI] 1.14-1.25) with moderate certainty of evidence and with an increased cardiovascular mortality (HR 1.19, 95%CI 1.06-1.33) with moderate certainty of evidence. Subgroup analysis showed that digoxin was associated with all-cause mortality both in patients with AF alone (HR 1.23, 95%CI 1.19-1.28) and in those with AF and HF (HR 1.14, 95%CI 1.12-1.16).

CONCLUSION

Data from this umbrella review suggests that digoxin use is associated with a moderate increased risk of all-cause and cardiovascular mortality in AF patients regardless of the presence of HF.

TRIAL REGISTRATION

This review was registered in PROSPERO (CRD42022325321).

Mitochondrial Effects of Common Cardiovascular Medications: The Good, the Bad and the Mixed

Mitochondria are central organelles in the homeostasis of the cardiovascular system via the integration of several physiological processes, such as ATP generation via oxidative phosphorylation, synthesis/exchange of metabolites, calcium sequestration, reactive oxygen species (ROS) production/buffering and control of cellular survival/death. Mitochondrial impairment has been widely recognized as a central pathomechanism of almost all cardiovascular diseases, rendering these organelles important therapeutic targets. Mitochondrial dysfunction has been reported to occur in the setting of drug-induced toxicity in several tissues and organs, including the heart. Members of the drug classes currently used in the therapeutics of cardiovascular pathologies have been reported to both support and undermine mitochondrial function. For the latter case, mitochondrial toxicity is the consequence of drug interference (direct or off-target effects) with mitochondrial respiration/energy conversion, DNA replication, ROS production and detoxification, cell death signaling and mitochondrial dynamics. The present narrative review aims to summarize the beneficial and deleterious mitochondrial effects of common cardiovascular medications as described in various experimental models and identify those for which evidence for both types of effects is available in the literature.

Drug therapy monitoring (TDM) of Digoxin: safety and efficacy review

Digoxin was developed as a novel medication for the treatment of heart failure and atrial fibrillation (AF) 200 years ago. This investigation began with a PubMed and Google Scholar search for various papers using the terms digoxin safety and efficacy, digoxin in heart failure, and digoxin in atrial fibrillation. Digoxin should be administered at a dose of 0.5–0.7 ng/mL in individuals with heart failure and reduced ejection fraction. Digoxin should be administered to decrease hospital readmissions, although SDC, creatinine, and potassium levels should be continuously maintained to limit the risk of toxicity. Digoxin may be used in conjunction with diuretics, spironolactone, ACE inhibitors, or beta-blockers. It is preferable to take digoxin on a regular basis. Digoxin should not be used in the pre-excitation syndrome because it can result in the rapid development of accessory route conductors, which can finally result in ventricular fibrillation. Due to the narrow therapeutic index of digoxin, it requires appropriate treatment and continuous monitoring.

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.

Digoxin exerts anticancer activity on human nonsmall cell lung cancer cells by blocking PI3K/Akt pathway

Lung cancer remains the leading cause of cancer mortality because of its metastatic potential and high malignancy. The discovery of new applications for old drugs is a shortcut for cancer therapy. We recently investigated the antitumor effect of digoxin, a well-established drug for treating heart failure, against nonsmall cell lung cancer A549 and H1299 cells. Digoxin inhibited the proliferation and colony-forming ability of the two cell lines and arrested the cell cycle at the G0/G1 phase in A549 cells and the G2/M phase in H1299 cells. Mitochondria-mediated apoptosis was induced in A549 cells but not in H1299 cells after treatment with digoxin. Moreover, digoxin inhibited the migration, invasion, adhesion and epithelial–mesenchymal transition of A549 and H1299 cells. Autophagy was induced in both cell lines after treatment with digoxin, with an increase in autophagosome foci. In addition, digoxin inhibited the phosphorylation of Akt, mTOR and p70S6K, signaling molecules of the PI3K/Akt pathway that are known to be involved in tumor cell survival, proliferation, metastasis and autophagy. Our findings suggest that digoxin has the potential to be used for therapy for human nonsmall cell lung cancer, but further evidence is required.

