Time Trends and Treatment Pathways in Prescribing Individual Oral Anticoagulants in Patients with Nonvalvular Atrial Fibrillation: An Observational Study of More than Three Million Patients from Europe and the United States

Prophylaxis of microvascular thrombosis using direct oral anticoagulants (DOAC) in microvascular free tissue transplantation - a pilot study

INTRODUCTION

We conducted this pilot study to assess direct oral anticoagulants (DOACs) in the prevention of microvascular thrombosis.

MATERIALS AND METHODS

Five patients undergoing microvascular free tissue transplantation received rivaroxaban or apixaban (depending on their home medication). We compared this group to 19 patients who received enoxaparin subcutaneously. We evaluated the rate of graft loss due to microvascular thrombosis and the number of transfusions administered intra- and postoperatively.

RESULTS

There was no graft loss due to microvascular thrombosis in either of the groups. There was no significant difference in the number of intraoperative (study group mean 1.00 (SE 0.32) vs. control group mean 1.11 (SE 0.59); p = 0.876) and postoperative (study group mean 1.2 (SE 0.37) vs. control group mean 1.74 (SE 0.34); p = 0.310) red blood cell transfusions.

CONCLUSION

Based on our results in this pilot study, DOACs can be used with microvascular flaps. Further studies with larger sample sizes should be performed to find an optimal medication regimen both for patients already taking DOACs and perhaps even for those not taking DOACs.

Effectiveness and Safety of Edoxaban Compared With Apixaban in Elderly Patients With Nonvalvular Atrial Fibrillation: A Real-World Population-Based Cohort Study

BACKGROUND

The very elderly (≥80 years) are at high risk of nonvalvular atrial fibrillation and thromboembolism. Given its recent approval, the comparative effectiveness and safety of edoxaban in this population, relative to the commonly used apixaban, remain unknown.

METHODS

Using the United Kingdom Clinical Practice Research Datalink, we identified a cohort of patients aged ≥80 with incident nonvalvular atrial fibrillation and newly treated with edoxaban or apixaban between 2015 and 2021. Cohort entry was defined as the first prescription for one of the 2 drugs. We used propensity score fine stratification and weighting for confounding adjustment. A weighted Cox proportional hazards model was used to estimate the hazard ratios (HR) with 95% CI of ischemic stroke/transient ischemic attack/systemic embolism (primary effectiveness outcome) and of major bleeding (primary safety outcome) associated with edoxaban compared with apixaban. We also assessed the risk of all-cause mortality and a composite outcome of ischemic stroke/transient ischemic attack, systemic embolism, gastrointestinal bleeding, and intracranial hemorrhage as secondary outcomes.

RESULTS

The cohort included 7251 new-users of edoxaban and 39 991 of apixaban. Edoxaban and apixaban had similar incidence rates of thromboembolism (adjusted rates, 20.38 versus 19.22 per 1000 person-years; adjusted HR, 1.06 [95% CI, 0.89-1.26]), although the rates of major bleeding were higher with edoxaban (adjusted rates, 45.57 versus 31.21 per 1000 person-years; adjusted HR, 1.42 [95% CI, 1.26-1.61]). The risk of the composite outcome was 21% higher with edoxaban (adjusted HR, 1.21 [95% CI, 1.07-1.38]). All-cause mortality was similar between edoxaban and apixaban (adjusted HR, 1.04 [95% CI, 0.96-1.12]).

CONCLUSIONS

In very elderly patients with nonvalvular atrial fibrillation, edoxaban resulted in similar thromboembolism prevention as apixaban, although it was associated with a higher risk of major bleeding. These findings may improve the management of nonvalvular atrial fibrillation by informing physicians on the choice of anticoagulant for this vulnerable population.

Trends in Drug Spending of Oral Anticoagulants for Atrial Fibrillation, 2014-2021

INTRODUCTION

This study documents cost trends in oral anticoagulants (OAC) in patients with newly diagnosed atrial fibrillation.

