Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation

Real world Data on the Concurrent Use of P-glycoprotein or Cytochrome 3A4 Drugs and Non-vitamin K Antagonist Oral Anticoagulants in Non-Valvular Atrial Fibrillation

AIM

To determine the concurrent use of P-glycoprotein (P-gp) or Cytochrome (CYP) 3A4 drugs and non-vitamin K antagonist oral anticoagulants (NOACs) among non-valvular AF (NVAF) patients in clinical practice.

METHODS AND RESULTS

Administrative databases identified all adults (≥ 18 years) with incident or prevalent NVAF who initiated a NOAC in an outpatient or inpatient setting, between July 2012-March 2019 in Alberta, Canada. Concurrent use was defined as a P-gp or CYP3A4 dispensation in the 100 days prior to and overlapping NOAC dispensation. The P-gp and CYP3A4 drugs were categorized into 3 groups and drug-drug interactions classified according to the 2018 European Heart Rhythm Association practical guide. Time-varying Cox models calculated crude hazard ratio (HR) of outcomes at 1-year. A total of 642,255 NOAC dispensations occurred for 36,566 NVAF patients. Of these, 71,643 (11.2%) had a concurrent dispensation of an interacting P-gp or CYP3A4 drug. Overall, the drug-drug interaction was defined as contraindicated in 2.5%, avoid/caution in 2.3%, and for another 6.7% should require a dose adjustment. When all drug-drug interactions were considered, inappropriate NOAC prescribing occurred in 63% (n = 45,080) of dispensations. There was a significantly higher risk of death (HR 1.58, 1.47-1.70) for a drug-drug interaction but not for stroke (p = 0.89) or major bleeding risk (p = 0.13).

CONCLUSIONS

The concurrent use of P-gp or CYP3A4 drugs and NOACs was uncommon but important since almost two-thirds of patients with drug-drug interactions had inappropriate NOAC dosing and a higher risk of death. More attention to this issue is needed.

CKD Progression in Medicare Beneficiaries With Nonvalvular Atrial Fibrillation Treated With Apixaban Versus Warfarin

RATIONALE & OBJECTIVE

Comparing kidney disease progression among patients treated with direct oral anticoagulants (DOACs) versus warfarin has not been well studied. We hypothesized that apixaban would be associated with lower risks of progression of chronic kidney disease (CKD) and progression to incident kidney failure than warfarin in patients with atrial fibrillation (AF).

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Medicare recipients with stage 3, 4, or 5 CKD and incident AF who received a new prescription for apixaban or warfarin from 2013 through 2017.

EXPOSURE

Apixaban or warfarin.

OUTCOMES

Progression to incident kidney failure or, separately, to a more advanced stage of CKD.

ANALYTICAL APPROACH

Marginal structural cause-specific proportional hazards models with inverse probability weighting to estimate marginal hazard ratios (HRs) for each outcome. HRs compared apixaban to warfarin in intention-to-treat and censored-at-drug-switch analyses.

RESULTS

12,816 individuals met inclusion criteria (50.3% received apixaban; 49.7% received warfarin). After weighting, the mean age of the cohort was 80 ± 7 years, 51% were women, and 88% were White. Approximately 84% had stage 3, 15% had stage 4, and 1% had stage 5 CKD. In the intention-to-treat analysis, apixaban, relative to warfarin, was associated with an HR of developing incident kidney failure of 0.98 (95% confidence interval [CI], 0.79-1.22) and of CKD stage progression of 0.90 (95% CI, 0.82-0.99). Corresponding HRs for censored-at-drug-switch analyses were 0.81 (95% CI, 0.56-1.17) and 0.81 (95% CI, 0.70-0.92). Results were similar for a series of subgroup and sensitivity analyses.

LIMITATIONS

CKD was defined based on diagnosis codes from claims; findings may not be generalizable to non-Medicare CKD populations.

CONCLUSIONS

Apixaban, compared with warfarin, was associated with lower risk of CKD stage progression, but not with incident kidney failure.

Patterns of anticoagulation therapy in atrial fibrillation: results from a large real-life single-center registry

Aim

To investigate the differences in the characteristics and clinical outcomes of recently diagnosed patients with atrial fibrillation (AF) receiving different types of anticoagulants in a real-life setting.

Methods

We retrospectively analyzed the charts of 1000 consecutive patients with non-valvular AF diagnosed and referred for hospitalization at our institution from 2013 to 2018.

Results

Over the observed period, the frequency of direct oral anticoagulation (DOAC) therapy use significantly increased (P = 0.002). Patients receiving warfarin had more unfavorable thromboembolic and bleeding risk factors than patients receiving DOAC. Predetermined stroke and major bleeding risks were similarly distributed among the dabigatran, rivaroxaban, and apixaban groups. Patients receiving warfarin had shorter time-to-major bleeding (TTB), time to thrombosis (TTT), and overall survival (OS) than patients receiving DOACs. After adjustment for factors unbalanced at baseline, the warfarin group showed significantly shorter OS (hazard ratio 2.27, 95% confidence interval 1.44-3.57, P < 0.001], while TTB and TTT did not significantly differ between the groups. Only 37% of patients on warfarin had optimal dosing control, and they did not differ significantly in TTB, TTT, and OS from patients on DOACs.

Conclusion

Warfarin and DOACs are administered to different target populations, possibly due to socio-economic reasons. Patients receiving warfarin rarely obtain optimal dosing control, and experience significantly shorter survival compared with patients receiving DOACs.

Appropriateness of direct oral anticoagulant dosing in patients with atrial fibrillation according to the drug labelling and the EHRA Practical Guide

BACKGROUND

This study aimed to evaluate the prevalence of potential drug-drug interactions (DDIs) and the appropriateness of direct oral anticoagulant (DOAC) dosing according to both the Summary of Product Characteristics (SmPC) and the European Heart Rhythm Association (EHRA) Practical Guide in a 'real-world' sample of non-valvular atrial fibrillation (NVAF) patients.

METHODS AND RESULTS

Data of a cross-sectional observational study in a primary care sample of 654 long-term DOAC users were used for this sub-analysis. A total of 262 potential DDIs were identified in 220 patients (33.6%). Pharmacodynamic DDIs were present in 163 patients (24.9%) and pharmacokinetic DDIs in 82 patients (12.5%). One-third of patients (33.8%) received reduced DOAC dose. According to the dosing recommendations in the SmPC, 81.7% of DOACs were dosed appropriately. According to the EHRA recommendations, 76.6% of DOACs were dosed appropriately. Dosing recommendations were consistent for 90.7% of patients, with both the SmPC and EHRA Practical Guide considering DOACs dosed appropriately in 74.5% of patients, overdosed in 7.8%, underdosed in 7.6% and contraindicated in 0.8%. However, for the remaining 9.3% dosing recommendations differed between SmPC and EHRA.

CONCLUSIONS

This 'real-world' analysis of DOAC dosing demonstrated that in about one-third of NVAF patients potential DDIs were present. In 18.3% and 23.4% of patients, DOACs were dosed inappropriately according to the SmPC and EHRA Practical Guide respectively. In almost 10% of the study population dosing advice was inconsistent between both references. More research is needed to ensure appropriate DOAC dosing in this 'grey zone' population.

Effects of ticagrelor on the pharmacokinetics of rivaroxaban in rats

CONTEXT

Rivaroxaban and ticagrelor are two common drugs for the treatment of atrial fibrillation and acute coronary syndrome. However, the drug-drug interaction between them is still unknown.

OBJECTIVE

To investigate the effects of ticagrelor on the pharmacokinetics of rivaroxaban in rats both in vivo and in vitro.

