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

Recent advances in microfluidic technology of arterial thrombosis investigations

Microfluidic technology has emerged as a powerful tool in studying arterial thrombosis, allowing researchers to construct artificial blood vessels and replicate the hemodynamics of blood flow. This technology has led to significant advancements in understanding thrombosis and platelet adhesion and aggregation. Microfluidic models have various types and functions, and by studying the fabrication methods and working principles of microfluidic chips, applicable methods can be selected according to specific needs. The rapid development of microfluidic integrated system and modular microfluidic system makes arterial thrombosis research more diversified and automated, but its standardization still needs to be solved urgently. One key advantage of microfluidic technology is the ability to precisely control fluid flow in microchannels and to analyze platelet behavior under different shear forces and flow rates. This allows researchers to study the physiological and pathological processes of blood flow, shedding light on the underlying mechanisms of arterial thrombosis. In conclusion, microfluidic technology has revolutionized the study of arterial thrombosis by enabling the construction of artificial blood vessels and accurately reproducing hemodynamics. In the future, microfluidics will place greater emphasis on versatility and automation, holding great promise for advancing antithrombotic therapeutic and prophylactic measures.

Evaluation of the safety and efficacy of direct oral anticoagulants compared with vitamin-k antagonists in the treatment of left ventricular thrombosis. A systematic review and meta-analysis

BACKGROUND

Since the introduction of direct oral anticoagulants (DOACs) and their comparison with vitamin K antagonists (VKAs), conflicting results have been reported regarding the optimal treatment for left ventricular thrombosis (LVT).

OBJECTIVES

In this meta-analysis, we intend to comprehensively evaluate the safety and efficacy of these treatments.

METHODS

All clinical trials and cohorts that compared the efficacy or safety of VKAs with DOACs in the treatment of LVTs were systematically searched until April 15, 2023.

RESULTS

The results of 32 studies with a pooled sample size of 4213 patients were extracted for meta-analysis. DOACs, especially rivaroxaban and apixaban, cause faster resolution, lower mortality, and fewer complications (SSE and bleeding events) than VKAs in the management of LVTs.

CONCLUSION

Compared with VKAs, DOACs result in significantly faster (only rivaroxaban) and safer resolution of left ventricular thrombosis.

AF-React study: Prevalence of thrombotic events in patients with atrial fibrillation receiving NOACs - real-world data analysis from northern Portugal primary healthcare

Introduction

Anticoagulation is recommended for stroke prevention in patients with atrial fibrillation (AF). The guidelines suggest non-vitamin K antagonist anticoagulants (NOACs) as the primary therapy for anticoagulation in AF. Several patient-related factors increase the risk of thrombotic events: elderly individuals, a previous history of stroke, and chronic kidney disease. This study aims to determine the association between NOACs and other patient variables in AF and the occurrence of thrombotic events.

Methods

The database included all adults with the code K78 (ICPC-2 code for AF) who received clinical care in Northern Portugal's Primary Health Care between January 2016 and December 2018 and were dispensed the same NOAC at the pharmacy.

Results

The results indicate that 10.2% of AF patients on NOAC anticoagulation experienced a stroke. Furthermore, patients treated with apixaban and dabigatran had higher odds of experiencing a stroke compared to those treated with rivaroxaban. Among patients with the same age, gender, and CHA2DS2Vasc Score, apixaban was significantly associated with a higher likelihood of thrombotic events than rivaroxaban.

Discussion

These results have not been previously reported in studies with real-world data; therefore, a more detailed analysis should be conducted to enhance the validity of these findings.

Andexanet alfa versus non-specific treatments for intracerebral hemorrhage in patients taking factor Xa inhibitors - Individual patient data analysis of ANNEXA-4 and TICH-NOAC

BACKGROUND

Data comparing the specific reversal agent andexanet alfa with non-specific treatments in patients with non-traumatic intracerebral hemorrhage (ICH) associated with factor-Xa inhibitor (FXaI) use are scarce.

AIM

The study aimed to determine the association between the use of andexanet alfa compared with non-specific treatments with the rate of hematoma expansion and thromboembolic complications in patients with FXaI-associated ICH.

METHODS

We performed an individual patient data analysis combining two independent, prospective studies: ANNEXA-4 (180 patients receiving andexanet alfa, NCT02329327) and TICH-NOAC (63 patients receiving tranexamic acid or placebo ± prothrombin complex concentrate, NCT02866838). The primary efficacy outcome was hematoma expansion on follow-up imaging. The primary safety outcome was any thromboembolic complication (ischemic stroke, myocardial infarction, pulmonary embolism, or deep vein thrombosis) at 30 days. We used binary logistic regression models adjusted for baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively.

RESULTS

Among 243 participants included, the median age was 80 (IQR 75-84) years, baseline hematoma volume was 9.1 (IQR 3.4-21) mL and anti-Xa activity 118 (IQR 78-222) ng/mL. Times from last FXaI intake and symptom onset to treatment were 11 (IQR 7-16) and 4.7 (IQR 3.0-7.6) h, respectively. Overall, 50 patients (22%) experienced hematoma expansion (ANNEXA-4: n=24 (14%); TICH-NOAC: n=26 (41%)). After adjusting for pre-specified confounders (baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively), treatment with andexanet alfa was independently associated with decreased odds for hematoma expansion (aOR 0.33, 95% CI 0.13-0.80, p = 0.015). Overall, 26 patients (11%) had any thromboembolic complication within 30 days (ANNEXA-4: n=20 (11%); TICH-NOAC: n=6 (10%)). There was no association between any thromboembolic complication and treatment with andexanet alfa (aOR 0.70, 95% CI 0.16-3.12, p = 0.641).

CONCLUSION

The use of andexanet alfa compared to any other non-specific treatment strategy was associated with decreased odds for hematoma expansion, without increased odds for thromboembolic complications.

Effect of China national centralized drug procurement policy on anticoagulation selection and hemorrhage events in patients with AF in Suining

Background: Launched in March 2019, the National Centralized Drug Procurement (NCDP) initiative aimed to optimize the drug utilization framework in public healthcare facilities. Following the integration of Non-Vitamin K Antagonist Oral Anticoagulants (NOACs) into the procurement catalog, healthcare establishments in Suining swiftly transitioned to the widespread adoption of NOACs, beginning 1 March 2020. Objective: This study aims to comprehensively assess the impact of the NCDP policy on the efficacy of anticoagulation therapy, patient medication adherence, and the incidence of hemorrhagic events in individuals with non-valvular atrial fibrillation (NVAF) residing in Suining. The analysis seeks to elucidate the broader impacts of the NCDP policy on this patient demographic. Methods: This study analyzed patient hospitalization records from the Department of Cardiology at Suining County People's Hospital, spanning 1 January 2017, to 30 June 2022. The dataset included demographic details (age, sex), type of health insurance, year of admission, hospitalization expenses, and comprehensive information on anticoagulant therapy utilization. The CHA2DS2-VASc scoring system, an established risk assessment tool, was used to evaluate stroke risk in NVAF patients. Patients with a CHA2DS2-VASc score of 2 or higher were categorized as high-risk, while those with scores below 2 were considered medium or low-risk. Results: 1. Treatment Cost Analysis: The study included 3,986 patients diagnosed with NVAF. Following the implementation of the NCDP policy, a significant increase in the average treatment cost for hospitalized patients was observed, rising from 8,900.57 ± 9,023.02 CNY to 9,829.99 ± 10,886.87 CNY (p < 0.001). 2. Oral Anticoagulant Utilization: Overall, oral anticoagulant use increased from 40.02% to 61.33% post-NCDP (p < 0.001). Specifically, NOAC utilization among patients dramatically rose from 15.41% to 90.99% (p < 0.001). 3. Hemorrhagic Events: There was a significant decrease in hemorrhagic events following the NCDP policy, from 1.88% to 0.66% (p = 0.01). Hypertension [OR = 1.979, 95% CI (1.132, 3.462), p = 0.017], history of stroke [OR = 1.375, 95% CI (1.023, 1.847), p = 0.035], age ≥65 years [OR = 0.339, 95% CI (0.188, 0.612), p < 0.001], combination therapy of anticoagulants and antiplatelets [OR = 3.620, 95% CI (1.752, 7.480), p < 0.001], hepatic and renal insufficiency [OR = 4.294, 95% CI (2.28, 8.084), p < 0.001], and the NCDP policy [OR = 0.295, 95% CI (0.115, 0.753), p = 0.011] are significant risk factors for bleeding in patients with atrial fibrillation. 4. Re-hospitalization and Anticoagulant Use: Among the 219 patients requiring re-hospitalization, there was a notable increase in anticoagulant usage post-NCDP, from 36.07% to 59.82% (p < 0.001). NOACs, in particular, saw a substantial rise in usage among these patients, from 11.39% to 80.92% (p < 0.001). 5. Anticoagulant Type Change: The NCDP policy [OR = 28.223, 95% CI (13.148, 60.585), p < 0.001] and bleeding events [OR = 27.772, 95% CI (3.213, 240.026), p = 0.003] were significant factors influencing the alteration of anticoagulant medications in patients. Conclusion: The NCDP policy has markedly improved anticoagulation management in patients with AF. This policy has played a crucial role in enhancing medication adherence and significantly reducing the incidence of hemorrhagic events among these patients. Additionally, the NCDP policy has proven to be a key factor in guiding the selection and modification of anticoagulant therapies in the AF patient population.