Supraventricular tachycardias in neonates and infants: factors associated with fatal or near-fatal outcome

Prognosis of supraventricular tachycardias in neonates and infants is thought to be excellent with rare fatal outcomes. Nevertheless, initial management can be challenging. The aim of this study was to perform a retrospective analysis in neonates/infants with non-pos-toperative supraventricular tachycardias regarding risk factors for clinical outcome and type of antiarrhythmic drug therapy. The data of 157 patients aged < 1 year who presented between 2000 and 2015 with symptomatic tachycardias were retrospectively reviewed. Pharmacological therapy was successful in 151 patients (96%); 1 patient (1%) required catheter ablation and 5 patients (3%) died (1 death linked to hemodynamical reasons after effective arrhythmia control). Serious complications following acute medical therapy occurred in 4 patients of survivors. Patients with complications or death had a lower bodyweight, more frequent intrauterine tachycardia, transplacental therapy, urgent caesarian section, higher PRISM II score, longer period to control tachycardia, more frequent proarrhythmia, and major adverse event-defined as life-threatening event without a documented new arrhythmia-compared to the group without complications. There was no significant difference between the groups regarding prematurity, structural heart disease, and type of tachycardia. Proarrhythmia occurred in 6 cases and was related to intravenous drug use with class IC antiarrhythmics in 3/6 cases, digoxin in 2/6 cases, and amiodarone in 1/6 cases. ECG signs of impending proarrhythmia without new-onset arrhythmia requiring cessation of therapy were detected in 6 patients.Conclusion: Although rare, non-post-operative supraventricular tachycardia in neonates and infants might be a serious disease. Acute intravenous pharmacological treatment to control tachycardia might pose a risk for fatal or near-fatal outcome. Detection of proarrhythmia related to class IC antiarrhythmics in neonates might be especially difficult and requires alertness. What is Known • Prognosis of supraventricular tachycardias in children are thought to be excellent with fatal outcomes being rare. • Mortality is increased in the very young and in those with structural heart disease. What is New • Complicated outcome of non-post-operative supraventricular tachycardias in neonates is associated with lower bodyweight, age, prenatal tachycardia, higher PRISM II score, longer period to control tachycardia, and proarrhythmia. • Detection of class IC proarrhythmic effect is especially difficult in neonates because of their narrow QRS and warrants alertness.

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.

Remote Monitoring of Cardiac Implantable Electronic Devices in Patients Undergoing Hybrid Comprehensive Telerehabilitation in Comparison to the Usual Care. Subanalysis from Telerehabilitation in Heart Failure Patients (TELEREH-HF) Randomised Clinical Trial

BACKGROUND

The impact of cardiac rehabilitation on the number of alerts in patients with remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) is unknown. We compared alerts in RM and outcomes in patients with CIEDs undergoing hybrid comprehensive telerehabilitation (HCTR) versus usual care (UC).

METHODS

Patients with heart failure (HF) after a hospitalization due to worsening HF within the last 6 months (New York Heart Association (NYHA) class I-III and left ventricular ejection fraction (LVEF) ≤40%) were enrolled in the TELEREH-HF study and randomised 1:1 to HCTR or UC. Patients with HCTR and CIEDs received RM (HCTR-RM). Patients with UC and CIEDs were offered RM optionally (UC-RM). Data from the initial 9 weeks of the study were analysed.

RESULTS

Of 850 enrolled patients, 208 were in the HCTR-RM group and 62 in the UC-RM group. The HCTR-RM group was less likely to have alerts of intrathoracic impedance (TI) decrease (p < 0.001), atrial fibrillation (AF) occurrence (p = 0.031) and lower mean number of alerts per patient associated with TI decrease (p < 0.0001) and AF (p = 0.019) than the UC-RM group. HCTR significantly decreased the occurrence of alerts in RM of CIEDs, 0.360 (95%CI, 0.189-0.686; p = 0.002), in multivariable regression analysis. There were two deaths in the HCTR-RM group (0.96%) and no deaths in the UC-RM group (p = 1.0). There were no differences in the number of hospitalised patients between the HCTR-RM and UC-RM group (p = 1.0).

CONCLUSIONS

HCTR significantly reduced the number of patients with RM alerts of CIEDs related to TI decrease and AF occurrence. There were no differences in mortality or hospitalisation rates between HCTR-RM and UC-RM groups.

