Frequency and Outcomes of Reduced Dose Non-Vitamin K Antagonist Anticoagulants: Results From ORBIT-AF II (The Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II)

Use of DOACs in frail elderly patients in light of class genericization

BACKGROUND

Frailty and comorbidity influence the therapeutic approach in everyday clinical practice. The DOACs genericization opens a reflection on their differences from a pharmacological and bioavailability point of view, particularly in elderly frail patients. The aim of this project was to create a national Delphi consensus on the topic of the use of DOACs for atrial fibrillation (AF) in such patients, in light of the genericization of the class.

METHODS AND RESULTS

The consensus dealt with 3 main topics: a) efficacy and safety of DOACs in elderly and/or frail patients; b) therapeutic choice in specific frailty scenarios; c) DOACs genericization. 56 cardiologists, two internists and two neurologists from Italy expressed their level of agreement on each statement by using a 5-point Likert scale (1: strongly disagree, 2: disagree, 3: uncertain, 4: agree, 5: strongly agree). A positive consensus was reached if the percentage of agreement (vote 1-2, positive consensus) or disagreement (votes 4-5, negative consensus) was >66%; otherwise, no consensus was reached. Results are displayed accordingly.

CONCLUSIONS

After 10 years of everyday clinical management of DOACs for AF, specific elements differentiating a molecule from another, either for efficacy or for safety, are consolidated. However, some uncertainties still exist in particular contexts, such as chronic kidney disease or cancer patients. Clinicians have an unsure attitude towards generic drugs, because clinical practice is lacking as well as a proper knowledge of the topic. Albeit being an alternative, the choice of the generic drug must remain the responsibility of the clinician.

How I treat the co-occurrence of venous and arterial thromboembolism: anticoagulation, antiplatelet therapy, or both?

ABSTRACT

Arterial and venous thromboses are classically considered distinct disease states, with arterial thrombosis mediated predominantly by platelets and therefore, treated with antiplatelet therapy, and venous thrombosis mediated by the plasmatic coagulation system and treated with anticoagulation. However, co-occurrence of arterial and venous events is common, and there is increasing evidence of shared risk factors and pathophysiologic overlap. This presents a management challenge: does the patient with venous and arterial thrombosis, require anticoagulation, antiplatelet therapy, or both? Herein, we present a structured approach to the evaluation and management of patients with venous thrombosis who are also at risk for or have a history of an arterial thromboembolic event. We emphasize the importance of defining the indications for antithrombotic therapy, as well as the evaluation of factors that influence both thrombotic and bleeding risk, including disorder-specific and patient-specific factors, as well as the inherent risk balance of antithrombotic therapy regimens. We illustrate this approach in 4 cases, discussing the unique considerations and recent updates in the management of venous thrombosis, acute noncardioembolic ischemic stroke, coronary artery disease and acute myocardial infarction, and peripheral artery disease after revascularization.

Role of Clinical Pharmacy anticoagulation service on Apixaban prescribing appropriateness in atrial fibrillation in Saudi Arabia

BACKGROUND

Inappropriate DAOC dosing is precuarious and frequently encountered. Apixaban is the most reported DOAC to be inappropriately dosed. We examined the effect of adding a Clinical Pharmacist to the cardiology team rounds to the standard practice in Apixaban prescription patterns in a tertiary center in KSA.

OBJECTIVE

To determine the effect of clinical pharmacy services on Apixaban dose appropriateness upon discharge in Atrial Fibrillation patient pobulation.

METHODS

This is a single-center, retrospective cohort of patients with atrial fibrillation using a quasi-experiment of pre-post design to evaluate Apixaban dose appropriateness using clinical pharmacy services. Clinical pharmacist was added to the team to evaluate and change the regimen according to FDA dosing. Data were collected for 9 months for each, patients were followed up for efficacy and safety outcomes for 1 year.

RESULTS

A total of 550 patients were initially collected after follow-up, the number of patients was in the pre-phase cohort (NO CCP; n= 112) from July 2018 to the March 2019 and compared to post phase cohort (CCP, n=103) from July 2019 to March 2020. 215 Patients were included, For primary end point, CCP cohort had significantly appropriate prescriptions of apixaban compared to Non-CCP (90.2 % vs 71.5 %, p<0.001)., no differences in thromboembolic and hemorrhagic adverse events betewwn 2 cohorts.

CONCLUSION

A multidisciplinary team approach including clinical pharmacy services is effective in increasing the appropriate use of Apixaban upom discharge without apparent increased risk of bleeding or Adverse events.

The Impact of Clinical Pharmacy Services on Direct Oral Anticoagulant Medication Selection and Dosing in the Ambulatory Care Setting

Background: Off-label dosing of direct oral anticoagulants (DOACs) is both common and associated with adverse patient outcomes. Evidence describing best practices to support optimal direct oral anticoagulant (DOAC) dosing is limited. Objective: To describe the impact of clinical pharmacist intervention on DOAC prescribing. Methods: This retrospective study was a descriptive analysis conducted within an integrated healthcare system with a centralized, pharmacist-led Anticoagulation Management Service (AMS). Patients prescribed a DOAC between January 1, 2020 and December 31, 2020 were included. Pharmacy dispensing reports were generated for pharmacist review and anticoagulant drug therapy changes were recommended to physicians where appropriate. The primary objective was to describe the number and type of recommendations made. Secondary objectives were to determine the provider acceptance rate based on the intervention type and on clinical vs formulary recommendations. Results: Clinical pharmacists made 147 recommendations for 2331 unique patients included in the analysis. Twenty-three recommendations (16%) were to decrease the dose, 46 (31%) were to increase the dose, 14 (10%) were to change the medication due to clinical scenario, 62 (42%) were to change the medication due to cost, and 2 (1%) were another issue. One hundred twenty-three (84%) recommendations were accepted. The provider acceptance rate was similar for clinical and formulary recommendations (85% and 82% respectively). Conclusion: Implementation of report-driven clinical pharmacist intervention led to an improvement in appropriate DOAC medication selection and dosing.

Appropriateness of prescribing profiles and intake adherence to non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation: analysis of a retrospective longitudinal study using real-world data from Northern Portugal (AF-React Study)

OBJECTIVES

This study aimed to assess the appropriateness of prescribing profiles and intake adherence to non-vitamin K antagonist oral anticoagulants (NOACs) in patients with atrial fibrillation (AF).

DESIGN

Retrospective longitudinal study.

SETTING

The study was conducted in the Regional Health Administration of Northern Portugal.

PARTICIPANTS

The authors selected a database of 21 854 patients with prescriptions for NOACs between January 2016 and December 2018 and were classified with AF until December 2018.

OUTCOME MEASURES

The appropriate dosage of NOAC for patients with AF divided into three categories: contraindicated, inconsistent and consistent, based on the 2020 European Society of Cardiology guidelines for AF.

RESULTS

Dabigatran had a lower percentage of guideline-consistent doses (n=1657, 50.1%) than other drugs such as rivaroxaban (n=4737, 81.6%), apixaban (n=3830, 78.7%) and edoxaban (n=436, 82.1%). Most patients with an inconsistent dose were prescribed a lower dose than recommended based on their glomerular filtration rate (GFR). Among patients younger than 75 years with GFR >60 mL/min, 59.8% (n=10 028) had an adequate GFR range, while 27.8% (n=7166) of GFR measurements from patients older than 75 years old and 29.4% (n=913) of GFR measurements from patients younger than 75 years with GFR <60 mL/min were within an adequate time range. Adherence to NOACs varied across different drugs, with 59.1% (n=540) adhering to edoxaban, 56.3% (n=5443) to rivaroxaban, 55.3% (n=3143) to dabigatran and 53.3% (n=4211) to apixaban.

CONCLUSIONS

Dabigatran had the lowest percentage of guideline-consistent doses. Patients younger than 75 years with GFR >60 mL/min had the highest percentage with an adequate GFR range, while other groups who require closer GFR monitoring had lower percentages within an adequate GFR range. Adherence to NOACs differed among different drugs, with greater adherence to treatment with edoxaban and less adherence to apixaban.

A real-world study of different doses of rivaroxaban in patients with nonvalvular atrial fibrillation

To explore the anticoagulant effect and safety of utilizing different doses of rivaroxaban for the treatment of patients with atrial fibrillation (AF) in the real world. A retrospective case-control analysis was performed by applying the hospital database, and 3595 patients with non-valvular atrial fibrillation (NVAF) who were hospitalized and taking rivaroxaban at Wuhan Asia Heart Hospital and Wuhan Asia General Hospital from March 2018 to December 2021 were included in the study, and were divided into the rivaroxaban 10 mg and 15 mg groups according to the daily prescribed dose, of which 443 cases were in the 10 mg group and 3152 cases were in the 15 mg group. The patients were followed up regularly, and the incidence of thrombotic events, bleeding events and all-cause deaths were recorded and compared between the 2 groups, and logistic regression was applied to analyze the influencing factors for the occurrence of adverse events. Comparison of the incidence of thrombosis, bleeding and all-cause death between the 2 groups of patients showed that the 10 mg group was higher than the 15 mg group, but the difference was not statistically significant (χ2 = 0.36, 3.26, 1.99, all P > .05); the incidence of total adverse events between the 2 groups of patients was higher in the 10 mg group than in the 15 mg group, with a statistically significant difference (χ2 = 4.53, P = .033); multifactorial logistic regression results showed that age [OR (95% CI) = 1.02 (1.00-1.04)], diabetes mellitus [OR (95% CI) = 1.69 (1.09-2.62)], D-dimer level [OR (95% CI) = 1.06 (1.00-1.11)] and persistent AF [OR (95% CI) = 1.54 (1.03-2.31)] were risk factors for adverse events (P < .05). In the real world, Asian clinicians recommend rivaroxaban 10 mg once daily for NVAF patients for a variety of reasons; however, this dose is not superior or even inferior to the 15 mg group in terms of effectiveness and safety. Advanced age, elevated D-dimer levels, history of diabetes mellitus, and persistent AF are risk factors for adverse events, and the optimal dosage of rivaroxaban or optimal anticoagulation strategy for Asian patients with nonvalvular AF requires further study.

