Comparing risk of major bleeding between users of different oral anticoagulants in patients with nonvalvular atrial fibrillation

Left Atrial Appendage Closure Compared With Oral Anticoagulants for Patients With Atrial Fibrillation: A Systematic Review and Network Meta-Analysis

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) has been suggested as an alternative to long-term oral anticoagulation for nonvalvular atrial fibrillation, but comparative data remain scarce. We aimed to assess ischemic and bleeding outcomes of LAAC compared with vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs) for the prevention of cardioembolic events in patients with atrial fibrillation.

METHODS AND RESULTS

Embase and MEDLINE were searched for randomized trials comparing LAAC, VKAs, and DOACs. The primary efficacy end point was any stroke or systemic embolism. Treatment effects were calculated from a network meta-analysis and ranked according to the surface under the cumulative ranking curve. Seven trials and 73 199 patients were included. The risk of the primary end point was not statistically different between LAAC versus VKAs (odds ratio [OR], 0.92 [95% CI, 0.62-1.50]) and LAAC versus DOACs (OR, 1.11 [95% CI, 0.71-1.73]). LAAC and DOACs resulted in similar risk of major or minor (OR, 0.93 [95% CI, 0.61-1.42]) and major bleeding (OR, 0.92 [95% CI, 0.58-1.46]); however, after exclusion of procedural bleeding, bleeding risk was significantly lower in those undergoing LAAC. Both LAAC and DOACs reduced the risk of all-cause death  compared with VKAs (LAAC versus VKAs: OR, 0.70 [95% CI, 0.53-0.91]; DOACs versus VKAs: OR, 0.90 [95% CI, 0.85-0.95], respectively). DOACs ranked as the best treatment for stroke or systemic embolism prevention (66.9%) and LAAC for reducing major bleeding (63.9%) and death (96.4%).

CONCLUSIONS

As a nonpharmacological alternative to oral anticoagulation for atrial fibrillation, LAAC showed similar efficacy and safety compared with VKAs or DOACs. Prospective confirmation from larger studies is warranted.

Safety outcomes of direct oral anticoagulants in older adults with atrial fibrillation: a systematic review and meta-analysis of (subgroup analyses from) randomized controlled trials

Balancing stroke prevention and risk of bleeding in patients with atrial fibrillation (AF) is challenging. Direct oral anticoagulants (DOACs) are by now considered standard of care for treating patients with AF in international guidelines. Our objective was to assess the safety of long-term intake of DOACs in older adults with AF. We included RCTs in elderly (≥ 65 years) patients with AF. A systematic search in MEDLINE and EMBASE was performed on 19 April 2022. For determination of risk of bias, the RoB 2 tool was applied. We pooled outcomes using random-effects meta-analyses. The quality of evidence was assessed using GRADE. Eleven RCTs with a total of 63,374 patients were identified. Two RCTs compared apixaban with either warfarin or aspirin, four edoxaban with either placebo, aspirin, or vitamin K antagonists (VKAs), two dabigatran with warfarin and three rivaroxaban with warfarin. DOACs probably reduce mortality in elderly patients with AF (HR 0.89 95%CI 0.77 to 1.02). Low-dose DOACs likely reduce bleeding compared to VKAs (HR ranged from 0.47 to 1.01). For high-dose DOACS the risk of bleeding varied widely (HR ranged from 0.80 to 1.40). We found that low-dose DOACs probably decrease mortality in AF patients. Moreover, apixaban and probably edoxaban are associated with fewer major or clinically relevant bleeding (MCRB) events compared to VKAs. For dabigatran and rivaroxaban, the risk of MCRB varies depending on dose. Moreover, subgroup analyses indicate that in the very old (≥ 85) the risk for MCRB events might be increased when using DOACs.Registration: PROSPERO: CRD42020187876.

Patients on vitamin K treatment: is switching to direct-acting oral anticoagulation cost-effective? A target trial on a prospective cohort

AIMS

Direct-acting oral anticoagulants (DOACs) have, to a substantial degree, replaced vitamin K antagonists (VKA) as treatments for stroke prevention in atrial fibrillation (AF) patients. However, evidence on the real-world causal effects of switching patients from VKA to DOAC is lacking. We aimed to assess the empirical incremental cost-effectiveness of switching patients to DOAC compared with maintaining VKA treatment.

