Comparative risk of gastrointestinal bleeding with dabigatran, rivaroxaban, and warfarin: population based cohort study

Comparative safety and effectiveness of oral anticoagulants in patients with non-valvular atrial fibrillation and high risk of gastrointestinal bleeding: A nationwide French cohort study

BACKGROUND

This observational study compared effectiveness and safety of direct oral anticoagulants (DOACs; apixaban, rivaroxaban, dabigatran) or vitamin K antagonists (VKAs) in patients with non-valvular atrial fibrillation (NVAF) at high risk for gastrointestinal bleeding (GIB).

METHODS

Anticoagulant-naïve adults with NVAF with ≥1 GIB risk factor, initiating anticoagulant treatment January 2016-December 2019, and covered by the French national health data system were eligible. Outcomes included major bleeding (MB) and stroke/systemic embolism (SE). Patient characteristics were balanced using propensity score matching.

RESULTS

A total of 314,184 patients were identified with 162,150 (51.5%) in the apixaban cohort, 88,427 (28.1%) in the rivaroxaban cohort, 16,465 (5.2%) in the dabigatran cohort, and 47,142 (15.0%) in the VKA cohort (mean age 79.0 years, standard deviation 10.5; 51.0% female). A total of 45,124 apixaban-VKAs, 38,737 rivaroxaban-VKAs, 16,415 dabigatran-VKAs, 88,414 apixaban-rivaroxaban, 16,464 apixaban-dabigatran, and 16,459 rivaroxaban-dabigatran pairs were retained after propensity score matching. Apixaban had lower risk of MB versus dabigatran (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.63-0.83) and rivaroxaban (HR, 0.63; 95% CI, 0.59-0.66). Apixaban had lower risk of GIB versus dabigatran (HR, 0.46; 95% CI, 0.37-0.56) and rivaroxaban (HR, 0.54; 95% CI, 0.49-0.59). Risk of GIB was similar with dabigatran versus rivaroxaban (HR, 1.05; 95% CI, 0.89-1.24). Apixaban had lower risk of stroke/SE versus rivaroxaban (HR, 0.90; 95% CI, 0.84-0.96), while risk was similar versus dabigatran (HR, 1.1; 95% CI, 0.9-1.3). All DOACs had lower risk of MB and stroke/SE versus VKAs (p<0.001 for all).

CONCLUSIONS

DOACs had improved safety and effectiveness from bleeding and stroke/SE, respectively, versus VKAs among patients with NVAF at high risk for GIB. Apixaban was associated with lower MB and GIB risk versus other DOACs. For stroke/SE, apixaban was associated with reduced risk versus rivaroxaban and similar risk versus dabigatran.

Antithrombotics and Gastrointestinal Prophylaxis: A Systematic Review

Antithrombotic medications include both antiplatelet and anticoagulants and are used for a wide variety of cardiovascular conditions. A common complication of antithrombotic use is gastrointestinal bleeding. As a result, gastrointestinal prophylaxis is a common consideration for patients on a single or combination antithrombotic regimen. Prophylaxis is typically achieved through use of either proton pump inhibitors or histamine 2 receptor antagonists. Current recommendations for use of gastrointestinal prophylaxis with concomitant use of antithrombotic medications are scarce. In this systematic review, we explore the current evidence and recommendations regarding gastrointestinal prophylaxis for patients on antiplatelet or anticoagulant therapy as well as combination regimens.

Real-World Risk of Gastrointestinal Bleeding for Direct Oral Anticoagulants and Warfarin Users: A Distributed Network Analysis Using a Common Data Model

Background/Aims

Early studies on direct oral anticoagulants (DOACs) reported a higher risk of gastrointestinal bleeding (GIB) compared with warfarin; however, recent studies have reported a reduced risk. Therefore, this study was designed to evaluate the risk of GIB in users of DOAC and warfarin.

Methods

Using a common data model, we investigated the comparative risk of GIB in subjects from eight hospitals who were newly prescribed DOACs or warfarin. We excluded subjects who had a prior history of GIB or had been prescribed both medications. After propensity score matching, we analyzed 3,347 matched pairs of new DOAC and new warfarin users.

Results

The risk of GIB in new DOAC users was comparable to that in new warfarin users (hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.65 to 1.40; p=0.808). New DOAC users had a similar risk of GIB to new warfarin users among older patients >65 years (HR, 1.00; 95% CI, 0.69 to 1.52; p=0.997) and in older patients >75 years (HR, 1.21; 95% CI, 0.68 to 2.10; p=0.509). In addition, the risk of GIB was not significantly different between two groups according to sex. We also found that the risk of GIB in DOAC users was 26% lower in edoxaban or apixaban subgroups compared to rivaroxaban or dabigatran subgroups (HR, 0.74; 95% CI, 0.69 to 1.00; p=0.049).

