Effect of Renal Function on Dosing of Non-Vitamin K Antagonist Direct Oral Anticoagulants Among Patients With Nonvalvular Atrial Fibrillation

Clinical characteristics, adherence to anticoagulation therapy and prognosis in patients with atrial fibrillation: a real-life study

BACKGROUND

Atrial fibrillation (AF) is a prevalent tachyarrhythmia, and a comprehensive understanding of its clinical features is essential for optimizing therapeutic management. However, the unregulated use of anticoagulants in AF remains a concern, as their efficacy and safety profiles are not yet fully understood.

METHODS

Data from AF patients were collected in 2013, 2018, and 2023. First, cross-sectional data on AF patients were gathered during each period to longitudinally evaluate long-term trends in AF characteristics and the progression of anticoagulation therapy. Additionally, predictors of non-regulated dosing of oral anticoagulants (OAC) were analyzed. Second, patients with non-valvular atrial fibrillation (NVAF) were prospectively followed for 24 and 60 months with different NOAC doses to assess the risk of clinical outcome events and to analyze independent risk factors for clinical outcomes.

RESULTS

This study included 2825 AF patients, with 394 patients undergoing longitudinal follow-up. Paroxysmal AF (49.70%) and non-valvular atrial fibrillation (NVAF) (86.30%) were the most prevalent forms with advanced age being a prominent characteristic. Independent predictors of unregulated NOAC use included age, renal insufficiency, BMI, diabetes, hypertension, and bleeding risk. At the 24-month follow-up, patients who received overdosed NOAC exhibited a higher mortality rate compared to those who were inappropriately underdosed (18.75 vs.10.92 events/patient-year, P = 0.017). At the 60-month follow-up, both all-cause mortality (10.00 vs. 6.49 events per patient-year, P = 0.019; 10.00 vs. 6.21 events per patient-year, P = 0.005) and the composite endpoint event rate (12.50 vs. 9.61 events per patient-year, P = 0.017; 12.50 vs. 9.32 events per patient-year, P = 0.013) were significantly higher in the overdosing group compared to standard and underdosing groups. Age and anemia were identified as risk factors for all-cause mortality, while renal insufficiency was associated with an increased risk of composite endpoint events.

CONCLUSION

AF remains a major disease burden, especially in elderly patients. For Asians, NOAC underdosing was still effective in preventing stroke, but its efficacy and safety need to be further validated through larger-scale clinical trials. Meanwhile, overdosing of NOAC should be avoided.

CLINICAL TRIAL NUMBER

Not applicable.

Adherence and persistence with direct oral anticoagulants by dose regimen: A systematic review

INTRODUCTION

Direct oral anticoagulants (DOACs) are used in patients with non-valvular atrial fibrillation (NVAF) to prevent complications such as embolic events. Poor adherence to DOACs increases the risk of these complications. This manuscript reviews the impact of once-daily (OD) vs twice-daily (BID) dosing regimens on adherence and persistence to the authorized DOACs (dabigatran, rivaroxaban, apixaban and edoxaban) in patients with NVAF, aiming to provide insights into guide clinical decision-making.

METHODS

A systematic review was performed. First, a bibliographical search was carried out in PubMed, Scopus and the Cochrane Library. Articles that provided quantitative data comparing adherence and/or persistence associated with OD vs BID regimens of DOACs among patients receiving treatment for NVAF were included. Two analyses of adherence and persistence were conducted, one based on the overall outcomes and another, more restricted, to minimize the risk of overestimating results. Additionally, univariate analyses were conducted based on the number of follow-up days and the DOAC molecule.

RESULTS

Thirty-nine studies, involving 976 494 patients, were analysed. The OD regimen demonstrated significantly higher adherence and persistence (P < .05) than the BID regimen in most outcomes. Adherence favoured OD in 53.1% of cases, while only 12.2% favoured BID. Similarly, persistence was higher with the OD regimen in 67.7% of cases compared to 14.9% for the BID regimen. These results remained consistent over time; nevertheless, variations were observed depending on the specific DOAC molecules.

CONCLUSION

Adherence and persistence of treatment with DOACs in patients with NVAF were greater for the OD than for the BID regimen.