Inappropriate Underdosing of Direct Oral Anticoagulants in Atrial Fibrillation Patients: Results from the START2-AF Registry

Background: Direct oral anticoagulants (DOACs) are recommended for stroke prevention in non-valvular atrial fibrillation (NVAF) patients. We aimed to describe the prevalence of inappropriate DOACs dose prescription in the START2-AF Registry, the outcomes according to the appropriateness of the dosage, and the factors associated with inappropriate dose prescription. Methods: Patients' demographics and clinical data were prospectively collected as electronic files in an anonymous form on the website of the START2-Registry; DOACs dosage was determined to be appropriate when prescribed according to the European Heart Rhythm Association Guidelines. Results: We included 5943 NVAF patients on DOACs; 2572 (46.3%) were female patients. The standard dose (SD) was prescribed to 56.9% of patients and the low dose (LD) was prescribed to 43.1% of patients; 38.9% of all NVAF patients received an inappropriate LD DOAC and 0.3% received inappropriate SD. Patients treated with LD DOAC had a significantly higher rate of all bleedings (RR 1.5; 95% CI 1.2-2.0), major bleedings (RR 1.8; 95% CI 1.3-1.7), and mortality (RR 2.8; 95% CI 1.9-4.1) with respect to patients treated with SD DOAC. No difference was found among patients treated with appropriate and inappropriate LD regarding bleeding, thrombotic, and mortality rates. Age, body weight <60 kg, and renal failure were significantly associated with inappropriate LD DOAC prescription. Conclusions: Inappropriate LD DOACs in NVAF patients is not associated with a reduction in bleeding risk, nor with an increased thrombotic risk. Instead, it is associated with higher mortality rate, suggesting that, in clinical practice, underdosing is preferred for patients at particularly high risk for adverse events.

Minimally invasive left atrial appendage occlusion plus reduced dose direct oral anticoagulant to prevent stroke in patients with atrial fibrillation-the LAAO-PlusRE

The onset of atrial fibrillation (AF) has a direct association with left atrial appendage (LAA) function, as demonstrated by recent studies demonstrating the link between left atrial (LA) wall fibrosis, impaired contractility, and the development of AF. Non-valvular AF (NVAF) affects almost 30 million people worldwide, with this number expected to increase in the next 20 years. It is the main cause of ischemic stroke, with significant subsequent economic and social impact. Currently, the mainstay of stroke prevention in patients with NVAF is oral anticoagulation (OAC), which reduces the incidence of ischemic events at the stake of increased hemorrhagic events. Despite the introduction and widespread use of direct oral anticoagulants (DOACs), which almost completely replaced vitamin K antagonists (VKAs), the adherence to OAC is still low, hindering the efficacy of stroke prevention. Percutaneous LAA occlusion (LAAO) is now indicated (class IIB) in patients with NVAF at increased ischemic risk who cannot undergo OAC. Recently published data demonstrated that a reduced dose of DOAC after percutaneous LAAO is superior to long-term dual antiplatelet therapy (DAPT) for stroke prevention in the mid-term. One of the possible pitfalls of percutaneous LAAO is postprocedural peri-device leaks (PDLs) that have been associated with increased thromboembolic events. According to LAAOS III results, surgical LAAO during cardiac surgery brings a 33% reduction in risk of stroke at five years, independently from the OAC regimen with a high rate of complete appendage occlusion. The combination of surgical LAAO and reduced dose DOAC might ensure adequate embolic prevention, lowering the hemorrhagic risk. The present manuscript aims to describe the rationale and design of the Minimally Invasive Left Atrial Appendage Occlusion Plus REduced Dose DOAC To Prevent Stroke In Patients With Atrial Fibrillation Randomized Clinical Trial (LAAO-PlusRE).

Ischaemic stroke in a patient with non-valvular atrial fibrillation (NVAF) despite non-vitamin K oral anticoagulant (NOAC) therapy

Primary stroke prevention in non-valvular atrial fibrillation (NVAF) is primarily with non-vitamin K oral anticoagulant (NOAC) therapy. However, 20-36% of ischaemic strokes seem to occur in patients with atrial fibrillation while already on anticoagulation. We present a case of an ischaemic stroke in an elderly female in her 70s with medical history significant for hypertension and NVAF. She had a CHA2DS2-VASc score of 3 and was on apixaban for thromboprophylaxis. She presented with neurological deficits consistent with a left middle cerebral artery stroke, confirmed via head imaging; the most likely stroke aetiology was determined to be cardioembolic in the setting of NVAF. She was treated with continuation of her apixaban at the same dosage She displayed improved function, although with residual expressive aphasia at her 2-month neurology follow-up. Cardioembolic ischaemic stroke in NVAF despite current NOAC therapy does not have current management guidelines.

Changes in cardiac output, rhythm regularity, and symptom severity after electrical cardioversion of atrial fibrillation

OBJECTIVES

Symptoms in atrial fibrillation (AF) range from none to disabling. The physiological correlates of AF symptoms are not well characterized. This study investigated the association between physiological parameters and symptom severity before and after electrical cardioversion (EC) of AF.

DESIGN

We studied 44 patients with persistent AF (age 66.2 ± 7.9 years, 16% females) 4 ± 2 days before and 5 ± 2 days after EC. Physiological parameters included cardiac output (CO; non-invasive inert gas rebreathing), heart rate (HR), RR variability and resting and ambulatory blood pressure (BP). Symptoms and quality of life (QoL) were assessed by the modified European Heart Rhythm Association score (mEHRA), the Atrial Fibrillation Effect on Quality of Life (AFEQT) and the Symptom Checklist for frequency and severity of symptoms (SCL).

RESULTS

28 of 44 patients were still in sinus rhythm (SR) at post EC evaluation. Those in SR had a decreased HR (-15.4 ± 13.1 bpm, p < 0.001), and an increased CO (+0.8 ± 0.7 L/min, p < 0.001) as compared to those with recurrent AF. Changes in CO after EC correlated with symptom improvement as scored by AFEQT (r = 0.36; p < 0.05), AFEQT symptoms subscore (r = 0.46; p < 0.01), SCL for frequency (r = 0.62; p < 0.01) and severity (r = 0.33; p < 0.05) of symptoms, and the mEHRA score (r = 0.50; p < 0.01). A decrease in RR variability showed similar correlations with these measures of symptom improvement.

CONCLUSIONS

Improvements in symptoms and quality of life experienced by patients after electrical conversion of atrial fibrillation are correlated with an increase in CO and a decreased RR variability.

Outcomes of Oral Anticoagulation in Atrial Fibrillation Patients With or Without Comorbid Vascular Disease: Insights From the GARFIELD-AF Registry

BACKGROUND

Many patients with atrial fibrillation suffer from comorbid vascular disease. The comparative efficacy and safety of different types of oral anticoagulation (OAC) in this patient group have not been widely studied.

METHODS

Adults with newly diagnosed atrial fibrillation were recruited into the prospective observational registry, GARFIELD-AF, and followed for 24 months. Associations of vascular disease with clinical outcomes were analyzed using adjusted hazard ratios (HR) obtained via Cox proportional-hazard modeling. Outcomes of OAC vs no OAC, and of non-vitamin K antagonist OAC (NOAC) vs vitamin K antagonist (VKA) treatment, were compared by overlap propensity-weighted Cox proportional-hazard models.

RESULTS

Of 51,574 atrial fibrillation patients, 25.9% had vascular disease. Among eligible atrial fibrillation patients, those with vascular disease received OAC less frequently than those without (63% vs 73%). Over 2-year follow-up, patients with vascular disease showed a higher risk of all-cause mortality (HR 1.30; 95% confidence interval [CI], 1.16-1.47) and cardiovascular mortality (HR 1.59; 95% CI, 1.28-1.97). OAC was associated with a significant decrease in all-cause mortality and non-hemorrhagic stroke, and increased risk of major bleeding in non-vascular disease. In vascular disease, similar but non-significant trends existed for stroke and major bleeding. A significantly lower risk of all-cause mortality (HR 0.74; 95% CI, 0.61-0.90) and major bleeding (HR 0.45; 95% CI, 0.29-0.70) was observed in vascular disease patients treated with NOACs, compared with VKAs.

CONCLUSIONS

Atrial fibrillation patients with a history of vascular disease have worse long-term outcomes than those without. The association of NOACs vs VKA with clinical outcomes was more evident in atrial fibrillation patients with vascular disease.

Predictors of intracranial hemorrhage in patients with atrial fibrillation treated with oral anticoagulants: Insights from the GARFIELD-AF and ORBIT-AF registries

BACKGROUND

An unmet need exists to reliably predict the risk of intracranial hemorrhage (ICH) in patients with atrial fibrillation (AF) treated with oral anticoagulants (OACs).

HYPOTHESIS

An externally validated model improves ICH risk stratification.

METHODS

Independent factors associated with ICH were identified by Cox proportional hazard modeling, using pooled data from the GARFIELD-AF (Global Anticoagulant Registry in the FIELD-Atrial Fibrillation) and ORBIT-AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) registries. A predictive model was developed and validated by bootstrap sampling and by independent data from the Danish National Patient Register.

RESULTS

In the combined training data set, 284 of 53 878 anticoagulated patients had ICH over a 2-year period (0.31 per 100 person-years; 95% confidence interval [CI]: 0.28-0.35). Independent predictors of ICH included: older age, prior stroke or transient ischemic attack, concomitant antiplatelet (AP) use, and moderate-to-severe chronic kidney disease (CKD). Vitamin K antagonists (VKAs) were associated with a significantly higher risk of ICH compared with non-VKA oral anticoagulants (NOACs) (adjusted hazard ratio: 1.61; 95% CI: 1.25-2.08; p = .0002). The ability of the model to discriminate individuals in the training set with and without ICH was fair (optimism-corrected C-statistic: 0.68; 95% CI: 0.65-0.71) and outperformed three previously published methods. Calibration between predicted and observed ICH probabilities was good in both training and validation data sets.

CONCLUSIONS

Age, prior ischemic events, concomitant AP therapy, and CKD were important risk factors for ICH in anticoagulated AF patients. Moreover, ICH was more frequent in patients receiving VKA compared to NOAC. The new validated model is a step toward mitigating this potentially lethal complication.

Prescription of DOACs in Patients with Atrial Fibrillation at Different Stages of Renal Insufficiency

Atrial fibrillation (AF) and renal insufficiency often coexist and are increasingly prevalent with advancing age. Both the risk of thromboembolic events and bleeding propensity are higher in patients with AF and impaired renal function versus those with good renal health. Direct oral anticoagulants (DOACs) are being increasingly preferred over vitamin K antagonists (VKAs) in the treatment of patients with AF and impaired renal function as VKAs may accelerate progression of chronic kidney disease. DOACs, however, are eliminated by the kidneys to varying degrees, and their dosages must be adapted in accordance with renal function. Since creatinine clearance (CrCl) monitoring is recommended in patients with AF receiving DOAC therapy, CrCl must be routinely monitored in patients at the start and during the course of anticoagulation to avoid deviation from Summary of Product Characteristics dosage specifications. This review article provides an overview of current knowledge on the selection and dose of DOACs including apixaban, dabigatran, edoxaban and rivaroxaban in AF patients at different stages of renal insufficiency, with a special focus on elderly patients with comorbidities and receiving multiple medications. The groups discussed in this review include patients with varying levels of CrCl including hyperfiltration or CrCl > 90 ml/min, CrCl < 90-50 ml/min, CrCl < 50-30 ml/min, CrCl < 30-15 ml/min and end-stage renal disease or on dialysis.