METHODS

The target trial approach was applied to the prospective observational Swiss-AF cohort, which enrolled 2415 AF patients from 2014 to 2017. Clinical data, healthcare resource utilisation and EQ-5D-based utilities representing quality of life were collected in yearly follow-ups. Health insurance claims were available for 1024 patients (42.4%). Overall survival, quality-of-life, costs from the Swiss statutory health insurance perspective and cost-effectiveness were estimated by emulating a target trial in which patients were randomly assigned to switch to DOAC or maintain VKA treatment.

RESULTS

228 patients switching from VKA to DOAC compared with 563 patients maintaining VKA treatment had no overall survival advantage over a 5-year observation period (HR 0.99, 95% CI 0.45, 1.55). The estimated gain in quality-adjusted life years (QALYs) was 0.003 over the 5-year period at an incremental costs of CHF 23 033 (€ 20 940). The estimated incremental cost-effectiveness ratio was CHF 425 852 (€ 387 138) per QALY gained.

CONCLUSIONS

Applying a causal inference method to real-world data, we could not demonstrate switching to DOACs to be cost-effective for AF patients with at least 1 year of VKA treatment. Our estimates align with results from a previous randomised trial.

Heterogeneity after harmonisation: A retrospective cohort study of bleeding and stroke risk after the introduction of direct oral anticoagulants in four Western European countries

PURPOSE

Database heterogeneity can impact effect estimates. Harmonisation provided by common protocols and common data models (CDMs) can increase the validity of pharmacoepidemiologic research. In a case study measuring the changes in the safety and effectiveness of stroke prevention therapy after the introduction of direct oral anticoagulants (DOACs), we performed an international comparison.

METHODS

Using data from Stockholm, Denmark, Scotland and Norway, harmonised with a common protocol and CDM, two calendar-based cohorts were created: 2012 and 2017. Patients with a diagnosis code of atrial fibrillation 5 years preceding the 1-year cohort window were included. DOAC, vitamin K antagonist and aspirin treatment were assessed in the 6 months prior to the start of each year while strokes and bleeds were assessed during the year. A Poisson regression generated incidence rate ratios (IRRs) to compare outcomes from 2017 to 2012 adjusted for changes in individual-level baseline characteristics.

RESULTS

In 280 359 patients in the 2012 cohort and 356 779 in the 2017 cohort, treatment with OACs increased on average from 45% to 65%, while treatment with aspirin decreased from 30% to 10%. In all countries except Scotland, there were decreases in the risk of stroke and no changes in bleeding risk, after adjustment for changes in baseline characteristics. In Scotland, major bleeding (IRR 1.09, 95% confidence interval [CI] [1.00; 1.18]) and intracranial haemorrhage (IRR 1.31, 95% CI [1.13; 1.52]) increased from 2012 to 2017.

CONCLUSIONS

Stroke prevention therapy improved from 2012 to 2017 with a corresponding reduction in stroke risk without increasing the risk of bleeding in all countries, except Scotland. The heterogeneity that remains after methodological harmonisation can be informative of the underlying population and database.

Systematic Review and Meta-Analysis of Direct Oral Anticoagulants Versus Warfarin in Atrial Fibrillation With Low Stroke Risk