Potentially inappropriate prescribing in multimorbid and polymedicated older adults with AF: A Systematic Review and Meta-Analysis

AIM

Polypharmacy in multimorbid older patients with atrial fibrillation (AF) is a risk factor for potentially inappropriate prescribing (PIP). We aimed to systematically assess the evidence on the prevalence of PIP and its impact on adverse health outcomes in this patient group.

METHODS

A systematic search of the published peer-reviewed literature describing the prevalence of PIP and/or its association with adverse health outcomes in multimorbid (AF plus one comorbidity) and polymedicated (≥ 2 drugs) adults ≥ 65 years was done up to March 2023. A meta-analysis of the prevalence of PIP of (direct) oral anticoagulants ((D)OACs) was conducted using a random-effects model. Leave-one-out analysis was performed with R (version 4.2.2) and RStudio (version 2022.12.0+353).

RESULTS

Of the 12 studies included, only one reported on the prevalence of overall PIP (65%). The meta-analysis of 10 studies assessing PIP of (D)OACs produced a pooled prevalence [95% confidence interval (CI)] of 35% [30-40%], with significant heterogeneity between the included studies (I2 95%). No statistically significant association was reported in three studies between PIP of (D)OACs, cardiovascular (CV) and all-cause mortality, hospital readmission, CV hospitalisation and stroke. Reported associations between PIP and major bleeding differed, with one study demonstrating a significant association (odds ratio 2.17; 95% CI 1.14-4.12) and the other study not showing such association.

CONCLUSION

This systematic review highlights the scarce evidence regarding the prevalence of PIP and its association with adverse health outcomes in multimorbid older adults with AF. Large, prospective and better-designed studies are needed.

Controversies in Stoppage of Antiplatelet and Anticoagulant Medications Prior to Oral Surgery

Dental procedures can pose a risk of bleeding, and it is not uncommon for dentists to consult prescribing physicians regarding a mutual patient's antiplatelet and anticoagulant medication to prevent excessive bleeding during or after an upcoming procedure. However, there has been a growing controversy in the dental community surrounding the stoppage of these medications prior to dental procedures. Some believe that stopping these medications prior to dental procedures is necessary to reduce the risk of bleeding complications, while others argue that stopping them can increase the risk of stroke or other thromboembolic events. The debate has left many dentists and specialists unsure about the best course of action when it comes to managing bleeding risk during dental procedures.In this article, we will review the antithrombotic medications, indications, mechanism of action, and its effects on the coagulation pathway, laboratory testing and reversal agents. Also, we will explore the controversy surrounding the stoppage of novel anitplatelets (eg,: prasurgrel and ticagrelor), dual-antiplatelets, triple-antiplatelet, vitamin K antagonists (eg,: wafarin, coumadin), and direct oral anticoagulants (eg,: dabigatran, rivaroxaban, xarelto and endoxaban) in dentistry and examine the current evidence and guidelines for managing dental patients undergoing oral surgery.

The Primary Prevention of Poststroke Epilepsy in Patients With Middle Cerebral Artery Infarct: Protocol for a Randomized Controlled Trial

BACKGROUND

Poststroke epilepsy poses a significant clinical challenge for individuals recovering from strokes, leading to a less favorable long-term outlook and increased mortality rates. Existing studies have primarily concentrated on administering antiseizure or anticonvulsant treatments only after the onset of late-onset seizures, without intervening during the epileptogenesis phase following a stroke.

OBJECTIVE

This research protocol is designed to conduct a randomized controlled trial to assess whether the early, preventive introduction of low-dose antiepileptic drug therapy (levetiracetam [LEV] or perampanel [PER]) in patients who have experienced middle cerebral artery (MCA) infarction can reduce the risk of developing poststroke epilepsy (primary prevention).

METHODS

Participants with MCA infarction, either with or without reperfusion treatments, will be recruited and promptly receive preventive intervention within 72 hours of the stroke occurrence. These participants will be randomly assigned to receive either PER (4 mg per day), LEV (1000 mg per day), or a placebo that matches the active drugs. This treatment will continue for 12 weeks after allocation. Brain magnetic resonance imaging will be used to confirm the presence of MCA territory infarction, and an electroencephalography will be used to ensure the absence of epileptiform discharges or electrographic seizures at the time of the stroke. All participants will undergo follow-up assessments for 72 weeks after allocation.

RESULTS

The primary outcome under evaluation will be the incidence of poststroke epilepsy in the 3 groups following the 18-month study period. Secondary outcomes will encompass the time to the occurrence of the first seizure, the severity of seizures, any treatment-related adverse events, and the modified Rankin scale score at 3 and 18 months. Exploratory outcomes will involve comparing the effectiveness and safety of PER and LEV.

CONCLUSIONS

We anticipate that the intervention groups will experience a lower incidence and reduced severity of poststroke epilepsy compared to the control group after 18 months. We aim to establish evidence supporting the potential preventive effects of LEV and PER on poststroke seizures and epilepsy in patients with MCA infarction, as well as to explore the antiepileptogenic potential of both LEV and PER in patients with major ischemic strokes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04858841; https://clinicaltrials.gov/study/NCT04858841.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/49412.

Effectiveness and safety of edoxaban versus warfarin in patients with nonvalvular atrial fibrillation: a systematic review and meta-analysis of observational studies

Background: Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia type. Patients with AF are often administered anticoagulants to reduce the risk of ischemic stroke due to an irregular heartbeat. We evaluated the efficacy and safety of edoxaban versus warfarin in patients with nonvalvular AF by conducting an updated meta-analysis of real-world studies. Methods: In this comprehensive meta-analysis, we searched two databases, PubMed and EMBASE, and included retrospective cohort observational studies that compared edoxaban with warfarin in patients with nonvalvular AF from 1 January 2009, to 30 September 2023. The effectiveness and safety outcomes were ischemic stroke and major bleeding, respectively. In the final analysis, six retrospective observational studies involving 87,236 patients treated with warfarin and 40,933 patients treated with edoxaban were included. To analyze the data, we used a random-effects model to calculate the hazard ratio (HR). Results: Patients treated with edoxaban had a significantly lower risk of ischemic stroke [hazard ratio (HR) = 0.66; 95% confidence interval (CI) = 0.61-0.70; p < 0.0001] and major bleeding (HR = 0.58; 95% CI = 0.49-0.69; p < 0.0001) than those treated with warfarin. The sensitivity analysis results for ischemic stroke and major bleeding were as follows: HR = 0.66; 95% CI = 0.61-0.70; p < 0.0001 and HR = 0.58; 95% CI = 0.49-0.69; p < 0.0001, respectively. Conclusion: Our findings revealed that edoxaban performed better than warfarin against major bleeding and ischemic stroke.

Is there a reduced confidence towards direct oral anticoagulants compared to vitamin K antagonists in patients scheduled for an elective electrical cardioversion? The results of the BLITZ-AF study

OBJECTIVE

To study the confidence of cardiologists in performing an electrical cardioversion in patients on oral anticoagulation (OA) with or without transoesophageal echocardiography (TOE).

METHODS

Data about atrial fibrillation (AF) patients admitted to cardiology wards for elective cardioversion (ECV) were extrapolated from the BLITZ-AF study. Percentage of vitamin K antagonists (VKAs), direct oral anticoagulants (DOAC) and heparin prescription were analysed in relation to the use of TOE before ECV.

RESULTS

Overall rate of TOE was 33.7% (240/713); it was used before ECV in 124/313 (39.6%) of DOACs patients and in 96/372 (25.8%) of the patients on VKAs, showing a significant reduced resort to TOE in VKAs patients (p = 0.0001). Among non-valvular patients TOE was more frequently performed in males, at younger ages and in patients on heparin when compared to patients treated with OA. TOE was also more frequently performed in tertiary hospitals and in hospitals with cardiology wards and electrophysiology labs, when compared to hospital provided only with cardiology wards. At multivariable analysis there was a significant less recourse to TOE in patients on VKAs (OR 0.47; 95% CI: 0.33-0.67) and higher recourse in the heparin group (OR: 3.85; 95% CI:1.59-9.28) with respect to patients on DOACs; a higher recourse to TOE was observed also in tertiary hospitals (OR 4.25; 95% CI 2.69-6.69) and in hospitals with cardiology wards and electrophysiology (EP) labs (OR 1.87; 95% CI 1.23-2.82).

CONCLUSION

our study shows the reluctance in cardioverting patients on DOACs respect to VKAs without a previous TOE, despite adequate anticoagulant treatment.

In vivo evaluation of time-dependent antithrombotic effect of rivaroxaban-loaded poly(lactic-co-glycolic acid)/sodium lauryl sulfate or didodecyl dimethylammonium bromide nanoparticles in Wistar rats

Rivaroxaban (RVX), an oral direct factor Xa inhibitor, is being explored as an alternative to traditional anticoagulans. However, RVX still faces pharmacokinetic limitations and adverse effects, highlighting the need for more effective formulations. In this regard, pharmaceutical nanotechnology, particularly the use of polymeric nanoparticles (PNPs), offers a promising approach for optimizing RVX delivery. This study aimed to develop and physicochemically characterize RVX-loaded poly(lactic-co-glycolic acid) (PLGA)/sodium lauryl sulfate (SLS) or didodecyl dimethylammonium bromide (DMAB) nanoparticles, and also evaluate their pharmacological and toxicological profiles as a potential therapeutic strategy. The PNPs exhibited sizes below 300 nm and spherical morphology, with both negative and positive surface charges, according to surfactant used. They demonstrated high encapsulation efficiency and suitable yields, as well as rapid initial liberation followed by sustained release in different pH environments. Importantly, in vivo evaluations revealed a time-dependent antithrombotic effect surpassing the free form of RVX when administered orally in SLS or DMAB PNP. No hemolytic or cytotoxic effects were observed at various concentrations of the PNPs. Interestingly, the PNPs did not induce hemorrhagic events or cause liver enzyme alterations in vivo. These findings suggest that RVX-loaded SLS or DMAB PNPs are promising innovative therapeutic alternatives for the treatment of thromboembolic diseases.