Efficacy of ablation therapy on clinical outcomes in patients with atrial fibrillation: a systematic review and meta-analysis

Background

Optimal treatment regimen for patients with atrial fibrillation (AF) remains unclear. Therefore, the authors sought to compare the outcomes of ablation therapy versus pharmacological regimens in patients with AF.

Methods

MEDLINE, Embase, and Cochrane Central databases were searched for randomized controlled trials and observational studies comparing clinical outcomes between of ablation and pharmacological therapy in patients with AF. Stroke, all-cause mortality, cardiovascular mortality, cardiovascular hospitalization, heart failure (HF), and bleeding were among outcomes of interest. Mantel-Haenszel weighted random-effects model was used to calculate relative risks (RRs) with 95 % CIs.

Results

The analysis included ~200 000 patients from 4 randomized controlled trials and 7 observational studies. Meta-analysis showed statistically significant reduction in stroke among patients on ablation therapy [hazard ratio (HR) 0.51, 95% CI (0.43, 0.60), P<0.00001, I2=10%], all-cause mortality [HR 0.64, 95% CI (0.45, 0.93), P=0.02, I2=58%], cardiovascular mortality [HR 0.35, 95% CI (0.25, 0.50), P<0.0001, I2=0%], and HF [HR 0.40, 95% CI (0.31, 0.53), P<0.00001, I2=30%]. However, no significant difference was revealed in the risk of cardiovascular hospitalization [HR 1.04, 95% CI (0.88, 1.23), P=0.66, I2=89%] and bleeding [HR 1.11, 95% CI (0.97, 1.27), P=0.13, I2=0%].

Conclusion

Ablation significantly reduces the risk of stroke, cardiovascular mortality, all-cause mortality, and HF in AF patients, compared with medical therapy alone, supporting its use in clinical practice.

Anticoagulant use in older persons at risk for falls: therapeutic dilemmas-a clinical review

PURPOSE

The aim of this clinical narrative review was to summarise the existing knowledge on the use of anticoagulants and potential adverse events in older people at risk of falls with a history of atrial fibrillation or venous thromboembolism. The review also offers practical steps prescribers can take when (de-)prescribing anticoagulants to maximise safety.

METHODS

Literature searches were conducted using PubMed, Embase and Scopus. Additional articles were identified by searching reference lists.

RESULTS

Anticoagulants are often underused in older people due to concerns about the risk of falls and intracranial haemorrhage. However, evidence suggests that the absolute risk is low and outweighed by the reduction in stroke risk. DOACs are now recommended first line for most patients due to their favourable safety profile. Off-label dose reduction of DOACs is not recommended due to reduced efficacy with limited reduction in bleeding risk. Medication review and falls prevention strategies should be implemented before prescribing anticoagulation. Deprescribing should be considered in severe frailty, limited life expectancy and increased bleeding risk (e.g., cerebral microbleeds).

CONCLUSION

When considering whether to (de-)prescribe anticoagulants, it is important to consider the risks associated with stopping therapy in addition to potential adverse events. Shared decision-making with the patient and their carers is crucial as patient and prescriber views often differ.

Clinical profile and prognosis of elderly patients with left ventricular thrombus after anticoagulation

BACKGROUND

Contemporary data regarding the clinical characteristics and prognosis of left ventricular thrombus (LVT) in older adults (aged ≥ 65 years old) are lacking. In this study, we characterized elderly patients with LVT (aged ≥ 65 years old) and investigated the long-term prognosis in this highly vulnerable patient population.

METHODS

This single-center, retrospective study was conducted from January 2017 to December 2022. Patients with a reported LVT were assessed primarily by transthoracic echocardiography (TEE) and classified into two groups: elderly LVT groups and younger LVT groups. All patients were treated with anticoagulant treatment. Major adverse cardiovascular event (MACE) was defined as the composite of all-cause mortality, systemic embolism, and rehospitalization for cardiovascular events. Survival analyses were performed with the Kaplan-Meier method and Cox proportional-hazard model.

RESULTS

A total of 315 eligible patients were included. Compared to the younger LVT group (n = 171), the elderly LVT group (n = 144) had a lower proportion of males and lower serum creatinine clearance, as well as a higher level of NT-proBNP, and a higher rate of history of systemic embolism. LVT resolution occurred in 59.7% and 69.0% of patients in the elderly LVT group and younger LVT group, respectively, with no significant difference (adjusted HR, 0.97; 95% CI, 0.74-1.28; P = 0.836). Yet, elderly patients with LVT, had higher prevalence rates of MACE (adjusted HR, 1.52; 95% CI, 1.10-2.11; P = 0.012), systemic embolism (adjusted HR, 2.81; 95% CI, 1.20-6.59; P = 0.017) and all-cause mortality (adjusted HR, 2.20; 95% CI, 1.29-3.74; P = 0.004) compared with younger patients with LVT. After adjusting for mortality in the Fine-Gray model, similar results were observed. Additionally, patients treated with different anticoagulation therapies (DOACs vs. warfarin) achieved a similar improvement in prognosis (P > 0.05) or LVT resolution (P > 0.05) in elderly patients with LVT.

CONCLUSIONS

Our results found that elderly patients experiencing LVT have a poor prognosis compared with the younger ones. Clinical prognosis in elderly patients did not significantly differ with the type of anticoagulant used. With aging societies worldwide, further evidence of antithrombotic therapy in elderly individuals with LVT is necessary.

Clinical consequences of off-label reduced dosing of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation: a systematic review and meta-analysis

OBJECTIVE

Postmarketing observational studies report that a substantial percentage of patients with atrial fibrillation (AF) receive a reduced non-vitamin K antagonist oral anticoagulant (NOAC) dose without a clear indication. Recently, increasing evidence has become available to explore the clinical consequences of such off-label reduced dosing (OLRD). This study aims to systematically review and meta-analyse observational studies that report clinical outcomes associated with OLRD of NOACs compared with on-label non-reduced dosing (OLNRD) of NOACs in patients with AF.

METHODS AND ANALYSIS

We performed a systematic literature review and meta-analysis of observational studies reporting clinical outcomes in AF patients with OLRD of an NOAC compared with AF patients with OLNRD of an NOAC. Using random effects meta-analyses, we estimated the risk of stroke/thromboembolism, bleeding and all-cause mortality.

RESULTS

We included 19 studies with a total of 170 394 NOAC users. In these studies, the percentage of OLRD among patients with an indication for an on-label non-reduced NOAC dose ranged between 9% and 53%. 7 of these 19 studies met the predefined criteria for meta-analysis (n=80 725 patients). The pooled HR associated with OLRD of NOACs was 1.04 (95% CI 0.83 to 1.29; 95% prediction interval (PI) 0.60 to 1.79) for stroke/thromboembolism, 1.10 (95% CI 0.95 to 1.29; 95% PI 0.81 to 1.50) for bleeding and 1.22 (95% CI 0.81 to 1.84; 95% PI 0.55 to 2.70) for all-cause mortality.

CONCLUSION

This meta-analysis shows no statistically significant increased risk of stroke/thromboembolism, nor a decreased bleeding risk, nor a difference in risk of all-cause mortality in patients with OLRD of NOACs. Future research may focus on differences between NOACs.

Incidence and Predictors of Switching and Dose Change of Direct Oral Anticoagulants among Elderly Patients with Nonvalvular Atrial Fibrillation: A 5-Year Analysis of a Large Administrative Database

In the last decade, novel oral anticoagulants (NOACs) have emerged as prominent therapeutic options in non-valvular atrial fibrillation (NVAF). We analysed the clinical burden and the switching rate between all available NOACs, and their dosage change over a period of 5 years in a representative population of patients with NVAF aged between 70 and 75 years. Methods and Results: This is a retrospective observational study on administrative databases, covering approximately 6.2 million health-assisted individuals by the Italian National Health System (around 11% of the entire Italian residents). Out of 4640 NVAF patients treated with NOACs and aged 70-75 years in 2017, 3772 (81.3%) patients were still in treatment with NOAC up to 2021 and among them, 3389 (73.0%) patients remained in treatment with the same NOAC during 2017-2021. In fact, 10.2% of patients switched NOAC type and 10.3% changed the dose of the same NOAC. Overall, after switching, the dabigatran and rivaroxaban groups lost, respectively, 13.5% and 2.8% of patients, while apixaban and edoxaban resulted in a relative percentage increase of 6.8% and 44.6% of patients, respectively. By a logistic regression analysis, the treatment with rivaroxaban, apixaban, and edoxaban (respect to dabigatran) was associated with a significant risk reduction of switch of 57%, 68%, and 44%, respectively. On the other hand, several features of high risk were associated with dose reduction. Conclusions. In our 5-year analysis of a large administrative database, a switching among NOACs or a change in NOAC dosages occurred in around 20% of elderly patients with NVAF. The type of NOAC was associated with a high switching rate, while several characteristics of high risk resulted as predictors of dose reduction of NOACs. Moreover, a worsening trend of clinical conditions occurred in patients maintaining the same NOAC treatment across 2017-2021.

Safety and Efficacy Re-Evaluation of Edoxaban and Rivaroxaban Dosing With Plasma Concentration Monitoring in Non-Valvular Atrial Fibrillation: With Observations of On-Label and Off-Label Dosing

Background: Off-label dosing of direct oral anticoagulants (DOAC) as a treatment for non-valvular atrial fibrillation (NVAF) is problematic. Here, we investigated the status of rivaroxaban and edoxaban dosing by monitoring plasma concentrations (PCs). Methods and Results: We monitored drug PCs in 391 and 333 outpatients receiving rivaroxaban and edoxaban, respectively, for NVAF. Drug doses were adjusted if the PC was above the cut-off value (rivaroxaban: 404 ng/mL; edoxaban: 402 ng/mL), determined from receiver operating characteristic curves for predicting bleeding events. On-label standard dosing was reduced to off-label underdosing due to high PCs above the cut-off more often for rivaroxaban (28.1%) than edoxaban (12.6%; P<0.001). Over a median follow-up of 13 months for rivaroxaban and 10 months for edoxaban, the annual incidence of bleeding events was higher with rivaroxaban than with edoxaban (4.88 vs. 3.73 patient-years; P<0.05), although no thromboembolic events occurred in either group. Furthermore, for patients with creatinine clearance >50 mL/min and body weight ≤60 kg, there was a greater incidence of bleeding events with rivaroxaban on-label 15 mg dosing than with edoxaban on-label 30 mg dosing (22.2% vs 2.9%; P<0.01). Conclusions: Monitoring the PCs of rivaroxaban and edoxaban in NVAF patients enables dose adjustments to reduce bleeding risk. The incidence of bleeding under drug PC monitoring was less in the edoxaban than rivaroxaban group.