The ABCs of atrial fibrillation

This article provides an outline of the diagnosis and pathogenesis of atrial fibrillation. It introduces a mnemonic for atrial fibrillation treatment guidelines based on recent evidence. Mnemonics use has been associated with improved learning and task organization. Articles using mnemonics to inform clinical practice have been well-received and implemented.

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.

Novel rate control strategy with landiolol in patients with cardiac dysfunction and atrial fibrillation

While patients with acute heart failure often have tachycardia with atrial fibrillation, there have been no established medical tools that control tachycardia safely and definitely. Digoxin has been recommended as a first choice in the former guidelines, but it takes time to affect and has a risk of adverse events particularly for those with chronic kidney disease. Landiolol is a recently innovated ultra‐short‐acting beta‐blocker with 251‐fold β1/β2 selectivity, which was originally indicated only to control peri‐operative supra‐ventricular tachyarrhythmia by 2013 in Japan. We aimed to review how to use landiolol in patients with cardiac dysfunction and tachycardia due to atrial fibrillation. We reviewed recently conducted randomized control trials using landiolol, recently updated guidelines, as well as current practical use of landiolol. Japan landiolol vs. Digoxin (J‐Land) study demonstrated that landiolol was more effective to control tachycardia than digoxin in atrial fibrillation patients with left ventricular dysfunction in 2013. Given the result, the revised Japanese heart failure guideline recommends landiolol for rate control during atrial fibrillation in acute heart failure patients as Class IIa with evidence level B. Currently in Japan, landiolol is used for rate control, even in patients with advanced heart failure receiving continuous infusion of inotropes. The clinical use of landiolol in patients with cardiac dysfunction and tachycardia due to atrial fibrillation is increasing. Further studies are warranted to investigate the implication of faster and safer rate control using landiolol.

Atrial Fibrillation in Patients with Heart Failure: Current State and Future Directions

Heart failure affects nearly 26 million people worldwide. Patients with heart failure are frequently affected with atrial fibrillation, and the interrelation between these pathologies is complex. Atrial fibrillation shares the same risk factors as heart failure. Moreover, it is associated with a higher-risk baseline clinical status and higher mortality rates in patients with heart failure. The mechanisms by which atrial fibrillation occurs in a failing heart are incompletely understood, but animal studies suggest they differ from those that occur in a healthy heart. Data suggest that heart failure-induced atrial fibrosis and atrial ionic remodeling are the underlying abnormalities that facilitate atrial fibrillation. Therapeutic considerations for atrial fibrillation in patients with heart failure include risk factor modification and guideline-directed medical therapy, anticoagulation, rate control, and rhythm control. As recommended for atrial fibrillation in the non-failing heart, anticoagulation in patients with heart failure should be guided by a careful estimation of the risk of embolic events versus the risk of hemorrhagic episodes. The decision whether to target a rate-control or rhythm-control strategy is an evolving aspect of management. Currently, both approaches are good medical practice, but recent data suggest that rhythm control, particularly when achieved through catheter ablation, is associated with improved outcomes. A promising field of research is the application of neurohormonal modulation to prevent the creation of the "structural substrate" for atrial fibrillation in the failing heart.

Augmentation of Ouabain-Induced Increase in Heart Muscle Contractility by Akt Inhibitor MK-2206

Cardiac steroids (CSs), such as ouabain and digoxin, increase the force of contraction of heart muscle and are used for the treatment of congestive heart failure (CHF). However, their small therapeutic window limits their use. It is well established that Na+, K+-ATPase inhibition mediates CS-induced increase in heart contractility. Recently, the involvement of intracellular signal transduction was implicated in this effect. The aim of the present study was to test the hypothesis that combined treatment with ouabain and Akt inhibitor (MK-2206) augments ouabain-induced inotropy in mammalian models. We demonstrate that the combined treatment led to an ouabain-induced increase in contractility at concentrations at which ouabain alone was ineffective. This was shown in 3 experimental systems: neonatal primary rat cardiomyocytes, a Langendorff preparation, and an in vivo myocardial infarction induced by left anterior descending coronary artery (LAD) ligation. Furthermore, cell viability experiments revealed that this treatment protected primary cardiomyocytes from MK-2206 toxicity and in vivo reduced the size of scar tissue 10 days post-LAD ligation. We propose that Akt activity imposes a constant inhibitory force on muscle contraction, which is attenuated by low concentrations of MK-2206, resulting in potentiation of the ouabain effect. This demonstration of the increase in the CS effect advocates the development of the combined treatment in CHF.