Pivotal trials comparing direct oral anticoagulants (DOACs) against warfarin in patients with atrial fibrillation (AF) predominantly involved patients with high stroke risk. This study aimed to evaluate the efficacy and safety of DOAC versus warfarin in patients with low stroke risk. An online literature search was conducted to retrieve studies comparing clinical outcomes between patients treated with DOAC versus warfarin for AF, reporting outcomes for patients at low or minimal risk of stroke (CHA2DS2-VASc scores ranging from 0 to 2 or CHADS2 scores ranging from 0 to 1). The primary outcome was the occurrence of stroke or systemic embolism. Secondary outcomes included major bleeding, intracranial hemorrhage, and all-cause mortality. Hazard ratios for all outcomes were pooled in random-effects meta-analyses. A network meta-analysis of individual DOACs versus warfarin was also conducted. In total, 11 studies (132,980 patients) were included. DOAC was associated with a significantly lower risk of stroke or systemic embolism (hazard ratio 0.85, 95% confidence interval 0.75 to 0.96, p = 0.008, I2 = 0%), major bleeding, intracranial hemorrhage, and mortality compared with warfarin. This benefit persisted even when study arms which had CHA2DS2-VASc scores of 2 were excluded. When restricted to 3 studies investigating only patients with a single nongender-related stroke risk factor, significant benefit was seen only for the outcome of major bleeding. In the network meta-analysis, only dabigatran was superior to warfarin for all 4 outcomes. In conclusion, DOACs should be the standard of care in low-risk patients with AF who require anticoagulation. In particular, dabigatran appears to have the best balance of stroke prevention and reduction in major bleeding.

Prescribing of low-dose rivaroxaban in patients with atherosclerotic cardiovascular disease in the United Kingdom and the Netherlands

AIMS

Low-dose rivaroxaban has been indicated for the management of atherosclerotic cardiovascular disease (ASCVD) after recent (2019-2020) updates to European guidelines. We aimed to describe prescription trends of low-dose rivaroxaban in ASCVD patients over the period 2015-2022 in two European countries, to compare the trends before and after guideline changes, and to determine the characteristics of users.

METHODS

In a cross-sectional interrupted time series analysis, utilization of low-dose rivaroxaban (2.5 mg, twice daily) was measured in Clinical Practice Research Datalink Aurum (United Kingdom [UK]) and the PHARMO Database Network (the Netherlands) from 1 January 2015 to 28 February 2022 in patients with an ASCVD diagnosis. Incidence rates (IRs) and incidence rate ratios (IRRs) of new use (within 182 days) compared to the reference period, 2015-2018, were calculated. Age, sex and comorbidities of users were compared to those of nonusers.

RESULTS

In the UK, from 721 271 eligible subjects the IR of new use of low-dose rivaroxaban in the period 2015-2018, before guideline changes, was 12.4 per 100 000 person-years and after guideline changes in 2020-2022 was 124.0 (IRR 10.0, 95% confidence interval [CI] 8.5, 11.8). In the Netherlands from 394 851 subjects, the IR in 2015-2018 was 2.4 per 100 000 person-years and in 2020 was 16.3 (IRR 6.7, 95% CI 4.0, 11.4). Users were younger (UK mean difference [MD] -6.1 years, Netherlands -2.4 years; P < .05) and more likely to be male (UK difference 11.5%, Netherlands 13.4%; P < .001) than nonusers.

CONCLUSIONS

There was a statistically significant increase in the use of low-dose rivaroxaban for the management of ASCVD after guideline changes in the UK and the Netherlands. There were international differences, but low-dose rivaroxaban has not been put into widespread practice.

Management of Gastrointestinal Bleeding and Resumption of Oral Anticoagulant Therapy in Patients with Atrial Fibrillation: A Multidisciplinary Discussion

Direct oral anticoagulants (DOACs) are recommended for the prevention of thromboembolism in patients with atrial fibrillation (AF), and are now preferred over vitamin K antagonists due to their beneficial efficacy and safety profile. However, all oral anticoagulants carry a risk of gastrointestinal (GI) bleeding. Although the risk is well documented and acute bleeding well codified, there is limited high-quality evidence and no guidelines to guide physicians on the optimal management of anticoagulation after a GI bleeding event. The aim of this review is to provide a multidisciplinary critical discussion of the optimal management of GI bleeding in patients with AF receiving oral anticoagulants to help physicians provide individualized treatment for each patient and optimize outcomes. It is important to perform endoscopy when a patient presents with bleeding manifestations or hemodynamic instability to determine the bleed location and severity of bleeding and then perform initial resuscitation. Administration of all anticoagulants and antiplatelets should be stopped and bleeding allowed to resolve with time; however, anticoagulant reversal should be considered for patients who have life-threatening bleeding or when the bleeding is not controlled by the initial resuscitation. Anticoagulation needs to be timely resumed considering that bleeding risk outweighs thrombotic risk when anticoagulation is resumed early after the bleeding event. To prevent further bleeding, physicians should prescribe anticoagulant therapy with the lowest risk of GI bleeding, avoid medications with GI toxicity, and consider the effect of concomitant medications on potentiating the bleeding risk.