MATERIALS AND METHODS

A sensitive and reliable UPLC-MS/MS method was developed for the determination of rivaroxaban in rat plasma. Ten Sprague-Dawley rats were randomly divided into ticagrelor pre-treated group (10 mg/kg/day for 14 days) and control group. The pharmacokinetics of orally administered rivaroxaban (10 mg/kg, single dose) with or without ticagrelor pre-treatment was investigated with developed UPLC-MS/MS method. Additionally, Sprague-Dawley rat liver microsomes were also used to investigate the drug-drug interaction between these two drugs in vitro.

RESULTS

The C _max (221.34 ± 53.33 vs. 691.18 ± 238.31 ng/mL) and the AUC_(0-t) (1060.97 ± 291.21 vs. 3483.03 ± 753.83 μg·h/L) of rivaroxaban increased significantly (p < 0.05) with ticagrelor pre-treatment. The MRT_(0-∞) of rivaroxaban increased from 4.41 ± 0.79 to 5.97 ± 1.11 h, while the intrinsic clearance decreased from 9.93 ± 2.55 to 2.89 ± 0.63 L/h/kg (both p < 0.05) after pre-treated with ticagrelor. Enzyme kinetic study indicated that ticagrelor decreased rivaroxaban metabolic clearance with the IC₅₀ value of 14.04 μmol/L.

CONCLUSIONS

Our in vivo and in vitro results demonstrated that there is a drug-drug interaction between ticagrelor and rivaroxaban in rats. Further studies need to be carried out to verify whether similar interactions truly apply in humans and whether these interactions have clinical significance.

Non-vitamin K antagonist oral anticoagulants for stroke prevention in atrial fibrillation: safety issues in the elderly

INTRODUCTION

Non-vitamin K antagonist oral anticoagulants (NOACs) are increasingly used for stroke prevention in patients with atrial fibrillation (AF). Since NOACs are predominantly used in the elderly with AF at high risk for stroke and bleeding and with comorbidities requiring polypharmacy, it is important to assess their safety and efficacy in this population.

AREAS COVERED

We review changes in pharmacokinetics and pharmacodynamics observed with senescence and the effect on NOACs and drug and food interactions. We also provide an update on challenges related to NOAC use in situations that increases the risk for bleeding or require temporary discontinuation and address practical issues in the elderly AF patients managed on NOACs. Clinical studies and trials with cardiovascular outcomes reported from January 1990 to August 2020 were identified through the Medline database using PubMed, Cochrane Library, and EMBASE database.

EXPERT OPINION

NOACs are highly effective in preventing stroke in AF patients with non-inferior or superior efficacy to warfarin, with reduced risk of major bleeding. However, in the older-elderly, evidence comes mainly from observational studies or extrapolation from studies in populations with minimal functional limitations or comorbidities. The high upfront cost and out-of-pocket expense for copayment or deductibles also limit the use of this effective therapy in a substantial number of patients. The cost reduction may further improve long-term use for NOACs in stroke prevention in elderly patients with AF.

Outcomes Associated With 4-Factor Prothrombin Complex Concentrate Administration to Reverse Oral Factor Xa Inhibitors in Bleeding Patients

Compared with vitamin K antagonists (VKAs), oral factor Xa inhibitors are associated with at least equivalent efficacy and a lower incidence of major bleeding. Despite this benefit, bleeding remains the most common adverse event. Prior to the approval of andexanet alfa, alternative agents such as 4-factor prothrombin complex concentrate (4F-PCC) were utilized for reversal. This was a retrospective, descriptive study conducted on patients 18 years of age or older who received 4F-PCC for reversal of oral factor Xa inhibitors-associated bleeding. Patients were excluded if they received a VKA or dabigatran in the previous 48 hours. A subgroup analysis comparing 4F-PCC with andexanet alfa was conducted on patients who met the inclusion and exclusion criteria of the ANNEXA-4 trial. The primary end point of this study was to evaluate the incidence of hemostasis and associated dosing strategies in patients receiving 4F-PCC for reversal of oral factor Xa inhibitors-associated bleeding. Thirty-eight patients were included, and 28 patients (74%) achieved hemostasis. The median dose of 4F-PCC was 50 units/kg. In patients who achieved hemostasis, the median dose was 50 units/kg, and in those who failed to reach hemostasis, a median dose of 30 units/kg was seen. Within the subgroup analysis, there was no difference in overall rates of hemostasis between the 4F-PCC and andexanet alfa groups. Remaining a reasonable option to utilize for reversal of oral factor Xa inhibitors is 4F-PCC, especially when andexanet alfa is unavailable, with 50 units/kg appearing to be the most effective dose to achieve hemostasis. Further studies are needed to determine a preferential agent.

Trends in the Prescription of Non-Vitamin K Antagonist Oral Anticoagulants for Atrial Fibrillation: Results of the Polish Atrial Fibrillation (POL-AF) Registry

Background: Current guidelines do not suggest in which groups of patients with atrial fibrillation (AF) individual non-vitamin K antagonist oral anticoagulants (NOACs) should be used for the prevention of thromboembolic complications. The aim of this study was to evaluate the frequency of use of apixaban, dabigatran, and rivaroxaban, and attempt to identify factors predisposing their administration. Methods: The Polish Atrial Fibrillation (POL-AF) registry is a prospective, non-interventional study, including consecutive patients with AF hospitalized in ten Polish cardiology centers during the period ranging from January to December 2019. In this study, all patients were treated with NOACs. Results: Among the 2971 patients included in the analysis, 40.4% were treated with rivaroxaban, 32% with apixaban, and 27.6% with dabigatran. The mean age of the total population was 72 ± 11.5 years and 43% were female. A reduced dose of NOAC was used in 35% of patients treated with apixaban, 39.7% of patients treated with dabigatran, and 34.4% of patients treated with rivaroxaban. Independent predictors of the use of apixaban were previous bleeding (OR 2.37, CI 1.67–3.38), GFR < 60 mL/min (OR 1.38, CI 1.25–1.64), heart failure (OR 1.38, CI 1.14–1.67) and age (per 5 years) (OR 1.14, CI 1.09–1.19). GFR < 60 mL/min (OR 0.79, CI 0.66–0.95), female (OR 0.8, CI 0.67–0.96) and age (per 5 years) (OR 0.95, CI 0.91–0.99) diminished the chance of using dabigatran. Previous bleeding (OR 0.43, CI 0.28–0.64), vascular disease (OR 0.84, CI 0.70–0.99), and age (per 5 years) (OR 0.94, CI 0.90–0.97) diminished the chance of choosing rivaroxaban. Conclusions: In hospitalized patients with AF, the most frequently chosen NOAC was rivaroxaban. Apixaban was chosen more often in patients after bleeding, and in those who were advanced in years, with heart failure and impaired renal function. Impaired renal function and female gender were factors that diminished the chance of using dabigatran. Previous bleeding and vascular disease was the factor that diminished the chance of using rivaroxaban. Dabigatran and rivaroxaban have been used less frequently in elderly patients.

[How to anticoagulate elderly and fragile patients?]

Risks of thrombosis, bleeding and renal impairment are increasing with age. The efficacy and safety of the direct oral anticoagulants (DOACs) in fragile patients (age > 75 years and/or creatinine clearance levels < 50 ml/min and/or body weight below 50 kg) with indication for anticoagulation is one of the most challenging topic in cardiovascular medicine. New registry data from subgroup analyses of landmark studies and registries point towards to superiority of DOACs. This article summarizes new insights and describes pathways for anticoagulation in fragile patients.

Non-Vitamin K Antagonist Oral Anticoagulants and Factors Influencing the Ischemic and Bleeding Risk in Elderly Patients With Atrial Fibrillation: A Review of Current Evidence

ABSTRACT

Non-vitamin K antagonist oral anticoagulants (NOACs) are a widely prescribed treatment to prevent stroke in patients with nonvalvular atrial fibrillation, and a therapy and preventative measure to prevent recurrences following venous thromboembolism. Optimal use of NOACs requires a thorough knowledge of the pharmacology of these drugs, as well as an understanding of patient factors affecting their use. The 4 NOACs-dabigatran, apixaban, edoxaban, and rivaroxaban are available in a range of doses suitable for differing indications and with a variety of dose reduction criteria. Identification of the correct dose is one of the key challenges in the individualization of treatment. Elderly patients with atrial fibrillation are at a greater risk of both ischemic and bleeding events than younger patients. Consequently, it is essential to achieve balance in anticoagulation strategies. Medication adherence to NOACs is important for safe and effective treatment, particularly in elderly populations. A growing body of evidence shows that once-daily dosing improves adherence and persistence to therapy, without having an impact on bleeding risk.