Conclusions

In real-world practice, the risk of GIB in new DOAC users is comparable to that in new warfarin users. In DOAC users, the risk of GIB was lower in edoxaban or apixaban subgroups than rivaroxaban or dabigatran subgroups.

Comparative effectiveness of warfarin management strategies: a systematic review and network meta-analysis

Background

The management of warfarin therapy presents clinical challenges due to its narrow therapeutic index. We aimed to evaluate the comparative effectiveness of different management strategies in patients using warfarin.

Methods

PubMed, Embase, Cochrane CENTRAL, CINAHL, and EBSCO Open Dissertation were searched from inception to 8 May 2024. Randomized controlled trials that compared the following interventions: patient self-management (PSM), patient self-testing (PST), anticoagulation management services (AMS), and usual care in patients prescribed warfarin for any indication were included. Risk ratios (RR) with 95% confidence interval (CI) were estimated using a random-effects model. Surface under the cumulative ranking curves (SUCRA) were used to rank different interventions. The certainty of evidence was assessed using the Confidence in Network Meta-Analysis (CINeMA) online platform. This study is registered with PROSPERO (CRD42023491978).

Findings

Twenty-eight trials involving 8100 participants were included, with follow-up periods of 1-24 months. Mean warfarin dosages were 4.9-7.2 mg/day. Only PSM showed a significant reduction of major TE risk compared with usual care (RR = 0.41; 95% CI: 0.24, 0.71; I2 = 0.0%) with moderate certainty of evidence. The 97.6% SUCRA also supported the beneficial effects of PSM over other interventions. The combined direct and indirect evidence showed significantly higher TTR in PSM compared with usual care (MD = 7.39; 95% CI: 2.39, 12.39), with very low certainty. However, direct evidence showed non-significant TTR improvement (MD = 6.49; 95% CI: -3.09, 16.07, I2 = 96.1%). No differences across various strategies were observed in all-cause mortality, major bleeding, stroke, transient ischemic attack, and hospitalization.

Interpretation

PSM reduces the risk of major TE events compared with usual care, tends to improve anticoagulation control, and should be considered where appropriate.

Funding

Agency for Healthcare Research and Quality (grant ID 5R18HS027960).

Coagulation Tests and Reversal Agents in Patients Treated with Oral Anticoagulants: The Challenging Scenarios of Life-Threatening Bleeding and Unplanned Invasive Procedures

In clinical practice, the number of patients treated with direct oral anticoagulants (DOACs) has consistently increased over the years. Since anticoagulant therapy has been associated with an annual incidence of major bleeding (MB) events of approximately 2% to 3.5%, it is of paramount importance to understand how to manage anticoagulated patients with major or life-threatening bleeding. A considerable number of these patients' conditions necessitate hospitalization, and the administration of reversal agents may be imperative to manage and control bleeding episodes effectively. Importantly, effective strategies for reversing the anticoagulant effects of DOACs have been well recognized. Specifically, idarucizumab has obtained regulatory approval for the reversal of dabigatran, and andexanet alfa has recently been approved for reversing the effects of apixaban or rivaroxaban in patients experiencing life-threatening or uncontrolled bleeding events. Moreover, continuous endeavors are being made to develop supplementary reversal agents. In emergency scenarios where specific reversal agents might not be accessible, non-specific hemostatic agents such as prothrombin complex concentrate can be utilized to neutralize the anticoagulant effects of DOACs. However, it is paramount to emphasize that specific reversal agents, characterized by their efficacy and safety, should be the preferred choice when suitable. Moreover, it is worth noting that adherence to the guidelines for the reversal agents is poor, and there is a notable gap between international recommendations and actual clinical practices in this regard. This narrative review aims to provide physicians with a practical approach to managing specific reversal agents.

ISCHEMIC STROKE AND MAJOR BLEEDING WHILE ON DIRECT ORAL ANTICOAGULANTS IN NAÏVE PATIENTS WITH ATRIAL FIBRILLATION: IMPACT OF RESUMPTION OR DISCONTINUATION OF ANTICOAGULANT TREATMENT. A population-based study

AIMS

We assessed the cumulative incidence of recurrent stroke, major bleeding and all-cause mortality associated with restarting antithrombotic treatment, in patients experiencing an anticoagulation-related event (stroke or major bleeding), occurred during anticoagulation therapy for AF.

