Indications for suboptimal low-dose direct oral anticoagulants for non-valvular atrial fibrillation patients

Incidence and predictors of major gastrointestinal bleeding in patients on aspirin, low-dose rivaroxaban, or the combination: Secondary analysis of the COMPASS randomised controlled trial

BACKGROUND

The incidence of major gastrointestinal bleeding (GIB) in patients on low-dose direct-acting oral anticoagulants (DOACs) is relatively unknown. Estimates from randomised controlled trials (RCTs) are lacking.

AIMS

To assess GIB incidence and predictors from RCT data of patients on aspirin, low-dose rivaroxaban, or both.

METHODS

This was a secondary analysis of RCT data wherein patients received aspirin 100 mg daily and rivaroxaban 2.5 mg b.d., aspirin alone, or rivaroxaban 5 mg b.d. Patients were followed from 2013 to 2016 at 602 centres. Outcomes included overall, upper, and lower GIB. We employed multivariable logistic regression to yield odds ratios (ORs) and 95% confidence intervals for potential exposures.

RESULTS

Among 27,395 patients, the annual incidence of GIB on rivaroxaban 2.5 mg b.d. with aspirin was 801.7 per 100,000 compared with 372.3 in 100,000 for aspirin. Age (OR 4.16, 2.53-6.82 for ≥75 vs. 55-64), peptic ulcer disease (PUD, OR 1.57, 1.01-2.44), liver disease (OR 2.09, 1.01-4.33), hypertension (OR 1.42, 1.04-1.94), and smoking (OR 1.85, 1.26-2.73) were associated with overall GIB. Kidney disease (OR 1.68, 1.12-2.51) was significantly associated with upper GIB, whereas diverticular disease (OR 3.75, 1.88-7.49) was associated with lower GIB. Addition of rivaroxaban to aspirin was associated more with lower GIB (OR 2.82, 1.64-4.84) than upper GIB (OR 1.86, 1.18-2.92).

CONCLUSIONS

We established incidences and identified risk factors for GIB in users of low-dose DOACs. Novel risk factors included current or former smoking and diverticulosis. Future studies should aim to validate these risk factors.

Ischaemic stroke in a patient with non-valvular atrial fibrillation (NVAF) despite non-vitamin K oral anticoagulant (NOAC) therapy

Primary stroke prevention in non-valvular atrial fibrillation (NVAF) is primarily with non-vitamin K oral anticoagulant (NOAC) therapy. However, 20-36% of ischaemic strokes seem to occur in patients with atrial fibrillation while already on anticoagulation. We present a case of an ischaemic stroke in an elderly female in her 70s with medical history significant for hypertension and NVAF. She had a CHA2DS2-VASc score of 3 and was on apixaban for thromboprophylaxis. She presented with neurological deficits consistent with a left middle cerebral artery stroke, confirmed via head imaging; the most likely stroke aetiology was determined to be cardioembolic in the setting of NVAF. She was treated with continuation of her apixaban at the same dosage She displayed improved function, although with residual expressive aphasia at her 2-month neurology follow-up. Cardioembolic ischaemic stroke in NVAF despite current NOAC therapy does not have current management guidelines.

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.

Efficacy and Safety of Clinically Driven Low-Dose Treatment with Direct Oral Anticoagulants in Asians with Atrial Fibrillation: a Systematic Review and Meta-analysis

PURPOSE

Although clinically driven low-dose (CDLD) treatment with direct oral anticoagulants (DOACs) is frequently administered to Asian patients with atrial fibrillation, clinical evidence confirming its efficacy remains insufficient. We evaluated the clinical efficacy and safety of CDLD treatment with DOACs compared to on-label dose treatment in Asian patients with atrial fibrillation and assessed the differences in the baseline characteristics between patients receiving these treatments.

METHODS

We searched the MEDLINE, CENTRAL, EMBASE, Web of Science, and Scopus databases for articles from inception through July 2020.