Lifeday coverage of oral anticoagulants and one-year relative survival in patients with atrial fibrillation: a population-based study in Estonia

BACKGROUND

Routine oral anticoagulation (OAC) is recommended for almost all high-risk patients with atrial fibrillation, yet registries show that OACs are still underused. Our aim was to study the lifeday coverage (LDC) of OAC prescriptions and its relationship with one-year mortality rates of AF patients aged ≥ 65 in Estonia for the years 2019 and 2020.

METHODS

Medical data for AF patients aged ≥ 65 years from 2018 and alive as of 01.01.2019 (cohort I) and new AF documentation from 2019 and alive as of 01.01.2020 (cohort II) was obtained from the Health Insurance Fund's electronic database. The data was linked to the nationwide Estonian Medical Prescription Centre's database of prescribed OACs. For LDC analysis, daily doses of guideline-recommended OACs were used. The patients were categorized into three LDC groups: 0%, 1-79%, and ≥ 80%. The data was linked to the Estonian Causes of Death Registry to establish the date of death and mortality rate for the whole Estonian population aged ≥ 65.

RESULTS

There were 34,018 patients in cohort I and 9,175 patients with new AF documentation (cohort II), previously not included in cohort I. Of the patients, 77.7% and 68.6% had at least one prescription of OAC in cohorts I and II respectively. 57.4% in cohort I and 44.5% in cohort II had an LDC of ≥ 80%. The relative survival estimates at 1 year for LDC lifeday coverage groups 0%, 1-79%, and ≥ 80% were 91.2%, 98.2%, and 98.5% (cohort I), and 91.9%, 95.2%, and 97.6% (cohort II), respectively.

CONCLUSIONS

Despite clear indications for OAC use, LDC is still insufficient and anticoagulation is underused for stroke prevention in Estonia. Further education of the medical community and patients is needed to achieve higher lifeday coverage of prescribed OACs.

Extracorporeal hemoadsorption therapy as a potential therapeutic option for rapid removal of Apixaban in high risk-surgical patients: a case report

BACKGROUND

Apixaban is a non-vitamin K antagonist oral anticoagulant (NOACs) recently emerged as an effective alternative to conventional vitamin K antagonists (VKAs) in the treatment of several thromboembolic disorders. However, in case of overdose or in patients requiring emergency surgery there is a high bleeding rate and severe adverse side effects due to the absence of an antidote. There is promising data from in vitro and clinical studies, that certain antithrombotic agents (that is Rivaroxaban and Ticagrelor) have been successfully removed by the extracorporeal hemoadsorption therapy CytoSorb. Here, we present the case of a patient successfully treated with CytoSorb as a kind of antidote to enable emergency surgery for bilateral nephrostomy.

CASE PRESENTATION

A 82-year-old Caucasian man was admitted to the Emergency Room with acute kidney injury (AKI) in the context of severe bilateral hydroureteronephrosis. The patient's medical history included chronic obstructive pulmonary disease, arterial hypertension, atrial fibrillation (anticoagulated with Apixaban) and a locally advanced prostate adenocarcinoma treated with trans-ureteral resection of the bladder and radiotherapy in the previous months. The indication for a bilateral nephrostomy could not be considered immediately given the major bleeding risk due to Apixaban, which was discontinued and replaced with calciparin. After 36 hours of continuous renal replacement therapy (CRRT), the Apixaban blood level was still elevated and it was decided to install CytoSorb into the running CRRT to accelerate the drug clearance. After 2 hours 30 minutes, there was good reduction of Apixaban from 139 to 72 ng/ml (reduction rate of 48.2%) registered, and this allowed for an easy placement of bilateral nephrostomies without complications. Four days after surgery renal function parameters further normalized, the patient did not require additional dialysis treatments and Apixaban therapy was prescribed again once the patient returned home.

CONCLUSIONS

In this case we report the findings of a patient with post-renal AKI requiring emergency nephrostomy placement while on chronic anticoagulation with Apixaban therapy. Combined treatment with CRRT and CytoSorb was associated with the rapid and effective removal of Apixaban allowing for prompt and urgent surgery while simultaneously ensuring the low risk of bleeding as well as an uneventful post-operative course.

Early Versus Delayed Oral Anticoagulation in Patients With Acute Ischemic Stroke Due to Atrial Fibrillation: A Meta-Analysis

The aim of this study was to compare the safety and efficacy of early oral anticoagulation with delayed anticoagulant therapy in patients who have had a recent stroke and have atrial fibrillation (AF). This meta-analysis was conducted following the Preferred Reporting Items for Systemic Reviews and Meta-analyses (PRISMA) statement. The literature search was independently performed by two authors. We searched PubMed and Scopus using search strings that included the following terms: "stroke," "atrial fibrillation," "oral anticoagulants," "recurrent stroke," and "intracerebral hemorrhage." Our search spanned from the inception of databases to May 25, 2023. The primary outcome assessed in this study was the composite efficacy outcome (as defined by individual studies). Recurrent ischemic stroke (IS), intracranial hemorrhage (ICH), and death from any cause were assessed as secondary outcomes. For safety analysis, bleeding events were compared between the two study groups. We included five articles in this meta-analysis, comprising a total of 7958 patients (including 3793 in the early treatment group and 4165 in the delayed treatment group). Pooled analysis showed that the risk of composite efficacy outcome (RR: 0.69, 95% CI: 0.51-0.93, p-value: 0.01) and recurrent ischemic stroke (RR: 0.71, 95% CI: 0.53-0.94, p-value: 0.02) were lower in the early treatment group. However, no significant differences were observed between the two groups in terms of all-cause mortality, intracranial hemorrhage, or bleeding events. In light of the findings, healthcare professionals should carefully evaluate the risks and benefits of early versus delayed DOAC treatment in individual patients, considering factors such as stroke severity, bleeding risk, and patient preferences.

Challenges of Anticoagulant Therapy in Atrial Fibrillation-Focus on Gastrointestinal Bleeding

The rising prevalence and the complexity of atrial fibrillation (AF) pose major clinical challenges. Stroke prevention is accompanied by non-negligible risks, making anticoagulant treatment an ongoing challenge for the clinician. Current guidelines recommend direct oral anticoagulants (DOACs) over warfarin for stroke prevention in most AF patients, mainly due to the ease of their use. However, assessing the bleeding risk in patients receiving oral anticoagulants remains-particularly in the case of DOACs-highly challenging. Using dose-adjusted warfarin increases threefold the risk of gastrointestinal bleeding (GIB). Although the overall bleeding risk appears to be lower, the use of DOACs has been associated with an increased risk of GIB compared to warfarin. Accurate bleeding (including GIB-specific) risk scores specific for DOACs remain to be developed. Until then, the assessment of bleeding risk factors remains the only available tool, although the extent to which each of these factors contributes to the risk of bleeding is unknown. In this paper, we aim to provide a comprehensive review of the bleeding risk associated with oral anticoagulant therapy in AF patients, with a highlight on the latest insights into GIB associated with oral anticoagulation; we emphasize questions that remain to be answered; and we identify hotspots for future research.

New score for predicting major bleeding in patients with atrial fibrillation using direct oral anticoagulants

PURPOSE

Our aim was to identify factors associated with major bleeding in patients with atrial fibrillation (AF) on direct oral anticoagulants (DOACs) and to construct and externally validate a predictive model that would provide a validated tool for clinical assessment of major bleeding.

METHODS

In the development cohort, prediction model was built by logistic regression, the area under the curve (AUC), and Nomogram. External validation, analytical identification and calibration of the model using AUC, calibration curves and Hosmer-Lemeshow test.

RESULTS

The development cohort consisted of 4209 patients from 7 centers and the external validation cohort consisted of 1800 patients from 12 centers. Multifactorial analysis showed that age > 65 years, history of bleeding, anemia, vascular disease, antiplatelet therapy/non-steroidal anti-inflammatory drugs and rivaroxaban were independent risk factors for major bleeding, and gastrointestinal protective agents was a protective factor. The Alfalfa-MB model was constructed using these seven factors (AUC = 0.807), and in the external validation cohort, the model showed good discriminatory power (AUC = 0.743) and good calibration (Hosmer-Lemeshow test P value of 0.205). The predictive power of the six bleeding scores was ORBIT (AUC = 0.706), HAS-BLED (AUC = 0.648), ATRIA (AUC = 0.645), HEMORR2 HAGES (AUC = 0.632), ABC (AUC = 0.619) and Shireman (AUC = 0.599) in descending order.

CONCLUSION

Based on 7 factors, we derived and externally validated a predictive model for major bleeding with DOACs in patients with AF (Alfalfa-MB). The model has good predictive value and may be an effective tool to help reduce the occurrence of major bleeding in patients with DOACs.

Severe Bleeding Risk of Direct Oral Anticoagulants Versus Vitamin K Antagonists for Stroke Prevention and Treatment in Patients with Atrial Fibrillation: A Systematic Review and Network Meta-Analysis

PURPOSE

We aimed to determine the safety of direct oral anticoagulants (DOACs) for stroke prevention and treatment in patients with atrial fibrillation (AF).