Reducing upper digestive bleeding risk in patients treated with direct oral anticoagulants and concomitant infection with

Direct oral anticoagulants (DOACs) such as apixaban or dabigatran are excellent options in preventing embolic cardiovascular events. Observational studies have shown that gastrointestinal bleeding risks produced by DOACs could be lowered when correcting some host co-factors i.e. Helicobacter pylori (HP) infection. The upper digestive bleeding (UDB) rates in patients with DOAC indication and the usefulness of anti-HP therapy addition were compared. An observational retrospective study was conducted of medical records of 260 patients treated with DOACs, 130 of whom were concomitantly treated for HP infection in accordance with Maastricht V/Florence consensus. The severity of bleeding, the complexity of endoscopic treatment required to stop the bleeding, the re-bleeding rates, the surgical treatment indication and the overall mortality rates were compared between the groups. The risk of UDB was higher in HP-untreated patients in both types of DOACs used (respectively 2.08, 2.02). HP-untreated Forrest Ia/Ib/IIa and IIb DOACs patients had more severe bleedings compared with same class of HP-treated patients (P=0.007/0.005; 0.009/0.006; 0.048/0.005, 0.044/0.049, respectively). Endoscopic treatments such as adrenaline injections combined with metallic clip attachments were more frequently mandatory in HP-untreated DOACs patients for classes Ia/b and IIa (respectively, P=0.000/0.001, P=0.003/0.003). The re-bleeding rates were higher in HP-untreated patients with concomitant DOACs (OR 82.5; 95% CI 30.1-121.7; P=0.005). A history of peptic ulcer or UDB was associated with a 2.9-fold higher risk of UDB in HP-untreated compared with HP-treated patients, slightly increased for dabigatran compared with apixaban (RR 3.06, 2.72, P<0.5, respectively). Surgical intervention and the UDB-related mortality rates were higher in HP-untreated patients (P=0.041/0.044, P=0.007, respectively). HP-eradication treatment and bacterial clearance improve the safety profile of DOACs treatment, especially in fragile patients, in whom the UDB rates can be lowered, and the overall outcome can be enhanced by this combined approach.

Trends in anticoagulation management services following incorporation of direct oral anticoagulants at a large academic medical center

The introduction of direct oral anticoagulants (DOACs) to the market has expanded anticoagulation options for outpatient use. Routine evaluation by health care professionals is recommended as it is with warfarin, therefore requiring adjustments in practices of anticoagulation management services (AMS). This study aims to describe trends that occurred following the incorporation of DOACs into AMS at a large academic medical center. A retrospective chart review of pharmacist-run AMS was used to compare patients on DOAC therapy versus other types of anticoagulation, including warfarin and parenteral agents. Primary outcomes included trends in the number of unique patients, management encounters, and telephone encounters throughout the study period. Secondary outcomes included trends in new encounters, and changes in patient characteristics, resources utilized, and patient satisfaction scores. A total of 2976 unique patients, 74,582 management encounters, and 13,282 telephone encounters were identified. From study beginning to end, results showed stable numbers of unique patients, an increase in management encounters for the DOAC group and decrease in the other anticoagulants group, and stable numbers of telephone encounters. Additionally, the number of new encounters for both groups increased. Throughout the study, pharmacy resources were reallocated within anticoagulation to adapt to the changing trends and patient satisfaction reached targets. Patients' characteristics remained stable, with the DOAC group having fewer comorbid conditions and concomitant medications that could increase bleed risk. This study showed that by reallocating resources within anticoagulation, AMS can maintain stable patient populations while continuing to expand access and satisfy patients following DOAC inclusion.

Heparin dosing in uninterrupted anticoagulation with dabigatran vs. warfarin in atrial fibrillation ablation: RE-CIRCUIT study

AIMS

To describe heparin dosing requirements in patients who underwent catheter ablation of atrial fibrillation with uninterrupted anticoagulation using dabigatran etexilate (dabigatran) or warfarin to attain therapeutic activated clotting time (ACT) in the RE-CIRCUIT® study. The RE-CIRCUIT study showed significantly fewer major bleeding events in the dabigatran vs. warfarin treatment group. Unfractionated heparin was administered during the procedure to maintain ACT >300 s.

METHODS AND RESULTS

Patients were randomly assigned to dabigatran 150 mg bid or international normalized ratio-adjusted warfarin. Ablation was performed with uninterrupted anticoagulation and continued for 8 weeks after the procedure. Heparin was administered after placement of femoral sheaths before or immediately after transseptal puncture. Ablation was performed in 635 patients (dabigatran, 317; warfarin, 318); data were available from 396 patients administered heparin (dabigatran, 191; warfarin, 205). Most frequent time window from last dose of study drug to septal puncture was 0 to <4 h in the dabigatran (41.3%) and 16 to <24 h in the warfarin arms (44.7%). Overall mean (standard deviation) heparin dose was similar between the dabigatran and warfarin groups [12 402 (10 721) vs. 11 910 (8359) IU, respectively]. Heparin dosing requirement to reach therapeutic ACT was lowest when time from last dose of dabigatran to septal puncture was 0 to <4 h.

CONCLUSION

Patients treated with dabigatran required a similar amount of unfractionated heparin as those treated with warfarin to achieve an ACT of >300 s during ablation. More heparin units were required when the time from the last dose of dabigatran to septal puncture increased.

Bleeding and thromboembolism due to drug-drug interactions with non-vitamin K antagonist oral anticoagulants-a Swedish, register-based cohort study in atrial fibrillation outpatients

PURPOSE

To study the association between interacting drugs and bleeding or thromboembolism in atrial fibrillation outpatients treated with non-vitamin K antagonist oral anticoagulants (NOACs).

METHODS

Population-based cohort study of outpatients treated with NOACs in Sweden from 2008 to 2017. Patients with atrial fibrillation and newly initiated NOAC treatment were identified in the Prescribed Drug Register. Comorbidities and outcome data were retrieved from the Patient Register and the Cause of Death Register. Cox-regression analyses were performed to evaluate the primary endpoints any severe bleed and ischemic stroke/transient ischemic attack/stroke unspecified during the first six months of treatment. Secondary endpoints were gastrointestinal bleeding, intracranial bleeding, ischemic stroke, and venous thromboembolism.

RESULTS

Increased risk of any severe bleed was found when NOAC treatment, and drugs with pharmacodynamic effect on bleeding were combined, compared to NOAC only. An increased risk with these combinations was evident for apixaban (hazard ratio (HR) 1.47; 95% CI 1.33-1.63), rivaroxaban (HR 1.7; 95% CI 1.49-1.92), and dabigatran (HR 1.26; 95% CI 1.05-1.52). For apixaban, there was an increased risk of any severe bleed when combined with CYP3A4 and/or P-glycoprotein (P-gp) inhibitors (HR 1.23; 95% CI 1.01-1.5). The use of inducers of CYP3A4 and/or P-gp was low in this cohort, and effects on ischemic stroke/TIA/stroke unspecified could not be established.

CONCLUSION

Increased risk of bleeding was seen for pharmacodynamic and pharmacokinetic interactions with NOACs. Prescribers need to be vigilant of the effect of interacting drugs on the risk profile of patients treated with NOACs.

