Atrial fibrillation and heart failure: Factors influencing the choice of oral anticoagulant

Oral anticoagulation in heart failure complicated by atrial fibrillation: A nationwide routine data study

BACKGROUND

This nationwide routine data analysis evaluates if oral anticoagulant (OAC) use in patients with heart failure (HF) and atrial fibrillation (AF) leads to a lower mortality and reduced readmission rate. Superiority of new oral anticoagulants (NOACs), compared to vitamin K antagonists (VKA), was analyzed for these endpoints.

METHODS

Anonymous data of patients with a health insurance at the Allgemeine Ortskrankenkasse and a claims record for hospitalization with the main diagnosis of HF and secondary diagnosis of AF (2017-2019) were included. A hospital stay in the previous year was an exclusion criterion. Mortality and readmission for all-cause and stroke/intracranial bleeding (ICB) were analyzed 91-365 days after the index hospitalization. Kaplan-Meier survival curves and multivariable Cox regression models were used to evaluate the impact of medication on outcome.

RESULTS

180,316 cases were included [81 years (IQR 76-86), 55.6% female, CHA2DS2-VASc score ≥ 2 (96.81%)]. In 80.6%, OACs were prescribed (VKA: 21.7%; direct factor Xa inhibitors (FXaI): 60.0%; direct thrombin inhibitors (DTI): 3.4%; with multiple prescriptions per patient included). Mortality rate was 19.1%, readmission rate was 29.9% and stroke/ICB occurred in 1.9%. Risk of death was lower with any OAC (HR 0.77, 95% CI [0.75-0.79]) but without significant differences in OAC type (VKA: HR 0.73, [0.71-0.76]; FXaI: HR 0.77, [0.75-0.78]; DTI: HR 0.71, [0.66-0.77]). The total readmission rate (HR 0.97, [0.94 to 0.99]) and readmission for stroke/ICB (HR 0.71, [0.65-0.77]) was lower with OAC.

CONCLUSIONS

Nationwide data confirm a reduction in mortality and readmission rate in HF-AF patients taking OACs, without NOAC superiority.

Risk of heart failure in elderly patients with atrial fibrillation and diabetes taking different oral anticoagulants: a nationwide cohort study

BACKGROUND

Heart failure (HF) is a critical complication in elderly patients with atrial fibrillation (AF) and diabetes mellitus (DM). Recent preclinical studies suggested that non-vitamin K antagonist oral anticoagulants (NOACs) can potentially suppress the progression of cardiac fibrosis and ischemic cardiomyopathy. Whether different oral anticoagulants influence the risk of HF in older adults with AF and DM is unknown. This study aimed to evaluate the risk of HF in elderly patients with AF and DM who were administered NOACs or warfarin.

METHODS

A nationwide retrospective cohort study was conducted based on claims data from the entire Taiwanese population. Target trial emulation design was applied to strengthen causal inference using observational data. Patients aged  ≥ 65 years with AF and DM on NOAC or warfarin treatment between 2012 and 2019 were included and followed up until 2020. The primary outcome was newly diagnosed HF. Propensity score-based fine stratification weightings were used to balance patient characteristics between NOAC and warfarin groups. Hazard ratios (HRs) were estimated using Cox proportional hazard models.

RESULTS

The study included a total of 24,835 individuals (19,710 NOAC and 5,125 warfarin users). Patients taking NOACs had a significantly lower risk of HF than those taking warfarin (HR = 0.80, 95% CI 0.74-0.86, p < 0.001). Subgroup analyses for individual NOACs suggested that dabigatran (HR = 0.86, 95% CI 0.80-0.93, p < 0.001), rivaroxaban (HR = 0.80, 95% CI 0.74-0.86, p < 0.001), apixaban (HR = 0.78, 95% CI 0.68-0.90, p < 0.001), and edoxaban (HR = 0.72, 95% CI 0.60-0.86, p < 0.001) were associated with lower risks of HF than warfarin. The findings were consistent regardless of age and sex subgroups and were more prominent in those with high medication possession ratios. Several sensitivity analyses further supported the robustness of our findings.