METHODS

A systematic search of four databases (PubMed, EMBASE, Web of Science, and Cochrane Library) was performed to identify randomized controlled trials (RCTs) reporting severe bleeding events in patients taking DOACs or vitamin K antagonists (VKAs). In this frequency-based network meta-analysis, odds ratios and 95% confidence intervals were used for reporting. Based on the surface under the cumulative ranking curves (SUCRA), the relative ranking probability of each group was generated.

RESULTS

Twenty-three RCTs met the inclusion criteria, and a total of 87,616 patients were enrolled. The bleeding safety of DOACs for stroke prevention and treatment in patients with AF was ranked from highest to lowest as follows: fatal bleeding: edoxaban (SUCRA,80.2), rivaroxaban (SUCRA,68.3), apixaban (SUCRA,48.5), dabigatran (SUCRA,40.0), VKAs (SUCRA,12.9); major bleeding: dabigatran (SUCRA,74.0), apixaban (SUCRA,71.5), edoxaban (SUCRA,66.5), rivaroxaban (SUCRA,22.7), VKAs (SUCRA,15.4); gastrointestinal bleeding: apixaban (SUCRA,55.9), VKAs (SUCRA,53.7), edoxaban (SUCRA,50.5), rivaroxaban (SUCRA,50.4), dabigatran (SUCRA,39.5); intracranial hemorrhage: dabigatran (SUCRA,84.6), edoxaban (SUCRA,74.1), apixaban (SUCRA,65.8), rivaroxaban (SUCRA,24.4), VKAs (SUCRA,1.1).

CONCLUSION

Based on current evidence, for stroke prevention and treatment in patients with AF, the most safe DOAC is edoxaban in terms of fatal bleeding; dabigatran in terms of major bleeding and intracranial hemorrhage and apixaban in terms of gastrointestinal bleeding. However, given the nature of indirect comparisons, more high-quality evidence from head-to-head comparisons is still needed to confirm them.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Personalizing Direct Oral Anticoagulant Therapy for a Diverse Population: Role of Race, Kidney Function, Drug Interactions, and Pharmacogenetics

Oral anticoagulants (OACs) are commonly used to reduce the risk of venous thromboembolism and the risk of stroke in patients with atrial fibrillation. Endorsed by the American Heart Association, American College of Cardiology, and the European Society of Cardiology, direct oral anticoagulants (DOACs) have displaced warfarin as the OAC of choice for both conditions, due to improved safety profiles, fewer drug-drug and drug-diet interactions, and lack of monitoring requirements. Despite their widespread use and improved safety over warfarin, DOAC-related bleeding remains a major concern for patients. DOACs have stable pharmacokinetics and pharmacodynamics; however, variability in DOAC response is common and may be attributed to numerous factors, including patient-specific factors, concomitant medications, comorbid conditions, and genetics. Although DOAC randomized controlled trials included patients of varying ages and levels of kidney function, they failed to include patients of diverse ancestries. Additionally, current evidence to support DOAC pharmacogenetic associations have primarily been derived from European and Asian individuals. Given differences in genotype frequencies and disease burden among patients of different biogeographic groups, future research must engage diverse populations to assess and quantify the impact of predictors on DOAC response. Current under-representation of patients from diverse racial groups does not allow for proper generalization of the influence of clinical and genetic factors in relation to DOAC variability. Herein, we discuss factors affecting DOAC response, such as age, sex, weight, kidney function, drug interactions, and pharmacogenetics, while offering a new perspective on the need for further research including frequently excluded groups.

Cardiorenal Outcomes Among Patients With Atrial Fibrillation Treated With Oral Anticoagulants

RATIONALE & OBJECTIVE

Direct oral anticoagulants (DOACs) have progressively replaced vitamin K antagonists (VKAs) for stroke prevention in patients with nonvalvular atrial fibrillation (AF). DOACs cause fewer bleeding complications, but their other advantages, particularly related to kidney outcomes, remain inconclusive. We studied the risks of chronic kidney disease (CKD) progression and acute kidney injury (AKI) after DOAC and VKA administration for nonvalvular AF.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Cohort study of Swedish patients enrolled in the Stockholm Creatinine Measurements (SCREAM) project with a diagnosis of nonvalvular AF during 2011-2018.

EXPOSURE

Initiation of DOAC or VKA treatment.

OUTCOME

Primary outcomes were CKD progression (composite of >30% estimated glomerular filtration rate [eGFR] decline and kidney failure) and AKI (by diagnosis or KDIGO-defined transient creatinine elevations). Secondary outcomes were death, major bleeding, and the composite of stroke and systemic embolism.

ANALYTICAL APPROACH

Propensity score weighted Cox regression was used to balance 50 baseline confounders. Sensitivity analyses included falsification end points, subgroups, and estimation of per-protocol effects.

RESULTS

We included 32,699 patients (56% initiated DOAC) who were observed for a median of 3.8 years. Their median age was 75 years, 45% were women, and 27% had an eGFR <60mL/min/1.73m². The adjusted HRs for DOAC versus VKA were 0.87 (95% CI, 0.78-0.98) for the risk of CKD progression and 0.88 (95% CI, 0.80-0.97) for AKI. HRs were 0.77 (95% CI, 0.67-0.89) for major bleeding, 0.93 (95% CI, 0.78-1.11) for the composite of stroke and systemic embolism, and 1.04 (95% CI, 0.95-1.14) for death. The results were similar across subgroups of age, sex, and baseline eGFR when restricting to patients at high risk for thromboembolic events and when censoring follow up at treatment discontinuation or change in type of anticoagulation.

LIMITATIONS

Missing information on time in therapeutic range and treatment dosages.

CONCLUSIONS

Among patients with nonvalvular AF treated in routine clinical practice compared with VKA use, DOAC use was associated with a lower risk of CKD progression, AKI, and major bleeding but a similar risk of the composite of stroke, systemic embolism, or death.

A Cardiologists’ Survey on the Use of Anticoagulants and Antiplatelets in Patients With Atrial Fibrillation and Acute Coronary Syndrome or Those Undergoing Percutaneous Coronary Intervention in India

PURPOSE

The management of patients with atrial fibrillation (AF) and acute coronary syndrome (ACS) or undergoing percutaneous coronary intervention (PCI) requires appropriate antithrombotic regimens for stroke prevention and in-stent thrombosis. Current practice recommendations are largely based on consensus options as there is limited evidence from randomized clinical trials. Hence, by surveying a group of cardiologists across India, we sought to better understand the current practice patterns of using oral anticoagulants (vitamin K antagonist, VKA or non-vitamin K antagonist oral anticoagulant, NOAC) and antiplatelet therapy in those patients in India.

METHODS

A cross-sectional questionnaire-based survey was conducted across India to better understand the clinical practices in AF management.

RESULTS

A total of 151 cardiologists participated in this survey. The most commonly prescribed combination therapy in patients with AF and ACS/undergoing PCI was triple therapy (NOAC + dual antiplatelet [aspirin and P2Y12 inhibitor]) (54.30%) followed by NOAC + single antiplatelet (33.11%). Only 11.26% of cardiologists prescribed VKA + dual antiplatelet therapy. Among anticoagulants, cardiologists prescribed NOACs to 66.11% of patients and VKAs to 25.54% of patients. Among P2Y12 inhibitors, ticagrelor (50.99%) and clopidogrel (47.02%) were the most preferred medication. The physician reported patient adherence rates to NOACs were higher compared to VKAs. Around 41.06% of cardiologists reportedly changed antiplatelet therapy for patients from dual antiplatelet to single antiplatelet therapy in three months; 36.42%, in one month; and 19.21% in six months after PCI. Around 61.59% of cardiologists stopped prescribing antiplatelet therapy for patients by one year.

CONCLUSION

Our survey demonstrated that the majority of cardiologists used triple therapy (NOAC + dual antiplatelet), followed by NOAC + single antiplatelet for managing patients with AF and ACS or undergoing PCI in line with the available guidelines.

Bleeding events among patients concomitantly treated with direct oral anticoagulants and macrolide or fluoroquinolone antibiotics

Fluoroquinolones and macrolides may, due to a potential drug-drug interaction, increase the concentration of any concomitantly administered direct oral anticoagulant (DOAC) and thereby increase the risk of severe bleeding. However, clinical evidence for such an effect is scarce. The present study aimed to evaluate the association between the use of fluoroquinolones or macrolides and bleeding events in patients with concomitant DOAC use. This was a nationwide cohort study including 19 288 users of DOACs in 2008-2018 using information from Swedish national health registers. We compared the incidence of bleeding events associated with use of fluoroquinolones or macrolides using doxycycline as a negative control. Cox regression was used to calculate crude and adjusted hazard ratios (aHRs) in time windows of various length of follow-up after the start of antibiotic use. The incidence rates for fluoroquinolones and macrolides ranged from 12 to 24 and from 12 to 53 bleeding events per 100 000 patients in the investigated time windows. The aHRs (95% confidence interval) for use of fluoroquinolones and macrolides were 1.29 (0.69-2.44) and 2.60 (0.74-9.08) at the concomitant window, 1.31 (0.84-2.03) and 1.79 (0.75-4.29) at 30 days, and 1.34 (0.99-1.82) and 1.28 (0.62-2.65) at 150 days, respectively. With regard to fluoroquinolones, the present study suggests that the risk of bleeding when combined with DOACs, if any, is small. Codispensation of macrolides in patients on DOACs was not associated with an increased risk of bleeding. However, due to the small number of macrolide users, the results must be interpreted with caution.

The effect of contrast agents on the anticoagulant properties of oral factor Xa inhibitors

BACKGROUND

Contrast agents may affect the anticoagulant properties of novel oral anticoagulants.