RESULTS

Thirteen studies were included in this meta-analysis. The baseline characteristics of the CDLD group were significantly different from those of the standard dose (STD) and standard low-dose (SLD) groups. The incidences of thromboembolic events (risk ratio [RR] 0.46, 95% confidence interval [CI] 0.29-0.73, p < 0.001) and major bleeding (RR 0.55, 95% CI 0.35-0.87, p = 0.01) in the CDLD group were lower than those in the SLD group; however, they were comparable with those in the STD group. The incidence of a composite endpoint in the CDLD group was not significantly different from that in the STD group but was significantly lower than that in the SLD group (RR 0.50, 95% CI 0.38-0.65, p < 0.001).

CONCLUSION

The clinical outcomes of CDLD treatment showed no difference compared to those of the STD treatment despite the vulnerable baseline characteristics of the CDLD group for thromboembolic and major bleeding events.

Comparison of non-vitamin K antagonist oral anticoagulants on bleeding and thrombosis

WHAT IS KNOWN AND OBJECTIVE

Limited data are available for the comparison between different non-vitamin K antagonist oral anticoagulants (NOACs) on clinical outcomes. We aimed to provide evidence of different NOACs for patients with non-valvular atrial fibrillation (NVAF).

METHODS

Electronic databases were searched from inception through 22 March 2020 to identify eligible studies in which clinical outcomes (stroke, systemic embolism [SE], bleeding or death events) were directly compared between different NOACs.

RESULTS

29 real-world studies enrolled more than 700,000 patients were included. Compared with dabigatran, apixaban had higher risk of death (OR 1.07), major bleeding (1.43), GI bleeding (1.64), ischaemic stroke and stroke/SE events (1.10); rivaroxaban had higher risk of death (1.28), major bleeding (1.24), GI bleeding (1.14) and ischaemic stroke (1.08). Compared with rivaroxaban, apixaban had lower risk of death (0.8), major bleeding (0.56) and ischaemic stroke events (0.71). Compared with edoxaban, rivaroxaban had higher risk of major bleeding (2.83), GI bleeding (5.18) and ischaemic stroke (2.28).

WHAT IS NEW AND CONCLUSION

In view of the global burden of disease and the routine use of NOACs worldwide, the findings have immediate and important implications. Our data suggested that apixaban might be the priority choice in prevention of bleeding and stroke and dabigatran could be the priority choice in prevention of death events.

TRIAL REGISTRATION

This systematic review and meta-analysis were conducted and reported according to the Preferred Reporting Items for Systematic Reviews (PRISMA), Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines and was registered with PROSPERO (CRD42019140553).

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.

Off-label use of reduced dose direct oral factor Xa inhibitors in subjects with atrial fibrillation: a review of clinical evidence

In real-world clinical practice, underdosing, i.e. off-label use of reduced doses (RDs), of oral factor Xa inhibitors (oFXaIs) is quite common in stroke prevention in non-valvular atrial fibrillation, possibly reflecting the hope to increase safety without reducing efficacy in selected patients. To assess whether this strategy is associated with some clinical benefit, we used a physician-centred approach to evaluate whether current evidence supports the hypothesis that a substantial proportion of underdosing may be voluntary rather than casual, whether and to what extent oFXaIs' dose rather than patients' characteristics are associated with bleeding events, and which are the safety and efficacy clinical implications of oFXaIs' underdosing. Our review found consistent evidence that underdosing is often an intentional strategy; however, available studies do not demonstrate a sizeable net clinical benefit of using off-label RD oFXaIs.

Apixaban for Stroke Prevention in Atrial Fibrillation: Why are Event Rates Higher in Clinical Practice than in Randomized Trials?—A Systematic Review

Background Recent reports suggest an important contribution from frequent off-label use of apixaban 2.5 mg twice daily to the higher rates of thromboembolic events observed in observational studies (OSs) relative to in randomized controlled trials (RCTs), and consequently, advocate against such use in all patients.

Objectives To examine factors contributing to the higher thromboembolic event rates, we estimated the prevalence of off-label use in contemporary practice, and compared patient characteristics and rates of stroke/systemic embolism, major bleeding, and mortality by apixaban dose and by study design in a systematic review and meta-analysis.