CONCLUSIONS

This nationwide cohort study demonstrated that elderly patients with AF and DM taking NOACs had a lower risk of incident HF than those taking warfarin. Our findings suggested that NOACs may be the preferred oral anticoagulant treatment when considering the prevention of heart failure in this vulnerable population. Future research is warranted to elucidate causation and investigate the underlying mechanisms.

Heart Failure and Atrial Fibrillation, Like Fire and Fury

Heart failure and atrial fibrillation are 2 common cardiovascular disorders that frequently complicate one another and exert a significant detrimental effect on cardiovascular health and well-being. Both heart failure and atrial fibrillation continue to increase in prevalence as the risk factors underlying each condition become more common. This review encompasses what is currently known about the epidemiology and pathophysiology of these comorbidities along with incorporation of landmark trials that have contributed to current guidelines. The focus is on clinically relevant considerations, including the contribution of inflammation in the pathophysiology of atrial fibrillation and heart failure. We explore the emerging role of catheter ablation relative to medical therapy in the management of heart failure with reduced ejection fraction, along with indications for biventricular pacing modalities in cardiac resynchronization therapy. We discuss current guideline-directed therapies and how practice models and national recommendations will likely change based on the most recent randomized controlled trials.

The Role of Antithrombotic Therapy in Heart Failure

Heart failure is a major contributor to global morbidity and mortality burden affecting approximately 1-2% of adults in developed countries, mounting to over 10% in individuals aged >70 years old. Heart failure is characterized by a prothrombotic state and increased rates of stroke and thromboembolism have been reported in heart failure patients compared with the general population. However, the impact of antithrombotic therapy on heart failure remains controversial. Administration of antiplatelet or anticoagulant therapy is the obvious (and well-established) choice in heart failure patients with cardiovascular comorbidity that necessitates their use, such as coronary artery disease or atrial fibrillation. In contrast, antithrombotic therapy has not demonstrated any clear benefit when administered for heart failure per se, i.e. with heart failure being the sole indication. Randomized studies have reported decreased stroke rates with warfarin use in patients with heart failure with reduced left ventricular ejection fraction, but at the expense of excessive bleeding. Non-vitamin K oral anticoagulants have shown a better safety profile in heart failure patients with atrial fibrillation compared with warfarin, however, current evidence about their role in heart failure with sinus rhythm is inconclusive and further research is needed. In the present review, we discuss the role of antithrombotic therapy in heart failure (beyond coronary artery disease), aiming to summarize evidence regarding the thrombotic risk and the role of antiplatelet and anticoagulant agents in patients with heart failure.

The management of atrial fibrillation in heart failure: an expert panel consensus

Heart failure (HF) and atrial fibrillation (AF) often coexist, being closely interrelated as the one increases the prevalence and incidence and worsens the prognosis of the other. Their frequent coexistence raises several challenges, including under-diagnosis of HF with preserved ejection fraction in AF and of AF in HF, characterization and diagnosis of atrial cardiomyopathy, target and impact of rate control therapy on outcomes, optimal rhythm control strategy in the era of catheter ablation, HF-related thromboembolic risk and management of anticoagulation in patients with comorbidities, such as chronic kidney disease or transient renal function worsening, coronary artery disease or acute coronary syndromes, valvular or structural heart disease interventions and cancer. In the present document, derived by an expert panel meeting, we sought to focus on the above challenging issues, outlining the existing evidence and identifying gaps in knowledge that need to be addressed.