PURPOSE

To evaluate the effect of iohexol as a contrast agent on the anticoagulant activity of oral factor Xa inhibitors.

MATERIAL AND METHODS

The study included 65 individuals who underwent contrast computed tomography(CT). Group 1 comprised 20 patients using rivaroxaban, Group 2, 20 patients using apixaban, and Group 3, 20 patients using edoxaban. Group 4 was the control group of five healthy volunteers. Iohexol (60 mL) was used as a contrast agent. Blood samples of 2 mL were withdrawn into two tubes at 4 h after the drug dose and 1 h after the contrast CT (CT was performed 3 h after the drug was taken) from all the patients, and for the control group, at any time before and 1 h after contrast CT. The anticoagulant properties of rivaroxaban, apixaban, and edoxaban were evaluated using anti-factor Xa levels.

RESULTS

The anti-factor Xa level was increased after using the contrast agent in the rivaroxaban group (0.66 ± 0.32 U/mL vs. 0.67 ± 0.32 U/mL; P = 0.01) and the edoxaban group (0.74 ± 0.35 U/mL vs. 0.76 ± 0.36 U/mL; P = 0.006). No significant difference was observed in the apixaban group (0.66 ± 0.33 U/mL vs. 0.66 ± 0.32 U/mL; P = 0.21) and control group (0.02 ± 0.01 U/mL vs. 0.03 ± 0.01 U/mL; P = 0.33).

CONCLUSION

The anticoagulant properties of rivaroxaban and edoxaban tended to increase significantly, but there was no statistically significant difference in the anticoagulant properties of apixaban after the administration of contrast agent. To determine whether the small laboratory difference has a clinical effect, there is a need for larger clinical trials (NCT04611386).

Trends in direct oral anticoagulant (DOAC) prescribing in English primary care (2014-2019)

BACKGROUND

In England, most prescribing of direct-acting oral anticoagulants for atrial fibrillation (AF) is in primary care. However, there remain gaps in our understanding of dosage and disparities in use. We aimed to describe trends in direct oral anticoagulant (DOAC) prescribing, including dose reduction in people with renal impairment and other criteria, and adherence.

METHODS

Using English primary care sentinel network data from 2014 to 2019, we assessed appropriate DOAC dose adjustment with creatinine clearance (CrCl). Our primary care sentinel cohort was a subset of 722 general practices, with 6.46 million currently registered patients at the time of this study.

RESULTS

Of 6 464 129 people in the cohort, 2.3% were aged ≥18 years with a diagnosis of AF, and 30.8% of these were prescribed vitamin K antagonist and 69.1% DOACs. Appropriate DOAC prescribing following CrCl measures improved between 2014 and 2019; dabigatran from 21.3% (95% CI 15.1% to 28.8%) to 48.7% (95% CI 45.0% to 52.4%); rivaroxaban from 22.1% (95% CI 16.7% to 28.4%) to 49.9% (95% CI 48.5% to 53.3%); edoxaban from 10.0% (95% CI 0.3% to 44.5%) in 2016 to 57.6% (95% CI 54.5% to 60.7%) in 2019; apixaban from 30.8% (95% CI 9.1% to 61.4%) in 2015 to 60.5% (95% CI 57.8% to 63.2%) in 2019.Adherence was highest for factor Xa inhibitors, increasing from 50.1% (95% CI 47.7% to 52.4%) in 2014 to 57.8% (95% CI 57.4% to 58.2%) in 2019. Asian and black/mixed ethnicity was associated with non-adherence (OR 1.81, 95% CI 1.56 to 2.09) as was male gender (OR 1.19, 95% CI 1.15 to 1.22), higher socioeconomic status (OR 1.60, 95% CI 1.52 to 1.68), being an ex-smoker (OR 1.12, 95% CI 1.06 to 1.19) and hypertension (OR 1.07, 95% CI 1.03 to 1.17).

CONCLUSIONS

The volume and quality of DOAC prescribing has increased yearly. Future interventions to augment quality of anticoagulant management should target disparities in adherence.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

To Measure or Not to Measure: Direct Oral Anticoagulant Laboratory Assay Monitoring in Clinical Practice

The need for therapeutic drug monitoring of direct oral anticoagulants (DOACs) remains an area of clinical equipoise. Although routine monitoring may be unnecessary given predictable pharmacokinetics in most patients, there may be altered pharmacokinetics in those with end organ dysfunction, such as those with renal impairment, or with concomitant interacting medications, at extremes of body weight or age, or in those with thromboembolic events in atypical locations. We aimed to assess real-world practices in situations in which DOAC drug-level monitoring was used at a large academic medical center. A retrospective review of the records of patients who had a DOAC drug-specific activity level checked from 2016 to 2019 was included. A total of 119 patients had 144 DOAC measurements (apixaban (n = 62) and rivaroxaban (n = 57)). Drug-specific calibrated DOAC levels were within an expected therapeutic range for 110 levels(76%), with 21 levels (15%) above the expected range and 13 levels (9%) below the expected range. The DOAC levels were checked in the setting of an urgent or emergent procedure in 28 patients (24%), followed by renal failure in 17 patients (14%), a bleeding event in 11 patients (9%), concern for recurrent thromboembolism in 10 patients (8%), thrombophilia in 9 patients (8%), a history of recurrent thromboembolism in 6 patients (5%), extremes of body weight in 7 patients (5%), and unknown reasons in 7 patients (5%). Clinical decision making was infrequently affected by the DOAC monitoring. Therapeutic drug monitoring with DOACs may help predict bleeding events in elderly patients, those with impaired renal function, and in the event of an emergent or urgent procedure. Future studies are needed to target the select patient-specific scenarios where monitoring DOAC levels may impact clinical outcomes.

Pharmacist management of atrial fibrillation in UK primary care: a qualitative study

BACKGROUND

Atrial fibrillation (AF) affects up to 2% of the UK population. AF is a potentially long-term condition that needs management, and as such primary care pharmacists may have a substantial role in supporting the management of AF.

OBJECTIVES

This study aims to explore the role of primary care pharmacists, working in community pharmacies and general practices (GPs), in supporting the management of AF. Furthermore, this study investigates pharmacists' confidence in their knowledge and their attitudes towards incorporating AF-associated mobile apps use into their current practice.

METHODS

A qualitative study was conducted, using one-to-one semi-structured, audio-recorded interviews with primary care pharmacists. The topic guide was developed based on pharmacy visits and included the most relevant constructs from the 'consolidated framework for implementation research (CFIR)'. All interviews were audio-recorded, transcribed verbatim and thematically analysed until saturation was achieved, guided by Braun and Clarke's 6-step research method. This study was given a favourable opinion on 5 September 2019 by the University of Birmingham (UOB) Research Ethics Committee (Reference ERN_19-0908).

RESULTS

Thematic saturation was achieved after 11 interviews with primary care pharmacists (seven community pharmacists, and four GP pharmacists). Three main themes emerged relating to (1) the clinical role of pharmacists in the management of AF; (2) knowledge and awareness; and (3) prioritisation of resources. The first highlighted that primary care pharmacists were an underutilised resource within AF management. The second demonstrated that pharmacists, especially those based in the community, felt a lack of confidence in their knowledge of AF and its management, mainly community pharmacists due to other roles taking precedence over clinical roles. Both community and GP pharmacists expressed the need to have further training in this therapeutic area to be able to effectively support patients with AF. The third shed light on the pharmacists' views relating to the technological revolution in healthcare. Pharmacists expressed an interest in using apps to support their current practice.

CONCLUSIONS

Primary care pharmacists supported an extended care to AF management from screening to consultations, yet the provision of such services remains limited and inconsistent. Future research should focus on understanding the ways in which pharmacists' role can be adapted toward greater involvement in clinical care.

Genetic variations in relation to bleeding and pharmacodynamics of dabigatran in Chinese patients with nonvalvular atrial fibrillation: A nationwide multicentre prospective cohort study

INTRODUCTION

To identify the potential factors responsible for the individual variability of dabigatran, we investigated the genetic variations associated with clinical outcomes and pharmacodynamics (PD) in Chinese patients with nonvalvular atrial fibrillation (NVAF).

MATERIALS AND METHODS

Chinese patients with NVAF taking dabigatran etexilate with therapeutic doses were enrolled. The primary (bleeding events) and secondary (thromboembolic and major adverse cardiac events) outcomes for a 2-year follow-up were evaluated. Peak and trough PD parameters (anti-FIIa activity, activated partial thromboplastin time and prothrombin time) were detected. Whole-exome sequencing, genome-wide sequencing and candidate gene association analyses were performed.

RESULTS

There were 170 patients with NVAF treated with dabigatran (110 mg twice daily) who were finally included. Two single-nucleotide polymorphisms (SNPs) were significantly related with bleeding, which include UBASH3B rs2276408 (odds ratio [OR] = 8.79, 95% confidence interval [CI]: 2.99-25.83, p = 7.77 × 10-5 at sixth month visit) and FBN2 rs3805625 (OR = 8.29, 95% CI: 2.87-23.89, p = 9.08 × 10-5 at 12th month visit), as well as with increased trends at other visits (p < .05). Furthermore, minor allele carriers of 16 new SNPs increased PD levels, and those of one new SNP decreased PD values (p < 1.0 × 10-5 ). Lastly, 33 new SNPs were found to be associated with bleeding and PD among 14 candidate genes. Unfortunately, the low number of secondary outcomes precluded further association analyses.