Safety of off-label dose reduction of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

AIM

To investigate the effects of off-label non-vitamin K oral anticoagulant (NOAC) dose reduction compared with on-label standard dosing in atrial fibrillation (AF) patients in routine care.

METHODS

Population-based cohort study using data from the United Kingdom Clinical Practice Research Datalink, comparing adults with non-valvular AF receiving an off-label reduced NOAC dose to patients receiving an on-label standard dose. Outcomes were ischaemic stroke, major/non-major bleeding and mortality. Inverse probability of treatment weighting and inverse probability of censoring weighting on the propensity score were applied to adjust for confounding and informative censoring.

RESULTS

Off-label dose reduction occurred in 2466 patients (8.0%), compared with 18 108 (58.5%) on-label standard-dose users. Median age was 80 years (interquartile range [IQR] 73.0-86.0) versus 72 years (IQR 66-78), respectively. Incidence rates were higher in the off-label dose reduction group compared to the on-label standard dose group, for ischaemic stroke (0.94 vs 0.70 per 100 person years), major bleeding (1.48 vs 0.83), non-major bleeding (6.78 vs 6.16) and mortality (10.12 vs 3.72). Adjusted analyses resulted in a hazard ratio of 0.95 (95% confidence interval [CI] 0.57-1.60) for ischaemic stroke, 0.88 (95% CI 0.57-1.35) for major bleeding, 0.81 (95% CI 0.67-0.98) for non-major bleeding and 1.34 (95% CI 1.12-1.61) for mortality.

CONCLUSION

In this large population-based study, the hazards for ischaemic stroke and major bleeding were low, and similar in AF patients receiving an off-label reduced NOAC dose compared with on-label standard dose users, while non-major bleeding risk appeared to be lower and mortality risk higher. Caution towards prescribing an off-label reduced NOAC dose is therefore required.

Direct Oral Anticoagulant (DOAC) Dosing in Patients with Non-valvular Atrial Fibrillation (NVAF) in the United Kingdom: A Retrospective Cohort Study Using CPRD Gold Database

INTRODUCTION

Per-label dosing of direct oral anticoagulants (DOACs) is important for the prevention of stroke and systemic embolism among patients with non-valvular atrial fibrillation (NVAF), especially those with poor renal function, advanced age, low body weight or concomitant P-glycoprotein inhibitors. The study described DOAC use and dosing patterns in patients with NVAF in the UK.

METHODS

Using Clinical Practice Research Datalink (CPRD Gold), patients' profiles were described at DOAC initiation (1 January 2016-31 March 2021) and followed for a mean [standard deviation (SD)] 2 (1) years. Patients were categorised as under-dosing: received a lower dose with no indication for a reduced dose; over-dosing: received a standard dose with an indication for a reduced dose; per-label dosing, according to Summary Product Characteristics (SmPC).

RESULTS

Forty thousand seven hundred forty-four adult patients with NVAF were identified (mean age: 75.3 (11.2) years; males: 55.4%); 22,827 (56.0%) initiated treatment with apixaban, 930 (2.3%) dabigatran, 5633 (13.8%) edoxaban and 11,354 (27.9%) rivaroxaban. Baseline Charlson comorbidity index ≥ 4 was 65.1%; CHA₂DS₂-VASc score ≥ 4 was 22.5%; HAS-BLED score ≥ 3 was 18.3%; ~ 2% had prior major bleed and 4.4% a stroke ≤ 2 years before DOAC initiation. Overall, 18.0% of patients received incorrect dosing (~ one in five). Under-dosing was highest for dabigatran (156, 16.8%) and over-dosing was highest for rivaroxaban (1084, 9.6%). Per-label dosing was highest for edoxaban (4773, 84.7%), followed by apixaban (18,756, 82.2%), rivaroxaban (9161, 80.7%) and dabigatran (732, 78.7%). Treatment persistence (no switching or discontinuation) was 79% among edoxaban users, followed by 75% for apixaban, 69% for rivaroxaban and 62% for dabigatran. About 15% of dabigatran users, 10% of rivaroxaban users, 5% of apixaban users and 4% of edoxaban users switched treatment to another DOAC during follow-up.

CONCLUSION

Although most patients received per-label dosing, ~ one in five patients was incorrectly dosed with DOAC, which may lead to serious clinical consequences and increased healthcare burden.

Outcomes and drivers of inappropriate dosing of non-vitamin K antagonist oral anticoagulants (NOACs) in patients with atrial fibrillation: a systematic review and meta-analysis

OBJECTIVE

There has been limited systematic evaluation of outcomes and drivers of inappropriate non-vitamin K antagonist oral anticoagulants (NOACs) dosing among patients with atrial fibrillation (AF). This review identified and systematically evaluated literature on clinical and economic outcomes of inappropriate NOAC dosing and associated patient characteristics.

METHODS

MEDLINE, Embase, Cochrane Library, International Pharmaceutical Abstracts, Econlit, PubMed and NHS EEDs databases were searched for English language observational studies from all geographies published between 2008 and 2020, examining outcomes of, or factors associated with, inappropriate NOAC dosing in adult patients with AF.

RESULTS

One hundred and six studies were included in the analysis. Meta-analysis showed that compared with recommended NOAC dosing, off-label underdosing was associated with a null effect on stroke outcomes (ischaemic stroke and stroke/transient ischaemic attack (TIA), stroke/systemic embolism (SE) and stroke/SE/TIA). Meta-analysis of 15 studies examining clinical outcomes of inappropriate NOAC dosing found a null effect of underdosing on bleeding outcomes (major bleeding HR=1.04, 95% CI 0.90 to 1.19; p=0.625) but an increased risk of all-cause mortality (HR=1.28, 95% CI 1.10 to 1.49; p=0.006). Overdosing was associated with an increased risk of major bleeding (HR=1.41, 95% CI 1.07 to 1.85; p=0.013). No studies were found examining economic outcomes of inappropriate NOAC dosing. Narrative synthesis of 12 studies examining drivers of inappropriate NOAC dosing found that increased age, history of minor bleeds, hypertension, congestive heart failure and low creatine clearance (CrCl) were associated with an increased risk of underdosing. There was insufficient evidence to assess drivers of overdosing.

CONCLUSIONS

Our analysis suggests that off-label underdosing of NOACs does not reduce bleeding outcomes. Patients prescribed off-label NOAC doses are at an increased risk of all-cause mortality. These data underscore the importance of prescriber adherence to NOAC dosing guidelines to achieve optimal clinical outcomes for patients with AF.

PROSPERO REGISTRATION NUMBER

CRD42020219844.

Reduced dose direct oral anticoagulants compared with warfarin with high time in therapeutic range in nonvalvular atrial fibrillation

Direct oral anticoagulants (DOACs) used in nonvalvular atrial fibrillation (NVAF) are dose-reduced in elderly and patients with impaired renal function. Only reduced dose dabigatran is concluded as having similar stroke risk reduction and lower risk of major bleeding than warfarin in the pivotal studies. In clinical practice, reduced dose is prescribed more often than expected making this an important issue. The objective of this study was to compare effectiveness and safety between reduced dose DOACs and high TTR warfarin treatment (TTR ≥ 70%) in NVAF. A Swedish anticoagulation registry was used in identifying eligible patients from July 2011 to December 2017. The study cohort consisted of 40,564 patients with newly initiated DOAC (apixaban, dabigatran, or rivaroxaban) (11,083 patients) or warfarin treatment (29,481 patients) after exclusion of 374,135 patients due to not being warfarin or DOAC naïve, not being prescribed reduced dose, having previous mechanical heart valve (MHV), or being under 18 years old. The median durations of follow up were 365, 419, 432 and 473 days for apixaban, dabigatran, rivaroxaban and warfarin, respectively. Warfarin TTR identified from Auricula was 70.0%. Endpoints (stroke and major bleeding) and baseline characteristics were collected from hospital administrative registers using ICD-10 codes. Cohorts were compared using weighted adjusted Cox regression after full optimal matching based on propensity scores. DOACs are associated with lower risk of major bleeding (HR with 95% CI) 0.85 (0.78-0.93), intracranial bleeding HR 0.64 (0.51-0.80), hemorrhagic stroke HR 0.68 (0.50-0.92), gastrointestinal bleeding HR 0.81 (0.69-0.96) and all-cause stroke HR 0.87 (0.76-0.99), than warfarin. Apixaban and dabigatran are associated with lower risk of major bleeding, HR 0.70 (0.63-0.78) and HR 0.80 (0.69-0.94), and rivaroxaban is associated with lower risk of ischemic stroke, HR 0.73 (0.59-0.96), with higher major bleeding risk, HR 1.31 (1.15-1.48), compared to warfarin. Apixaban is associated with higher all-cause mortality compared to warfarin, HR 1.12 (1.03-1.21). DOACs are associated with lower risk of major bleeding and all-cause stroke, than high quality warfarin treatment, with exception of rivaroxaban that carried higher risk of major bleeding and lower risk of stroke or systemic embolism. In this large observational registry-based NVAF cohort, DOACs are preferred treatment in patients with indication for DOAC dose reduction, even in a high TTR setting.

Safety and efficacy of direct oral anticoagulants in geriatric patients with non-valvular atrial fibrillation: A single-center retrospective study

INTRODUCTION

Direct oral anticoagulants (DOACs) are widely employed for antithrombotic prophylaxis in patients with atrial fibrillation (AF). However, there is still uncertainty about their risk-benefit profile in older patients. Here, we evaluated the efficacy, safety, and dose appropriateness of DOACs in a real-world population of outpatients with non-valvular AF, with a specific focus on subjects aged over 80 years and/or with reduced renal function.

MATERIALS AND METHODS

Single-center retrospective study including patients who had been prescribed a DOAC between May 2014 and May 2021 for long-term anticoagulation in non-valvular AF. Patients anticoagulated for <4 weeks were excluded. The primary efficacy outcome was a composite of cardiovascular (CV) death, stroke, or systemic embolism. The primary safety outcome was major bleeding.

