The safety of NOACs in atrial fibrillation patient subgroups: A narrative review

Characteristics and Mechanism of Acute Ischemic Stroke in NAVF Patients With Prior Oral Anticoagulant Therapy

OBJECTIVES

We aimed to analyze the characteristics and mechanisms of acute ischemic stroke (AIS) in patients with nonvalvular atrial fibrillation (NVAF) who received prior anticoagulant therapy.

METHODS

We retrospectively analyzed the data of patients with NVAF and AIS between January 2016 and December 2021. Patients were divided into non-anticoagulant, adequate anticoagulant, and insufficient anticoagulant groups according to their prior anticoagulant status. Patients with prior anticoagulant therapy were further divided into warfarin and direct oral anticoagulant groups.

RESULTS

A total of 749 patients (661 without anticoagulants, 33 with adequate anticoagulants, and 55 with insufficient anticoagulants) were included. Patients with adequate anticoagulant had a milder National Institute of Health Stroke Scale at presentation ( P =0.001) and discharge ( P =0.003), a higher proportion of Modified Rankin Scale (mRS) ≤2 at discharge ( P =0.011), and lower rates of massive infarction ( P =0.008) than patients without anticoagulant. Compared with the non-anticoagulant group, the proportion of intravenous thrombolysis was significantly lower in the adequate anticoagulant ( P <0.001) and insufficient anticoagulant ( P =0.009) groups. Patients in the adequate anticoagulant group had higher rates of responsible cerebral atherosclerotic stenosis ( P =0.001 and 0.006, respectively) and competing large artery atherosclerotic mechanisms ( P =0.006 and 0.009, respectively) than those in the other 2 groups. Compared with warfarin, direct oral anticoagulant was associated with higher rates of Modified Rankin Scale ≤2 at discharge ( P =0.003).

CONCLUSIONS

Adequate anticoagulant therapy may be associated with milder stroke severity and better outcomes at discharge in patients with NVAF. Competing large artery atherosclerotic mechanisms may be associated with anticoagulant failure in patients with NAVF with prior adequate anticoagulant therapy.

Plasma Drug Values of DOACs in Patients Presenting with Gastrointestinal Bleeding: A Prospective Observational Study

Background and Objectives: Anticoagulants are a well-known risk factor for gastrointestinal bleeding (GIB). In recent years, direct oral anticoagulants (DOACs) have taken a leading role in the treatment and prevention of thromboembolic incidents. The aim of this study was to investigate the prevalence of DOAC-treated patients with GIB whose plasma drug concentrations exceeded the cut-off values reported in the literature and to evaluate their clinical characteristics. Materials and Methods: Patients who were admitted to the Intensive Care Unit in the period 2/2020-3/2022 due to GIB were prospectively included in the study and classified into three groups according to the prescribed type of DOAC (apixaban, rivaroxaban, and dabigatran). For all participants, it was determined if the measured plasma drug levels exceeded the maximum serum concentration (Cmax) or trough serum concentration (Ctrough) obtained from the available data. A comparison of clinical parameters between the patients with and without excess drug values was performed. Results: There were 90 patients (54.4% men) included in the study, of whom 27 were treated with dabigatran, 24 with apixaban, and 39 with rivaroxaban. According to Cmax, there were 34 (37.8%), and according to Ctrough, there were 28 (31.1%) patients with excess plasma drug values. A statistically significant difference regarding excess plasma drug values was demonstrated between DOACs according to both Cmax (p = 0.048) and Ctrough (p < 0.001), with the highest rate in the group treated with dabigatran (55.6% for Cmax and 59.3% for Ctrough). Multivariate logistic regression showed that age (OR 1.177, p = 0.049) is a significant positive and glomerular filtration rate (OR 0.909, p = 0.016) is a negative predictive factor for excess plasma drug values. A total of six (6.7%) patients had fatal outcomes. Conclusions: Plasma drug concentrations exceed cut-off values reported in the literature in more than one-third of patients with GIB taking DOAC, with the highest rate in the dabigatran group. Clinicians should be more judicious when prescribing dabigatran to the elderly and patients with renal failure. In these patients, dose adjustment, plasma drug monitoring, or substitution with other, more appropriate DOACs should be considered.