Comparative Effectiveness and Safety of Oral Anticoagulants Across Kidney Function in Patients With Atrial Fibrillation

BACKGROUND

Patients with atrial fibrillation and severely decreased kidney function were excluded from the pivotal non-vitamin K antagonist oral anticoagulants (NOAC) trials, thereby raising questions about comparative safety and effectiveness in patients with reduced kidney function. The study aimed to compare oral anticoagulants across the range of kidney function in patients with atrial fibrillation.

METHODS AND RESULTS

Using a US administrative claims database with linked laboratory data, 34 569 new users of oral anticoagulants with atrial fibrillation and estimated glomerular filtration rate ≥15 mL/(min·1.73 m²) were identified between October 1, 2010 to November 29, 2017. The proportion of patients using NOACs declined with decreasing kidney function-73.5%, 69.6%, 65.4%, 59.5%, and 45.0% of the patients were prescribed a NOAC in estimated glomerular filtration rate ≥90, 60 to 90, 45 to 60, 30 to 45, 15 to 30 mL/min per 1.73 m² groups, respectively. Stabilized inverse probability of treatment weighting was used to balance 4 treatment groups (apixaban, dabigatran, rivaroxaban, and warfarin) on 66 baseline characteristics. In comparison to warfarin, apixaban was associated with a lower risk of stroke (hazard ratio [HR], 0.57 [0.43-0.75]; P<0.001), major bleeding (HR, 0.51 [0.44-0.61]; P<0.001), and mortality (HR, 0.68 [0.56-0.83]; P<0.001); dabigatran was associated with a similar risk of stroke but a lower risk of major bleeding (HR, 0.57 [0.43-0.75]; P<0.001) and mortality (HR, 0.68 [0.48-0.98]; P=0.04); rivaroxaban was associated with a lower risk of stroke (HR, 0.69 [0.51-0.94]; P=0.02), major bleeding (HR, 0.84 [0.72-0.99]; P=0.04), and mortality (HR, 0.73 [0.58-0.91]; P=0.006). There was no significant interaction between treatment and estimated glomerular filtration rate categories for any outcome. When comparing one NOAC to another NOAC, there was no significant difference in mortality, but some differences existed for stroke or major bleeding. No relationship between treatments and falsification end points was found, suggesting no evidence for substantial residual confounding.

CONCLUSIONS

Relative to warfarin, NOACs are used less frequently as kidney function declines. However, NOACs appears to have similar or better comparative effectiveness and safety across the range of kidney function.

Impact of gene polymorphisms in drug-metabolizing enzymes and transporters on trough concentrations of rivaroxaban in patients with atrial fibrillation

Rivaroxaban is excreted from the body via multiple pathways involving glomerular filtration, drug-metabolizing enzymes and transporters. In this study, we aimed to examine the impact of single nucleotide polymorphisms in P-glycoprotein, breast cancer resistance protein, cytochrome P450 (CYP) 3A5 and CYP2J2 on the pharmacokinetics of rivaroxaban. Eighty-six patients with non-valvular atrial fibrillation (NVAF) undergoing AF catheter ablation were enrolled in this study. In these analyses, the dose-adjusted plasma trough concentration ratio (C_0h /D) of rivaroxaban was used as the pharmacokinetic index. The median (quartile range) rivaroxaban C_0h /D was 3.39 (2.08-5.21) ng/mL/mg (coefficient of variation: 80.5%). The C_0h /D did not differ significantly among ABCB1 c.3435C>T, c.2677G>A/T, c.1236C>T, ABCG2 c.421C>A, CYP3A5*3 and CYP2J2*7 genotypes. Stepwise selection multiple linear regression analysis showed that the estimated glomerular filtration rate was the only independent factor influencing the C_0h /D of rivaroxaban (R²  = 0.152, P < 0.001). There was a significant correlation between the C_0h of rivaroxaban and prothrombin time (PT) (rho = 0.357, P = 0.001). In patients with NVAF, pharmacokinetic genotype tests are unlikely to be useful for prediction of the C_0h of rivaroxaban.

Microdosed Cocktail of Three Oral Factor Xa Inhibitors to Evaluate Drug-Drug Interactions with Potential Perpetrator Drugs

OBJECTIVES

The aim of this study was to prove the suitability of simultaneously administered microdoses of the factor Xa inhibitors (FXaIs) rivaroxaban, apixaban and edoxaban (100 µg in total). To evaluate drug-drug interactions, the impact of ketoconazole, a known strong inhibitor of cytochrome P450 3A4 and P-glycoprotein, was studied.

METHODS

In a crossover clinical trial, 18 healthy volunteers were randomized to the two treatments using microdoses of rivaroxaban, apixaban and edoxaban alone and when coadministered with ketoconazole. Plasma and urine concentrations of microdosed apixaban, edoxaban and rivaroxaban were quantified using a validated ultra-performance liquid chromatography-tandem mass spectrometry assay with a lower limit of quantification of 2.5 pg/ml.

RESULTS

The microdosed FXaI cocktail showed similar pharmacokinetic parameters compared with published data, using normal therapeutic doses of each FXaI. Ketoconazole significantly increased exposure, with geometric mean AUC ratios of 1.90 (apixaban), 2.35 (edoxaban) and 2.27 (rivaroxaban).

CONCLUSION

The microdosed FXaI cocktail approach was able to precisely predict the drug interaction with ketoconazole. This is the first study that has been conducted to evaluate drug-drug interactions with a drug class, and the low administered doses also allow evaluation in vulnerable target populations.

STUDY PROTOCOL

EudraCT 2016-003024-23.

Novel Oral Anticoagulants in Renal Transplant Recipients: A Retrospective Cohort Study

AIM

Data on the use of novel anticoagulant drugs (NOACc) in renal transplant recipients is scarce. The aim of our study was to investigate the safety and efficacy of NOACs in renal transplant recipients.

MATERIALS AND METHODS

In a single-centre retrospective cohort study we assessed adverse reactions, thromboembolic events, and interactions of calcineurin inhibitors in patients treated with NOACs.

RESULTS

Twenty-three renal transplant recipients were treated with NOACs (70% male), mean age of 65.8 ± 1.8 years. Fourteen (61%) patients were treated with rivaroxaban, apixaban was given to 8 (35%) of our patients, and dabigatran to one patient (4%). The main indications for NOAC therapy was atrial fibrillation in 61% and deep venous thrombosis in 23% of patients. Bleeding occurred in 2 patients (1 treated with rivaroxaban and 1 with dabigatran). None of our patients developed thrombosis while treated with NOAC. During the median follow-up of 24 months graft function, as well as hematological parameters, remained stable in patients that were treated with rivaroxaban and apixaban, while dabigatran was ceased after a month of therapy due to a bleeding event.

CONCLUSION

Our results show that both rivaroxaban and apixaban are safe and efficient oral anticoagulant drugs in renal transplant patients. Additional studies are needed to prove these results.

Arrhythmias and COVID-19: A Review

Current understanding of the impact of coronavirus disease-2019 (COVID-19) on arrhythmias continues to evolve as new data emerge. Cardiac arrhythmias are more common in critically ill COVID-19 patients. The potential mechanisms that could result in arrhythmogenesis among COVID-19 patients include hypoxia caused by direct viral tissue involvement of lungs, myocarditis, abnormal host immune response, myocardial ischemia, myocardial strain, electrolyte derangements, intravascular volume imbalances, and drug sides effects. To manage these arrhythmias, it is imperative to increase the awareness of potential drug-drug interactions, to monitor QTc prolongation while receiving COVID therapy and provide special considerations for patients with inherited arrhythmia syndromes. It is also crucial to minimize exposure to COVID-19 infection by stratifying the need for intervention and using telemedicine. As COVID-19 infection continues to prevail with a potential for future surges, more data are required to better understand pathophysiology and to validate management strategies.