Results and Discussion We identified 18 OSs and 2 RCTs that included 155,228 and 11,928 patients, respectively. Patients in OSs more often received apixaban 2.5 mg twice daily (31.3% vs. 5.1%), were older (mean age 73.8 vs. 69.8 years), and had higher CHA2DS2-VASc scores (mean 3.6 vs. 2.9) versus those in RCTs. We observed a consistent pattern of higher rates of thromboembolic events, bleeding, and mortality in patients treated with 2.5 versus 5 mg twice daily apixaban in both OSs and RCTs.

Conclusion The higher risk profiles of patients in OSs versus RCTs, and higher rates of both bleeding and mortality not attributable to thromboembolism in patients treated with apixaban 2.5 versus 5 mg twice daily suggest that differences in patient characteristics are additional important contributors to the higher than expected thromboembolic event rates in clinical practice.

Impact of direct oral anticoagulant off-label doses on clinical outcomes of atrial fibrillation patients: A systematic review

AIMS

Worldwide observational studies are evidencing discordance between guidelines and real-world practice regarding direct oral anticoagulant drug (DOAC) doses. This systematic review summarizes and evaluate DOACs use in real-world practice.

METHODS

This review was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines searching PubMed (MEDLINE) and Medscape databases.

RESULTS

Data from 75 studies showed that most of the patients treated with DOACs for stroke prevention in atrial fibrillation received doses in accordance to the guidelines. However, a significant number of patients received off-label doses (25-50% in most of the studies evaluated). DOAC overdosing was associated with increased all-cause mortality and worse bleeding events while underdosing was associated with increased cardiovascular hospitalization and, particularly for apixaban, with a nearly 5-fold increased risk of stroke.

CONCLUSION

Patients prescribed with off-label DOAC doses did not receive the full benefit of anticoagulation and presented an increased risk of stroke, bleeding and/or adverse effects.

Profiling Clinical Characteristics and Treatment Patterns Among Non-Valvular Atrial Fibrillation Patients: A Real-World Analysis in Dubai, United Arab Emirates

Background:

There is a dearth of real-world evidence regarding patient characteristics, Oral Anti-Coagulant (OAC) treatment, and International Normalized Ratio (INR) patterns in Dubai, United Arab Emirates (UAE).

Methods:

This was a retrospective observational study among newly diagnosed adult Non-valvular Atrial Fibrillation (NVAF) patients in the Dubai Real World Claims Database. Selected patients had at least one activity claim during the 12 months pre-index date (baseline period), and a pharmacy claim for apixaban, dabigatran, rivaroxaban, or warfarin from 01 JAN 2015-31 JUL 2017. Patients with valvular heart disease, cardiac surgery, venous thromboembolism, transient atrial fibrillation, pregnancy, or OAC claims during baseline were excluded. Comorbidities and treatment patterns related to OAC use, index dosing, baseline medications, and INR patterns were described.

Results:

Among 5,072 NVAF patients, 468 met the study criteria. A minority of them (14.3%) were prescribed warfarin, and the most frequently prescribed non-vitamin K antagonist OACs (NOACs) were rivaroxaban (33.3%) and apixaban (31.4%), followed by dabigatran (20.9%). Patients’ mean age was 59 years and mean CHA2DS2-VASc score was 2.3, with most frequent comorbidities of diabetes mellitus, hypertension, coronary artery disease, and peripheral vascular disease. Additionally, 51% and 33% were on statins and aspirin, respectively, while 39% were on other anticoagulant agents. A large proportion of dabigatran patients were on a lower dose (57%). INR patterns revealed 13% of rivaroxaban, 12% of apixaban, and 7% of dabigatran patients had INR claims.

Conclusion:

This study provides relevant insights into the use of OACs in real-world clinical practice settings in Dubai, UAE.