Effect of tramadol and DOACs with special attention to dabigatran on concomitant use, on the risk of mayor bleeding using BIFAP database in Spain

BACKGROUND

Tramadol, a weak opioid, inhibits the reuptake of serotonin, a key feature on vascular homeostasis. A suspected interaction exists between dabigatran and tramadol, which might trigger an excess on risk of bleeding however, there is a gap in knowledge on this topic.

PURPOSE

To estimate the effects of tramadol, dabigatran and concomitant use on the risk of hospitalized major bleeds (Gastrointestinal bleeding and intra-extracranial bleeds).

METHODS

Among a validated established cohort of new users of oral anticoagulants for non-valvular atrial fibrillation (NVAF) aged 18 years or older, we identified all hospitalized bleed episodes (GIB and extra/intracranial bleeds) within 2008-2015. A nested case-control analysis was conducted using conditional logistic regression. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were calculated for dabigatran, tramadol, and concomitant use. Several sensitivity analyses were carried out.

RESULTS

aORs (95%CIs) for current use of only dabigatran, only tramadol and concomitant users were 1.73 (1.37-2.18) and 1.38 (1.13-1.67) and 2.04 (0.74-5.67) compared with non-users of both drugs (>365 days). aORs for current continuers and non-continuer users of dabigatran were 1.36 (1.00-1.86) and 2.19 (1.61-2.98), respectively. For the latter, non-continuer users with a short duration of dabigatran cumulated the highest risk (3.36 [1.88-5.99]). There also was an increased risk with concomitant use of tramadol and rivaroxaban (2.24 [1.19-4.21]), or antagonist of vitamin K (1.30 [1.00-1.69]).

CONCLUSION

There was a trend towards and increased risk of excess bleeds when using concomitantly with dabigatran. The effect decreases with a narrower definition of current use.

Head-to-head efficacy and safety of rivaroxaban, apixaban, and dabigatran in an observational nationwide targeted trial

AIMS

The advantages of direct oral anticoagulants (DOACs) over warfarin are well established in atrial fibrillation (AF) patients, however, studies that can guide the selection between different DOACs are limited. The aim was to compare the clinical outcomes of treatment with apixaban, rivaroxaban, and dabigatran in patients with AF.

METHODS AND RESULTS

We conducted a retrospective, nationwide, propensity score-matched-based observational study from Clalit Health Services. Data from 141 992 individuals with AF was used to emulate a target trial for head-to-head comparison of DOACs therapy. Three-matched cohorts of patients assigned to DOACs, from January-2014 through January-2020, were created. One-to-one propensity score matching was performed. Efficacy/safety outcomes were compared using KaplanMeier survival estimates and Cox proportional hazards models. The trial included 56 553 patients (apixaban, n = 35 101; rivaroxaban, n = 15 682; dabigatran, n = 5 770). Mortality and ischaemic stroke rates in patients treated with rivaroxaban were lower compared with apixaban (HR,0.88; 95% CI,0.78-0.99; P,0.037 and HR 0.92; 95% CI,0.86-0.99; P,0.024, respectively). No significant differences in the rates of myocardial infarction, systemic embolism, and overall bleeding were noticed between the different DOACs groups. Patients treated with rivaroxaban demonstrated lower rate of intracranial haemorrhage compared with apixaban (HR,0.86; 95% CI,0.74-1.0; P,0.044). The rate of gastrointestinal bleeding in patients treated with rivaroxaban was higher compared with apixaban (HR, 1.22; 95% CI,1.01-1.44; P, 0.016).

CONCLUSION

We demonstrated significant differences in outcomes between the three studied DOACs. The results emphasize the need for randomized controlled trials that will compare rivaroxaban, apixaban, and dabigatran in order to better guide the selection among them.