Patients Taking Direct Oral Anticoagulants (DOAC) Undergoing Oral Surgery: A Review of the Literature and a Proposal of a Peri-Operative Management Protocol

Patients on anticoagulant therapy for the prevention of cardiovascular accidents present an increased risk of bleeding following dental and oral surgery. Four recently introduced non-vitamin K antagonist oral anticoagulants, namely dabigatran etexilate (direct thrombin inhibitor), rivaroxaban, apixaban, and edoxaban (Xa factor direct inhibitor), are widely spreading for convenience of use compared to the older drug class. Dental management of patients taking these drugs has substantial differences compared to patients on vitamin K antagonist therapy. Anticoagulation is not assessed directly through a hematological test, but indirectly by renal function. The interventions must be scheduled at the time of minimum blood concentration of the drug. Bleeding can occur even after several days following the surgery. The interaction with drugs administered for dental care must be carefully evaluated. The peri-operative diet can influence the risk of bleeding. Local measures favoring coagulation must be adopted. The interventions with higher risk must be divided into multiple less invasive interventions. Although antidotes exist for these drugs, their use does not seem necessary for dental interventions that have been planned optimally. Furthermore, in this review of the literature a decision protocol is proposed for the evaluation of the suspension of the anticoagulant drug before oral surgery. Cessation of any anticoagulant should only be made in consultation with the patient’s general practitioner/cardiologist, who will weigh up the risk of bleeding from the proposed procedure with the risk of thrombosis/stroke in each individual patient.

Results of Therapy Using Oral Anticoagulants in the Acute Phase after Mechanical Thrombectomy

Objective

The usage of oral anticoagulants (OACs) in the acute phase of cerebral infarction has increased, but the optimal timing for starting OACs after mechanical thrombectomy (MT) is unclear. We report the usage of OACs after MT at our hospital and evaluated the outcomes.

Methods

OACs were selected as secondary preventive drugs for 64 patients who underwent MT for anterior circulatory embolism between July 2016 and January 2019. Of the 64 patients, 28 and 36 received direct oral anticoagulants (DOACs) and warfarin (Wf), respectively. We compared the frequency of intracranial hemorrhage in the acute phase and that of recurrent cerebral infarction within 30 days.

Results

The median diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Scores + white matter (DWI-ASPECTS + W) score at admission was 7.5 (IQR 6-9)/8 (IQR, 6-9) in the DOACs group/Wf group. The rate of recanalization with modified thrombolysis in cerebral infarction (TICI) ≥2B by MT was 89.3/80.6%. In patients with subarachnoid hemorrhage (SAH) associated with MT and patients with hemorrhagic transformation (HT) on MRI the next day, administration was started after hemostasis. The median timing of the first anticoagulant administration was 3 (IQR, 2-4)/2 (IQR, 1-4) days. In the case of no HT the next day, the rate of new HT after 1 week was 7.1%/29.1%. In the case of HT the next day, the rate of HT deterioration the next day was 7.1%/16.6%. The percentage of symptomatic bleeding was 0%/2.8%. The percentage of recurrent cerebral infarction within 30 days was 0%/2.8%.

Conclusion

OACs in the acute phase after MT can be safely used and are expected to be effective at preventing recurrence.

Long term efficacy and safety of rivaroxaban plus cilostazol in the treatment of critical ischemia of the lower limbs in a frail, elderly patient with non valvular atrial fibrillation

Background

Many patients with critical lower limb ischemia are not eligible for revascularization procedures. Still, given the emerging role of both platelet and coagulation activation in the formation of arterial thrombi, they may benefit from the novel anticoagulant and antiplatelet drugs.

Case presentation

We describe the case of a male with critical lower limb ischemia complicated by older age, frailty, polymorbidity and non valvular atrial fibrillation, who was deemed as non eligible for surgery. The patient was successfully treated with the combination of rivaroxaban and cilostazol, and the clinical benefit was maintained throughout 32 months, with no occurrence of major or minor hemorrhagic or thrombotic events.

Conclusions

To our knowledge, this is the first report on the efficacy and safety of such a combination therapy in critical lower limb ischemia. In a clinical setting in which alternative pharmacological approaches are urgently needed, the association of rivaroxaban and cilostazol warrants further investigations.

Direct-Acting Oral Anticoagulants Versus Warfarin in Medicare Patients With Chronic Kidney Disease and Atrial Fibrillation

Background and Purpose:

The comparative effectiveness of direct-acting oral anticoagulants, compared with warfarin, for risks of stroke/systemic embolism, major bleeding, or death have not been studied in Medicare beneficiaries with atrial fibrillation and nondialysis-dependent chronic kidney disease.

Methods:

Medicare data from 2011 to 2017 were used to identify patients with stages 3, 4, or 5 chronic kidney disease and new atrial fibrillation who received a new prescription for warfarin, apixaban, rivaroxaban, or dabigatran. We estimated marginal hazard ratios with 95% CIs for the association of each direct-acting oral anticoagulant, compared with warfarin, for the outcomes of interest using inverse-probability-of-treatment weighted Cox proportional hazards models in as-treated and intention-to-treat analyses.

Results:

A total of 22 739 individuals met criteria (46.3% warfarin, 29.6% apixaban, 17.2% rivaroxaban, 6.9% dabigatran). Across the groups of anticoagulant users, mean age was 78.4 to 79.0 years; 50.3% to 51.4% were women, and 80.3% to 82.8% had stage 3 chronic kidney disease. In the as-treated analysis, for stroke/systemic embolism, hazard ratios, all compared with warfarin, were 0.70 (0.51–0.96) for apixaban, 0.80 (0.54–1.17) for rivaroxaban, and 1.15 (0.69–1.94) for dabigatran. For major bleeding, analogous hazard ratios were 0.47 (0.37–0.59) for apixaban, 1.05 (0.85–1.30) for rivaroxaban, and 0.95 (0.70–1.31) for dabigatran. There was no difference in the risk of all-cause mortality between the direct-acting oral anticoagulants and warfarin. Results of the intention-to-treat analysis were similar.

Conclusions:

Apixaban, compared with warfarin, was associated with decreased risk of stroke/systemic embolism and major bleeding; risks for both outcomes with rivaroxaban and dabigatran did not differ from risks with warfarin.

Management of Outpatient Warfarin Therapy amid COVID-19 Pandemic: A Practical Guide

Many healthcare resources have been and continue to be allocated to the management of patients with COVID-19. Therefore, the ongoing care of patients receiving oral anticoagulation with warfarin is likely to be compromised amid this unprecedented crisis. This article discusses a stepwise algorithm for the management of outpatient warfarin therapy. Alternative management strategies are presented and discussed, including alternative pharmacological therapy options and self-monitoring. Our algorithm aims to help clinicians safely optimize the treatment of patients requiring anticoagulation therapy in the context of the global response to the current pandemic.

Predictive ability of creatinine clearance versus estimated glomerular filtration rate for outcomes in patients with non-valvular atrial fibrillation: Subanalysis of the J-RHYTHM Registry

BACKGROUND

Renal impairment is a risk factor for various adverse events, especially for death. In general, creatinine clearance (CrCl) is used for dose-adjustments of many drugs including oral anticoagulants, and estimated glomerular filtration rate (eGFR) is adopted for the diagnosis of chronic kidney disease. Predictive ability of CrCl versus eGFR for outcomes in patients with non-valvular atrial fibrillation (NVAF) remains controversial; therefore, this was compared using data from the J-RHYTHM Registry.

METHODS

Out of 7406 outpatients with NVAF from 158 institutions, 6004 (age, 69.7 ± 9.9 years; men, 71.2%) having data of CrCl (mL/min, by the Cockcroft-Gault formula), eGFR (mL/min/1.73 m2, by the equations of the Japanese Society of Nephrology), and body surface area (BSA) were analyzed. C-statistics (area under the receiver-operating characteristic curve) of CrCl and eGFR for events were compared by DeLong's test.