Characteristics of Japanese Patients with Nonvalvular Atrial Fibrillation on Anticoagulant Treatment: A Descriptive Analysis of J-dabigatran Surveillance and JAPAF Study

INTRODUCTION

Following approval of dabigatran and other antithrombotics in Japan, few studies have specifically evaluated the clinical characteristics of patients prescribed these antithrombotics for nonvalvular atrial fibrillation (NVAF) in real-world practice.

METHODS

We conducted a descriptive analysis of data from two real-world studies [J-dabigatran surveillance and Japanese study on current Anticoagulation therapies for Patients with nonvalvular Atrial Fibrillation (JAPAF); conducted at sites common to both studies] to determine the characteristics of patients with NVAF initiated on dabigatran etexilate [110 mg twice daily (BID; DE110) or 150 mg BID (DE150)], warfarin, rivaroxaban, or antiplatelets as their first antithrombotic treatment. Inferential statistical analyses were not performed, and no statistical hypothesis was tested.

RESULTS

Data for 1270 and 3011 eligible patients from the J-dabigatran surveillance (DE110, 976; DE150, 273) and JAPAF study (warfarin, 82.5%; rivaroxaban, 10.3%; antiplatelets, 21%), respectively, were extracted. In the J-dabigatran surveillance, 31.8% (full cohort, 28.1%) of patients had been switched from warfarin to dabigatran. Among patients prescribed DE110/DE150, 41.4%/57.5% and 41.5%/18.7% of patients had low-to-intermediate risk for ischemic stroke (CHADS₂ score of 0 or 1) and high risk for bleeding (HAS-BLED score ≥ 3), respectively. Similarly, 33.7%/41.3%/40.2% and 48.7%/42.6%/75.7% of patients taking warfarin/rivaroxaban/antiplatelets had a CHADS₂ score of 0 or 1 and HAS-BLED score ≥ 3, respectively. Dabigatran was favored in patients with creatinine clearance > 50 ml/min.

CONCLUSIONS

In Japan, physicians who attempt stroke prevention in patients with atrial fibrillation choose appropriate anticoagulant treatment, taking into consideration the individual patient backgrounds as well as the features of each antithrombotic agent.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier, NCT01491178 and University Hospital Medical Information Network (UMIN) Clinical Trial Registry Identifier, UMIN000009644.

FUNDING

Nippon Boehringer Ingelheim Co., Ltd. Plain language summary available for this article.

Overview of oral antithrombotic treatment in elderly patients with atrial fibrillation

Atrial fibrillation (AF) is an age-related arrhythmia, particularly affecting elderly patients. The ultimate goals in the treatment of AF are to improve prognosis and quality of life. Anticoagulants are effective for stroke prevention in AF patients, however, managing anticoagulation in elderly patients is especially challenging; requiring a comprehensive assessment of the patient and deep understanding of available therapies and doses to maximize the net benefit. This review summarizes available evidence on the efficacy and safety of anticoagulation therapy, and provides contemporary updates on the management of elderly patients with AF.

Expanding anticoagulation management services to include direct oral anticoagulants

Despite the ease of use of direct oral anticoagulants (DOACs), these agents remain high risk medications and their clinical efficacy can be impacted by factors such as patient adherence, drug procurement barriers, bleeding leading to discontinuation, and prescribing that deviates from approved dosing regimens. Clinical monitoring of patients on DOACs should be performed by clinicians who specialize in anticoagulation and are familiar with the nuances of DOAC dosing, monitoring, and other components of anticoagulation management including peri-procedural management and care transitions. Although data for centralized warfarin management have consistently demonstrated improved clinical outcomes compared to traditional management by individual community providers, there are no published data addressing the impact of centralized management of DOACs on clinical outcomes or anticoagulation control. In addition, there is currently no consensus on how to incorporate patients on DOACs into this centralized model, despite recommendations for systematic follow-up by both the Anticoagulation Forum and the Institute for Safe Medication Practices. Based on the national recommendations and an identified institutional need, the Brigham and Women's Hospital Anticoagulation Management Service implemented a pilot program to expand services to include patients newly initiated on, or transitioned to, a DOAC. We describe our model for expansion of the AMS to include patients on DOACs.