Real‐world direct oral anticoagulant experience in atrial fibrillation: falls risk and low dose anticoagulation are predictive of both bleeding and stroke risk

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

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

A ten-year review of the impact of the transition from warfarin to direct oral anticoagulant - Has venous thromboembolism treatment become safer?

BACKGROUND

The introduction of direct oral anticoagulants (DOAC) has resulted in a paradigm shift in the management of venous thromboembolism (VTE). We evaluate the impact of the transition to DOAC, over the last decade, on overall VTE clinical outcomes including in first unprovoked major VTEs.

METHOD

A retrospective analysis of all VTE admissions in non-cancer patients from January 2011 to December 2020 at Northern Health, Victoria, Australia. "Warfarin era" included events that occurred between January 2011 and December 2014 and "DOAC era" from January 2016.

RESULTS

There were 2687 cases involving 2508 patients (45.9 % males; median age 63 years). 98 % were symptomatic and 1261 events (47 %) were unprovoked. 1003 events occurred during the warfarin era (79 % warfarin, 6 % DOAC) and 1479 during the DOAC era (18 % warfarin, 70 % DOAC). While recurrent thrombosis during the acute phase of treatment was comparable, there were fewer recurrences during the long-term preventative phase of treatment in the DOAC era compared to warfarin era (HR 0.602, 95 % CI: 0.393-0.924, p0.020). Clinically significant bleeding events were lower in the DOAC era (HR 0.623, 95 % CI: 0.395-0.985, p = 0.043). A subanalysis of first unprovoked major VTE events (n = 602) demonstrated a significant reduction in recurrent VTE during the long-term preventative phase of treatment in the DOAC era (HR 0.296, 95 % CI: 0.097-0.901, p = 0.032) with no difference in clinically significantly bleeding rates (HR 0.529, 95 % CI 0.219-1.280, p = 0.158) between the eras.

CONCLUSION

Treatment outcomes for VTE appear to have improved over time with reduced rate of thrombotic and clinically significant bleeding complications in the DOAC era.

Clinical effects of off-label reduced doses of Direct Oral Anticoagulants: A systematic review and meta-analysis

BACKGOUND

Atrial Fibrillation (AF) is the most prevalent cardiac arrhythmia among older patients, associated with thromboembolic events. Direct Oral Anticoagulants (DOAC) are the treatment of choice for most patients, but its use may have risks on standard dose. However, it is still unclear the effects related with the use of a lower dose off labelled DOAC.

OBJECTIVES

We conducted a systematic review and meta-analysis to assess the effects of off-label underdose use of DOAC in patients with AF.

METHODS

MEDLINE, Cochrane Central Register of Controlled Trials, PsycINFO databases and EMBASE were searched for observational longitudinal studies evaluating the outcomes on off label underdosed patients compared with standard dosed patients with AF. We performed a random-effects meta-analysis to estimate the pooled Hazard Ratios (HR) with 95%Cis.

RESULTS

Eighteen cohort studies evaluating 237,533 patients with AF were included. Off-label underdose DOAC use is associated with higher risk of all-cause mortality [HR = 1.27 (95%CI 1.09-1.48)] and cardiovascular composite outcomes [HR = 1.32 (95%CI 1.08-1.62)], when compared with standard dose DOAC use. The effects in thromboembolic events [HR = 1.14 (95%CI 1.00-1.31)], major bleeding [HR = 1.02 (95%CI 0.91-1.15)], and composite of ischemic and bleeding events [HR = 1.22 (95%CI 0.79-1.88)] were not statistically significant. The certainty in the evidence was low or very low.

CONCLUSIONS

Off label underdose DOAC use is associated with higher risk of all-cause mortality and cardiovascular composite outcomes, compared with standard dose.

Real-World Comparisons of Low-Dose NOACs versus Standard-Dose NOACs or Warfarin on Efficacy and Safety in Patients with AF: A Meta-Analysis

Objective

We aimed to further investigate the efficacy and safety of low-dose NOACs by performing a meta-analysis of cohort studies.

Background

Meta-analyses of randomized controlled trials (RCTs) have demonstrated that low-dose non-vitamin K antagonist oral anticoagulants (NOACs) showed inferior efficacy compared with standard-dose NOACs, although they are still frequently prescribed for patients with atrial fibrillation (AF) in the clinical practice.