RESULTS

Thromboembolism, major hemorrhage, and all-cause death occurred in 107 (1.8%), 117 (1.9%), and 154 (2.6%) patients during the 2-year follow-up period. C-statistics of CrCl for each event were 0.609 (95% confidence interval, 0.559-0.658), 0.599 (0.548-0.657), and 0.746 (0.706-0.786); and those of eGFR were 0.542 (0.487-0.597), 0.573 (0.519-0.626), and 0.677 (0.631-0.723), respectively. C-statistics of CrCl for thromboembolism and all-cause death were significantly higher than those of eGFR (P < 0.001 for both). These results were consistent when BSA-unadjusted eGFR was used instead of eGFR (P = 0.002 for thromboembolism and P < 0.001 for all-cause death).

CONCLUSIONS

CrCl was superior to eGFR in the prediction of adverse outcomes, i.e., thromboembolism and all-cause death in Japanese patients with NVAF.

[Second look: practical diagnostic and therapeutic checks in neurorehabilitation]

Post-acute inpatient neurorehabilitation facilities are increasingly treating patients who are not only severely ill and multimorbid but who are also referred from non-neurological departments. These patients are still often medically unstable so that the previous diagnostics and treatment must be reevaluated and when necessary adapted or supplemented. Certain interdisciplinary diagnostic and therapeutic problems, such as antithrombotic therapy, regularly reoccur. This article presents these problems in a checklist fashion, which should provide indications in individual cases when previously carried out measures need to be questioned and adapted.

Prevention and Treatment of Bleeding with Direct Oral Anticoagulants

Anticoagulant-related bleeding carries considerable morbidity and mortality. Major or life-threatening bleeding is among the most severe of these complications. As the number of patients treated with direct oral anticoagulants (DOACs) continues to increase, so does the number of DOAC-related bleeding events. The incidence of CRNM bleeding related to DOAC therapy ranges from 15 to 18% per 100-year patients, while the incidence of major bleeding ranges from 2.71 to 3.6%. Many of these bleeding events can be prevented with tailored dosing regimens or proper peri-procedural management. When unable to be prevented, DOAC-related bleeding can lead to significant long-term disability or death. Management with newer reversal agents such as andexanet alfa and idarucizumab, as well as prothrombin complex concentrates, may improve outcomes for patients with DOAC-related bleeding. The purpose of this review is to explore strategies for preventing and treating bleeding in patients receiving DOACs for anticoagulant therapy.

Oral anticoagulants and risk of acute liver injury in patients with nonvalvular atrial fibrillation: a propensity-weighted nationwide cohort study

Insufficient real-world data on acute liver injury (ALI) risk associated with oral anticoagulants (OACs) exist in patients with nonvalvular atrial fibrillation (NVAF). Using the French national healthcare databases, a propensity-weighted nationwide cohort study was performed in NVAF patients initiating OACs from 2011 to 2016, considering separately those (1) with no prior liver disease (PLD) as main population, (2) with PLD, (3) with a history of chronic alcoholism. A Cox proportional hazards model was used to estimate the hazard ratio with 95% confidence interval (HR [95% CI]) of serious ALI (hospitalised ALI or liver transplantation) during the first year of treatment, for each non-vitamin K antagonist (VKA) oral anticoagulant (NOAC: dabigatran, rivaroxaban, apixaban) versus VKA. In patients with no PLD (N = 434,015), only rivaroxaban new users were at increased risk of serious ALI compared to VKA initiation (adjusted HR: 1.41 [1.05–1.91]). In patients with chronic alcoholism history (N = 13,173), only those initiating dabigatran were at increased risk of serious ALI compared to VKA (2.88 [1.74–4.76]) but an ancillary outcome suggested that differential clinical follow-up between groups might partly explain this association. In conclusion, this study does not suggest an increase of the 1-year risk of ALI in NOAC versus VKA patients with AF.

Novel Perspective for Antithrombotic Therapy in TAVI

:

While surgical aortic valve replacement (SAVR) was for years the only available treatment for symptomatic aortic stenosis, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 and the improvement of its technical aspects in the following years, has holistically changed the synchronous therapeutic approach of aortic valve stenosis. Recent evidence has expanded the indication of TAVI from high to lower surgical risk populations with symptomatic aortic stenosis. The administration of antithrombotic therapy periprocedurally and its maintenance after a successful TAVI is crucial for the prevention of complications and affects postprocedural survival. Randomized controlled trials investigating the appropriate combination and the duration of antithrombotic treatment after TAVI are for the moment scarce. This review article sheds light on the underlying pathogenetic mechanisms contributing in periprocedural TAVI thrombotic complications and discuss the efficacy of current antithrombotic policies as evaluated in randomized trials.

Safety of Anticoagulation in Patients Treated With Urgent Reperfusion for Ischemic Stroke Related to Atrial Fibrillation

BACKGROUND AND PURPOSE

The optimal timing for starting oral anticoagulant after an ischemic stroke related to atrial fibrillation remains a challenge, mainly in patients treated with systemic thrombolysis or mechanical thrombectomy. We aimed at assessing the incidence of early recurrence and major bleeding in patients with acute ischemic stroke and atrial fibrillation treated with thrombolytic therapy and/or thrombectomy, who then received oral anticoagulants for secondary prevention.

METHODS

We combined the dataset of the RAF and the RAF-NOACs (Early Recurrence and Major Bleeding in Patients With Acute Ischemic Stroke and Atrial Fibrillation Treated With Non-Vitamin K Oral Anticoagulants) studies, which were prospective observational studies carried out from January 2012 to March 2014 and April 2014 to June 2016, respectively. We included consecutive patients with acute ischemic stroke and atrial fibrillation treated with either vitamin K antagonists or nonvitamin K oral anticoagulants. Primary outcome was the composite of stroke, transient ischemic attack, symptomatic systemic embolism, symptomatic cerebral bleeding, and major extracerebral bleeding within 90 days from the inclusion. Treated-patients were propensity matched to untreated-patients in a 1:1 ratio after stratification by baseline clinical features.

RESULTS

A total of 2159 patients were included, 564 (26%) patients received acute reperfusion therapies. After the index event, 505 (90%) patients treated with acute reperfusion therapies and 1287 of 1595 (81%) patients untreated started oral anticoagulation. Timing of starting oral anticoagulant was similar in reperfusion-treated and untreated patients (median 7.5 versus 7.0 days, respectively). At 90 days, the primary study outcome occurred in 37 (7%) patients treated with reperfusion and in 146 (9%) untreated patients (odds ratio, 0.74 [95% CI, 0.50-1.07]). After propensity score matching, risk of primary outcome was comparable between the 2 groups (odds ratio, 1.06 [95% CI, 0.53-2.02]).

CONCLUSIONS

Acute reperfusion treatment did not influence the risk of early recurrence and major bleeding in patients with atrial fibrillation-related acute ischemic stroke, who started on oral anticoagulant.

Anti-Factor Xa Activity of Standard and Japan-Specific Doses of Rivaroxaban in Thai Patients With Non-Valvular Atrial Fibrillation

BACKGROUND

Recommended rivaroxaban doses for stroke prevention in atrial fibrillation (SPAF) are 20 and 15 mg/day in patients with normal and reduced renal function, respectively, but lower doses (15 and 10 mg) have been tested and approved in Japan. It is not known whether 15 and 10 mg rivaroxaban are appropriate in other Asian populations. This study compared the anti-Factor Xa (FXa) activity of 20 and 15 mg rivaroxaban in Thai patients with normal renal function and 15 and 10 mg rivaroxaban in patients with reduced renal function.Methods and Results:Sixty non-valvular atrial fibrillation patients receiving rivaroxaban (mean [±SD] age 69.3±9.1 years, mean creatinine clearance 59.2±22.7 mL/min) were enrolled. The anti-FXa activity of standard rivaroxaban and Japan-specific doses was measured at peak and trough concentrations. Median anti-FXa activity at peak concentrations was significantly higher for the standard than Japan-specific dose. Median anti-FXa activity measured at the trough was significantly higher for the standard dose only in those with impaired renal function. A higher proportion of patients receiving the Japan-specific rather than standard dose had anti-FXa activity at peak concentrations within the expected range (87.7% vs. 64.4%; P=0.001). One-third of those receiving the standard dose had anti-FXa activity higher than the expected range.

