Amiodarone and risk of death in contemporary patients with atrial fibrillation: Findings from The Retrospective Evaluation and Assessment of Therapies in AF study

Atrial Fibrillation and Chronic Kidney Disease: Aetiology and Management

Chronic kidney disease (CKD) and atrial fibrillation (AF) are associated with significant cardiovascular morbidity and mortality. Recent studies have highlighted an increased prevalence and incidence of AF in patients with CKD. This article aims to provide a comprehensive review of current management strategies and considerations of treating atrial fibrillation with concomitant CKD. Potential electrophysiological mechanisms between AF and CKD are explored. Current evidence and literature focusing on pharmacological rate and rhythm control along with procedural intervention is reviewed and presented. The management of AF and CKD together is complex, but particularly pertinent when considering the close cyclical relationship in the progression of both diseases.

Etiologies, Mechanisms, Management, and Outcomes of Electrical Storm

Electrical storm (ES) is characterized by three or more discrete sustained ventricular tachyarrhythmia episodes occurring within a limited time frame (generally ≤ 24 h) or an incessant ventricular tachyarrhythmia lasting > 12 h. In patients with an implantable cardioverterdefibrillator (ICD), ES is defined as three or more appropriate device therapies, separated from each other by at least 5 min, which occur within a 24-h period. ES may constitute a medical emergency, depending on the number arrhythmic episodes, their duration, the type, and the cycle length of the ventricular arrhythmias, as well as the underlying ventricular function. This narrative review was facilitated by a search of MEDLINE to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and other clinically relevant studies. The search was limited to English-language reports published between 1999 and 2023. ES was searched using the terms mechanisms, genetics, channelopathies, management, pharmacological therapy, sedation, neuraxial modulation, cardiac sympathetic denervation, ICDs, and structural heart disease. Google and Google scholar as well as bibliographies of identified articles were reviewed for additional references. This manuscript examines the current strategies available to treat ES and compares pharmacological and invasive treatment strategies to diminish ES recurrence, morbidity, and mortality.

Amiodarone and pulmonary toxicity in atrial fibrillation: a nationwide Israeli study

BACKGROUND AND AIMS

Amiodarone-related interstitial lung disease (ILD) is the most severe adverse effect of amiodarone treatment. Most data on amiodarone-related ILD are derived from periods when amiodarone was given at higher doses than currently used.

METHODS

A nationwide population-based study was conducted among patients with incident atrial fibrillation (AF) between 1 December 1999 and 31 December 31 2021. Amiodarone-exposed patients were matched 1:1 with controls unexposed to amiodarone based on age, sex, ethnicity, and AF diagnosis duration. The final patient cohort included only matched pairs where amiodarone therapy was consistent throughout follow-up. Directed acyclic graphs and inverse probability treatment weighting (IPTW) modelling were used. Patients with either prior ILD or primary lung cancer (PLC) were excluded. The primary outcome was the incidence of any ILD. Secondary endpoints were death and PLC.

RESULTS

The final cohort included 6039 amiodarone-exposed patients who were matched with unexposed controls. The median age was 73.3 years, and 51.6% were women. After a mean follow-up of 4.2 years, ILD occurred in 242 (2.0%) patients. After IPTW, amiodarone exposure was not significantly associated with ILD [hazard ratio (HR): 1.45, 95% confidence interval (CI): 0.97, 2.44, P = 0.09]. There was a trivial higher relative risk of ILD among amiodarone-exposed patients between Years 2 and 8 of follow-up [maximal risk ratio (RR): 1.019]. Primary lung cancer occurred in 97 (0.8%) patients. After IPTW, amiodarone was not associated with PLC (HR: 1.18, 95% CI: 0.76, 2.08, P = 0.53). All-cause death occurred in 2185 (18.1%) patients. After IPTW, amiodarone was associated with reduced mortality risk (HR: 0.65, 95% CI: 0.60, 0.72, P < 0.001). The results were consistent across a variety of sensitivity analyses.

CONCLUSION

In a contemporary AF population, low-dose amiodarone was associated with a trend towards increased risk of ILD (15%-45%) but a clinically negligible change in absolute risk (maximum of 1.8%), no increased risk of PLC, and a lower risk of all-cause mortality.

Association of CHA2DS2-VASc and HAS-BLED to frailty and frail outcomes: From the TREAT-AF study

BACKGROUND

Morbidity and mortality associated with high CHA₂DS₂-VASc and HAS-BLED scores is not specific to atrial fibrillation (AF). Frailty could be an important contributor to this morbidity and mortality while being mechanistically independent from AF. We sought to evaluate the association of stroke and bleeding risk to noncardiovascular frail events and the association of stroke prevention therapy to outcomes in frail patients with AF.