Methods

Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and MEDLINE were systematically searched from the inception to September 9, 2021, for cohort studies that compared the efficacy and/or safety of low-dose NOACs in patients with AF. The primary outcomes were ischemic stroke and major bleeding, and the secondary outcomes were mortality, intracranial hemorrhage (ICH), and gastrointestinal hemorrhage (GH). Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated with the random-effect model.

Results

Twenty-five publications involving 487856 patients with AF were included. Compared with standard-dose NOACs, low-dose NOACs had comparable risks of ischemic stroke (HR = 1.03, 95% CI 0.96 to 1.11), major bleeding (HR = 1.12, 95% CI 0.97 to 1.28), ICH (HR = 1.09, 95% CI 0.88 to 1.36), and GH (HR = 1.11, 95% CI 0.92 to 1.33), except for a higher risk of mortality (HR = 1.41, 95% CI 1.21 to 1.65). Compared with warfarin, low-dose NOACs were associated with lower risks of ischemic stroke (HR = 0.72, 95% CI .67 to 0.78), mortality (HR = 0.67, 95% CI 0.59 to 0.77), major bleeding (HR = 0.64, 95% CI 0.53 to 0.79), ICH (HR = 0.57, 95% CI 0.42 to 0.77), and GH (HR = 0.78, 95% CI 0.64 to 0.95).

Conclusions

Low-dose NOACs were comparable to standard-dose NOACs considering risks of ischemic stroke, major bleeding, ICH, and GH, and they were superior to warfarin. Low-dose NOACs might be prescribed effectively and safely for patients with AF. Considering limitations, further well-designed prospective studies are foreseen.

Real-world safety and efficacy of direct oral anticoagulants in atrial fibrillation: a systematic review and meta-analysis of 605 771 patients

AIMS

To analyse the safety and efficacy of direct oral anticoagulants (DOACs) in real-world studies including atrial fibrillation (AF) patients.

METHODS AND RESULTS

Systematic review and meta-analysis of observational studies including AF patients on DOACs. Primary endpoints: any, major, gastrointestinal (GI), intracranial haemorrhage (ICH), and haemorrhagic stroke (HS). Secondary endpoints: ischaemic stroke (IS), systemic embolism (SE), myocardial infarction (MI), and all-cause of death. A set of pair-wise meta-analyses using a random effect model and a random effect network meta-analysis under a Bayesian framework were performed. Prospero registration number: CRD42019137111. We included 21 studies with 605 771 AF patients. Apixaban was associated with lower major and GI bleeding compared with Rivaroxaban [hazard ratio (HR) 2.0, 95% confidence interval (CI) 1.6-2.5] and Dabigatran (HR 1.6, 95% CI 1.3-2.1). The latter drug performed better than Rivaroxaban (HR 1.2, 95% CI 1.0-1.5). Dabigatran and Apixaban had a similar association with HS, but Apixaban performed better than Rivaroxaban (HR 1.8, 95% CI 1.1-3.0). Apixaban had a similar association with Rivaroxaban and Dabigatran for ICH, the latter drug performing better than Rivaroxaban (HR 1.3, 95% CI 1.0-1.7). Rankograms showed that Apixaban was likely to be the first-choice treatment in relation to any (65%) major (100%) and GI bleeding (100%) followed by Dabigatran (46%, 100%, 99%, respectively). Dabigatran and Apixaban had similar rank as first choice for ICH (44% and 55%) and HS (52% and 48%). DOACs showed similar association with IS/SE, MI, all-cause of death.

CONCLUSIONS

Analysis of real-world studies shows significant differences for safety among DOACs.

Anticoagulant Therapy for Frail Patients with Atrial Fibrillation

The prevalence of atrial fibrillation (AF) increases with age, as does the proportion of patients with frailty. AF patients with frailty have a higher risk of stroke than those without frailty, and progressive frailty caused by stroke is also associated with a worse prognosis. Despite this, anticoagulant therapy tends to not be used in frail patients because of the risk of falls and bleeding complications. However, some studies have shown that anticoagulant therapy improves the prognosis in patients with frailty. An accurate assessment of the "net-clinical-benefits" is needed in patients with frailty, with the aim of improving the prognoses of patients with frailty by selecting those who will benefit from anticoagulant therapy and actively reducing the risk of bleeding. A comprehensive intervention that includes a team of doctors and social resources is required. We herein review the effectiveness and bleeding risk associated with anticoagulant therapy in frail patients investigated in clinical studies.