METHODS

Using MarketScan databases, the mean annual patients' out-of-pocket costs, insurance payments, and the proportion of patients initiating OAC within 90 days from atrial fibrillation diagnosis were calculated from July 2014 to June 2021. Costs of OACs (apixaban, dabigatran, edoxaban, rivaroxaban, and warfarin) and the payments by three insurance types (commercial payers, Medicare, and Medicaid) were calculated. Patients' out-of-pocket costs and insurance payments were adjusted to 2021 prices. Joinpoint regression models were used to test trends of outcomes and average annual percent changes (AAPC) were reported. Data analyses were performed in 2022-2023.

RESULTS

From July 2014 to June 2021, the mean annual out-of-pocket costs of any OAC increased for commercial insurance (AAPC 3.0%) and Medicare (AAPC 5.1%) but decreased for Medicaid (AAPC -3.3%). The mean annual insurance payments for any OAC significantly increased for all insurance groups (AAPC 13.1% [95% CI 11.3-15.0] for Medicare; AAPC 11.8% [95% CI 8.0-15.6] for commercial insurance; and AAPC 16.3% [95% CI 11.3-21.4] for Medicaid). The initiation of any OAC increased (AAPC 7.3% for commercial insurance; AAPC 10.2% for Medicare; AAPC 5.3% for Medicaid).

CONCLUSIONS

There was a substantial increase in the overall cost burden of OACs and OAC initiation rates in patients with newly diagnosed atrial fibrillation in 2014-2021; these findings provide insights into the current and anticipated impact of rising drug prices on patients' and payers' financial burden.

Correct dosing, adherence and persistence of DOACs in atrial fibrillation and chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

Chronic kidney disease (CKD) and atrial fibrillation (AF) are increasing in prevalence globally and share common risk factors.Our aim was to characterise real-world evidence on direct oral anticoagulant (DOAC) prescribing for people with AF and CKD, in terms of adherence, persistence and renal dose titration.

METHODS

PubMed, EMBASE and CINAHL were searched from inception to June 2022. Our search terms included a combination of Medical Subject Headings (MeSH) terms and keywords including 'atrial fibrillation', 'chronic kidney disease', 'adherence', 'persistence', 'direct oral anticoagulants' and 'dosing'. Data extraction and quality assessment were undertaken by two reviewers independently. Meta-analyses for pooled estimates were performed using DerSimonian and Laird random-effects models. Age, sex, diabetes, hypertension and heart failure were chosen as variables of interest.

RESULTS

From 19 studies, a total of 252 117 patients were included with CKD and AF. Meta-analysis was only possible in seven studies with 128 406 patients, five on DOAC dose titration and two on adherence. There were insufficient studies on persistence. Our meta-analysis of dosing showed that 68% of patients with CKD and AF had correct dosing. There was no evidence to show any association between correct DOAC dosing and variables of interest. Overall, 67% of patients were DOAC adherent.

CONCLUSION

Adherence and correct dosing of DOACs were suboptimal compared with other medications in the pooled studies with respect to CKD and AF. Thus, further research is required as the lack of generalisation of findings is a rate-limiting factor for improved DOAC management in AF and CKD.

PROSPERO REGISTRATION NUMBER

CRD;42022344491.

Contemporary trends and barriers to oral anticoagulation therapy in Non-valvular atrial fibrillation during DOAC predominant era

There is a need to reassess contemporary oral anticoagulation (OAC) trends and barriers against guideline directed therapy in the United States. Most previous studies were performed before major guideline changes recommended direct oral anticoagulant (DOAC) use over warfarin or have otherwise lacked patient level data. Data on overuse of OAC in low-risk group is also limited. To address these knowledge gaps, we performed a nationwide analysis to analyze current trends. This is a retrospective cohort study assessing non-valvular AF identified using a large United States de-identified administrative claims database, including commercial and Medicare Advantage enrollees. Prescription fills were assessed within a 90-day follow-up from the patient's index AF encounter between January 1, 2016, and December 31, 2020. Among the 339,197 AF patients, 4.4%, 8.0%, and 87.6% were in the low-, moderate-, and high-risk groups (according to CHA₂DS₂-VASc score). An over (29.6%) and under (52.2%) utilization of OAC was reported in low- and high-risk AF patients. A considerably high frequency for warfarin use was also noted among high-risk group patients taking OAC (33.1%). The results suggest that anticoagulation use for stroke prevention in the United States is still comparable to the pre-DOAC era studies. About half of newly diagnosed high-risk non-valvular AF patients remain unprotected against stroke risk. Several predictors of OAC and DOAC use were also identified. Our findings may identify a population at risk of complications due to under- or over-treatment and highlight the need for future quality improvement efforts.