METHODS AND RESULTS

We performed a retrospective population-based analysis on linked claims data of patients resident in the Veneto Region, treated with DOACs for AF and discharged (2013-2020) from the hospital for stroke, intracranial haemorrhage (ICH), and major bleeding. To adjust for competing risk of death and reduce confounding, we started the follow up after a 120-days blanking period, counting events in patients resuming oral anticoagulation versus those that did not. Risks of all-cause mortality, ischemic stroke (IS)intracranial haemorrhage (ICH), and other major bleeding events (MB) were estimated with multivariable Cox proportional hazard models and propensity score to adjust for differences in baseline characteristics. Overall, 1029 patients (mean age 77 years) were included in the final cohort: 23% experienced an IS, 18% an ICH, and 59% MB. Of these, 77% resumed anticoagulation. The cumulative incidence of events was significantly lower in patients resuming therapy. In the multivariable analysis considering age, sex and propensity score as covariates, resumption of anticoagulation significantly reduced the risk of a cumulative event (HR 0.45, 95%CI 0.35-0.57, p < 0.01). Stratifying for the index event, among patients with IS (92% resumed therapy), we observed a risk reduction of 81%; in patients with ICH (64% resumed therapy), we observed a risk reduction of 64% and for patients with MB (76% resuming therapy), we observed a risk reduction of 49%.

CONCLUSIONS

In patients with AF who experienced an anticoagulation-related event, resuming oral anticoagulation was associated with better outcomes for all-cause mortality and subsequent events as compared with patients who did not resume treatment.

CURRENT PHARMACOLOGICAL MANAGEMENT IN UPPER GASTROINTESTINAL BLEEDING

Upper gastrointestinal bleeding is a common reason for presentation to the hospital. Appropriate resuscitation followed by endoscopic assessment and endotherapy for high-risk lesions (active bleeding or non-bleeding with visible vessels) forms the cornerstone of management. Pharmacological therapies are utilised at each stage of management in both variceal and non-variceal bleeding. Proton pump inhibitors and prokinetic agents can be administered pre-endoscopically with vasoactive medication and antibiotics utilised in suspected variceal bleeding. Epinephrine may be used as a temporising measure to improve visualisation during endoscopy but should not applied as a single agent. Topical endoscopic therapies have also shown promise in achieving haemostasis. Following endoscopy, a high dose of proton pump inhibitor should be given to patients who require endotherapy and vasoactive medications, and antibiotics continued in confirmed variceal bleeds. The timing of resumption of antithrombotic medication is dependent on the agent utilised and underlying thrombotic risk.

Noninvasive Colorectal Cancer Prevention Options in Older Adults

Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide and its incidence increases with age. The proportion of older adults in the United States continues to rise, making CRC prevention a key health priority for our aging population. CRC is a largely preventable disease through screening and polyp surveillance, and noninvasive modalities represent an important option for older adults in whom the burdens and risks of invasive testing are higher compared with younger adults. This review highlights the evidence, risks, and benefits of noninvasive CRC screening and surveillance options in older adults and discusses the challenges of CRC prevention in this cohort.

Proton pump inhibitors and gastroprotection in patients treated with antithrombotic drugs: A cardiologic point of view

Aspirin, other antiplatelet agents, and anticoagulant drugs are used across a wide spectrum of cardiovascular and cerebrovascular diseases. A concomitant proton pump inhibitor (PPI) treatment is often prescribed in these patients, as gastrointestinal complications are relatively frequent. On the other hand, a potential increased risk of cardiovascular events has been suggested in patients treated with PPIs; in particular, it has been discussed whether these drugs may reduce the cardiovascular protection of clopidogrel, due to pharmacodynamic and pharmacokinetic interactions through hepatic metabolism. Previously, the concomitant use of clopidogrel and omeprazole or esomeprazole has been discouraged. In contrast, it remains less known whether PPI use may affect the clinical efficacy of ticagrelor and prasugrel, new P2Y12 receptor antagonists. Current guidelines recommend PPI use in combination with antiplatelet treatment in patients with risk factors for gastrointestinal bleeding, including advanced age, concurrent use of anticoagulants, steroids, or non-steroidal anti-inflammatory drugs, and Helicobacter pylori (H. pylori) infection. In patients taking oral anticoagulant with risk factors for gastrointestinal bleeding, PPIs could be recommended, even if their usefulness deserves further data. H. pylori infection should always be investigated and treated in patients with a history of peptic ulcer disease (with or without complication) treated with antithrombotic drugs. The present review summarizes the current knowledge regarding the widespread combined use of platelet inhibitors, anticoagulants, and PPIs, discussing consequent clinical implications.