RESULTS

A total of 1154 patients (median age 84 yrs., range 57-100 yrs.), among which 862 were 80 years and older, were included. In the subgroup of subjects ≥80 yrs., a subtherapeutic dose of DOAC was associated with an increased incidence of CV mortality, stroke, or systemic embolism (multivariable Cox regression, HR = 2.09, 95 % CI: 1.09-4.02), with no benefit in terms of prevalence of bleeding events (21.5 % vs. 18.6 %, p = 0.428), and the incidence of adverse safety and efficacy outcomes was not increased in patients with a reduced renal function (eGFR ≤30 mL/min). Plasma concentration of DOACs, assessed in a subset of 367 patients, did not increase with advanced age (≥ 80 yrs., two-way ANOVA, p = 0.656) nor with declining eGFR (≤30 mL/min, two-way ANOVA, p = 0.643) and was not associated with adverse safety and efficacy outcomes.

CONCLUSIONS

Data from our study support the use of DOACs in populations of older adults and remark on the risks associated with inappropriate prescriptions in terms of CV mortality and adverse events.

Oral Anticoagulant Use and Appropriateness in Elderly Patients with Atrial Fibrillation in Complex Clinical Conditions: ACONVENIENCE Study

Non-valvular atrial fibrillation (NVAF) is the most common arrhythmia in older patients. Although direct-acting oral anticoagulants (DOAC) are the antithrombotic treatment of choice, irrespective of age, certain factors may limit their use. The aim of the ACONVENIENCE study was to consult the opinion of a multidisciplinary panel of experts on the appropriateness of using OACs in elderly patients (>75 years) with NVAF associated with certain complex clinical conditions. A consensus project was performed on the basis of a systematic review of the literature, and application of a two-round Delphi survey. The agreement of 79 panellists on 30 Delphi-type statements was evaluated, and their opinion on the appropriateness of different oral anticoagulants in 16 complex clinical scenarios was assessed. A total of 27 consensus statements were agreed upon, including all statements addressing anticoagulation in older patients and in patients at high risk of bleeding complications, and most of those addressing frailty, dementia, risk of falling, and complex cardiac situations. It was almost unanimously agreed upon that advanced age should not influence the anticoagulation decision. Apixaban was the highest-rated therapeutic option in 14/16 situations, followed by edoxaban. There is a high degree of agreement on anticoagulation in older patients with NVAF. Age should not be the single limiting factor when prescribing OACs, and the decision should be made based on net clinical benefit and a comprehensive geriatric assessment. Apixaban, followed by edoxaban, was considered the most appropriate treatment in the various complex clinical situations examined.

Effectiveness and safety of low-dose versus standard-dose rivaroxaban and apixaban in patients with atrial fibrillation

BACKGROUND

Low-dose direct oral anticoagulant (DOAC) use is quite prevalent in clinical practice, but evidence of its effectiveness and safety compared with high-dose DOAC in patients with atrial fibrillation (AF) remains limited. We aimed to assess the effectiveness and safety of low-dose and high-dose DOACs in patients with AF with similar baseline characteristics.

METHODS

We used a cohort of hospitalized patients with a primary or secondary diagnosis of AF after discharge to the community, whose data were stored in the Quebec administrative databases, from 2011 to 2017. Older adults with AF newly prescribed with rivaroxaban (15 or 20 mg) or apixaban (2.5 mg or 5 mg) were classified as under treatment (UT) and intent to treat (ITT). We used an inverse probability treatment weighting study of new users of rivaroxaban and apixaban to address confounding by indication. The primary effectiveness outcome was ischemic stroke/systemic embolism (SE), while the primary safety outcome was major bleeding (MB). We used Cox proportional models to estimate the marginal hazard ratios (HRs).

FINDINGS

A total of 1,722 and 4,639 patients used low-dose and standard-dose rivaroxaban, respectively, while 3,833 and 6,773 patients used low-dose and standard-dose apixaban, respectively. No significant difference was observed in the incidence of comparative stroke/SE and MB between low-dose and standard-dose rivaroxaban, except for the risk of acute myocardial infarction (AMI), which was increased with the low dose in the UT analysis. For apixaban, no difference was found in the bleeding rates, but the risk of stroke/SE (HR: 1.95; 95% confidence interval (CI): 1.38-2.76) and death (HR: 1.99; 95% CI: 1.46-2.70) were greater in the low-dose group than in the standard-dose group in the UT analysis. Similar results were observed for the ITT analysis.

CONCLUSION

No significant differences were observed in the effectiveness or safety outcome between low-dose and standard-dose rivaroxaban, except for AMI. However, low-dose apixaban was associated with a greater risk of stroke/SE and death without a reduction in the bleeding rates.

Do Patients with Atrial Fibrillation and a History of Ischemic Stroke Overuse Reduced Doses of NOACs?-Results of the Polish Atrial Fibrillation (POL-AF) Registry

BACKGROUND

The aim of our study was to assess if patients with AF (atrial fibrillation) and a history of ischemic stroke (IS) excessively receive reduced doses of NOACs (non-vitamin K antagonist oral anticoagulants).

METHODS

The Polish AF (POL-AF) registry is a prospective, observational, multicenter study, including patients with AF from 10 cardiology hospital centers. In this study we focused on patients with IS in their past.

RESULTS

Among 3999 patients enrolled in the POL-AF registry, 479 (12%) had a previous history of IS. Compared to patients without IS history, post-stroke subjects had a higher CHA₂DS₂-VASc score (median score 7 vs. 4, p < 0.05). Of these subjects, 439 (92%) had anticoagulation therapy, 83 (18.9%) were treated with a vitamin K antagonist (VKA), 135 (30.8%) with rivaroxaban, 112 (25.5%) with dabigatran, and 109 (24.8%) with apixaban. There were a significant number of patients after IS with reduced doses of NOACs (48.9% for rivaroxaban, 45.5% for dabigatran, and 36.7% for apixaban). In many cases, patients were prescribed reduced doses of NOACs without any indication for reduction (28.8% of rivaroxaban use, 56.9% of dabigatran use, and 60.0% of apixaban use-out of reduced dosage groups, p = 0.06).

CONCLUSIONS

A significant proportion of AF patients received reduced doses of NOAC after ischemic stroke in a sizeable number of cases, without indication for dose reduction.

Prevalence, risk factors, and prediction of inappropriate use of non-vitamin K antagonist oral anticoagulants in elderly Chinese patients with atrial fibrillation: A study protocol

Background

Atrial fibrillation (AF) is an arrhythmia that is prevalent globally, and its incidence grows exponentially with aging. Non-vitamin K antagonist oral anticoagulants (NOACs) have been developed in recent years, and it challenges the supremacy of warfarin for thromboembolism prophylaxis in AF. Nevertheless, there are limited data specifically evaluating the real-life use of NOACs in elderly patients with AF in China.

Methods

This is a national, multicenter, non-interventional, cross-sectional study that enrolls patients with AF aged 75 years and above from 31 institutions across China. Data were collected using the Hospital Information System. The primary outcomes include (1) profiles of NOAC use in the elderly; (2) frequency of inappropriate NOAC use based on guidelines and approved labeling recommendations; (3) exploring potential risk factors related to NOACs inappropriate use; and (4) creating a prediction tool for inappropriate NOACs use.

Conclusion

The results of this study reveal the prevalence, risk factors, and corresponding prediction tool of inappropriate NOACs use in older patients with AF in China, as well as provide valuable insights into the clinical application of NOACs in high-risk populations in the real-world setting.

Clinical trial registration

www.ClinicalTrials.gov, identifier: NCT 05361889.

Aetiology, secondary prevention strategies and outcomes of ischaemic stroke despite oral anticoagulant therapy in patients with atrial fibrillation

OBJECTIVE

To investigate the aetiology, subsequent preventive strategies and outcomes of stroke despite anticoagulation in patients with atrial fibrillation (AF).

METHODS

We analysed consecutive patients with AF with an index imaging-proven ischaemic stroke despite vitamin K-antagonist (VKA) or direct oral anticoagulant (DOAC) treatment across 11 stroke centres. We classified stroke aetiology as: (i) competing stroke mechanism other than AF-related cardioembolism; (ii) insufficient anticoagulation (non-adherence or low anticoagulant activity measured with drug-specific assays); or, (iii) AF-related cardioembolism despite sufficient anticoagulation. We investigated subsequent preventive strategies with regard to the primary (composite of recurrent ischaemic stroke, intracranial haemorrhage, death) and secondary endpoint (recurrent ischaemic stroke) within 3 months after index stroke.

RESULTS

Among 2946 patients (median age 81 years; 48% women; 43% VKA, 57% DOAC), stroke aetiology was competing mechanism in 713 patients (24%), insufficient anticoagulation in 934 (32%) and cardioembolism despite sufficient anticoagulation in 1299 (44%). We found high rates of the primary (27% of patients; completeness 91.6%) and secondary endpoint (4.6%; completeness 88.5%). Only DOAC (vs VKA) treatment after index stroke showed lower odds for both endpoints (primary: adjusted OR (aOR) (95% CI) 0.49 (0.32 to 0.73); secondary: 0.44 (0.24 to 0.80)), but not switching between different DOAC types. Adding antiplatelets showed higher odds for both endpoints (primary: aOR (95% CI) 1.99 (1.25 to 3.15); secondary: 2.66 (1.40 to 5.04)). Only few patients (1%) received left atrial appendage occlusion as additional preventive strategy.

CONCLUSIONS

Stroke despite anticoagulation comprises heterogeneous aetiologies and cardioembolism despite sufficient anticoagulation is most common. While DOAC were associated with better outcomes than VKA, adding antiplatelets was linked to worse outcomes in these high-risk patients. Our findings indicate that individualised and novel preventive strategies beyond the currently available anticoagulants are needed.

TRIAL REGISTRATION NUMBER

ISRCTN48292829.

Efficacy and Safety Considerations With Dose-Reduced Direct Oral Anticoagulants: A Review

Importance

Dose-reduced regimens of direct oral anticoagulants (DOACs) may be used for 2 main purposes: dose-adjusted treatment intended as full-intensity anticoagulation (eg, for stroke prevention in atrial fibrillation [AF] in patients requiring dose reduction) or low-intensity treatment (eg, extended-duration treatment of venous thromboembolism [VTE]). We reviewed randomized clinical trials (RCTs) to understand the scenarios in which dose-adjusted or low-intensity DOACs were tested and reviewed the labeled indications by regulatory authorities, using data from large registries to assess whether the use of dose-reduced DOACs in routine practice aligned with the findings of RCTs.