A Descriptive Analysis of Direct Oral Anticoagulant Drugs Dosing Errors Based on Spontaneous Reports from the EudraVigilance Database

Direct oral anticoagulant drugs (DOACs) interfere with the coagulation process, thus improving patient care for those who require anticoagulant treatment. This study presents a descriptive analysis of adverse reactions (ADRs) attributed to DOAC dosage errors (overdose, underdose, and improper dose). The analysis was performed based on the Individual Case Safety Reports from the EudraVigilance (EV) database. Results show that data reported for rivaroxaban, apixaban, edoxaban, and dabigatran are mostly regarding underdosing (51.56%) compared to overdosing (18.54%). The most dosage error reports were identified for rivaroxaban (54.02%), followed by apixaban (33.61%). Dabigatran and edoxaban had similar percentages (6.26% and 6.11%, respectively) regarding dosage error reports. Since coagulation issues can become life-threatening events, and factors such as advanced age and renal failure can influence the pharmacokinetics of drugs, the correct usage of DOACs is of utmost importance for the management and prevention of venous thromboembolism. Thus, the collaboration and the complementarity of knowledge of physicians and pharmacists may offer a reliable solution for DOAC dose management and improve patient care.

Oral Anticoagulation in Patients with Chronic Liver Disease

The administration of an anticoagulant in patients with liver disease (nonalcoholic steatohepatitis-NASH, nonalcoholic fatty liver disease-NAFLD, chronic hepatitis, or cirrhosis) who have an indication (atrial fibrillation, venous thrombosis, or pulmonary embolism) is challenging because there is an imbalance between thrombosis and bleeding. There is a need to focus our attention on preventing risk factors because diabetes, obesity, dyslipidemia, smoking, and sedentary behavior are risk factors for both NASH/NAFLD and AF, and these patients require anticoagulant treatment. Patients with advanced liver disease (Child-Pugh C) were excluded from studies, so vitamin K antagonists (VKAs) are still recommended. Currently, VKAs are recommended for other conditions (antiphospholipid syndrome, mitral valve stenosis, and mechanical valve prosthesis). Amongst the patients under chronic anticoagulant treatment, especially for the elderly, bleeding as a result of the improper use of warfarin is one of the important causes of emergency admissions due to adverse reactions. DOACs are considered to be efficient and safe, with apixaban offering superior protection against stroke and a good safety profile as far as major bleeding is concerned compared to warfarin. DOACs are safe in the Child-Pugh A and B classes (except rivaroxaban), and in the Child-Pugh C class are contraindicated. Given that there are certain and reliable data for chronic kidney disease regarding the recommendations, in liver function impairment more randomized studies must be carried out, as the current data are still uncertain. In particular, DOACs have a simple administration, minimal medication interactions, a high safety and effectiveness profile, and now a reversal agent is available (for dabigatran and idarucizumab). Patients are also statistically more compliant and do not require INR monitoring.

Time Trends in Patient Characteristics of New Rivaroxaban Users with Atrial Fibrillation in Germany and the Netherlands

BACKGROUND

Use of the direct oral anticoagulant rivaroxaban has strongly increased in Europe since its market approval for non-valvular atrial fibrillation in 2011. Patients characteristics of rivaroxaban initiators may have changed over time but this has not been investigated so far.

OBJECTIVE

We aimed to describe time trends of patient baseline characteristics among new rivaroxaban users with non-valvular atrial fibrillation from 2011 to 2016/17 in two European countries.

METHODS

We used data from Germany (German Pharmacoepidemiological Research Database) and the Netherlands (PHARMO Database Network). We included new rivaroxaban users with (i) a first dispensing between 2011 and 2016/17, (ii) ≥ 2 years of age, and (iii) a diagnosis of non-valvular atrial fibrillation and described their baseline medication and comorbidity prior to starting rivaroxaban stratified by year of inclusion.