Edoxaban versus Warfarin in high-risk patients with atrial fibrillation: A comprehensive analysis of high-risk subgroups

BACKGROUND

To compare the efficacy and safety of edoxaban vs warfarin in high-risk subgroups.

METHODS

ENGAGE AF-TIMI 48 was a multicenter randomized, double-blind, controlled trial in 21,105 patients with atrial fibrillation (AF) within 12 months and CHADS₂ score >2 randomized to higher-dose edoxaban regimen (HDER) 60 mg/reduced 30 mg, lower-dose edoxaban regimen (LDER) 30 mg/reduced 15 mg, or warfarin, and followed for 2.8 years (median). The primary outcome for this analysis was the net clinical outcome (NCO), a composite of stroke/systemic embolism events, major bleeding, or death. Multivariable risk-stratification analysis was used to categorize patients by the number of high-risk features.

RESULTS

The annualized NCO rates in the warfarin arm were highest in patients with malignancy (19.2%), increased fall risk (14.0%), and very-low body weight (13.5%). The NCO rates increased with the numbers of high-risk factors in the warfarin arm: 4.5%, 7.2%, 9.9% and 14.6% in patients with 0 to 1, 2, 3, and >4 risk factors, respectively (P_trend <0.001). Versus warfarin, HDER was associated with significant reductions of NCO in most of the subgroups: elderly, patients with moderate renal dysfunction, prior stroke/TIA, of Asian race, very-low body weight, concomitant single antiplatelet therapy, and VKA-naïve. With more high-risk features (0->4+), the absolute risk reductions favoring edoxaban over warfarin increased: 0.3%->2.0% for HDER; 0.4%->3.4% for LDER vs warfarin (P = .065 and P < .001, respectively).

CONCLUSIONS

While underuse of anticoagulation in high-risk patients with AF remains common, substitution of effective and safer alternatives to warfarin, such as edoxaban, represents an opportunity to improve clinical outcomes.

Use of NOACS in high-risk patients with atrial fibrillation in Saudi Arabia: Perspectives on improving patient care

BACKGROUND

Despite the widespread and increasing use of NOACs in Saudi Arabia, there is a lack of contemporary guidance specific to the region. In particular, guidance on NOAC use in high-risk patients who are more likely to experience bleeding with oral anticoagulant therapy is needed. There is an unmet need for a review of contemporary evidence coupled with expert insights on safe and effective NOAC use in high-risk patients with AF in Saudi Arabia.

RESEARCH DESIGN AND METHODS

This article provides a detailed review of contemporary literature on NOAC use in high-risk patients with AF. Additionally, key gaps in the literature are identified and expert insights are shared to guide effective management of patients and the significance of local data is evaluated with respect to challenges in optimizing the use of NOACs.

CONCLUSIONS

This article provides information that complements and expands on existing reviews and guidelines on NOAC use in patients with AF, with a focus on challenges specific to the Saudi Arabian context with the potential to make a positive contribution to the medical community in Saudi Arabia and in other nations.

A rare case of acquired factor V inhibitor, during treatment with dabigatran for chronic atrial fibrillation, successfully treated with bypassing agents

Acquired factor V inhibitor represents a rare condition, described only in case reports. The use of activated bypassing agents in bleeding control could be of aid and improve the survival in symptomatic patients with acquired factor V inhibitor.

Real-world evaluation of perception, convenience and anticoagulant treatment satisfaction of patients with atrial fibrillation switched from long-term vitamin K antagonist treatment to dabigatran

Background and purpose

Real-world data about treatment convenience and satisfaction in Asian non-valvular atrial fibrillation (NVAF) patients after switching from vitamin K antagonists (VKAs) to non-VKA oral anticoagulants were evaluated.

Methods

In this non-interventional study involving 49 sites across five countries in Southeast Asia and South Korea, 379 stable NVAF patients who switched from VKA therapy to dabigatran during routine clinical practice were recruited and followed up for 6 months. Treatment convenience and satisfaction were evaluated using Perception on Anticoagulant Treatment Questionnaire-2 (PACT-Q2). Through post hoc analysis, factors associated with improved treatment convenience scores at visit 2 were described.