Observations

Among 4191 screened publications, 35 RCTs that used dose-adjusted DOACs were identified for dabigatran, apixaban, rivaroxaban, and edoxaban. Of these 35 RCTs, 29 were related to stroke prevention in AF. Efficacy and safety results for dose-adjusted DOACs in large RCTs of AF were similar to those found for full-dose DOACs. To our knowledge, dabigatran, apixaban, and rivaroxaban have not been studied as dose-adjusted therapy for acute VTE treatment. Low-intensity DOACs were identified in 37 RCTs. Low-intensity DOACs may be used for extended-duration treatment of VTE (apixaban and rivaroxaban), primary prevention in orthopedic surgeries (dabigatran, apixaban, and rivaroxaban), primary prevention in ambulatory high-risk cancer patients (apixaban and rivaroxaban) or (postdischarge) high-risk medical patients (rivaroxaban), in stable atherosclerotic vascular disease, or after a recent revascularization for peripheral artery disease in conjunction with aspirin (rivaroxaban). Minor variations exist between regulatory authorities in different regions regarding criteria for dose adjustment of DOACs. Data from large registries indicated that dose-reduced DOACs were used occasionally with doses or for clinical scenarios different from those studied in RCTs or recommended by regulatory authorities.

Conclusions and Relevance

Dose adjustment and low-intensity treatment are 2 different forms of dose-reduced DOACs. Dose adjustment is mostly relevant for AF and should be done based on the approved criteria. Dose adjustment of DOACs should not be used for acute VTE treatment in most cases. In contrast, low-intensity DOACs may be used for primary or secondary VTE prevention for studied and approved indications. Attention should be given to routine practice patterns to align the daily clinical practice with existing evidence of safety and efficacy.

Eight-Year Trends in Direct-Acting Oral Anticoagulant Dosing, Based on Age and Kidney Function, in Patients With Atrial Fibrillation

OBJECTIVE

Concerns have been raised over the appropriateness of dosing of direct-acting oral anticoagulants (DOACs) in clinical practice. We investigated this issue in patients who were initiated on a DOAC in Australian general practices.

METHODS

This was a retrospective study among patients newly diagnosed with atrial fibrillation (AF) who were prescribed DOACs, using data obtained from 417 general practice sites across Australia over 8 years (2011-2019). Direct-acting oral anticoagulant dosing was compared with published recommendations, in relation to age and kidney function.

RESULTS

A total of 11,251 patients (mean age, 72.8 y; 46.8% female) newly diagnosed with AF were prescribed a DOAC. Of these, 2667 patients (23.7%) had a recorded prescription of a potentially inappropriate DOAC dosage, of whom 2304 (86.4%) and 283 (10.6%) were prescribed lower and higher than the recommended dosage, respectively. The remaining 80 patients (3.0%) were initiated on DOACs when contraindicated based on renal function. Overall, the proportion of patients who seemed to be initiated on a potentially inappropriate DOAC dose decreased from 38.3% (95% confidence interval, 26.1%-51.8%) in 2012 to 22.7% (95% confidence interval, 19.8%-26.0%; P < 0.001) in 2019. By 2019, 19.4%, 20.3%, and 9.3% of the patients with a recorded prescription of apixaban, rivaroxaban, and dabigatran, respectively, received a lower-than-guideline-recommended dose. The patients were more likely to be prescribed a potentially inappropriate dosage if they were elderly with multiple comorbidities.

CONCLUSIONS

Potential inappropriate DOAC dosing is a problem in the prevention of stroke associated with AF. Nearly 1 in 5 patients received a lower-than-guideline-recommended dose, indicating a need for strategies to raise awareness among prescribers.

Vitamin-K-antagonist phenprocoumon versus low-dose direct oral anticoagulants (DOACs) in patients with atrial fibrillation: a real-world analysis of German claims data

Background

For stroke prevention in patients with atrial fibrillation (AF), direct oral anticoagulants (DOACs) have been increasingly prescribed instead of vitamin-K-antagonists (VKA). For some patients a lower dosage of DOACs (ld-DOACs) is recommended. Ld-DOAC prescribing seems to be common, although previous studies did not show clear superiority of ld-DOACs over warfarin. In Germany, phenprocoumon is used almost exclusively as VKA. Randomized controlled trials comparing DOACs and phenprocoumon in the general population of patients with AF do not exist. Therefore, we aimed to compare ld-DOACs and phenprocoumon in a real-world setting in Germany.

Methods

In a retrospective observational cohort study, claims data from a group of small to medium-sized health insurance companies were analysed. Risks for the outcomes thromboembolism, death and major bleeding were estimated by Cox regression. Out of 93,685 patients with atrial fibrillation and a first prescription of an oral anticoagulant, 20,179 receiving VKA and 21,724 ld-DOACs (29.6% of all DOAC patients) were included. For the sensitivity analysis phenprocoumon was compared to the five ld-DOAC groups (ld-apixaban, ld-dabigatran, ld-edoxaban, ld-rivaroxaban, and the composite of all ld-DOACs) after propensity-score matching.

Results

Phenprocoumon was associated with statistically significant fewer thromboembolic events (HR = 1.29, 95% CI [1.13, 1.48], p < .001) and deaths (HR = 1.52, 95% CI [1.41, 1.63], p < .001) and a non-significant higher bleeding risk (HR = 0.89, 95% CI [0.79, 1.00], p = .051) than composite ld-DOAC. Regarding the subgroups, only patients with ld-apixaban had a statistically significant higher risk for thromboembolic events (HR = 1.42, 95% CI [1.21, 1.65], p < .001) and a lower bleeding risk (HR = 0.75, 95% CI [0.65, 0.86], p < .001). Ld-apixaban, ld-edoxaban, and ld-rivaroxaban were associated with a higher risk of death. The sensitivity analysis confirmed these associations.

Conclusion

Phenprocoumon seems to be superior to ld-DOACs for patients with AF. As a hypothesis phenprocoumon might turn out to be the wiser choice for high-risk patients with AF as compared to ld-DOACs, especially regarding thromboembolic events and death. Therefore, RCTs comparing ld-DOACs with phenprocoumon are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00389-9.

Effectiveness and Safety of Reduced and Standard Daily Doses of Direct Oral Anticoagulants in Patients with Nonvalvular Atrial Fibrillation: A Cohort Study Using National Database Representing the Japanese Population

Purpose

To compare the effectiveness and safety of reduced or standard daily doses of direct oral anticoagulants (DOACs) with warfarin in Japanese patients with nonvalvular atrial fibrillation (NVAF). We used post-hoc analyses to identify patient groups that could benefit from reduced-dose DOACs.

Patients and Methods

Using the National Database of Health Insurance Claims and Specific Health Checkups of Japan, we identified 944,776 patients with NVAF who had started an oral anticoagulant after at least one year of non-use between April 2011 and March 2016. We matched patients taking any, reduced, or standard doses of DOACs 1:1 with those taking warfarin. We measured treatment effectiveness based on admission due to stroke or systemic embolism (S/SE) and safety based on admission due to any bleeding (defined as major bleeding, MB). We compared both outcomes between DOACs and warfarin using the Cox proportional hazards model. We used post-hoc analysis to match patients receiving reduced-dose DOACs to those receiving standard-dose DOACs and compared treatment effectiveness and safety.

Results

More than half of patients receiving DOACs used a reduced dose. The occurrences of S/SE and MB in patients receiving any, reduced, or standard doses of DOACs were equal to or lower than those receiving warfarin. In the post-hoc analysis, the risk of S/SE and MB was similar between reduced and standard doses of DOACs except for those with a history of cerebral infarction and CHA₂DS₂-VASc score ≥3, where the risk of S/SE was lower for reduced doses of any and individual DOACs.

Conclusion

Findings from the current study are consistent with recent Asian and global studies but different from most studies conducted in North America and Europe, where patients receiving a reduced dose of DOACs had an increased risk of S/SE. Future studies should test the reproducibility of results from the current study.

Assessment of treatment patterns and patient awareness in atrial fibrillation patients using non-vitamin K antagonist oral anticoagulants (ASPECT-NOAC)

Background and Aim

Despite the advances in oral anticoagulation with NOACs, careful patient and dose selection is required with NOAC therapy. Our study aimed to assess treatment patterns of NOACs in AF along with patients’ continuity to NOAC treatments in first year, and their knowledge level of AF and NOAC treatment.

Methods

ASPECT-NOAC was designed as an observational, prospective, and multicenter study. AF patients who were prescribed NOACs within last four months were recruited from 34 outpatient cardiology clinics covering all geographic regions of Turkey. Baseline data were collected initially whereas patient awareness was evaluated at 3 to 4 weeks. Final study visit was performed at 12 months.

Results

In total, 991 patients were included to the study. Mean ± standard deviation of age was 69.4 ± 10.2 years and 53.0% of patients were female. Mean duration from AF diagnosis was 24.9 ± 50.9 months. Mean CHA₂DS₂-VASc and HAS-BLED scores were 3.1 ± 1.5 and 1.6 ± 1.1, respectively. AF disease and NOAC treatment knowledge levels were found to be 48.9 ± 23.1% and 73.0 ± 19.3%, respectively. Among reduced dose users 71.4% of patients were prescribed inappropriate reduced doses. Through the study follow-up, 32 patients (3.2%) deceased and NOAC therapy was discontinued in 74 patients (8.7%).

Conclusion

AF patients who recently started NOAC treatment in Turkey were found to have variable knowledge about their disease and anticoagulation treatment. It was observed that most of the patients continued the NOAC treatment throughout the study. Reduced dosing of NOACs was common, which was associated with higher baseline risk for bleeding as well as stroke.

Efficacy and Safety of Clinically Driven Low-Dose Treatment with Direct Oral Anticoagulants in Asians with Atrial Fibrillation: a Systematic Review and Meta-analysis

PURPOSE

Although clinically driven low-dose (CDLD) treatment with direct oral anticoagulants (DOACs) is frequently administered to Asian patients with atrial fibrillation, clinical evidence confirming its efficacy remains insufficient. We evaluated the clinical efficacy and safety of CDLD treatment with DOACs compared to on-label dose treatment in Asian patients with atrial fibrillation and assessed the differences in the baseline characteristics between patients receiving these treatments.

METHODS

We searched the MEDLINE, CENTRAL, EMBASE, Web of Science, and Scopus databases for articles from inception through July 2020.

RESULTS

Thirteen studies were included in this meta-analysis. The baseline characteristics of the CDLD group were significantly different from those of the standard dose (STD) and standard low-dose (SLD) groups. The incidences of thromboembolic events (risk ratio [RR] 0.46, 95% confidence interval [CI] 0.29-0.73, p < 0.001) and major bleeding (RR 0.55, 95% CI 0.35-0.87, p = 0.01) in the CDLD group were lower than those in the SLD group; however, they were comparable with those in the STD group. The incidence of a composite endpoint in the CDLD group was not significantly different from that in the STD group but was significantly lower than that in the SLD group (RR 0.50, 95% CI 0.38-0.65, p < 0.001).

CONCLUSION

The clinical outcomes of CDLD treatment showed no difference compared to those of the STD treatment despite the vulnerable baseline characteristics of the CDLD group for thromboembolic and major bleeding events.