CONCLUSIONS

A significantly higher proportion of Thai patients receiving the Japan-specific dose of rivaroxaban had anti-FXa activity at peak concentrations within the expected range.

Slightly elevated international normalized ratio predicts bleeding episodes in patients treated with direct oral anticoagulants

Introduction

Patients treated with direct oral anticoagulants (DOACs) are at increased bleeding risk. It is therefore of increasing interest to identify predictors of bleeding episodes to increase safety during treatment with DOACs.

Methods

This retrospective cohort study systematically reviewed medical records of 235 patients treated with either apixaban, rivaroxaban or dabigatran for non-valvular atrial fibrillation or venous thromboembolism and collected data on the international normalized ratio (INR) and all bleeding episodes.

Results

INR ≥ 1.5 was significantly associated with increased risk of minor and major bleeding events in patients treated with direct factor Xa inhibitors. This association was not present in patients treated with dabigatran. However, a high negative predictive value was identified for INR < 1.5 for all drugs. The relative risks of bleeding episodes in patients with INR ≥ 1.5 and INR < 1.5 were 5.1 and 0.20, respectively.

Conclusions

Our results demonstrate a strong correlation between INR and risk of bleeding episodes during DOAC treatment. INR < 1.5 was a strong negative predictor for low bleeding risk independent of indication or choice of drug, and INR ≥ 1.5 was associated with increased risk of bleeding episodes in patients treated with direct factor Xa-inhibitors.

The Role of Antithrombotic Therapy in Heart Failure

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

Laboratory monitoring of rivaroxaban in Chinese patients with deep venous thrombosis: a preliminary study

Background

Rivaroxaban, a novel oral anticoagulant drug, is widely used in clinical practice. There is no standardized laboratory monitoring for rivaroxaban, and its plasma concentration in Chinese patients with deep vein thrombosis is unclear. The rivaroxaban concentrations in human plasma and determine the steady-state concentration of rivaroxaban in patients with deep vein thrombosis are needed.

Methods

An ultra-high-performance liquid chromatography with mass spectrometric detection method was developed. Chromatographic separation was performed on a Waters BEH C18 column with isocratic elution using a mobile phase composed of acetonitrile and water. Quantitation of the analytes was performed using positive ionization mode and mass transitions of m/z 437.3 → m/z 145.0 and m/z 440.1 → m/z 145.0 for rivaroxaban and the internal standard, respectively. Blood samples were collected at 0 h and 2 h after patients took rivaroxaban for 7 days or more.

Results

The method was validated over the concentration range of 0.5 ~ 400 ng•mL^− 1 with a very low limit of quantification of 0.5 ng·mL^− 1, and the intra- and inter-day precision (RSD%) were < 15%. The range of the steady state concentration in patients that took 15 mg rivaroxaban twice daily, 10 mg twice daily, 20 mg once daily, 15 mg once daily, and 10 mg once daily were 168.5 ~ 280.1 ng•mL^− 1, 74.2 ~ 271.4 ng•mL^− 1, 25.7 ~ 306.8 ng•mL^− 1, 24.5 ~ 306.4 ng•mL^− 1, and 15.4 ~ 229.2 ng•mL^− 1, respectively.

Conclusions

The plasma rivaroxaban concentration in patients who took 10 mg rivaroxaban twice daily fluctuated less than that in patients who took 20 mg rivaroxaban once daily. The plasma concentration can be used for therapeutic drug monitoring for rivaroxaban.

Durability of bioprosthetic aortic valves in patients under the age of 60 years - rationale and design of the international INDURE registry

BACKGROUND

There is an ever-growing number of patients requiring aortic valve replacement (AVR). Limited data is available on the long-term outcomes and structural integrity of bioprosthetic valves in younger patients undergoing surgical AVR.

METHODS

The INSPIRIS RESILIA Durability Registry (INDURE) is a prospective, open-label, multicentre, international registry with a follow-up of 5 years to assess clinical outcomes of patients younger than 60 years who undergo surgical AVR using the INSPIRIS RESILIA aortic valve. INDURE will be conducted across 20-22 sites in Europe and Canada and intends to enrol minimum of 400 patients. Patients will be included if they are scheduled to undergo AVR with or without concomitant root replacement and/or coronary bypass surgery. The primary objectives are to 1) determine VARC-2 defined time-related valve safety at one-year (depicted as freedom from events) and 2) determine freedom from stage 3 structural valve degeneration (SVD) presenting as morphological abnormalities and severe haemodynamic valve degeneration at 5 years. Secondary objectives include the assessment of the haemodynamic performance of the valve, all stages of SVD, potential valve-in-valve procedures, clinical outcomes (in terms of New York Heart Association [NYHA] function class and freedom from valve-related rehospitalisation) and change in patient quality-of-life.

DISCUSSION

INDURE is a prospective, multicentre registry in Europe and Canada, which will provide much needed data on the long-term performance of bioprosthetic valves in general and the INSPIRIS RESILIA valve in particular. The data may help to gather a deeper understanding of the longevity of bioprosthetic valves and may expand the use of bioprosthetic valves in patients under the age of 60 years.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03666741 (registration received September, 12th, 2018).

Simultaneous determination of Rivaroxaban and TAK-438 in rat plasma by LC-MS/MS: application to pharmacokinetic interaction study

Aim: A sensitive and reliable LC-MS/MS method has been established and validated to the quantitation of rivaroxaban (RIV) and TAK-438 in rat plasma using carbamazepine as internal standard. Results: The procedure of method validation was conducted according to the guidelines of EMA and US FDA. At the same time, the method was applied to pharmacokinetic interactions study between RIV and TAK-438 for the first time. When RIV and TAK-438 co-administration to rats, main pharmacokinetic parameters of TAK-438 like AUC_(0-t), AUC_(0-∞) and C_max had statistically significant increase. The main pharmacokinetic parameters of RIV have no statistically significant difference (p > 0.05) when co-administered except for t_1/2 (p < 0.01). Conclusion: The results indicated that drug-drug interactions occurred between RIV and TAK-438 when co-administered to rats.

Incidence Rates of Bleeding and Emergency Surgery Due to Trauma or Fracture Among Japanese Patients with Non-valvular Atrial Fibrillation Receiving Oral Anticoagulation Therapy

Introduction

In patients with nonvalvular atrial fibrillation (NVAF) receiving oral anticoagulants (OACs), reversal of coagulopathy can be achieved with specific reversal drugs such as idarucizumab, which is indicated for use in patients treated with dabigatran for cases of life-threatening or uncontrolled bleeding or during emergency procedures that may cause serious bleeding. This study examined the incidence rate (IR) of emergency surgeries and major bleeding episodes associated with fractures and trauma in Japanese patients with NVAF receiving OACs.

Methods

This retrospective, non-interventional analysis of health insurance claims was conducted using data from 62,888 OAC-naive adult patients with NVAF who initiated dabigatran, warfarin, apixaban, rivaroxaban, or edoxaban between March 2011 and June 2016. The primary endpoint was overall IR of emergency surgery or major bleeding due to fracture or trauma.

Results

Overall IR of emergency surgery or major bleeding due to fracture or trauma considering outcomes until OAC discontinuation was 0.489 per 100 patient-years (PY) (95% confidence interval [CI] 0.406–0.572). Considering first OAC exposure only, the IR was 0.483 per 100 PY (95% CI 0.394–0.573). Emergency surgery/major bleeding events due to fracture or trauma was highest in those aged ≥ 75 years (0.611 per 100 PY [95% CI 0.481–0.741]).

Conclusions

Fewer than one in 200 patients per year with NVAF receiving OACs experience emergency surgeries and major bleeding episodes associated with fractures and trauma; however, the IR of these events is markedly higher in patients of advanced age.