RESULTS

Overall, 130,652 new rivaroxaban users were included during the study period (Germany: N = 127,743, the Netherlands: N = 2909). The sex ratio and median age remained relatively stable over time. The proportion of patients without prior use of oral anticoagulants before initiation of rivaroxaban increased in both countries between 2011 and 2016/17 (Germany: from 51 to 76%, the Netherlands: from 57 to 85%). In Germany, we observed a relative decrease by 27% in the proportion of new rivaroxaban users with a history of ischemic stroke and by 18% in the proportion with a transient ischemic attack at baseline. No such a pattern was observed in the Netherlands. The proportion of patients with heart failure at baseline showed a three-fold increase in the Netherlands, while there was a relative decrease by 12% in Germany.

CONCLUSIONS

Patient characteristics of new rivaroxaban users with non-valvular atrial fibrillation changed between 2011 and 2016/17, but changes differed between countries. These patterns have methodological implications. They have to be considered in the interpretation of observational studies comparing effectiveness and safety of oral anticoagulants, especially regarding potential bias due to unmeasured confounding.

Meta‑analysis of the efficacy and safety of nifekalant in the conversion of atrial fibrillation

Atrial fibrillation (AF) is the most common type of supraventricular tachyarrhythmia. Nifekalant is a new class III antiarrhythmic drug approved for the treatment of ventricular tachyarrhythmias, but its effectiveness in converting AF to sinus rhythm remains unclear. The present analysis aimed to investigate the effect of nifekalant in the conversion of AF. PubMed, Cochrane Library and China National Knowledge Infrastructure databases were systematically used to search relevant studies published between 1999 (data at which the drug was first approved for marketing in Japan) and 2022. Randomized clinical trials, prospective studies and retrospective studies on the use of nifekalant for AF were screened. The study metrics included the success rate of the conversion of AF, the mean time to conversion, the success rate of 12 months after a single AF catheter ablation procedure and the incidence of adverse events. The eligible studies screened included six randomized clinical trials, three prospective studies and three retrospective studies, totalling 12 studies with 1,162 patients. The risk ratio (RR) for successful conversion in the nifekalant and control groups was 1.95 [95% confidence interval (CI), 1.23-3.08; P=0.005] and the mean difference for the mean time to conversion was -1.73 [95% CI, -2.69-(-0.77); P=0.0004]. Statistically significant differences were observed between nifekalant and control groups. Subgroup analysis revealed a statistically significant difference in the success rate of conversion following catheter ablation in the nifekalant group compared with the amiodarone group and the RR value was 1.95 (95% CI, 1.37-2.77; P=0.0002). Statistically significant difference was observed compared with the electrical cardioversion group and the RR value was 0.90 (95% CI, 0.84-0.98; P=0.01). However, the combined RR values for the two groups were 1.18 (95% CI, 0.85-1.65; P<0.0002). The RR value for adverse events was 0.85 (95% CI, 0.51-1.43; P=0.55), with no statistically significant differences between nifekalant and control groups. In conclusion, the results demonstrated that the success rate and time to conversion in the nifekalant group were improved compared with those in the control group, particularly after catheter ablation, and the conversion effect with nifekalant was significantly improved compared with that in the control group.

Evidence-based Management of Major Bleeding in Patients Receiving Direct Oral Anticoagulants: An Updated Narrative Review on the Role of Specific Reversal Agents

The indications of direct oral anticoagulants (DOACs) have expanded over the past 15 years. DOACs are effective and safe oral anticoagulants associated with lower bleeding risks and mortality than vitamin K antagonists. However, DOAC users are prone to a considerable bleeding risk, which can occur at critical sites or lead to severe life-threatening conditions. Recent statistics indicated that major bleeding occurs in up to 6.62 DOAC users per 100 treatment years. With the increased use of DOACs in clinical practice, DOAC-associated major bleeding is expected to be encountered more frequently in the emergency department. The current international guidelines recommend specific reversal agents for the management of DOAC users with severe bleeding to reverse the anticoagulant effect and restore normal hemostasis. An individualized assessment was incorporated in specific clinical situations to guide the decision pathway of major bleeding management. However, specific reversal agents are unavailable or have limited availability in many countries, which is expected to negatively impact the clinical outcomes of DOAC-associated major bleeding. Limited real-world evidence is available from these countries regarding the clinical outcomes of patients with DOAC-associated major bleeding. This narrative review provided an updated assessment of the evidence-based approaches for the management of major bleeding in DOAC users. We also explored the clinical outcomes of patients with major bleeding from clinical settings where specific reversal agents are unavailable.