CONCLUSIONS

Genetic variations indeed affected bleeding and PD in Chinese patients with NVAF treated with dabigatran. The functions of these suggestive genes and SNPs might further be explored and verified in more in vivo and in vitro investigations.

CytoSorb haemoadsorption for removal of apixaban-A proof-of-concept pilot case for a randomized controlled trial

WHAT IS KNOWN AND OBJECTIVE

Emergent cardiac surgery in patients under anticoagulant therapy is still a major point of concern. Recently approved reversal agents are often not available or not suitable in the cardiac surgery setting, and timely discontinuation of the drug is not always feasible. CytoSorb® haemoadsorption therapy has been approved in Europe for intraoperative ticagrelor and rivaroxaban removal during cardiopulmonary bypass (CPB), but thus far the efficacy of CytoSorb® haemoadsorber on other anticoagulants (apixaban, dabigatran, edoxaban) has only been tested in vitro, and some signals of clinical benefits have reported in a few case reports.

CASE SUMMARY

We describe a case of CPB implementation with CytoSorb® in a haemodynamic unstable patient with prosthetic aortic valve endocarditis on apixaban therapy.

WHAT IS NEW AND CONCLUSION

CytoSorb® proved to be effective for removal of apixaban in emergency surgery setting by direct measurements of drug levels before and during CPB circulation.

Patient Blood Management in Vascular Surgery

Patient blood management (PBM) is an evidence-based, multidisciplinary approach aimed at appropriately allocating blood products to patients requiring transfusion while simultaneously minimizing inappropriate transfusions. The 3 pillars of patient blood management are optimizing erythropoiesis, minimizing blood loss, and optimizing physiological reserve of anemia. Benefits seen from PBM include limiting hospital costs and mitigating harm from numerous risks of transfusion.

Influence of ABCB1, CYP3A5 and CYP3A4 gene polymorphisms on prothrombin time and the residual equilibrium concentration of rivaroxaban in patients with non-valvular atrial fibrillation in real clinical practice

OBJECTIVE

The study of ABCB1 and CYP3A4/3A5 gene polymorphism genes is promising in terms of their influence on prothrombin time variability, the residual equilibrium concentration of direct oral anticoagulants (DOACs) in patients with atrial fibrillation and the development of new personalized approaches to anticoagulation therapy in these patients. The aim of the study is to evaluate the effect of ABCB1 (rs1045642) C>T; ABCB1 (rs4148738) C>T and CYP3A5 (rs776746) A>G, CYP3A4*22(rs35599367) C>T gene polymorphisms on prothrombin time level and residual equilibrium concentration of rivaroxaban in patients with atrial fibrillation.

METHODS

In total 86 patients (42 men and 44 female), aged 67.24 ± 1.01 years with atrial fibrillation were enrolled in the study. HPLC mass spectrometry analysis was used to determine rivaroxaban residual equilibrium concentration. Prothrombin time data were obtained from patient records.

RESULTS

The residual equilibrium concentration of rivaroxaban in patients with ABCB1 rs4148738 CT genotype is significantly higher than in patients with ABCB1 rs4148738 CC (P  = 0.039). The analysis of the combination of genotypes did not find a statistically significant role of combinations of alleles of several polymorphic markers in increasing the risk of hemorrhagic complications when taking rivaroxaban.

CONCLUSION

Patients with ABCB1 rs4148738 CT genotype have a statistically significantly higher residual equilibrium concentration of rivaroxaban in blood than patients with ABCB1 rs4148738 CC genotype, which should be considered when assessing the risk of hemorrhagic complications and risk of drug-drug interactions. Further studies of the effect of rivaroxaban pharmacogenetics on the safety profile and efficacy of therapy are needed.

Outcomes in patients undergoing periprocedural interruption of warfarin or direct oral anticoagulants

BACKGROUND

Differences in clinical outcomes following a temporary interruption of warfarin or a direct oral anticoagulant (DOAC) for a surgical procedure are not well described. Differences in patient characteristics from practice-based cohorts have not typically been accounted for in prior analyses.

AIM

To describe risk-adjusted differences in postoperative outcomes following an interruption of warfarin vs DOACs.

METHODS

Patients receiving care at six anticoagulation clinics participating in the Michigan Anticoagulation Quality Improvement Initiative were included if they had at least one oral anticoagulant interruption for a procedure. Inverse probability of treatment weighting (IPTW) was used to balance baseline differences between the warfarin cohort and DOAC cohort. Bleeding and thromboembolic events within 30 days following the procedure were compared between the IPTW cohorts using the Poisson distribution test.

RESULTS

A total of 525 DOAC patients were matched with 1323 warfarin patients, of which 923 were nonbridged warfarin patients and 400 were bridged warfarin patients. The occurrence of postoperative minor bleeding (10.8% vs. 4.7%, p < .001), major bleeding (2.9% vs. 1.1%, p = .01) and clinically relevant nonmajor bleeding (CRNMB) (6.5% vs. 3.0%, p = .002) was greater in the DOAC cohort compared with the nonbridged warfarin cohort. The rates of postoperative bleeding outcomes were similar between the DOAC and the bridged warfarin cohorts.

CONCLUSION

Perioperative interruption of DOACs, compared with warfarin without bridging, is associated with a higher incidence of 30-day minor bleeds, major bleeds, and CRNMBs. Further research investigating the perioperative outcomes of these two classes of anticoagulants is warranted.

Nonvalvular atrial fibrillation in patients undergoing chronic hemodialysis. Should dialysis patients with atrial fibrillation receive oral anticoagulation?

Chronic kidney disease (CKD) is an independent risk factor for presenting atrial fibrillation (AF), which conditions an increased risk already present in CKD of suffering a thromboembolic event. And this risk is even higher in the hemodialysis (HD) population. On the other hand, in CKD patients and even more so in HD patients, the probability of suffering serious bleeding is also higher. Therefore, there is no consensus on whether or not to anticoagulate this population. Taking as a model what is advised for the general population, the most common attitude among nephrologists has been to opt for anticoagulation, even though there is no randomized studies to support it. Classically, anticoagulation has been done with vitamin K antagonists, at high cost for our patients: severe bleeding events, vascular calcification, and progression of nephropathy, among other complications. With the emergence of direct-acting anticoagulants, a hopeful outlook was opened in the field of anticoagulation, as they were postulated as more effective and safer drugs than antivitamin K. However, in clinical practice, this has not been the case. In this paper we review various aspects of AF and its anticoagulant treatment in the HD population.

N-terminal pro-B-type natriuretic peptide and D-dimer combined with left atrial diameter to predict the risk of ischemic stroke in nonvalvular atrial fibrillation

OBJECTIVES

We aimed to explore the potential role of N-terminal pro-B-type natriuretic peptide (NT-proBNP), d-dimer, and the echocardiographic parameter left atrial diameter (LAD) in identifying and predicting the occurrence of ischemic stroke (IS) in patients with nonvalvular atrial fibrillation (NVAF).

METHODS

We conducted a retrospective study of 445 patients with NVAF in the First Affiliated Hospital of Nanchang University. They were divided into the NVAF (309 cases) and NVAF with stroke (136 cases) groups according to whether acute ischemic stroke (AIS) occurred at admission. Multivariate logistic regression was used to analyze the odds ratio (OR) of NT-proBNP, d-dimer, and LAD for IS. The predictive value of NT-proBNP, d-dimer, and LAD in identifying the occurrence of IS in NVAF was determined by plotting the receiver operating characteristic (ROC) curves.

RESULTS

NT-proBNP, d-dimer, and LAD levels were significantly higher in the NVAF with stroke group than in the NVAF group (p < .05). NT-ProBNP, d-dimer, and LAD were independently associated with IS in NVAF patients (odds ratio [OR] = 1.12, 95% confidence interval [CI]: 1.08-1.16; OR = 1.87, 95% CI: 1.37-2.55; OR = 1.21, 95% CI: 1.13-1.28, p < .01). The optimal cutoff points for NT-ProBNP, d-dimer, and LAD levels to distinguish the NVAF group from the NVAF with stroke group were 715.0 pg/ml, 0.515 ng/ml, and 38.5 mm, respectively, with the area under the curve (AUC) being [0.801 (95% CI: 0.76-0.84); 0.770 (95% CI: 0.72-0.85); 0.752 (95% CI: 0.71-0.80), p < .01]. The combined score of NT-proBNP, d-dimer, and LAD improved the predictive efficacy of the single index, with an AUC of 0.846 (95% CI: 0.81-0.88, p < .01), sensitivity of 77.2%, and specificity of 76.4%.

CONCLUSION

NT-proBNP, d-dimer, and the echocardiographic parameter LAD have outstanding value in predicting the risk of IS in patients with NVAF.

Twice- or once-daily dosing of direct oral anticoagulants and gastrointestinal bleeding in patient with atrial fibrillation

Aims

Direct oral anticoagulant (DOAC) is widely used for the prevention of embolic stroke in non-valvular atrial fibrillation (NVAF) patients. However, the gastrointestinal bleeding risk in several DOAC regimens was higher than warfarin, especially in once-daily regimens.