Trial registration

ClinicalTrials.gov 207, NCT03254147.

Patients with an abnormal heart rhythm (nonvalvular atrial fibrillation [NVAF]) have a higher risk of blood clots and stroke (which is when the blood supply to part of the brain is blocked). To reduce these risks, patients can take anticoagulants that slow or prevent the formation of blood clots. However, if the patient needs major emergency surgery or has a severe injury, the anticoagulants can increase their risk of bleeding, which can sometimes be life-threatening. There are drugs (e.g., idarucizumab) that can be used to reverse the effects of anticoagulants in this type of emergency. What we don’t know is how many NVAF patients in Japan who are on anticoagulants have emergency surgeries or major bleeding after an injury, and therefore may require a reversal drug. The authors looked at Japanese health insurance claim data from 62,888 adult patients with NVAF who started taking an anticoagulant. They found that, annually, approximately 0.5% of the patients had emergency surgery or a major bleed associated with a fracture or injury. In very elderly patients (aged at least 75 years), the annual percentage was approximately 0.6%, which was almost double the annual percentage in patients aged less than 65 years. The authors concluded that, even though the number of people requiring a reversal agent are quite small, it is important to have an effective reversal agent for patients on anticoagulants, particularly older patients.

Development of an application for management of drug holidays in perioperative periods

Before surgery and other invasive treatments, decisions must be made on whether to discontinue drugs and provide appropriate drug holidays especially for antithrombotic drugs, and this is made difficult by the large number of available drugs and associated guidelines. We have therefore developed an online application for perioperative drug discontinuation and resumption management, named Saga Application for Management of Drug Holidays in PeriOperative Periods (SAMPOP).Multidisciplinary medical staff at Saga University Hospital (SUH) worked together to build an evidence-based Perioperative Drug Discontinuation Management Database (PDDMD) and developed the user-friendly SAMPOP online application via preliminary verification at SUH. From September 2018 to February 2020, 420 medical staff at SUH, including physicians, nurses, and pharmacists, installed and tested SAMPOP.Rate per surgical procedure for forgetting to discontinue antithrombotic drugs preoperatively decreased from 0.18% to 0.09% as of August 2019, 12 months after the introduction of SAMPOP (P = .1359). In addition, six months later, it decreased further to 0.03% as of February 2020 (P = .0436). Forgetting to resume antithrombotic drugs postoperatively decreased from 0.20% to 0.02% as of August 2019, 12 months after the introduction of SAMPOP (P = .0008). There was no case of forgetting to resume the medication in the last 6 months.SAMPOP may be useful for management of drug holidays in the clinic and warrants further evaluation of its safety and efficacy.

Perioperative management of patients receiving non-vitamin K antagonist oral anticoagulants: up-to-date recommendations

Indications of non-vitamin K antagonist oral anticoagulants (NOACs), consisting of two types: direct thrombin inhibitor (dabigatran) and direct factor Xa inhibitor (rivaroxaban, apixaban, and edoxaban), have expanded over the last few years. Accordingly, increasing number of patients presenting for surgery are being exposed to NOACs, despite the fact that NOACs are inevitably related to increased perioperative bleeding risk. This review article contains recent clinical evidence-based up-to-date recommendations to help set up a multidisciplinary management strategy to provide a safe perioperative milieu for patients receiving NOACs. In brief, despite the paucity of related clinical evidence, several key recommendations can be drawn based on the emerging clinical evidence, expert consensus, and predictable pharmacological properties of NOACs. In elective surgeries, it seems safe to perform high-bleeding risk surgeries 2 days after cessation of NOAC, regardless of the type of NOAC. Neuraxial anesthesia should be performed 3 days after cessation of NOACs. In both instances, dabigatran needs to be discontinued for an additional 1 or 2 days, depending on the decrease in renal function. NOACs do not require a preoperative heparin bridge therapy. Emergent or urgent surgeries should preferably be delayed for at least 12 h from the last NOAC intake (better if > 24 h). If surgery cannot be delayed, consider using specific reversal agents, which are idarucizumab for dabigatran and andexanet alfa for rivaroxaban, apixaban, and edoxaban. If these specific reversal agents are not available, consider using prothrombin complex concentrates.

Heterogeneity in Preferences for Anti-coagulant Use in Atrial Fibrillation: A Latent Class Analysis

Introduction

Recent reviews on patients’ preferences towards attributes of oral anti-coagulant therapy have shown that preference for convenience of therapy is heterogeneous. In this study, we used a novel approach—latent class analysis (LCA)—to assess heterogeneity.

Methods

We developed a health preference survey that consisted of 12 discrete choice questions. The following attributes of convenience were included: intake frequency; need for regular coagulation monitoring; diet or drug interactions; relation between medication and food intake; and pill type. Background questions about gender, age, current therapy [i.e., direct-acting oral anti-coagulant (DOAC) or vitamin K antagonist (VKA)], self-reported medication adherence, and pill burden were included. Mixed logit analysis (MLA) and LCA were performed. The scale-adjusted LCA model with two scale classes and four preference classes emerged as the model with the best fit and interpretability.

Results

A total of 508 patients with non-valvular atrial fibrillation from five European countries (Germany, Italy, Spain, France, and the UK) were surveyed in August 2017. The most important attributes were need for monitoring (37%) and intake frequency (27%). Patient preferences were significantly influenced by country, gender, and current anti-coagulant therapy. Four different preference classes of patients were identified in the LCA. First, most patients (57%) were in the “no need for regular coagulation monitoring” class. Current DOAC users and patients who were the least adherent to therapy were more likely to prefer no coagulation monitoring. Second, 20% of patients were in the “balanced” class of patients. Current VKA users with moderate adherence were more likely to be in this class. Patients who reported the lowest adherence were most likely in the “once daily, interactions likely” class (16%). Fourth, current VKA users and highly adherent patients were most likely to prefer therapies with a need for regular coagulation monitoring (7%).

Conclusions

This study demonstrated significant preference heterogeneity among patients with atrial fibrillation and linked these preferences to differences in background characteristics. Country of residence and currently prescribed therapy influenced patient preferences in both the MLA and LCA models.

Electronic supplementary material

The online version of this article (10.1007/s40271-020-00420-z) contains supplementary material, which is available to authorized users.

Interindividual Variability of Apixaban Plasma Concentrations: Influence of Clinical and Genetic Factors in a Real-Life Cohort of Atrial Fibrillation Patients

(1) Background: Prescribing apixaban for stroke prevention has significantly increased in patients with non-valvular atrial fibrillation (NVAF). The ABCB₁ genotype can influence apixaban absorption and bioavailability. The aim of the present study was to assess the factors that influence apixaban’s plasma level and to establish if a certain relationship has clinical relevance. (2) Methods: Fifty-three NVAF patients were treated with 5 mg apixaban twice/day (70.0 years, range: 65–77, 60.4% men). Trough and peak plasma concentrations of apixaban were determined by liquid chromatography-tandem mass-spectrometry (LC-MS/MS), and ABCB₁ genotyping was performed. (3) Results: Apixaban plasma concentrations varied considerably. They were higher in women than in men (311.2 ng/dL vs. 252.2 ng/dL; p = 0.05) and were lower in patients with heart failure (149.4 ng/dL vs. 304.5 ng/dL; p < 0.01). Creatinine clearance was inversely correlated with the apixaban plasma level (Spearman correlation: r = −0.365; p = 0.007 for trough concentrations). No statistically significant differences between the genotypic groups of ABCB₁ rs1045642 and ABCB₁ rs4148738 were found in the trough or peak apixaban plasma concentrations. (4) Conclusions: Pharmacokinetic parameters are influenced by several clinical factors of which renal function is the major determinant. Plasma concentrations measured in women had higher values than those measured in men, and heart failure was associated with decreased plasma levels of apixaban.