Low Exposure to Direct Oral Anticoagulants Is Associated with Ischemic Stroke and Its Severity

Background and purpose

In acute stroke patients, plasma concentrations of direct oral anticoagulants (DOAC) at hospital admission only poorly mirror DOAC exposure or the coagulation status at the time of the event. Here, we evaluated whether DOAC exposure and DOAC plasma concentration at the time of transient ischemic attacks (TIA) and ischemic strokes correlate with their likelihood of occurrence.

Methods

Prospectively, consecutive DOAC patients with acute ischemic stroke or TIA were included. Admission DOAC plasma concentrations were measured by ultraperformance liquid chromatography– tandem mass spectrometry. Individual DOAC exposure (area under the curve) and DOAC concentrations at event onset were derived from population pharmacokinetic analyses.

Results

DOAC exposure was successfully modeled in 211 patients (ischemic stroke 74.4%, TIA 25.6%). Compared to published values, 63.0% had relatively lower DOAC exposure and they more often received lower DOAC doses than recommended (odds ratio [OR], 2.125; 95% confidence interval [CI], 1.039 to 4.560; P=0.044). These patients more likely suffered ischemic strokes than TIA (OR, 2.411; 95% CI, 1.254 to 4.638; P=0.008) and their strokes were more severe (slope, 3.161; 95% CI, 0.741 to 5.58; P=0.011). Low relative DOAC concentrations at event onset were likewise associated with ischemic strokes (OR, 4.123; 95% CI, 1.834 to 9.268; P=0.001), but not to stroke severity (P=0.272). DOAC exposure had a higher explanatory value for stroke severity than concentrations at event.

Conclusions

Low DOAC exposure is strongly associated to ischemic stroke and its severity. By monitoring DOAC plasma concentrations, patients prone to ischemic stroke might be identified.

Can a Single Measurement of Apixaban Levels Identify Patients at Risk of Overexposure? A Prospective Cohort Study

Background Patients with atrial fibrillation (AF) are frequently treated with apixaban 2.5-mg twice daily (BID) off-label, presumably to reduce the bleeding risk. However, this approach has the potential to increase the risk of ischemic stroke. If a single measurement could reliably identify patients with high drug levels, the increased stroke risk may be mitigated by confining off-label dose reduction to such patients.

Objectives This study aimed to determine whether a single high apixaban level is predictive of a similarly high level when the test is repeated in 2 months.

Methods In this prospective cohort study of clinic patients receiving apixaban 5-mg BID for AF or venous thromboembolism, peak and trough apixaban levels were measured using the STA-Liquid anti-Xa assay at baseline and 2 months. We calculated the proportions of patients with levels that remained in the upper quintile.

Results Of 100 enrolled patients, 82 came for a second visit, 55 of whom were treated with apixaban 5-mg BID. Seven (63.6%, 95% confidence interval [CI]: 35.4–84.8%) and nine (81.8%, 95% CI: 52.3–94.9%) of 11 patients with a baseline trough and peak level in the upper quintile, respectively, had a subsequent level that remained within this range. Only one (9.1%, 95% CI: 1.6–37.7%) patient had a subsequent level that fell just lower than the median.

Conclusion The trough and peak levels of apixaban in patients who have a high level on a single occasion, usually remain high when the assay is repeated in 2 months. Accordingly, the finding of a high apixaban level in patients deemed to be at high risk of bleeding, allows physicians contemplating off-label use of the 2.5-mg BID dose to limit its use to selected patients who are less likely to be exposed to an increased risk of thrombosis.

Efficacy and Safety of Non-recommended Dose of New Oral Anticoagulants in Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis

Introduction: The real-world treatment of atrial fibrillation (AF) often involves the prescription of new oral anticoagulants (NOACs) using dosing both lower and higher than recommended guidelines. Our study aimed to evaluate the efficacy and safety of non-recommended dosage of NOACs in AF patients. Methods: A systematic search was performed for relevant studies across multiple electronic databases (PubMed, Embase, Cochrane Library, Clinical Trials Registry) from inception to May 1, 2021. Multicenter randomized trials and observational studies were selected with key reporting measures for inclusion involved efficacy outcomes including stroke or systemic thromboembolism along with safety endpoints assessing major or clinically relevant bleeding events. Results: A total of 11 eligible studies were included involving 48,648 patients receiving recommended dose of NOACs and 50,116 patients receiving non-recommended dosage. Compared to AF patients treated with recommended dose regimens, administration of low dose of NOACs was associated with higher risk of stroke/systemic embolism (RR = 1.24, 95% CI 1.14-1.35, P < 0.00001), but without reducing bleeding risk (RR = 1.18, 95% CI 0.91-1.53, P = 0.21) and a higher risk of all-cause mortality (RR = 1.58, 95% CI 1.25-1.99, P = 0.0001). Moreover, high dose of NOACs was associated with higher risk of stroke and systemic embolism efficacy (RR = 1.71, 95% CI 1.06-2.76, P = 0.03) and a non-significant trend to a greater risk of major or clinically relevant bleeding (RR = 1.57, 95% CI 0.96-2.58, P = 0.07). Conclusions: AF patients treated with low dose of NOACs showed equivalent safety but with worse efficacy compared with recommended dose. High dose of NOACs was not superior to recommended dose regimens in preventing stroke/systemic embolism outcomes in AF patients.

Prescription of oral anticoagulation in geriatric patients with atrial fibrillation

Objective

To determine the prevalence of prescription of oral anticoagulation in patients aged > 60 years with nonvalvular atrial fibrillation (NVAF).

Methods

Observational, cross-sectional, retrospective study based on a review of the clinical ­histories of patients aged >60 years diagnosed with NVAF from July 1 to September 30, 2019 and seen at the outpatient clinic (cardiology, internal medicine, geriatrics) of a secondary-level hospital in Queretaro, Mexico. Clinical profile and oral anticoagulant treatment were analyzed.

Results

The study population comprised 300 patients (mean age, 77.2±8.3 years; 53.3% women; 81% attended in cardiology). Of these, 91% had a high thromboembolic risk, 22.7% a high bleeding risk, and 1.7% contraindications for anticoagulation. Comorbidity was frequent. As for therapy, 82.7% were taking direct oral anticoagulants (DOAC), 11.0% vitamin K antagonists (VKA), and 6.3% no anticoagulant treatment. Anticoagulant therapy was inappropriate in 29.3% of patients, mainly because DOAC were prescribed without adjusting for age, weight, or serum creatinine and administered without indication according to thromboembolic risk. Only 39.4% of patients taking VKA were within the therapeutic range. Of all patients receiving DOAC, 48.0% were taking rivaroxaban, mainly at 20 mg/d (73.1%).

Conclusions

Thromboembolic risk is high in geriatric patients with NVAF. Anticoagulation is contraindicated in <2% of patients. Oral anticoagulants are prescribed inappropriately in three out of ten patients.

Off-label-dosing of non-vitamin K-dependent oral antagonists in AF patients before and after stroke: results of the prospective multicenter Berlin Atrial Fibrillation Registry

AIMS

We aimed to analyze prevalence and predictors of NOAC off-label under-dosing in AF patients before and after the index stroke.

METHODS

The post hoc analysis included 1080 patients of the investigator-initiated, multicenter prospective Berlin Atrial Fibrillation Registry, designed to analyze medical stroke prevention in AF patients after acute ischemic stroke.

RESULTS

At stroke onset, an off-label daily dose was prescribed in 61 (25.5%) of 239 NOAC patients with known AF and CHA₂DS₂-VASc score ≥ 1, of which 52 (21.8%) patients were under-dosed. Under-dosing was associated with age ≥ 80 years in patients on rivaroxaban [OR 2.90, 95% CI 1.05-7.9, P = 0.04; n = 29] or apixaban [OR 3.24, 95% CI 1.04-10.1, P = 0.04; n = 22]. At hospital discharge after the index stroke, NOAC off-label dose on admission was continued in 30 (49.2%) of 61 patients. Overall, 79 (13.7%) of 708 patients prescribed a NOAC at hospital discharge received an off-label dose, of whom 75 (10.6%) patients were under-dosed. Rivaroxaban under-dosing at discharge was associated with age ≥ 80 years [OR 3.49, 95% CI 1.24-9.84, P = 0.02; n = 19]; apixaban under-dosing with body weight ≤ 60 kg [OR 0.06, 95% CI 0.01-0.47, P < 0.01; n = 56], CHA₂DS₂-VASc score [OR per point 1.47, 95% CI 1.08-2.00, P = 0.01], and HAS-BLED score [OR per point 1.91, 95% CI 1.28-2.84, P < 0.01].

CONCLUSION

At stroke onset, off-label dosing was present in one out of four, and under-dosing in one out of five NOAC patients. Under-dosing of rivaroxaban or apixaban was related to old age. In-hospital treatment after stroke reduced off-label NOAC dosing, but one out of ten NOAC patients was under-dosed at discharge.

CLINICAL TRIAL REGISTRATION

NCT02306824.

How lower doses of direct oral anticoagulants are interpreted in clinical practice: a national survey of the Italian Atherosclerosis, Thrombosis and Vascular Biology (ATVB) Study Group

AIM

To evaluate the current interpretation of the lower doses of direct oral anticoagulants (DOAC) dabigatran, apixaban, edoxaban and rivaroxaban in nonvalvular atrial fibrillation.

METHODS

A questionnaire of 14 statements to which the possible answers were fully agree/partially agree/partially disagree/fully disagree or yes/no was prepared within the board of the Italian Atherosclerosis, Thrombosis and Vascular Biology Study Group and forwarded to individual Italian physicians.

RESULTS

A total of 620 complete questionnaires were received from nearly all the Italian regions and physicians of various medical specialists, either enabled or not for the prescription of DOAC. A wide agreement was found as regards the pharmacological, as well as clinical consequences of the administration of the lower dose of factor-Xa inhibitors both in patients with and without clinical and/or laboratory criteria requiring dose reduction. Wide agreement was also found as regards the presence of moderate kidney insufficiency in selecting the dose of DOAC. Instead, more debated were issues regarding the proportionality between dabigatran dose and plasma concentration and selection of dabigatran dose, as well as the role of measuring drug plasma concentration and/or determine the anticoagulant activity of factor-Xa inhibitors when used at the lower dose.

CONCLUSION

The interpretation of the lower doses of DOAC in current Italian clinical practice appears largely correct and shared. Because of the persistence of some residual uncertainties, essentially regarding dabigatran, however, continuous educational effort still appears warranted.