Management of Patients With Acute Lower Gastrointestinal Bleeding: An Updated ACG Guideline

Acute lower gastrointestinal bleeding (LGIB) is a common reason for hospitalization in the United States and is associated with significant utilization of hospital resources, as well as considerable morbidity and mortality. These revised guidelines implement the Grading of Recommendations, Assessment, Development, and Evaluation methodology to propose recommendations for the use of risk stratification tools, thresholds for red blood cell transfusion, reversal agents for patients on anticoagulants, diagnostic testing including colonoscopy and computed tomography angiography (CTA), endoscopic therapeutic options, and management of antithrombotic medications after hospital discharge. Important changes since the previous iteration of this guideline include recommendations for the use of risk stratification tools to identify patients with LGIB at low risk of a hospital-based intervention, the role for reversal agents in patients with life-threatening LGIB on vitamin K antagonists and direct oral anticoagulants, the increasing role for CTA in patients with severe LGIB, and the management of patients who have a positive CTA. We recommend that most patients requiring inpatient colonoscopy undergo a nonurgent colonoscopy because performing an urgent colonoscopy within 24 hours of presentation has not been shown to improve important clinical outcomes such as rebleeding. Finally, we provide updated recommendations regarding resumption of antiplatelet and anticoagulant medications after cessation of LGIB.

Warfarin Is Associated With Higher Rates of Upper But Not Lower Gastrointestinal Bleeding Compared with Direct Oral Anticoagulants: A Population-Based Propensity-Weighted Cohort Study

BACKGROUND AND AIMS

While overall gastrointestinal bleeding (GIB) rates have been extensively compared between warfarin and direct oral anticoagulants (DOACs), it is still unclear whether upper and lower GIB rates differ between these types of drugs. This study aimed to compare upper and lower GIB rates between warfarin and DOACs in a nationwide cohort.

METHODS

Data on all patients in Iceland who received a prescription for oral anticoagulation from 2014 to 2019 were collected and their personal identification numbers linked to the electronic medical record system of the National University Hospital of Iceland and the 4 regional hospitals in Iceland. Inverse probability weighting was used to yield balanced study groups and rates of overall, major, upper, and lower GIB were compared using Cox regression. All GIB events were manually confirmed by chart review.

RESULTS

Warfarin was associated with higher rates of upper GIB (1.7 events per 100 person-years vs 0.8 events per 100 person-years; hazard ratio [HR], 2.12; 95% confidence interval [CI], 1.26-3.59) but similar rates of lower GIB compared with DOACs. Specifically, warfarin was associated with higher rates of upper GIB compared with apixaban (HR, 2.63; 95% CI, 1.35-5.13), dabigatran (5.47; 95% CI, 1.87-16.05), and rivaroxaban (HR, 1.74; 95% CI, 1.00-3.05). Warfarin was associated with higher rates of major GIB compared with apixaban (2.3 events per 100 person-years vs 1.5 events per 100 person-years; HR, 1.79; 95% CI, 1.06-3.05), but otherwise overall and major GIB rates were similar in warfarin and DOAC users.

CONCLUSIONS

Warfarin was associated with higher rates of upper but not overall or lower GIB compared with DOACs. Warfarin was associated with higher rates of major GIB compared with apixaban.

Risk and Management of Bleeding Complications with Direct Oral Anticoagulants in Patients with Atrial Fibrillation and Venous Thromboembolism: a Narrative Review

Atrial fibrillation (AF) and venous thromboembolism (VTE) are highly prevalent conditions with a significant healthcare burden, and represent the main indications for anticoagulation. Direct oral anticoagulants (DOACs) are the first choice treatment of AF/VTE, and have become the most prescribed class of anticoagulants globally, overtaking vitamin K antagonists (VKAs). Compared to VKAs, DOACs have a similar or better efficacy/safety profile, with reduced risk of intracerebral hemorrhage (ICH), while the risk of major bleeding and other bleeding harms may vary depending on the type of DOAC. We have critically reviewed available evidence from randomized controlled trials and observational studies regarding the risk of bleeding complications of DOACs compared to VKAs in patients with AF and VTE. Special patient populations (e.g., elderly, extreme body weights, chronic kidney disease) have specifically been addressed. Management of bleeding complications and possible resumption of anticoagulation, in particular after ICH and gastrointestinal bleeding, are also discussed. Finally, some suggestions are provided to choose the optimal DOAC to minimize adverse events according to individual patient characteristics and bleeding risk.