Assessing the Safety and Efficacy of Rivaroxaban for Stroke Prevention in Patients With Atrial Fibrillation: A Systemic Review and Meta-Analysis

An effective anticoagulation therapy is required for patients with atrial fibrillation because it presents a significant risk of stroke. The current study evaluates the relative safety as well as efficacy of rivaroxaban in patients who are diagnosed with atrial fibrillation. A thorough literature review of relevant databases was conducted, focusing on academic and clinical studies that were published from 2017 onward. Inclusion criteria comprised randomized controlled trials and other observational studies comparing the incidence of stroke and the safety index of rivaroxaban in atrial fibrillation. We followed the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) for data overview reporting and overview. A total of 21 studies were selected based on the inclusion criteria. A total of 19/21 studies advocated the adoption of rivaroxaban for minimizing stroke incidence. Rivaroxaban also showed superiority in achieving the therapeutic objectives, i.e., reduction in the incidence of stroke. The results for rivaroxaban against warfarin showed an improved safety index and effectiveness of rivaroxaban. The total effect size for the analysis was calculated to be Z=2.62 (p-value=0.009). The individual effect of all studies favored the "rivaroxaban" group. The heterogeneity in the study was as follows: tau2=0.10; chi2=110.10, df=6; I2=95%. The second analysis for risk reduction and incidence of stroke after rivaroxaban therapy also showed a bias towards rivaroxaban therapy. The combined effect for the analysis was found to be as follows: HR=0.73 ((95% CI: 0.50, 1.07). The total effect was calculated to be Z=1.61 (p-value= 0.10). The heterogeneity was found to be as follows: tau2= 0.20, chi2=89.97, df=6, I2=93%. Standard dosing of rivaroxaban emerges as a preferred strategy for stroke prevention, balancing efficacy and safety. Clinical decision-making should consider individual patient characteristics and future research should delve into specific subpopulations and long-term outcomes to further refine treatment guidelines.

Efficacy and Safety of Different Dosing Regimens of Rivaroxaban in Patients With Atrial Fibrillation for Stroke Prevention: A Systematic Review and Meta-Analysis

Atrial fibrillation (AF) poses a substantial risk of stroke, necessitating effective anticoagulation therapy. This systematic review and meta-analysis (SRMA) evaluates the efficacy and safety of different dosing regimens of rivaroxaban in patients with AF. A comprehensive search of relevant databases, focusing on studies published from 2017 onward, was conducted. Inclusion criteria comprised randomized controlled trials (RCTs) and observational studies comparing standard and reduced dosing of rivaroxaban in AF. Data extraction and risk of bias (ROB) assessment were performed, and a meta-analysis was conducted for relevant outcomes. A total of 21 studies fulfilled the inclusion criteria. Standard dosing demonstrates a slightly lower risk of composite effectiveness outcomes and safety outcomes (HR: 0.79, 95% CI: 0.66-0.94, P=0.01) compared to reduced dosing (HR: 0.83, 95% CI: 0.71-0.97, P=0.02). Notable differences in major bleeding, gastrointestinal bleeding (GIB), and intracranial bleeding favored standard dosing. Hemorrhagic stroke and all-cause stroke rates differed significantly, with standard dosing showing a more favorable profile for ischemic stroke prevention. This study highlights the pivotal role of personalized anticoagulation therapy in AF. Standard dosing of rivaroxaban emerges as a preferred strategy for stroke prevention, balancing efficacy and safety. Clinical decision-making should consider individual patient characteristics and future research should delve into specific subpopulations and long-term outcomes to further refine treatment guidelines. The study bridges evidence from clinical trials to real-world practice, offering insights into the evolving landscape of AF management.

Kidney function estimators for drug dose adjustment of direct oral anticoagulants in older adults with atrial fibrillation

Background

The Cockcroft-Gault equation (CrClC-G) is recommended for dose adjustment of direct oral anticoagulant drugs (DOACs) to kidney function. We aimed to assess whether defining DOAC dose appropriateness according to various kidney function estimators changed the associations between dose appropriateness and adverse events in older adults with atrial fibrillation (AF).

Methods

Participants of the Berlin Initiative Study with AF and treated with DOACs were included. We investigated CrClC-G and estimated glomerular filtration rate (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration and European Kidney Function Consortium equations based on creatinine and/or cystatin C. Marginal structural Cox models yielded confounder-adjusted hazard ratios for the risk of mortality, thromboembolism and bleeding associated with dose status.

Results

A total of 224 patients were included in the analysis (median age 87 years). Using CrClC-G, 154 (69%) had an appropriate dose of DOACs, 52 (23%) were underdosed and 18 (8%) were overdosed. During a 39-month median follow-up period, 109 (14.9/100 person-years) participants died, 25 (3.6/100 person-years) experienced thromboembolism and 60 (9.8/100 person-years) experienced bleeding. Dose status was not associated with mortality and thromboembolism, independent of the equation. Underdose status was associated with a lower risk of bleeding with all the equations compared with the appropriate dose group. In participants with discrepancies in dose status using CrClC-G and eGFR equations, the occurrence of endpoints did not differ between participants having an appropriate dose using CrClC-G or eGFR.