Atrial fibrillation: a geriatric perspective on the 2020 ESC guidelines

BACKGROUND

The Task Force for the diagnosis and management of atrial fibrillation (AF) of the European Society of Cardiology (ESC) published in 2020 the updated Guidelines for the Diagnosis and Management of Atrial Fibrillation with the contribution of the European Heart Rhythm Association (EHRA) of the ESC and the European Association for Cardiothoracic Surgery (EACTS).

METHODS AND RESULTS

In this narrative viewpoint, we approach AF from the perspective of aging medicine and try to provide the readers with information usually neglected in clinical routine, mainly due to the fact that while the large majority of AF patients in real life are older, frail and cognitively impaired, these are mostly excluded from clinical trials, and physicians' attitudes often prevail over standardized algorithms.

CONCLUSIONS

On the basis of existing evidence, (1) opportunistic AF screening by pulse palpation or ECG rhythm strip is cost-effective, and (2) whereas advanced chronological age by itself is not a contraindication to AF treatment, a Comprehensive Geriatric Assessment (CGA) including frailty, cognitive impairment, falls and bleeding risk may assist in clinical decision making to provide the best individualized treatment.

Starting dose and dose adjustment of non-vitamin K antagonist oral anticoagulation agents in a nationwide cohort of patients with atrial fibrillation

This study aims to provide real-world data about starting-dose of NOACs and dose-adjustment in patients with atrial fibrillation (AF). In fact, even if new oral anticoagulation agents (NOACs) have a predictable effect without need for regular monitoring, dose-adjustments should be performed according to the summary of product information and international guidelines. We employed the Italian Medicines Agency monitoring registries comprising data on a nationwide cohort of patients with AF treated with NOACs from 2013 to 2018. Logistic regression analysis was used to evaluate the determinants of dosage choice. During the reference period, treatment was commenced for 866,539 patients. Forty-five percent of the first prescriptions were dispensed at a reduced dose (dabigatran 60.3%, edoxaban 45.2%, apixaban 40.9%, rivaroxaban 37.4%). The prescription of reduced dose was associated with older age, renal disease, bleeding risk and the concomitant use of drugs predisposing to bleeding, but not with CHA₂DS₂-VASc and HAS-BLED. A relative reduction of the proportion of patients treated with low dosages was evident overtime for dabigatran and rivaroxaban; whereas prescription of low dose apixaban and edoxaban increased progressively among elderly patients. Evidence based on real-world data shows a high frequency of low dose prescriptions of NOACs in AF patients. Except for older age, renal disease, bleeding risk and the concomitant use of drugs predisposing to bleeding, other factors that may determine the choice of reduced dose could not be ascertained. There may be potential under-treatment of AF patients, but further evaluation is warranted.

Anticoagulant-associated gastrointestinal bleeding: Framework for decisions about whether, when and how to resume anticoagulants

Gastrointestinal (GI) bleeding is the most frequent single site of oral anticoagulant (OAC)-associated major bleeding. Patients with major GI bleeding experience morbidity and a substantial risk of short-term all-cause mortality up to 10%. While OACs are frequently discontinued during acute bleeding, there is substantial uncertainty about whether, when, and how OACs should be resumed after bleeding has resolved. Limited evidence suggests a lower risk of thromboembolism and death, and a higher risk of recurrent bleeding with OAC resumption. However, the absolute risks and optimal timing of anticoagulation remain uncertain based on these observational studies at risk of bias, particularly due to baseline confounding. In addition to an individualized approach to determining the benefits and harms of treatment decisions informed by the best available evidence about thrombosis and recurrent bleeding, discussions should meaningfully incorporate patient values and preferences. The objective of this review is to provide a framework for decision-making by summarizing the epidemiology and clinical outcomes of OAC-associated GI bleeding, providing an approach for assessment and risk stratification for OAC resumption and its timing, and outlining strategies for the prevention of recurrent GI bleeding.

Off-Label Underdosing or Overdosing of Non-vitamin K Antagonist Oral Anticoagulants in Patients With Atrial Fibrillation: A Meta-Analysis

Background: Several studies have investigated the role of off-label non-vitamin K antagonist oral anticoagulants (NOACs) in patients with atrial fibrillation (AF). We aimed to compare the effectiveness and safety outcomes between off-label underdose or overdose vs. on-label dose of NOACs in AF patients.

Methods: The PubMed database was systematically searched until August 2021. Observational cohorts were included if they compared the outcomes of off-label underdose or overdose with on-label dose of NOACs in AF patients. The risk ratios (RRs) and 95% confidence intervals (CIs) were pooled using a fixed-effects model (I² ≤ 50%) or a random-effects model (I² > 50%).

Results: A total of 15 observational studies were included. Compared with on-label dose of NOACs, off-label underdose of NOACs was associated with increased risks of stroke or systemic embolism (RR = 1.09, 95% CI 1.02–1.16), and all-cause death (RR = 1.29, 95% CI 1.10–1.52) but not ischemic stroke (RR = 1.34, 95% CI 0.76–2.36), myocardial infarction (RR = 1.08, 95% CI 0.92–1.28), major bleeding (RR = 0.97, 95% CI 0.89–1.05), intracranial hemorrhage (RR = 1.12, 95% CI 0.90–1.40), and gastrointestinal bleeding (RR = 0.96, 95% CI 0.85–1.07), whereas off-label overdose of NOACs was associated with increased risks of SSE (RR = 1.20, 95% CI 1.05–1.36), all-cause death (RR = 1.22, 95% CI 1.06–1.39), and major bleeding (RR = 1.33, 95% CI 1.16–1.52) but not gastrointestinal bleeding (RR = 1.18, 95% CI 0.99–1.42) and myocardial infarction (RR = 0.98, 95% CI 0.75–1.30).

Conclusion: Compared with on-label dose of NOACs, off-label underdose was associated with increased risks of stroke or systemic embolism and all-cause death, whereas off-label overdose of NOACs was associated with increased risks of stroke or systemic embolism, all-cause death, and major bleeding.

Direct Oral Anticoagulants and Non-valvular Atrial Fibrillation: Compliance with Dose Level Guidelines in Patients Aged 80 Years and Over

BACKGROUND

Direct oral anticoagulants (DOACs) are currently recommended as first-line or (after vitamin K antagonists) second-line therapy for preventing stroke and systemic embolism in patients with non-valvular atrial fibrillation. In patients aged 80 years and over, however, the fear of DOAC-associated bleeding and the complexity of DOAC dosing regimes may prompt physicians to prescribe inappropriate dose levels.

OBJECTIVE

The objective of this study was to determine compliance with French and European guidelines of doses of three DOACs (apixaban, dabigatran and rivaroxaban) prescribed to patients aged over 80 years in an indication of non-valvular atrial fibrillation, and to identify factors associated with poor compliance.

METHODS

We performed a retrospective single-centre study of patients aged over 80 years routinely treated with a DOAC (apixaban, dabigatran or rivaroxaban) for non-valvular atrial fibrillation at Valenciennes General Hospital (Valenciennes, France) between 1 January, 2016 and 31 December, 2017. We determined compliance with French and European guidelines of DOAC doses as a function of each patient's clinical and laboratory parameters, and thus classified the regime as being appropriately dosed, overdosed or underdosed.

RESULTS

A total of 703 patients (371 taking apixaban, 92 taking dabigatran and 240 taking rivaroxaban) were included in the study. We found that 274 patients (39%) had been prescribed an inappropriate DOAC regime, with underdosing in 241 cases (34%) and overdosing in 33 cases (5%). Underdosing mainly concerned the two most widely prescribed DOACs, i.e. apixaban (39% of all apixaban prescriptions were underdosed) and rivaroxaban (40%). Concomitant treatment with an antidepressant was associated with underdosing of rivaroxaban or apixaban (p = 0.0339). In contrast, initial management in a neurology department was associated with appropriate dosing (p = 0.000146) for both these DOACs.

CONCLUSIONS

Among patients with non-valvular atrial fibrillation aged 80 years and over, about 40% of DOAC prescriptions feature inappropriate dose levels. It might be possible to reduce inappropriate dosing by raising awareness among hospital-based and private-practice prescribers, providing prescription support tools for DOACs, and performing medication reconciliations and reviews at hospital and in private practice.

Impact of Reduced-Dose Nonvitamin K Antagonist Oral Anticoagulants on Outcomes Compared to Warfarin in Korean Patients with Atrial Fibrillation: A Nationwide Population-Based Study

Reduced-dose nonvitamin K antagonist oral anticoagulants (NOACs) are commonly prescribed to Asian patients with nonvalvular atrial fibrillation (NVAF). We aimed to compare the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) between patients treated with reduced-dose NOACs and those treated with warfarin, using the claims database in Korea. Patients with NVAF newly initiated on oral anticoagulants (OACs; apixaban, dabigatran, rivaroxaban, and warfarin) between 1 July 2015 and 30 November 2016 were included. Among all patients with NVAF treated with OACs, 5249, 6033, 7602, and 8648 patients were treated with reduced-dose apixaban, dabigatran, rivaroxaban, and warfarin, respectively. Patients treated with reduced-dose NOACs were older and had higher CHA₂DS₂-VASc and HAS-BLED scores than those treated with warfarin. Compared to warfarin, all reduced-dose NOACs showed significantly lower risk of S/SE (hazard ratios (95% confidence interval), 0.63 (0.52–0.75) for apixaban; 0.51 (0.42–0.61) for dabigatran; and 0.67 (0.57–0.79) for rivaroxaban) and MB (0.54 (0.45–0.65) for apixaban; 0.58 (0.49–0.69) for dabigatran; 0.73 (0.63–0.85) for rivaroxaban). In the real-world practice among Asians with NVAF, all reduced-dose NOACs were associated with a significantly lower risk of S/SE and MB compared to those of warfarin.

Changing paradigms: from prevention of thromboembolic events to improved survival in patients with atrial fibrillation

Atrial fibrillation is associated with a five-fold increase in the risk of stroke. Current guidelines recommend the use of the CHA2DS2-VASc score to stratify the risk of stroke. In addition, guidelines recommend the identification of the conditions that increase the risk of haemorrhage to be modified and thus decrease the risk of bleeding. Nevertheless, many patients with a high thromboembolic risk are prescribed antiplatelet treatment or do not receive any antithrombotic therapy. In addition, therapeutic inertia is common in anticoagulated patients taking vitamin K antagonists, and underdosing is an emerging problem with direct oral anticoagulants, probably because many physicians consider the risk of stroke and the risk of major bleeding to be equal. It is necessary to develop a new approach to risk stratification, an approach that moves from morbidity to mortality, i.e., from stratification of the risk of stroke and major bleeding to stratification of the risk of mortality associated with stroke and the risk of mortality associated with bleeding. In this article, we propose a novel risk stratification approach based on the mortality associated with stroke and bleeding, illustrated by data derived from the literature.