METHODS

Using the TREAT-AF (The Retrospective Evaluation and Assessment of Therapies in AF) study from the Veterans Health Administration, we identified patients with newly diagnosed AF from 2004 to 2014. Baseline frailty was identified using a previously validated claims-based index requiring ≥2 of 12 ICD-9 diagnoses. Logistic regressions modeled the association between CHA₂DS₂-VASc and modified HAS-BLED and frailty. Cox proportional hazard regressions were used to evaluate the association between CHA₂DS₂-VASc and modified HAS-BLED and a composite of noncardiovascular frail events (fractures, urinary tract infections, bacterial pneumonia, or dehydration). We also evaluated the association of oral anticoagulant (OAC) use with stroke, bleeding, and 1-year mortality in frail patients and non-frail patients.

RESULTS

In 213,435 patients (age 70 ± 11; 98% male; CHA₂DS₂-VASc 2.4 ± 1.7) with AF, 8,498 (4%) were frail. CHA₂DS₂-VASc > 0 and HAS-BLED > 0 were strongly associated with frailty (odds ratio [OR] 13.3 (95% CI: 11.6-15.2) for CHA₂DS₂-VASc 4+ and OR 13.4 (10.2-17.5) for HAS-BLED 3+). After adjusting for covariates, CHA₂DS₂-VASc, and HAS-BLED > 0 were associated with higher risk of non-cardiovascular frail events (hazard ratio [HR] 2.1 (95% CI: 2.0-2.2) for CHA₂DS₂-VASc 4+ and HR 1.4 (95% CI: 1.3-1.5) for HAS-BLED 3+). In frail patients, OAC use was associated with significantly lower risk of 1-year mortality (HR 0.82; 95% CI 0.72-0.94, P = .0031) but did not reach significance for risk of stroke (HR 0.80; 95% CI 0.55-1.18, P = .26) or major bleeding (HR 1.08; 95% CI 0.93-1.25, P = .34).

CONCLUSIONS

High CHA₂DS₂-VASc and HAS-BLED scores are strongly associated with frailty. However, in frail patients, OAC use was associated with reduction in 1-year mortality. For this challenging clinical population with competing risks of frailty and frail events, focused prospective studies are needed to support clinical decision-making. Until then, careful evaluation of frailty should inform shared decision-making.

An Integrative Comparative Study Between Digoxin and Amiodarone as an Emergency Treatment for Patients With Atrial Fibrillation With Evidence of Heart Failure: A Systematic Review and Meta-Analysis

The emergency treatment of atrial fibrillation (AF) involves utilizing two strategies. The first strategy normally involves permitting the atrial fibrillation to persevere as the ventricular rate is controlled. The other method involves utilizing anti-arrhythmic drugs in cardioversion and attempting to maintain sinus rhythm. Different pharmacological treatments, including digoxin and amiodarone, have been used to manage AF. A literature review on amiodarone and digoxin in the treatment of AF among patients with heart failure (HF) has shown that both drugs have potential risks. Therefore, we are conducting this systematic review and meta-analysis to compare the effectiveness of amiodarone and digoxin in the treatment of AF among patients with evidence of HF. A literature search of relevant articles was conducted on six electronic databases (PubMed, Web of Science, Medline, ScienceDirect, Cochrane Library, and Google Scholar) from 2000 to 2022. The search yielded seven studies that had met the inclusion criteria. Our meta-analysis of four studies showed that there was no significant difference in the reduction of heart rate after treatment with either amiodarone or digoxin (mean difference (MD): -5.44; 95% confidence interval (CI): -9.53 to -1.34; I2 = 25%; p = 0.26). On the other hand, the statistical analysis showed that amiodarone had a better effect on the conversion to sinus rhythm than digoxin (63% versus 35%, respectively). Based on evidence from our meta-analysis, the clinical effect of amiodarone and digoxin in the emergency treatment of AF on heart rate control was unclear. However, amiodarone has a significant impact on the restoration of sinus rhythm compared with digoxin and can be considered the first-line drug regimen in conversion to sinus rhythm for AF patients with evidence of heart failure. However, the use of amiodarone and digoxin is complicated by adverse events and all-cause mortality.