Conclusion

In older adults with AF, the association of DOAC dose status with adverse events did not differ when using CrClC-G or eGFR. Our results suggest that eGFR equations are not inferior to CrClC-G within this context.

Effectiveness and Safety of Direct Oral Anticoagulants Among Patients with Non-valvular Atrial Fibrillation and Multimorbidity

INTRODUCTION

In the USA, there is a steady rise of atrial fibrillation due to the aging population with increased morbidity. This study evaluated the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) among elderly patients with non-valvular atrial fibrillation (NVAF) and multimorbidity prescribed direct oral anticoagulants (DOACs).

METHODS

Using the CMS Medicare database, a retrospective observational study of adult patients with NVAF and multimorbidity who initiated apixaban, dabigatran, or rivaroxaban from January 1, 2012 to December 31, 2017 was conducted. High multimorbidity was classified as having ≥ 6 comorbidities. Cox proportional hazard models were used to evaluate the hazard ratios of S/SE and MB among three 1:1 propensity score matched DOAC cohorts. All-cause healthcare costs were estimated using generalized linear models.

RESULTS

Overall 36% of the NVAF study population had high multimorbidity, forming three propensity score matched (PSM) cohorts: 12,511 apixaban-dabigatran, 60,287 apixaban-rivaroxaban, and 12,567 dabigatran-rivaroxaban patients. Apixaban was associated with a lower risk of stroke/SE and MB when compared with dabigatran and rivaroxaban. Dabigatran had a lower risk of stroke/SE and a similar risk of MB when compared with rivaroxaban. Compared to rivaroxaban, apixaban patients incurred lower all-cause healthcare costs, and dabigatran patients incurred similar all-cause healthcare costs. Compared to dabigatran, apixaban patients incurred similar all-cause healthcare costs.

CONCLUSION

Patients with NVAF and ≥ 6 comorbid conditions had significantly different risks for stroke/SE and MB when comparing DOACs to DOACs, and different healthcare expenses. This study's results may be useful for evaluating the risk-benefit ratio of DOAC use in patients with NVAF and multimorbidity.

Challenges and Possible Solutions to Direct-Acting Oral Anticoagulants (DOACs) Dosing in Patients with Extreme Bodyweight and Renal Impairment

This article aims to highlight the dosing issues of direct oral anticoagulants (DOACs) in patients with renal impairment and/or obesity in an attempt to develop solutions employing advanced data-driven techniques. DOACs have become widely accepted by clinicians worldwide because of their superior clinical profiles, more predictable pharmacokinetics, and hence more convenient dosing relative to other anticoagulants. However, the optimal dosing of DOACs in extreme bodyweight  patients and patients with renal impairment is difficult to achieve using the conventional dosing approach. The standard dosing approach (fixed-dose) is based on limited data from clinical studies. The existing formulae (models) for determining the appropriate doses for these patient groups leads to suboptimal dosing. This problem of mis-dosing is worsened by the lack of standardized laboratory parameters for monitoring the exposure to DOACs in renal failure and extreme bodyweight patients. Model-informed precision dosing (MIPD) encompasses a range of techniques like machine learning and pharmacometrics modelling, which could uncover key variables and relationships as well as shed more light on the pharmacokinetics and pharmacodynamics of DOACs in patients with extreme bodyweight or renal impairment. Ultimately, this individualized approach-if implemented in clinical practice-could optimise dosing for the DOACs for better safety and efficacy.

Determinants for under- and overdosing of direct oral anticoagulants and physicians' implementation of clinical pharmacists' recommendations

AIMS

To analyse the appropriateness of direct oral anticoagulant (DOAC) dosing and determinants for under-and overdosing as well as acceptance and implementation rates of pharmacists' interventions.

METHODS

Cross-sectional study in a tertiary hospital in hospitalized patients with atrial fibrillation on DOACs in 2019 (n = 1688). Primary outcome was the proportion of patients with inappropriate DOAC prescribing with identification of determinants for under-and overdosing. Secondary outcomes included acceptance and implementation rates of pharmacists' recommendations and determination of reasons for nonacceptance/nonimplementation.