Anticoagulation in atrial fibrillation with heart failure

Heart failure (HF) and atrial fibrillation (AF) frequently coexist, and they can beget one another due to similar factors and shared pathophysiology. These pathophysiologic changes promote the episodes of AF, while they in turn predispose to the exacerbation of HF. In this review, we will discuss pathophysiological mechanisms shared by AF and HF. Patients with concomitant HF and AF are at a particularly high risk of thromboembolism, which contribute to even worse symptoms and poorer prognosis. Vitamin K antagonists (VKA) (warfarin) were the traditional medication in AF patients for the prevention of stroke, whereas the advance of novel non-VKA oral anticoagulants (NOACs) (dabigatran, apixaban, rivaroxaban, and edoxaban) is challenging these standard prescriptions. NOACs' potential advantages over warfarin, including fixed dosing regimens, wide therapeutic window, and more sustained anticoagulant response, promote clinicians to consider these novel agents in the first place. However, some data suggested patients with AF and HF may receive different therapeutic response than those with AF alone in anticoagulant treatment. Accordingly, we aim to assess the potential role of oral anticoagulants, especially NOACs, in the management of patients with concomitant AF and HF.

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.

Reasons for and consequences of oral anticoagulant underuse in atrial fibrillation with heart failure

Objective

Atrial fibrillation (AF) is common in patients with heart failure (HF), and oral anticoagulants (OAC) are indicated. The aim was to assess prevalence of, predictors of and consequences of OAC non-use.

Methods

We included patients with AF, HF and no previous valve replacement from the Swedish Heart Failure Registry. High and low CHA2DS2-VASc and HAS-BLED scores were defined as above/below median. Multivariable logistic regressions were used to assess the associations between baseline characteristics and OAC use and between CHA2DS2-VASc and HAS-BLED scores and OAC use. Multivariable Cox regressions were used to assess associations between CHA2DS2-VASc and HAS-BLED scores, OAC use and two composite outcomes: all-cause death/stroke and all-cause death/major bleeding.

Results

Of 21 865 patients, only 12 659 (58%) received OAC. Selected predictors of OAC non-use were treatment with platelet inhibitors, less use of HF treatments, paroxysmal AF, history of bleeding, no previous stroke, planned follow-up in primary care, older age, living alone, lower income and variables associated with more severe HF. For each 1-unit increase in CHA2DS2-VASc and HAS-BLED, the ORs (95% CI) of OAC use were 1.24 (1.21–1.27) and 0.32 (0.30–0.33), and the HRs for death/stroke were 1.08 (1.06–1.10) and for death/major bleeding 1.18 (1.15–1.21), respectively. For high versus low CHA2DS2-VASc and HAS-BLED, the ORs of OAC use were 1.23 (1.15–1.32) and 0.20 (0.19–0.21), and the HRs for death/stroke were 1.25 (1.19–1.30) and for death/major bleeding 1.28 (1.21–1.34), respectively.

Conclusions

Patients with AF and concomitant HF do not receive OAC on rational grounds. Bleeding risk inappropriately affects decision-making more than stroke risk.

Atrial Fibrillation in Heart Failure: a Therapeutic Challenge of Our Times

Atrial fibrillation (AF) and heart failure (HF) are growing cardiovascular disease epidemics worldwide. There has been an exponential increase in the prevalence of AF and HF correlating with an increased burden of cardiac risk factors and improved survival rates in patients with structural heart disease. AF is associated with adverse prognostic outcomes in HF and is most evident in mild-to-moderate left ventricular (LV) dysfunction where the loss of "atrial kick" translates into poorer quality of life and increased mortality. In the absence of underlying structural heart disease, arrhythmia can independently contribute to the development of cardiomyopathy. Together, these 2 conditions carry a high risk of thromboembolism due to stasis, inflammation and cellular dysfunction. Stroke prevention with oral anticoagulation (OAC) remains a mainstay of treatment. Pharmacologic rate and rhythm control remain limited by variable efficacy, intolerance and adverse reactions. Catheter ablation for AF has resulted in a paradigm shift with evidence indicating superiority over medical therapy. While its therapeutic success is high for paroxysmal AF, it remains suboptimal in persistent AF. A better mechanistic understanding of AF as well as innovations in ablation technology may improve patient outcomes in the future. Refractory cases may benefit from atrioventricular junction ablation and biventricular pacing. The value of risk factor modification, especially with regard to obesity, sleep apnea, hypertension and diabetes, cannot be emphasized enough. Close interdisciplinary collaboration between HF specialists and electrophysiologists is an essential component of good long-term outcomes in this challenging population.