Methods and results

We conducted a single-center prospective registry of patients with NVAF treated with DOACs: the DIRECT registry (N = 2216; follow-up duration 650 [IQR 103-1574] days, UMIN000033283). All patients were divided into 2 groups: the twice-daily (BID) regimen group (dabigatran and apixaban) versus the once-daily (QD) regimen group (rivaroxaban and edoxaban). Out of 2216 patients, we successfully matched 904 patients in the QD group and 904 patients in the BID group using propensity score. The primary endpoint was gastrointestinal bleeding defined as any bleeding in the gastrointestinal tract that was identified through medical records regardless of bleeding site or severity. The BID group showed a significantly lower gastrointestinal bleeding rate than the QD group (3.5/100 person-year vs. 6.2/100 person-year, log-rank P < 0.0001). The secondary endpoints were all death, stroke, major bleeding, and any bleeding. The rate of major bleeding was significantly lower in patients with BID regimen group (log-rank P = 0.040). In contrast, all death, stroke, and any bleeding did not differ between both groups (log-rank P = 0.280, 0.520 and 0.066, respectively).

Conclusions

The BID regimen as compared with the QD regimen was associated with reduced risk of gastrointestinal bleeding.

Core shell stationary phase for a novel separation of some COVID-19 used drugs by UPLC-MS/MS Method: Study of grapefruit consumption impact on their pharmacokinetics in rats

A sensitive and selective UPLC-MS/MS method was developed for the synchronized determination of four drugs used in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), namely, azithromycin, apixaban, dexamethasone, and favipiravir in rat plasma. using a Poroshell 120 EC-C18 column (50 mm × 4.6 mm, 2.7 m) with a high-resolution ESI tandem mass spectrometer detection with multiple reaction monitoring. We used an Agilent Poroshell column, which is characterized by a stationary phase based on non-porous core particles. With a remarkable improvement in the number of theoretical plates and low column backpressure. In addition, the developed method was employed in studying the potential food-drug interaction of grapefruit juice (GFJ) with the selected drugs which affects their pharmacokinetics in rats. The LC-MS/MS operated in positive and negative ionization mode using two internal standards: moxifloxacin and chlorthalidone, respectively. Liquid- liquid extraction of the cited drugs from rat plasma was accomplished using diethyl ether: dichloromethane (70:30, v/v). The analytes were separated using methanol: 0.1 % formic acid in water (95: 5, v/v) as a mobile phase in isocratic mode of elution pumped at a flow rate of 0.3 mL/min. A detailed validation of the bio-analytical method was performed in accordance with US-FDA and EMA guidelines.

Concerning the in vivo pharmacokinetic study, the statistical significance between the results of the test groups receiving GFJ along with the cited drugs and the control group was assessed demonstrating that GFJ increased the plasma concentration of azithromycin, apixaban, and dexamethasone. Accordingly, this food–drug interaction requires cautious ingestion of GFJ in patients using (SARS-CoV-2) medications as it can produce negative effects in the safety of the drug therapy. A potential drug–drug interaction is also suggested between those medications requiring a suitable dose adjustment.

Appropriateness of Non-vitamin K Antagonist Oral Anticoagulants Dosing According to Different Prescription Guides Used in Belgian Ambulatory Care

Background

Non-vitamin K antagonist oral anticoagulants (NOACs) are the preferred choice of anticoagulants to prevent stroke in most patients with atrial fibrillation (AF). NOAC's dosing algorithms are defined in the respective Summary of Product Characteristics (SmPC) but the European Heart Rhythm Association (EHRA) Practical Guide can also be used as it considers more complex clinical scenarios. Nevertheless, suboptimal dosing of NOACs compromises the efficacy and safety of this commonly prescribed therapy in the AF population. Clearer objectification of inappropriate dosing and its influencing factors is needed to optimise management of AF patients.

Objectives

The primary aim of this study was  to investigate whether there is a difference in the perceived appropriateness of NOAC dosing with respect to the SmPC or the 2018 EHRA Practical Guide in AF patients criteria and influencing factors. The secondary aim was to explore if there were differences in appropriateness of NOAC dosing between primary care and specialist care, and when using different renal function formulas.

Methods

This retrospective study included AF patients treated with a NOAC in primary or in ambulatory specialist care in Antwerp (Belgium). Appropriateness of the NOAC dose was assessed according to the SmPC and 2018 EHRA recommendations. Univariate/multivariate analyses were performed to explore influencing factors for under- and overdosing of NOACs.

Results

Of the included 294 AF patients, 19.4% and 15.6% received an inappropriate dose according to the SmPC and the 2018 EHRA Practical Guide respectively (p = 0.003). Perceived frailty and higher weight were associated with underdosing relative to the SmPC, while a higher body mass index and the use of drugs/alcohol were associated with underdosing relative to the EHRA 2018 recommendations. Lower renal function and treatment with other NOACs than apixaban were associated with relative overdosing compared to both standards.

Conclusions

Inappropriate NOAC dosing is present in almost twenty percent of AF patients according to the SmPC and requires further education of health care professionals and frequent reassessment of NOAC dosing. However, a significant lower prevalence of underdosing was present when judged by the 2018 EHRA criteria, likely reflecting decision making in complex AF patients. Perceived frailty, weight, renal function and type of NOAC are the main determinants of deviated dosing.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40261-022-01190-2.

Do Apixaban Plasma Levels Relate to Bleeding? The Clinical Outcomes and Predictive Factors for Bleeding in Patients with Non-Valvular Atrial Fibrillation

Apixaban can significantly prevent stroke events in patients with non-valvular atrial fibrillation (NVAF), as can be observed from the large, randomized, controlled trial conducted in the present study. However, the real-world evidence of bleeding events related to the apixaban plasma levels in Asian populations is limited. This study aimed to investigate the apixaban plasma levels and clinical outcomes among NVAF patients receiving apixaban, including determining the risk factors associated with bleeding during routine care. Seventy-one patients were included in the study. The median values were 112.79 (5–95th percentiles: 68.69–207.8) μg/L and 185.62 (5–95th percentiles: 124.06–384.34) μg/L for the apixaban trough (C_trough) and apixaban peak plasma levels (C_peak), respectively. Stroke and bleeding were found in 8 (11.27%) and 14 patients (19.72%), respectively. There was no statistical significance for C_trough and C_peak in the stroke and non-stroke groups, respectively. The median of C_trough (139.15 μg/L) in patients with bleeding was higher than that in the non-bleeding group (108.14 μg/L), but there was no statistical significance. However, multivariate analyses showed that bleeding history (odds ratio (OR): 17.62; 95% confidence interval (CI): 3.54–176.64; and p-value = 0.002) and C_trough (OR: 1.01; 95%: CI 1.00–1.03; and p-value = 0.038) were related to bleeding events. Almost all of the patients presented apixaban plasma levels within the expected range. Interestingly, bleeding events were associated with the troughs of the apixaban plasma levels and bleeding history.

Safety and efficacy of the Amplatzer amulet and watchman2.5 for left atrial appendage occlusion: a Systematic review and meta-analysis

BACKGROUND

Left atrial appendage occlusion (LAAO) is an alternative to oral anticoagulation (OAC) to decrease the risk of stroke in patients with nonvalvular atrial fibrillation (NVAF); however, certain complications remain a concern. Amplatzer Amulet and Watchman are the two most popular used devices for preventing stroke in patients with NVAF. We assessed the safety and efficacy of LAAO using the Amplatzer Amulet and Watchman.

METHODS

A meta-analysis was conducted to compare the safety and efficacy outcomes associated with the use of the Amplatzer Amulet and Watchman 2.5. The Newcastle-Ottawa Scale has been utilized to assess the quality of study.

RESULTS

The meta-analysis includes seven studies involving 2,926 patients (1,418 patients with an amulet and 1,508 with a Watchman 2.5). Generally, adverse event rates for both systems were minimal. No significant differences between the two devices were found in safety (pericardial effusion, device embolization, and cardiac tamponade) or efficacy outcomes (death, TIA, stroke, major/minor bleeding, device leak, and thromboembolic events).

CONCLUSIONS

The data suggest LAAO is a safe procedure, regardless of which device was used. LAAO devices generally have low complication rates. Outcomes were comparable between the two groups with no significant differences in their safety or efficacy. This article is protected by copyright. All rights reserved.

An Updated Meta-Analysis of DOACs vs. VKAs in Atrial Fibrillation Patients With Bioprosthetic Heart Valve

Background

Current guidelines recommend the utilization of direct-acting oral anticoagulants (DOACs) in patients with non-valvular atrial fibrillation (AF). However, the optimal anticoagulation strategy for AF patients with bioprosthetic heart valves (BPHV) remains controversial. Therefore, we conducted this meta-analysis to explore the effect of DOACs versus vitamin K antagonists (VKAs) in this population.

Methods

We systematically searched the PubMed and Embase databases until November 2021 for studies reporting the effect of DOACs versus VKAs in AF patients with BPHV. Adjusted risk ratios (RRs) and 95% confidence intervals (CIs) were pooled using the random-effects model with an inverse variance method.

Results

We selected four randomized clinical trials and seven observational studies (2236 DOAC- and 6403 VKAs-users). Regarding the effectiveness outcomes, there were no significant differences between DOACs and VKAs in stroke or systemic embolism (RR = 0.74, 95%CI: 0.50–1.08), ischemic stroke (RR = 1.08, 95%CI: 0.76–1.55), all-cause death (RR = 0.98, 95%CI: 0.86–1.12), and cardiovascular death (RR = 0.85, 95%CI: 0.40–1.80). In terms of the safety outcomes, DOACs was associated with lower risks of major bleeding (RR = 0.70, 95%CI: 0.59–0.82) and intracranial bleeding (RR = 0.42, 95%CI: 0.26–0.70), but the risks of any bleeding (RR = 0.85, 95%CI: 0.65–1.13) and gastrointestinal bleeding (RR = 0.92, 95%CI: 0.73–1.17) are not significantly different when compared with VKAs. The subgroup analysis with follow-up as a covariate revealed that the DOACs had lower risks of SSE (RR = 0.59, 95%CI: 0.37–0.94) and major bleeding (RR = 0.69, 95%CI: 0.58–0.81) in patients with a mean follow-up of more than 24 months, but no statistical differences were found in patients with the follow-up less than 24 months (SSE: RR = 1.10, 95%CI: 0.92–1.32; major bleeding: RR = 0.91, 95%CI: 0.42–2.01).