Association between use of amiodarone for non-valvular atrial fibrillation and patient survival: from the prospective China Atrial Fibrillation Registry

Background

Post hoc analysis of the landmark atrial fibrillation follow-up investigation of rhythm management trial revealed that amiodarone was associated with higher risks of mortality, intensive care unit admission, and non-cardiovascular death. We aim to evaluate the association between amiodarone use and patient survival under updated medical mode and level using data from the China Atrial Fibrillation (China-AF) Registry study.

Methods

Clinical data of 8161 non-valvular atrial fibrillation (NVAF) patients who were antiarrhythmic drug (AAD)-naive before enrollment into the China-AF Registry, recruited between August 2011 and February 2017, were collected. The primary outcome was all-cause mortality. A Cox proportional hazard regression model was used to evaluate the association between amiodarone use and the outcome. We also calculated the rate of sinus rhythm maintenance at the penultimate follow-up.

Results

Compared with 6167 patients of non-AAD group, 689 patients of the amiodarone group were younger (mean age 65.6 vs. 68.6 years), more frequently completed high school education, had fewer comorbidities such as chronic heart failure, prior bleeding, and stroke, and were more likely to be treated in tertiary hospitals while less hospitalization. The proportion of persistent AF was much lower among users of amiodarone, who were also less likely to be taking oral anticoagulants. The patients in the amiodarone group had a statistically insignificant lower incidence of all-cause mortality (2.44 vs. 3.91 per 100 person-years) over a mean follow-up duration of 300.6 ± 77.5 days. After adjusting for potential confounders, amiodarone use was not significantly associated with a lower risk of all-cause mortality (adjusted hazard ratio, 0.79; 95% confidence interval, 0.42–1.49). Sub-group analysis revealed the consistent results. The rate of sinus rhythm maintenance at the penultimate follow-up in the amiodarone group was significantly higher than in the non-AAD group.

Conclusions

Our study indicated that amiodarone use was not significantly associated with a lower risk of 1-year all-cause mortality compared with a non-AAD strategy in “real-world” patients with NVAF.

Nanoparticles administered intrapericardially enhance payload myocardial distribution and retention

Pharmacological therapies for cardiovascular diseases are limited by short-term pharmacokinetics and extra-cardiac adverse effects. Improving delivery selectivity specifically to the heart, wherein therapeutic drug levels can be maintained over time, is highly desirable. Nanoparticle (NP)-based pericardial drug delivery could provide a strategy to concentrate therapeutics within a unique, cardiac-restricted compartment to allow sustained drug penetration into the myocardium. Our objective was to explore the kinetics of myocardial penetration and retention after pericardial NP drug delivery. Fluorescently-tagged poly(lactic-co-glycolic acid) (PLGA) NPs were loaded with BODIPY, a fluorophore, and percutaneously administered into the pericardium via subxiphoid puncture in rabbits. At distinct timepoints hearts were examined for presence of NPs and BODIPY. PLGA NPs were found non-uniformly distributed on the epicardium following pericardial administration, displaying a half-life of ~2.5days in the heart. While NPs were mostly confined to epicardial layers, BODIPY was capable of penetrating into the myocardium, resulting in a transmural gradient. The distinct architecture and physiology of the different regions of the heart influenced BODIPY distribution, with fluorophore penetrating more readily into atria than ventricles. BODIPY proved to have a long-term presence within the heart, with a half-life of ~7days. Our findings demonstrate the potential of utilizing the pericardial space as a sustained drug-eluting reservoir through the application of nanoparticle-based drug delivery, opening several exciting avenues for selective and prolonged cardiac therapeutics.

Atrial fibrillation after electrical cardioversion in elderly patients: a role for arterial stiffness? Results from a preliminary study

Background and aims

Atrial fibrillation (AF) is the most frequent arrhythmia of the elderly, and electrical cardioversion (ECV) is a common procedure, although incidence of recurrences remains high. We evaluated the possible association between arterial stiffness (AS) and the persistence or recurrence of AF in elderly patients after ECV.

Methods

We enrolled all subjects undergoing ECV over a 9-month period. AS was evaluated with the cardio-ankle vascular index (CAVI). Patients were then visited at follow-up (on average at 6 months).

Results

Thirty-one patients (age 78 ± 7 years; men 67.7 %; CHA₂DS₂-VASc 4.1 ± 1.6; AF length >2 months 51.6 %; CAVI 9.9 ± 1.6) underwent ECV. At follow-up, sinus rhythm was recorded in 16 (51.6 %) patients. At multivariate analysis, the presence of AF was directly associated with CHA₂DS₂-VASc score and CAVI. Amiodarone therapy reduced the risk of relapsed AF.

Conclusions

In elderly AF patients treated with ECV, AS at baseline seems to predict AF at follow-up.