RESULTS

Inappropriate prescribing was observed in 16.9% of patients (n = 286) with underdosing (9.7%) being more prevalent than overdosing (6.9%). For all DOACs considered together, body weight<60 kg (odds ratio [OR] 0.46 [0.27-0.77]), edoxaban use (OR 0.42 [0.24-0.74]), undergoing surgery (OR 0.57 [0.37-0.87]) and being DOAC naïve (OR 0.45 [0.29-0.71]) were associated with significantly lower odds of underdosing. Bleeding history (OR 1.86 [1.24-2.80]) and narcotic use (OR 1.67 [1.13-2.46]) were associated with significantly higher odds for underdosing. Determinants with a significantly higher odds of overdosing were renal impairment (OR 11.29 [6.23-20.45]) and body weight<60 kg (OR 2.34 [1.42-3.85]), whereas dabigatran use (OR 0.24 [0.08-0.71]) and apixaban (OR 0.18 [0.10-0.32]) were associated with a significantly lower odds of overdosing compared to rivaroxaban. Physicians accepted the pharmacists' advice in 179 cases (79.2%) consisting of 92 (51.4%) recommendations for underdosing, 82 (45.8%) for overdosing and 5 (2.8%) for contraindications.

CONCLUSION

Inappropriate DOAC prescribing remains common, although there is a slight improvement compared to our study of 2016. Clinical services led by pharmacists help physicians to reduce the number of inadequate prescriptions for high-risk medications such as DOACs.

Inappropriate dose of nonvitamin-K antagonist oral anticoagulants: prevalence and impact on clinical outcome in patients with nonvalvular atrial fibrillation

BACKGROUND

Limited real-world data are available regarding the outcome of patients treated with inappropriate dose of nonvitamin-K antagonist oral anticoagulants (NOACs).

OBJECTIVE

To assess the prevalence and factors associated with inappropriate dose prescription of NOACs and to evaluate adverse events that come from this inappropriate prescription.

METHODS

Single-center multidisciplinary registry including nonvalvular atrial fibrillation patients treated with NOACs. Based on guidelines criteria for dose reduction, two subcohorts were defined as treated with appropriate or inappropriate NOACs dose. Primary efficacy endpoint was 2-year rate of thromboembolic events. Primary safety endpoint was 2-year rate of major bleeding. Event-free survival curves among groups were compared using Cox-Mantel test.

RESULTS

A total of 760 nonvalvular atrial fibrillation patients were included; 32% patients were treated with dabigatran, 34% with apixaban, 24% with rivaroxaban and 10% with edoxaban. An inappropriate dose was prescribed in 96 patients (12.6%), and in most cases (68%) it was too low. Rivaroxaban (15%) and apixaban (18.5%) were the most frequently prescribed with an inappropriate dose. Patients treated with an inappropriate dose were elderly people, with low-creatinine clearance value, who had experienced previous bleeding and with a high CHADS2 VASc score. In 2 years, a trend for higher numbers of thromboembolic events (5.2 vs. 3.3%, P = 0.348) and less major bleeding (2.1 vs. 4.2%, P = 0.316) has been observed in patients with inappropriate NOACs prescriptions.

CONCLUSION

Nearly 13% of patients were treated with an inappropriate dose of NOACs, in this single-center study. A trend for higher numbers of thromboembolic events was observed in these patients. The results should be considered as hypothesis generating.

Real-World Data on Characteristics and Management of Community Patients Receiving Anticoagulation Therapy Who Presented with Acute Bleeding to the Emergency Department at a Regional Australian Hospital: A Prospective Observational Study

OBJECTIVE

To study patients receiving anticoagulants with or without antiplatelet therapy presenting at a regional Australian hospital with bleeding. The main aims are to explore: (1) patients' characteristics and management provided; (2) association between the type of anticoagulant and antiplatelet agent used and the requirement of reversal; (3) and the length of hospital stay (LoS) in conjunction with bleeding episode and management.

METHODS

A prospective cross-sectional review of medical records of all patients who presented at a tertiary referral centre with bleeding while receiving anticoagulation therapy between January 2016 and June 2018. Data included: patients, demographics, investigations (kidney and liver function tests, coagulation profile, FBC), LoS, bleeding site, type of and reason for anticoagulation therapy, and management provided. Data analysis included descriptive statistics, χ2 association, and regression models.