The Risk of Gastrointestinal Bleeding between Non-Vitamin K Antagonist Oral Anticoagulants and Vitamin K Antagonists in the Asian Atrial Fibrillation Patients: A Meta-Analysis

Background: Non-vitamin K antagonist oral anticoagulants (NOACs) are more commonly used to prevent atrial fibrillation (AF) patients from thromboembolic events than vitamin K antagonists (VKAs). However, the gastrointestinal bleeding (GIB) risk in the Asian AF patients associated with NOACs in comparison with VKAs remained unaddressed. Materials and Methods: A systematic search of studies on NOACs and VKAs in the Asian AF patients was conducted in PubMed, Cochrane Library, and ClinicalTrials.gov. The primary outcome was the hazard ratio (HR) of any GIB associated with NOACs versus VKAs. The secondary outcome was the GIB risks in different kinds of NOACs compared with VKAs. Results: This meta-analysis included two randomized controlled trials (RCTs) and four retrospective studies, comprising at least 200,000 patients in total. A significantly lower HR of GIB risks was found in all kinds of NOACs than VKAs in the Asian AF patients (HR: 0.633; 95% confidence interval: 0.535-0.748; p < 0.001). Additionally, the GIB risks of different NOACs were apixaban (HR: 0.392), edoxaban (HR: 0.603), dabigatran (HR: 0.685), and rivaroxaban (HR: 0.794), respectively. Conclusions: NOACs significantly reduced the risk of GIB in the Asian AF patients compared with VKAs. In the four NOACs compared with VKAs, apixaban probably had a trend of the least GIB risk. We need further head-to-head studies of different NOACs to confirm which NOAC is the most suitable for Asian AF patients and to know the optimal dosage regimen of different NOACs.

Management of oral anticoagulation in very old patients with non valvular atrial fibrillation related acute ischemic stroke

The optimal management of oral anticoagulation (OAC) in the acute phase of non valvular atrial fibrillation (NVAF)-related acute ischemic stroke (AIS) remains controversial, especially in very old patients. Therefore, the aim of our study was to evaluate the practical management of OAC in this context. We conducted an observational retrospective study on patients 85-years old and older admitted to two Italian hospitals for NVAF-related AIS. For each patient, clinical and brain computed tomography data were recorded. Type of OAC (vitamin K antagonists, VKAs or Direct Oral Anticoagulants, DOACs), dosage and starting day after AIS were registered. For each patient 90-day all cause mortality, stroke recurrence, any bleeding and modified Rankin scale (mRS) were reported. One-hundred-seventeen patients, with mean age 89.2 ± 3.4 years, were enrolled. In-hospital and 90-day mortality (out of 109 patients) were 6% and 19.7%, respectively. OAC was started in 93 patients (80.5%), on average after 6 ± 3 days from the acute event. Of them, 88 patients (94.6%) received DOACs, while 5 (5.4%) received VKAs. Patients receiving OAC were significantly younger and suffering from less severe stroke compared with patients who did not receive OAC. Patients receiving OAC presented a reduced in-hospital (2.2% vs. 20.8%, p < 0.004) and 90-day all-cause mortality (9.4% vs. 62.5%, p < 0.001). In patients receiving DOACs, low dosages were used in 87.5% of patients. The use of OAC was not associated with an increased rate of hemorrhagic transformation (HT) during hospitalization (13.2% vs. 9.5%, p = 0.54) or any bleeding at 90-day follow-up. Severe dysphagia and mRS ≥ 4 were found to be independent risk factors for not prescribing OAC. The optimal management of OAC in very old patients suffering from NVAF-related AIS remains a dilemma. In our real world study the majority of patients received OAC as secondary prevention treatment without increase in bleeding risk. Dysphagia and severe disability were independent factors for not prescribing OAC. Further investigations aimed at identifying the optimal approach to OAC during the acute phase of NVAF-related ischemic stroke in this subgroup of patients are warranted.