Trends in Use of Oral Anticoagulants in Older Adults With Newly Diagnosed Atrial Fibrillation, 2010-2020

IMPORTANCE

Undertreatment of older adults with atrial fibrillation with anticoagulation therapy is an important practice gap. It has been posited that the availability of direct oral anticoagulants (DOACs) would improve oral anticoagulant (OAC) initiation in older adults with atrial fibrillation given their superior safety profile compared with warfarin.

OBJECTIVES

To systematically examine trends in OAC initiation and nonadherence in older adults with atrial fibrillation and coexisting geriatric conditions.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study uses administrative claims data from Optum's Clinformatics Data Mart from January 1, 2010, to December 31, 2020. Participants included beneficiaries of Medicare Advantage plans aged 65 years and older with atrial fibrillation and elevated risk of ischemic stroke. Data analysis was performed from October 2021 to October 2022.

EXPOSURES

Coexisting dementia, frailty, and anemia.

MAIN OUTCOMES AND MEASURES

The primary outcomes were OAC initiation within 12 months after the first diagnosis of atrial fibrillation per year and nonadherence with OAC per year (defined as <80% of proportion of days covered among patients newly started on OAC in each year).

RESULTS

There were 21 603 to 51 236 patients per year (total for 2010-2020, 381 488 patients) in the OAC-eligible incident AF cohort (mean [SD] age, 77.2 [6.1] to 77.4 [6.8] years; 13 871 [51.8%] to 22 901 [49.8%] women). OAC initiation within 12 months after incident AF increased from 20.2% (5405 of 26 782 patients) in 2010 to 32.9% (7111 of 21 603 patients) in 2020. DOAC uptake increased from 1.1% (291 of 26 782 patients) to 30.9% (6678 of 21 603 patients), and warfarin initiation decreased from 19.1% (5114 of 26 782 patients) to 2.0% (436 of 21 603 patients). Older age (odds ratio [OR], 0.98; 95% CI, 0.98-0.98), dementia (OR, 0.57; 95% CI, 0.55-0.58), frailty (OR, 0.74; 95% CI, 0.72-0.76), and anemia (OR, 0.75; 95% CI, 0.74-0.77) were associated with lower odds of OAC initiation. During the study period, the median (IQR) proportion of days covered increased from 77.6% (41.0%-96.4%) to 90.2% (57.4%-98.6%), and OAC nonadherence decreased from 52.2% (2290 of 4389 patients) to 39.0% (3434 of 8798 patients).

CONCLUSIONS AND RELEVANCE

Since the introduction of DOACs, OAC initiation in older adults with has improved but remained suboptimal in 2020. Additional strategies are needed to improve stroke prophylaxis in all older adults with atrial fibrillation including those with coexisting dementia, frailty, and anemia.

Direct Oral Anticoagulants in Old and Frail Patients with Atrial Fibrillation: The Advantages of an Anticoagulation Service

Despite the recent advancements, oral anticoagulation is still challenging in some patients and this is the case for old and frail patients. The large majority of frail patients with atrial fibrillation should receive anticoagulation since the associated benefits outweigh the risk of bleeding. A multidisciplinary consensus document on the use and prescription of direct oral anticoagulants (DOACs) in older and frail patients with atrial fibrillation has been recently published. In this manuscript we provide a comment on this document and add insights into the management of these patients. The new DOAC age had imposed a paradigm shift in the management of patients with the need for clinically-oriented services rather than laboratory-oriented services. In this paper we provide tools for a structured patient-oriented DOACs treatment service supported by a multidisciplinary approach.