RESULTS

Among the 144 eligible patients, 75 (52.1%) were male, and the mean age was 76 years (SD=11.1). Gastrointestinal tract bleeding was the most common (n=48, 33.3%), followed by epistaxis (n=32, 22.2%). Atrial fibrillation was the commonest reason for anticoagulation therapy (n=65, 45.1%). Warfarin was commonly used (n=74, 51.4%), followed by aspirin (n=29, 20.1%), rivaroxaban (n=26, 18.1%), and apixaban (n=12, 8.3%). The majority had increased blood urea nitrogen (n=67, 46.5%), while 58 (40.3%) had an elevated serum creatinine level, and 59 (41.0%) had a mild reduction in eGFR. Thirty-five of the warfarinised patients (47.3%) had an INR above their condition's target range despite normal liver function. Severe anaemia (Hb<80g/L) was reported in 88 patients (61.1%). DOACs were associated with a reduced likelihood of receiving reversal (B= -1.7, P=<.001), and with a shorter LoS (B= -4.1, P=.046) when compared with warfarin, LMWH, and antiplatelet therapy.

CONCLUSION

Warfarin use was common among patients who presented with acute bleeding, and the INR in many warfarinised patients exceeded the target for their condition. DOACs were associated with a reduced likelihood of receiving reversal and a shorter LoS than warfarin, LMWH, which might support a broader application of DOACs into community practice.

Inappropriate direct oral anticoagulant prescriptions in patients with non-valvular atrial fibrillation: cross-sectional analysis of the French CACAO cohort study in primary care

Background

Direct oral anticoagulants (DOACs) account for an increasing proportion of prescriptions in patients with non-valvular atrial fibrillation (NVAF) in primary care. Inappropriate dosing of DOACs is a common problem, with under-dosing being a particular issue. However, conflicting results have been reported about the factors independently associated with inappropriate dosing.

Aim

To describe inappropriate prescriptions of DOACs among patients in the CACAO French nationwide general practice cohort, and to identify the factors independently associated with inappropriate DOAC doses.

Design and setting

Cross-sectional baseline analysis of the CACAO French national multicentre prospective cohort of adult patients in primary care receiving an oral anticoagulant who were recruited between April and October 2014.

Method

A total of 1111 patients from the CACAO cohort who received a DOAC for NVAF were included in this study. Inappropriate prescriptions of DOACs were described (inappropriate dosage, contraindications, non-indications, interactions, and non-compliance with the precautions for use). Multivariate logistic models were used to investigate factors associated with inappropriate DOAC dosing (under-dosing and over-dosing).

Results

Overall, 438 patients (39.4%) received at least one inappropriate DOAC prescription. The most common inappropriate prescription was inappropriate dosage (n = 374, 33.7%), particularly under-dosing (n = 348, 31.3%). Multivariate analysis revealed that factors independently associated with under-dosing were older age, prescription of apixaban or dabigatran, and a CHA2DS2-VASc score ≥2 vs. a score = 1. Factors with over-dosing were kidney failure, a HAS-BLED score ≥3, and older age.

Conclusion

The appropriateness of DOAC prescribing for NVAF can be improved, especially in older patients, and in patients with kidney failure, a higher risk of ischaemic stroke, and/or a higher risk of bleeding. GPs have a key role in increasing the proportion of appropriate DOAC prescriptions via informational, educational, and/or management strategies.

Prediction-Determining Outcomes and Their Predictors in Atrial Fibrillation Patients Receiving Multicomponent Antithrombotic Therapy in Real Clinical Practice