Conclusions

In AF with BPHV, patients on DOACs experienced a reduced risk of major bleeding and intracranial bleeding compared with VKAs, while the risks of stroke, cardiovascular death, and all-cause mortality were similar.

Drug-Related Problems and Factors Involved in the Imbalance of Oral Anticoagulants in Lebanese Patients: A Cross-Sectional Study

The goal of this study was to identify drug-related problems (DRPs) and the factors involved in the imbalance of new oral anticoagulants (NOACs) and vitamin K antagonists in a Lebanese adult population with cardiovascular diseases. An imbalance in the hemostatic systems between procoagulant and anticoagulant factors in circulating blood produces either hemorrhagic or thrombotic conditions. A prospective cross-sectional study was conducted during 5 months in a teaching hospital. All patients at least 18 years of age taking oral anticoagulants were included in the study. A standardized questionnaire was used, and information was obtained from the patients’ profiles and electronic medical records. DRPs were identified and categorized according to the Pharmaceutical Care Network Europe classification system. A total of 258 patients were included. The overall prevalence of DRPs was 87.2%; the highest prevalence was observed in patients taking acenocoumarol (96.0%), in contrast to 76.7% and 59.0% in patients taking dabigatran and rivaroxaban, respectively. Drug interaction was the most frequent DRP (83.3%), followed by inappropriate monitoring (42.6%) and excessive dose (26.7%). Having renal disease, and taking proton-pump inhibitors or nonsteroidal anti-inflammatory drugs were among the factors affecting the international normalized ratio (INR) range (adjusted odds ratio [ORa] = 2.513, 95% confidence interval [CI] 1.238, 5.101; ORa = 2.487, 95% CI 1.139, 5.430 and ORa = 2.114, 95% CI 1.043, 4.286, respectively), whereas smoking and renal disease significantly affected activated partial thromboplastin time (aPTT) (ORa = 8.325, 95% CI 1.577, 43.965 and ORa = 6.922, 95% CI 1.471, 32.570, respectively). Patients taking NOACs had greater aPTT control and fewer DRPs, with a wide therapeutic index enabling administration of fixed doses.

Challenging issues in the management of cancer-associated venous thromboembolism

Venous thromboembolism (VTE) is a common complication among patients with cancer and is associated with delays in underlying cancer treatment and increases in morbidity and mortality. Acute and long-term treatments with low-molecular-weight-heparin (LMWH) have been recommended as a standard of care for patients with cancer with VTE for the past 20 years. Direct oral anticoagulants (DOACs) have recently emerged as a new therapeutic modality for cancer-associated VTE because of the convenience of oral administration and rapid onset of action. Our knowledge regarding DOACs for cancer-associated VTD has expanded in recent years. Thus, this study aimed to review recent major pivotal trials comparing DOACs with LMWH for managing cancer-associated VTE. Moreover, a recently updated understanding of DOACs in the treatment of cancer-associated VTE in specific challenging situations is presented.

Switching from warfarin to direct-acting oral anticoagulants: it is time to move forward!

Oral vitamin K antagonists (VKAs), warfarin, have been in routine clinical use for almost 70 years for various cardiovascular conditions. Direct-Acting Oral Anticoagulants (DOACs) have emerged as competitive alternatives for VKAs to prevent stroke in patients with non-valvular atrial fibrillation (AF) and have become the preferred choice in several clinical indications for anticoagulation. Recent guidelines have limited the use of DOACs to patients with non-valvular AF to reduce the risk of cardioembolic complications and to treat venous thromboembolism (VTE). Although emerging evidence is suggestive of its high efficacy, there was a lack of data to support DOACs safety profile in patients with mechanical valve prosthesis, intracardiac thrombi, or other conditions such as cardiac device implantation or catheter ablation. Therefore, several clinical trials have been conducted to assess the beneficial effects of using DOACs, instead of VKAs, for various non-guideline-approved indications. This review aimed to discuss the current guideline-approved indications for DOACs, advantages, and limitations of DOACs use in various clinical indications highlighting the potential emerging indications and remaining challenges for DOACs use. Several considerations are in favour of switching from warfarin to DOACs including superior efficacy, better adverse effect profile, fewer drug-drug interactions, and they do not require frequent international normalized ratio (INR) monitoring. Large randomized controlled trials are required to determine the safety and efficacy of their use in various clinical indications.

Changes in the Gut Microbiota May Affect the Clinical Efficacy of Oral Anticoagulants

The mechanism underlying large individual differences in the response to oral anticoagulants has not been fully clarified, and the influence of the intestinal microbiome on exogenous drug metabolism has gradually become an area of increased research interest. However, there has been no research into the influence of the gut microbiota on the pharmacokinetics of oral anticoagulants. Therefore, our study is the first to investigate the effect of the intestinal flora on oral anticoagulant metabolism and the associated mechanism. Antibiotics affected the diversity and abundance of the intestinal flora. Compared with the control group, the bioavailability of warfarin and rivaroxaban were significantly increased in the amoxicillin-treated group, whereas the bioavailability of dabigatran increased and subsequently decreased. Compared with the control group, the expression of P-glycoprotein (P-gp), CYP1A2, CYP2C9, CYP3A4, and nuclear receptor, PXR, were altered in the amoxicillin -treated groups. This trend was consistent with the pharmacokinetic results. Changes in the intestinal flora can affect the expression of liver drug enzymes and P-gp, as well as affect the transport and metabolism of oral anticoagulants (e.g., warfarin, dabigatracin, and rivaroxaban), leading to differences in the efficacy of oral anticoagulants. This study revealed a novel mechanism for influencing individual differences in the treatment efficacy of oral anticoagulants.

Intracranial hemorrhage associated with direct oral anticoagulant after clipping for an unruptured cerebral aneurysm: A report of two cases

Background:

Two cases of patients who developed intracranial hemorrhage associated with direct oral anticoagulant (DOAC) use after clipping of an unruptured cerebral aneurysm (uAN) are presented. These cases will help neurosurgeons assess the risks of patients with atrial fibrillation or deep venous thrombosis receiving DOACs who require craniotomy.

Case Description:

Case 1 was a 65-year-old man on apixaban 10 mg/day who underwent clipping for a left middle cerebral artery uAN. Apixaban was discontinued 72 h before surgery. During surgery, a thin and pial artery bled slightly at 1 point of the frontal lobe, and hemostasis was easily achieved. Computed tomography (CT) 19 h after surgery showed no evidence of intracranial hemorrhage. He was treated with a heparin-apixaban bridge from 29 h to 41 h after surgery. CT showed a left subarachnoid hematoma 24 h later. Case 2 was a 73-year-old woman on dabigatran 110 mg/day who underwent clipping for a right MCA uAN. Dabigatran was discontinued 48 h before surgery. During surgery, a thin and pial artery bled slightly at 2 points of the temporal lobe, and hemostasis was easily achieved. CT 19 h after surgery showed no evidence of intracranial hemorrhage. Dabigatran (110 mg/day) was restarted 29 h after surgery. CT then showed a right subarachnoid hematoma 94 h later, and dabigatran was discontinued, and it was then restarted 38 h later. However, 31 h later, CT showed an additional slight subarachnoid hemorrhage. Finally, she developed a right chronic subdural hematoma.

Conclusion:

In patients undergoing neurosurgical procedures, discontinuation of DOACs should be individualized based on neurosurgical bleeding risk and patient renal function. Restarting of DOACs could be considered after at least 48 h when hemostasis has been achieved. Bridging of DOACs cannot be recommended.

Novel Anticoagulants and Hip Fractures in the Elderly

Introduction

Early surgery is recommended in hip fractures to reduce morbidity and mortality. Surgery is often delayed in patients on novel direct oral anticoagulants (DOACs). The purpose of our study was to investigate the impact of DOACs on patients with hip fractures.

Methods

A retrospective comparative analysis was performed. A total of 766 patients presented with neck of femur fractures in the study period. Patients under the age of 60, those managed conservatively and those on alternative anticoagulation (including warfarin, clopidogrel and aspirin) were excluded. Forty-seven (6.1%) patients were on DOACs, to which a group of 47 patients was matched for age, gender, fracture type and intervention to minimise confounding. Primary outcome data on time to surgery (TTS), pre-/postoperative haemoglobin, haemoglobin drop, length of stay (LOS) and 30-day mortality were collected, as well as secondary outcome data on blood transfusion and wound complications. The Charlson Comorbidity Index (CCI) was calculated for all patients.

Results

The mean Charlson Comorbidity Index was significantly increased in the DOAC group (p<0.0001). The mean time to surgery was 49.5 hours in the DOAC group versus 31.3 hours in the control group (p=0.0002). Haemoglobin drop for DOAC patients was 16.9 g/L and 15.9 g/L for control patients (p=0.6). Similarly, no significant increase in transfusion was required (p=0.74). Six DOAC patients and two control group patients died within 30 days of surgery (p=0.13). Wound complications were seen in five (10.6%) patients on DOAC and two (4.2%) patients in the control group (p=0.02).

Conclusion

The results demonstrate statistically significantly higher comorbidities, delay in surgery and higher wound complications in patients on DOAC but no significant difference in haemoglobin drop, blood transfusion and mortality.