Results

Treatment convenience and satisfaction significantly improved after switching from VKAs to dabigatran at visit 2 and visit 3 (convenience: p<0.001 each vs baseline; satisfaction: p=0.0174 (visit 2), p=0.0004 (visit 3) compared with baseline). Factors predictive of higher (>80th percentile) response on treatment convenience were female sex, younger age (<75 years), higher baseline stroke risk, higher creatinine clearance and absence of concomitant hypertension, stroke or gastrointestinal diseases.

Conclusion

Dabigatran was associated with a significant improvement in treatment convenience and satisfaction after switching from VKAs when used for stroke prevention in NVAF patients from Southeast Asia and South Korea.

Safety and effectiveness of non-vitamin K oral anticoagulants versus warfarin in real-world patients with non-valvular atrial fibrillation: a retrospective analysis of contemporary Japanese administrative claims data

Objective

To assess the safety (ie, risk of bleeding) and effectiveness (ie, risk of stroke/systemic embolism (SE)) separately for four non-vitamin K oral anticoagulants (NOACs; apixaban, dabigatran, edoxaban and rivaroxaban) versus warfarin in Japanese patients with non-valvular atrial fibrillation (NVAF), including those at high risk of bleeding and treated with reduced doses of NOACs.

Methods

We conducted a retrospective analysis of electronic health records and claims data from 372 acute care hospitals in Japan for patients with NVAF newly initiated on NOACs or warfarin. Baseline characteristics were balanced using inverse probability of treatment weighting with stabilised weights (s-IPTW). Bleeding risk and stroke/SE risk were expressed as HRs with 95% CIs. Two sensitivity analyses were conducted.

Results

A total of 73 989 patients were eligible for analysis. Notably, 52.8%-81.9% of patients received reduced doses of NOACs. After applying s-IPTW, patient characteristics were well balanced across warfarin/NOAC cohorts. The mean within-cohort age, CHADS₂ score and CHA₂DS₂-VASc score were 76 years, 2.2-2.3 and 3.8, respectively. In all age categories, the majority of the HRs for major bleeding, any bleeding and stroke/SE were equal to or below 1 for all NOACs versus warfarin. Apixaban was the only NOAC associated with a significantly lower risk of any bleeding. There was a trend towards increased risk reduction with NOACs versus warfarin in patients with body weight ≥60 kg. In patients with renal disease, the HRs for apixaban versus warfarin were below 1 for major bleeding, any bleeding and stroke/SE, with statistical significance observed for the risk reduction in stroke/SE versus warfarin. In the sensitivity analysis, there were no large differences in HRs between the two observational periods.

Conclusions

In patients with NVAF primarily treated with reduced-dose NOACs, the risks of stroke/SE and major bleeding were significantly lower with NOACs versus warfarin.

Evolving paradigms in antithrombotic therapy for anticoagulated patients undergoing coronary stenting

A sizable proportion of coronary artery disease (CAD) patients undergoing percutaneous coronary intervention (PCI) with stent implantation have an indication for treatment with oral anticoagulant therapy (OAC). The coexistence of atrial fibrillation (AF) and the need for PCI expose patients to a higher risk of developing thrombotic complications, and a multitargeted antithrombotic treatment strategy, addressing both platelet- and coagulation-mediated triggering mechanisms of thrombosis, is necessary for ensuring full protection from ischemic hazards. The increased bleeding risk identified with triple antithrombotic therapy has driven the search for alternative treatment modalities and pharmacological combination strategies aimed at achieving an optimal balance between safety and efficacy in this complex clinical scenario. Over a short time period, the paradigms surrounding the management of patients undergoing PCI who require OAC have substantially evolved. In this review, we summarize and critically evaluate the results of recent randomized clinical trials investigating the pharmacological management of patients who, in addition to antiplatelet therapy, have an indication for OAC treatment before or at the time of a PCI procedure.