Aim      Searching for clinical, angiographic, and biochemical predictors of cardiovascular complications (CVC) and hemorrhagic complications in patients with atrial fibrillation (AF) receiving a multicomponent antithrombotic therapy (MAT) for an elective percutaneous coronary intervention (PCI). Patients with ischemic heart disease (IHD) and AF who require MAT for PCI are at a high risk of thrombotic complications (stroke, systemic embolism, coronary events) and hemorrhage. This warrants searching for new risk factors determining prediction of the outcome.Materials and methods This study included 207 patients (146 males aged 70.1±8.3 years) with IHD and AF who received direct oral anticoagulants (DOAC) as a part of their MAT therapy. Median duration of the follow-up was 12 [8.0; 12.0] months. The efficacy endpoint was a sum of CVCs combining cardiovascular death, ischemic stroke, venous thromboembolic complications, acute coronary syndrome (ACS), and requirement for an unscheduled PCI. "Coronary events", including ACS and requirement for an unscheduled PCI were analyzed separately. The safety endpoint was BARC type 2-5 bleeding. Upon admission, biomarkers (growth-differentiation factor 15 (GDF-15), D-dimer, thrombin-activated fibrinolysis inhibitor (TAFI), and plasminogen activator inhibitor-1 (PAI-1)) were measured for all patients. Searching for prognostically significant indexes was performed with the Cox proportional hazards regression.Results Incidence of all CVCs was 16.4 %. Independent predictors of CVC included the DOAC treatment at a reduced dose (odds ratio (OR) 2.5 at 95 % confidence interval (CI) 1.02-6.15; p=0.0454), GDF-15 &gt;1191 pg /ml (OR 3.76 at 95 % CI, 1.26-11.18; p=0.0172), PAI-1 &gt;13.2 U/ml (OR 2.67 at 95 % CI, 1.13-6,26; p=0.0245). Incidence of coronary complications was 9.2 %. Independent predictors of coronary complications included a SYNTAX index &gt;26.5 (OR 4.5 at 95 % CI, 1.45-13.60; p=0.0090), PCI for chronic coronary occlusion (OR 3.21 at 95 % CI, 1.10-9.33; p=0.0326), a GDF-15 &gt;1191 pg/ml (ОR 4.70 at 95 % CI, 1.32-16.81; p=0.0172). Incidence of BARC type 2-5 bleeding was 26.1 %. The only independent predictor for hemorrhage complications was the total PRECISE-DAPT score &gt;30 (ОR 3.22; 95 % CI, 1.89-5.51; р&lt;0.0001).Conclusion      Three independent predictors of CVC were identified for patients with IHD and AF treated with MAT following an elective PCI: treatment with a reduced dose of DOAC, GDF-15 &gt;1191 pg /ml, and PAI-1&gt;13.2 U/ml. Independent predictors of coronary complications included a SYNTAX index &gt;26.5, PCI for chronic coronary occlusion, and GDF-15 &gt;1191 pg/ml. The factor associated with a risk of bleeding was the total PRECISE-DAPT score &gt;30.

Quality of clinical direct oral anticoagulant prescribing and identification of risk factors for inappropriate prescriptions

AIMS

Even though the use of direct oral anticoagulants (DOACs) is safe based on clinical outcomes, drug safety also depends on appropriateness of drug prescription, which is challenging for DOACs since many patient factors need to be considered. The aim of this study was to assess the appropriateness of DOAC prescriptions and to identify risk factors of determinants for inappropriate DOAC prescriptions.

METHODS

A retrospective study in a nonuniversity teaching hospital was performed of hospitalized patients (≥18 years) who received an initial DOAC prescription between February and August 2018. Appropriateness of prescribing was evaluated on 8 criteria by using a modified version of the medication appropriateness index.

RESULTS

A total of 770 initial DOAC prescriptions of inpatients were evaluated: 267 patients (34.6%) had at least met 1 inappropriate criterion for a DOAC prescription. The most frequent inappropriate criterion was dosage (17.4%). Of the 4 DOACs, dabigatran (21.6%) and apixaban (21.2%) were mostly inappropriate dosed. In a multivariable analysis, reduced renal function (estimated glomerular filtration rate <50 mL/min; odds ratio [OR] = 2.35; P < .001), a diagnosis of atrial fibrillation (OR = 1.87; P = .004), and 'prescribed by surgeons' (OR = 1.9; P = .013) were independently associated with inappropriateness of prescribing.

CONCLUSION

This study has highlighted a high degree of inappropriate prescribing of DOACs. These results underline the need for targeted interventions to improve DOAC prescribing.

Burden of Inappropriate Prescription of Direct Oral Anticoagulants at Hospital Admission and Discharge in the Elderly: A Prospective Observational Multicenter Study

INTRODUCTION

Direct oral anticoagulants (DOACs) were developed to overcome some of the limitations associated with vitamin K antagonists (VKAs), such as interindividual variability or the need for therapeutic drug monitoring. However, the complexity of DOAC dose regimens can still lead to dosing errors and potential bleeding-related or thromboembolic adverse events, especially in the elderly.

OBJECTIVE

Our objective was to evaluate the rate of inappropriate preadmission DOAC prescriptions at hospital and to evaluate the ability of hospitals to correct them.

METHODS

An observational prospective study was conducted in elderly patients (aged ≥ 65 years) hospitalized in six acute units of three Parisian university hospitals between February and July 2018. DOAC prescriptions prior to admission and at discharge were analyzed according to the guidelines in the summaries of product characteristics.