Gastrointestinal Bleeding on Oral Anticoagulation: What is Currently Known

Gastrointestinal bleeding (GIB) is the most common type of bleeding occurring in patients on oral anticoagulation. A meta-analysis of the landmark randomized controlled trials (RCTs) for patients with atrial fibrillation demonstrated that direct oral anticoagulants (DOACs) were associated with higher GIB rates compared to warfarin. However, significant heterogeneity existed between studies. While rivaroxaban, high-dose dabigatran, and high-dose edoxaban were associated with higher GIB rates than warfarin, GIB rates were similar between warfarin users and both apixaban and low-dose dabigatran users. Additionally, previous observational studies have yielded conflicting reports on whether GIB rates differ between warfarin and DOACs. Meta-analyses of observational studies demonstrated that warfarin is associated with lower rates of GIB compared to rivaroxaban, similar or lower rates compared to dabigatran, and higher rates compared to apixaban. Importantly, no RCT has compared individual DOACs directly and due to the different selection criteria of the initial RCTs, indirect comparisons between DOACs using these studies are unreliable. The best available information of comparisons between individual DOACs is therefore limited to observational studies. There is mounting evidence that suggests that rivaroxaban is associated with a higher risk of GIB compared to other DOACs. Finally, GIB induced by oral anticoagulation may have some positive aspects. Interestingly, there are studies that indicate oral anticoagulation facilitates colorectal cancer detection. Furthermore, results from RCTs and observational studies suggest that warfarin may even decrease the incidence of cancer.

Safety and efficacy of endovascular thrombectomy in acute ischemic stroke treated with anticoagulants: a systematic review and meta-analysis

Background

Endovascular thrombectomy (EVT) is an effective therapy in acute ischemic stroke (AIS) with large vessel occlusion, especially for those who are unsuitable for intravenous thrombolysis. However, the safety and efficacy of EVT in AIS patients who receiving oral anticoagulants (OACs) is unclear, especially for the risk of symptomatic intracranial hemorrhage (sICH). 

Methods

Database of PubMed, Embase, and Cochrane Library were searched from Jan 1, 2000, through the final search date of Jun 2, 2021. Eligible studies for enrollment required outcomes reported for events of sICH, mortality, functional status, and successful reperfusion. Meta-analysis was conducted to compare the outcomes difference after EVT between AIS patients with or without OACs use. The primary safety outcome was sICH after EVT, and the primary efficacy outcome was functional status at 3 months. 

Results

One thousand nine hundred forty studies were screened for eligibility and 15 of them were included in the meta-analysis. Compared the OACs group to control arm, vitamin K antagonists (VKAs) was associated with higher risk of sICH (OR 1.49, 95% CI 1.10–2.02) and mortality (OR 1.67, 95% CI 1.35–2.06). Poor functional outcomes were noted both in the VKAs and direct oral anticoagulants (DOACs) groups (OR 0.62, 95% CI 0.54–0.71 and OR 0.61, 95% CI 0.53–0.71, respectively). No differences in successful reperfusion were observed.

Conclusions

Comparing with DOACs, VKAs use was associated with a higher risk of sICH and mortality after EVT. Patients who did not receive OACs exhibited more favorable outcomes. The successful reperfusion did not differ between groups. However, results for mortality and functional outcomes have to be interpreted with caution since they are based on non-randomized data and unadjusted proportions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00394-y.

Effectiveness and Safety of Dabigatran Compared to Vitamin K Antagonists in Non-Asian Patients with Atrial Fibrillation: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Real-life data about the use of dabigatran in patients with non-valvular atrial fibrillation are warranted. The objective of this systematic review and meta-analysis was to assess the effectiveness and safety of dabigatran, globally and stratified by dose (110/150 mg twice daily), vs vitamin K antagonists in non-Asian patients with non-valvular atrial fibrillation from "real-world" studies.