NSAIDs Use and Reduced Metastasis in Cancer Patients: results from a meta-analysis

This meta-analysis investigated the relationship between non-steroidal anti-inflammatory drugs (NSAIDs) and lymph node/distant metastasis. Relevant sources were identified from MEDLINE, EMBASE, PubMed, and Cochrane Library. Studies that reported the odds ratio (OR)/risk ratio (RR)/hazard ratio (HR) with 95% confidence intervals (CIs) for the associations of interested outcomes were included. Pooled effect estimates were obtained by using random- or fixed-effect model depending on the heterogeneity across these studies. Sixteen studies involving 202780 participants, including prostate, breast, lung, and colorectal cancer patients, were included. Compared with the reference, generally patients exposed to NSAIDs at pre- and post-diagnosis experienced a significantly reduced risk of distant metastasis (RR 0.708, 95% CI 0.586–0.856 and RR: 0.484, 95% CI: 0.393–0.595, respectively), including prostate cancer (pre-diagnostic use: RR = 0.874, 95% CI, 0.787–0.97; post-diagnostic use: RR = 0.482, 95% CI 0.359–0.647), and breast cancer (pre-diagnostic use: RR = 0.644, 95% CI 0.565–0.735; post-diagnostic use: RR = 0.485, 95% CI 0.362–0.651). However, lymph node metastasis was weakly related with pre-diagnostic use of NSAIDs (RR = 0.949, 95% CI 0.914–0.985). NSAIDs are related to a significantly reduced risk of metastasis development, regardless of pre-diagnostic or post-diagnostic use. However, NSAIDs and lymph node metastasis are weakly associated. Our finding suggested a novel metastasis management.

Correlation between impedance cardiography and 6 min walk distance in atrial fibrillation patients

Background

The correlation between impedance cardiography (ICG) and 6 min walk distance (6MWD) in atrial fibrillation (AF) patients remains unknown.

Methods

We recruited 49 subjects in the study (21 AF patients and 28 patients without AF) and estimated hemodynamic parameters: cardiac output (CO), stroke volume (SV), stroke volume index (SVI), left stroke work (LSW), left stroke work index (LSWI), stroke systemic vascular resistance (SSVR), stroke systemic vascular resistance index (SSVRI); 6MWD, left ventricle ejection fraction (LVEF), NT-pro brain natriuretic peptide (NT-pro BNP) for the two groups.

Results

The AF group have apparently lower CO (2.26 ± 0.14 VS 4.11 ± 0.20 L/min, p = 0.039) and distinctly higher SVR (677.60 ± 69.10 VS 344.41 ± 22.98 dynes/cm⁵, p = 0.001), SSVRI (396.97 ± 36.80 VS 199.01 ± 11.72 dynes/cm⁵/m², p < 0.001) than the control group. NT-pro BNP (1409.48 ± 239.90 VS 332.59 ± 68.85 pg/ml, p = 0.001) in the AF group was significantly higher than the control group and 6MWD (264.33 ± 14.55 VS 428.79 ± 29.98 m, p < 0.001) in the AF group was lower than the control group. There was no significant difference in LVEF between the two groups (62.67 ± 7.62 % VS 63.93 ± 5.03 %, p = 0.470). Pearson correlation analysis revealed that CO (R = 0.494, p = 0.023), SV (R = 0.633, p = 0.002), LSW (R = 0.615, p = 0.003) and LSWI (R = 0.491, p = 0.024) significantly correlated positively with 6MWD in AF patients.

Conclusions

AF patients had lower cardiac output, shorter 6MWD and higher NT-pro BNP than patients with sinus rhythm. The cardiac output measured by impedance cardiography significantly correlated positively with 6MWD in AF patients.