RESULTS

A total of 157 patients were included in the study, with a median age of 84 years (interquartile range [IQR] 77-89). The median glomerular filtration rate, determined with the Cockcroft-Gault equation, was 48 mL/min (IQR 35-61). Apixaban was the most frequently prescribed drug, mainly for atrial fibrillation. Overall, 48 (30.6%) and 34 (22.4%) prescriptions were inappropriate prior to admission and at discharge, respectively, showing a significant decrease (p < 0.001). Hospitals significantly corrected more inappropriate prescriptions (37.5%) than they generated (4.6%) (p < 0.05). The nature of the inappropriate prescribing was underdosing (68.8% and 76.5% prior to admission and at discharge, respectively), followed by overdosing (stable rate at almost 20%) and indication errors. No risk factors for inappropriate use were identified by our analysis.

CONCLUSION

One-third of DOAC preadmission prescriptions for elderly patients were inappropriate, indicating that a need remains to strengthen DOAC prescribing guidelines in ambulatory clinical practice. However, the rate of inappropriate prescriptions decreased at patient discharge. Future studies are needed to test actions to promote the proper use of DOACs.

[Thrombotic and hemorrhagic complications in atrial fibrillation patients, undergoing elective percutaneous coronary intervention]

AIM

To evaluate efficacy and safety of reduced dose of direct oral anticoagulants (DOACs) as part of triple antithrombotic therapy in AF patients, undergoing elective percutaneous coronary intervention (PCI), and to identify factors, associated with this strategy.

MATERIALS AND METHODS

The study is a cohort analysis of AF patients with AF, who successfully underwent elective PCI and assigned DOACs as part of triple antithrombotic therapy (TAT).Influence of a reduced DOACs dose as a part of TAT on the frequency of thecomposite efficacy endpoint (acute coronary syndrome, ischemic stroke, venous thromboembolic events, cardiovascular death and angina pectoris aggravation/need for unplanned PCI) and safety endpoint (hemorrhagic complications BARC types 2-5) were assessed using the Log-Rank criterion.

RESULTS

The study included 124 pts (69.4% women, mean aged 69±8.2 years). Themedian total score CHA2DS2-VASc was 5, the median of the Charlson index composed 7. Half (52%) of AF patients with high risk of thrombotic events after elective PCI received reduced-DOACs dose. Median follow up period was 11.0 month. 17 adverse thrombotic events were recorded during this period, BARC 2-5 bleedings occurred in 27 patients. Reduced DOACs doses in AF patients undergoing PCI were associated with significant increase of thrombotic events during follow up period compared to patients received full DOACs doses (0.79 vs 0.93, Log-Rank p=0.0292). Patients, who received full and reduced DOAC doses, were comparable in the frequency of BARC 2-5 bleedings (0.78 vs 0.75, Log-Rank p=0.06742).

CONCLUSIONS

The administration of a reduced DOACs dose as a part of TAT in patients with AF, who underwent PCI, was associated with significant increase in the incidence of all thrombotic events, compared to patients, who received full dose of anticoagulants. The number of hemorrhagic complications was comparable.

Incidence of direct oral anticoagulant use in patients with nonvalvular atrial fibrillation and characteristics of users in 6 European countries (2008-2015): A cross-national drug utilization study

Aims

To estimate the incidence of direct oral anticoagulant drug (DOAC) use in patients with nonvalvular atrial fibrillation and to describe user and treatment characteristics in 8 European healthcare databases representing 6 European countries.

Methods

Longitudinal drug utilization study from January 2008 to December 2015. A common protocol approach was applied. Annual period incidences and direct standardisation by age and sex were performed. Dose adjustment related to change in age and by renal function as well as concomitant use of potentially interacting drugs were assessed.

Results

A total of 186 405 new DOAC users (age ≥18 years) were identified. Standardized incidences varied from 1.93–2.60 and 0.11–8.71 users/10 000 (2011–2015) for dabigatran and rivaroxaban, respectively, and from 0.01–8.12 users/10 000 (2012–2015) for apixaban. In 2015, the DOAC incidence ranged from 9 to 28/10 000 inhabitants in SIDIAP (Spain) and DNR (Denmark) respectively. There were differences in population coverage among the databases. Only 1 database includes the total reference population (DNR) while others are considered a population representative sample (CPRD, BIFAP, SIDIAP, EGB, Mondriaan). They also varied in the type of drug data source (administrative, clinical). Dose adjustment ranged from 4.6% in BIFAP (Spain) to 15.6% in EGB (France). Concomitant use of interacting drugs varied between 16.4% (SIDIAP) and 70.5% (EGB). Cardiovascular comorbidities ranged from 25.4% in Mondriaan (The Netherlands) to 82.9% in AOK Nordwest (Germany).