METHODS

A systematic review was performed according to Cochrane methodological standards. The results were reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement) statement. The ROBINS-I tool was used to assess bias risk. MEDLINE and EMBASE, from inception up to May 2021, using appropriate controlled vocabulary and free search terms, were searched.  RESULTS: A total of 34 studies, corresponding to 37 articles involving 1,600,722 participants (1,154,283 exposed to vitamin K antagonists and 446,439 to dabigatran) were eligible for this review. Dabigatran 150 mg reduced the risk of ischemic stroke compared with vitamin K antagonists, with a 14% risk reduction (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.74-0.98). Globally, dabigatran reduced the risk of all-cause mortality compared with vitamin K antagonists (HR 0.76, 95% CI 0.69-0.84), with a greater effect observed with dabigatran 150 mg (HR 0.65, 95% CI 0.58-0.73). There was a trend towards a lower risk of myocardial infarction with dabigatran 150 mg (HR 0.86, 95% CI 0.71-1.04). Regarding the primary safety outcomes, dabigatran (either at a dose of 150 mg or 110 mg) reduced the risk of major bleeding compared with vitamin K antagonists (HR 0.77, 95% CI 0.70-0.83), as well as the risk of intracranial bleeding (HR 0.44, 95% CI 0.39-0.50) and fatal bleeding (HR 0.76, 95% CI 0.60-0.95), but with a slight increase in gastrointestinal bleeding risk (HR 1.16, 95% CI 1.08-1.26).

CONCLUSIONS

Dabigatran has a favorable impact on effectiveness and safety outcomes compared with vitamin K antagonists in real-world populations.

[Pathophysiology of bleeding]

Bleeding is associated with an increased morbidity and mortality. Anatomic and hemostatic causes play a central role in the pathophysiology of bleeding, with anatomic causes being by far more common. While trauma and invasive procedures are the leading causes of bleeding in surgical disciplines, gastrointestinal bleeding is the major cause of bleeding in internal medicine. Major bleedings lead to secondary homeostatic changes, which in turn not only contribute to further bleeding, but also to the pathogenesis of organ dysfunction. Acquired coagulopathies due to antithrombotic treatment or an underlying disease also contribute to the extent and the dynamics of bleeding, while hereditary bleeding disorders are seldom. The balance between the physiological pro- and anticoagulant pathway plays a significant role in the pathophysiology of bleeding and coagulation. Therefore, the pathophysiology of bleeding cannot be described by means of easily available laboratory coagulation workup. The aim of coagulation correction during the management of life-threatening bleeding is not to normalize coagulation, but rather to stop bleeding. Besides a careful clinical evaluation of the course of bleeding coupled with basic understanding of the physiology of coagulation, targeted laboratory coagulation workup can contribute to a rational coagulation treatment concept.

Adverse event rates associated with oral anticoagulant treatment early versus later after hospital discharge in older adults: a retrospective population-based cohort study

BACKGROUND

Oral anticoagulants are commonly used high-risk medications, but little is known about their safety in transition from hospital to home. Our objective was to measure the rates of hemorrhage and thromboembolic events among older adults receiving oral anticoagulant treatment early after hospital discharge compared to later.

METHODS

We conducted a retrospective population-based cohort study among Ontario residents aged 66 years or more who started, continued or resumed oral anticoagulant therapy at hospital discharge between September 2010 and March 2015. We calculated the rates of hemorrhage and thromboembolic events requiring hospital admission or an emergency department visit over a 1-year follow-up period, stratified by the first 30 days after discharge and the remainder of the year. We used multivariable regression models, adjusting for covariates, to estimate the effect of sex, prevalent versus incident use, and switching anticoagulants on events.

RESULTS

A total of 123 139 patients (68 408 women [55.6%]; mean age 78.2 yr) were included. About one-quarter (32 563 [26.4%]) had a Charlson Comorbidity Index score of 2 or higher. The rates of hemorrhage and thromboembolic events per 100 person-years were highest during the first 30 days after hospital discharge (25.8, 95% CI 24.8-26.8 and 19.3, 95% CI 18.4-20.2, respectively), falling to 15.7 (95% CI 15.3-16.1) and 6.9 (95% CI 6.6-7.1), respectively, during the subsequent 11 months. Multivariable analysis showed that patients whose anticoagulant was switched in hospital and men had more hemorrhages and thromboembolic events in follow-up.

INTERPRETATION

The first few weeks following hospital discharge represent a very high-risk period for adverse events related to oral anticoagulant treatment among older adults. The results support an intervention trial addressing anticoagulation management in the early postdischarge period.