Conclusion

Overall, apixaban and rivaroxaban increased its use during the study period while dabigatran decreased. There was variability in patient characteristics such as comorbidities, potentially interacting drugs and dose adjustment. (EMA/2015/27/PH).

Initial rivaroxaban dosing in patients with atrial fibrillation

Background

Rivaroxaban is a non‐vitamin K oral anticoagulant and has been approved for prevention of stroke and systemic embolism in patients with non‐valvular atrial fibrillation (AF). Current labeling recommends 20 mg once a day (q.d.) as a standard dose and a reduced dose of 15 mg q.d. in patients with renal impairment.

Hypothesis

The aim of this study was to analyze the adherence to current labeling concerning initial rivaroxaban dosing and to determine whether potential lack of such adherence is medically justified.

Methods

Patients with AF initiated on rivaroxaban between January 1, 2016 and January 31, 2017, were identified in the Heart Center Leipzig database. Health records were screened to identify prescribed rivaroxaban dose, presence or absence of renal impairment, patient characteristics, further dosing‐relevant diagnoses and co‐medication with antiplatelet drugs and non‐vitamin K oral anticoagulants (NOACs).

Results

We identified a total of 378 consecutive patients. In 282 cases (74.6%), rivaroxaban was prescribed in a standard dose and in 96 (25.4%) in a reduced dose. Out of 96 patients receiving a reduced dose, 50 (52.1%) did not meet labeling criteria for dose reduction. In uni‐ and multivariate regression analysis, estimated glomerular filtration rate (eGFR) (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.12‐0.95, P = .04) was the only independent predictor of rivaroxaban underdosage.

Conclusions

In clinical practice, rivaroxaban dosing is frequently incoherent with labeling. In this study, rivaroxaban was often administered underdosed. Potentially inappropriate dose reduction was significantly associated with eGFR, the same factor that is used as criterion for dose adjustment.

Appropriateness of DOAC Prescribing Before and During Hospital Admission and Analysis of Determinants for Inappropriate Prescribing

Background and Objectives: Appropriate dosing of direct oral anticoagulants (DOACs) is required to avoid under- and overdosing that may precipitate strokes or thromboembolic events and bleedings, respectively. Our objective was to analyze the appropriateness of DOAC dosing according to the summaries of product characteristics (SmPC). Furthermore, determinants for inappropriate prescribing were investigated. Methodology: Retrospective cohort study of hospitalized patients aged ≥60 years with at least one DOAC intake during hospital stay. Descriptive analyses were used to summarize the characteristics of the study population. Chi-square test was used to evaluate differences between DOACs. Binary logistic regression analysis was performed to assess determinants for inappropriate prescribing. Results: For the 772 included patients, inappropriate dosing occurred in 25.0% of hospitalizations with 23.4, 21.9, and 29.7% for dabigatran, rivaroxaban, and apixaban, respectively (p = 0.084). Underdosing was most prevalent for apixaban (24.5%) compared to dabigatran (14.0%) and rivaroxaban (12.8%), p < 0.001. In 67.1% (apixaban), 26.7% (dabigatran), and 51.2% (rivaroxaban) of underdosed DOAC cases according to the SmPC, the dose would be considered appropriate according to the European Heart Rhytm Association (EHRA) guidelines. Overdosing was observed in 4.5% (apixaban), 4.7% (dabigatran), and 7.7% (rivaroxaban) of patients. For all DOACs, our analysis showed an age ≥80 years (p = 0.036), use of apixaban (p = 0.026), DOAC use before hospitalization (p = 0.001), intermediate renal function (p = 0.014), and use of narcotic analgesics (p = 0.019) to be associated with a higher rate of inappropriate prescribing. Undergoing surgery was associated with a lower odds of inappropriate prescribing (p = 0.012). For rivaroxaban, use of medication for hypothyroidism (p = 0.027) and the reduced dose (p < 0.001) were determinants for inappropriate prescribing. Treatment of venous thromboembolism was associated with less errors (p = 0.002). For apixaban, severe renal insufficiency (p < 0.001) and initiation in hospital (p = 0.016) were associated with less and the reduced dose (p < 0.001) with more inappropriate prescribing. No determinants were found in the dabigatran subgroup. Conclusions: Inappropriate DOAC prescribing is frequent with underdosing being the most common drug related problem when using the SmPC as reference. More appropriate prescriptions were found when taking the EHRA guidelines into account. Analysis of determinants of inappropriate prescribing yielded insights in the risk factors associated with inappropriate DOAC prescriptions.