A new model to predict the risk of major gastrointestinal bleeding in patients on direct oral anticoagulants (dabigatran and rivaroxaban)

AIMS

The aim of this study was to identify factors associated with gastrointestinal bleeding (GIB) in patients on direct oral anticoagulants (DOACs) and develop a risk score that would provide an effective tool for the clinical assessment of GIB.

METHODS

This was a multicentre retrospective analysis of clinical and follow-up data of patients treated with DOACs. The score was developed through logistic regression. The performance of score was evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, specificity and Hosmer-Lemeshow test.

RESULTS

The 11 903 patients had a mean age of 65.1 years. In multivariate analysis, age ≥65 years, alcohol use, history of peptic ulcer, history of major bleeding, abnormal liver function or renal function, cancer, platelet count <100 × 10⁹ /L, anaemia, and concurrent antiplatelet agent or non-steroidal anti-inflammatory drug treatment were independent risk factors for GIB, and concurrent treatment with gastrointestinal protective agents were a protective factor. The Alfalfa-DOAC-GIB score was constructed using these 12 factors. The AUC of the Alfalfa-DOAC-GIB score was 0.77 (95% CI 0.74-0.81), which was higher than that of the HAS-BLED score (0.69; 95% CI 0.65-0.72) and the New score (0.65; 95% CI 0.61-0.68).

CONCLUSIONS

Based on 12 factors, we developed a gastrointestinal bleeding risk score. The newly developed Alfalfa-DOAC-GIB score has better predictive value than the HAS-BLED score and the New score, and might be an effective tool to help reduce the occurrence of GIB in patients using DOACs.

The Evolution of Gastrointestinal Bleeding: A Holistic Investigation of Global Outputs with Bibliometric Analysis

BACKGROUND

Gastrointestinal bleeding is one of the main presentations in emergency department admissions. Although there has been much improvement in prevention, diagnosis, and treatment recently, patients with GIB still have high morbidity and mortality. This study aimed to analyze the scientific articles on gastrointestinal bleeding published between 1980 and 2020 using statistical and bibliometric methods.

METHODS

Articles about gastrointestinal bleeding published between 1980 and 2020 were downloaded using the Web of Science data base and analyzed using statistical methods. Network visualization maps were used to identify trending topics. Correlation studies were evaluated using Spearman's correlation coefficient. Nonlinear regression analysis (exponential model) was used to estimate the number of articles in future years.

RESULTS

A total of 12 568 publications about gastrointestinal bleeding were found. Forty percent (n = 5033) of these publications were articles. The top 3 contributing countries to the literature were the United States of America (1646, 32.7%), the United Kingdom (433, 9%), and Germany (391, 7.7%). The top three journals with the most publications were Gastrointestinal Endoscopy (172), American Journal of Gastroenterology (165), and Digestive Diseases and Sciences (161). The effect of countries' gross domestic product levels on article productivity on gastrointestinal bleeding was significant (r = 0. 770, P < .001).

CONCLUSION

In this comprehensive study, a summary of 5033 articles was presented. We think that these detailed analyses will be a quick source to show the past, present, and future of this subject to those who are currently working on gastrointestinal bleeding.

Mortality Rate in Upper Gastrointestinal Bleeding Associated with Anti-Thrombotic Therapy Before and During Covid-19 Pandemic

INTRODUCTION

During the last few years, a progressive higher proportion of patients have had upper gastrointestinal bleeding (UGIB) related to antithrombotic therapy. The introduction of direct oral anticoagulant (DOAC) and COVID-19 pandemic may change the incidence, mortality, and follow-up, especially in patients at high risk of bleeding.

PATIENTS AND METHODS

We studied the use of anti-thrombotic therapy (AT) in patients with upper gastrointestinal bleeding for 5 years (January 2017-December 2021) including Covid-19 pandemic period (March 2020-December 2021). We analyzed mortality rate, rebleeding rate and need for transfusion in patients with AT therapy compared with those without AT therapy and risk factors for mortality, and also the incidence of gastrointestinal bleeding in patients admitted for COVID-19 infection.

RESULTS

A total of 824 patients were admitted during Covid-19 pandemic period and 1631 before pandemic period; a total of 426 cases of bleeding were recorded in patients taking antithrombotic therapy and the frequency of antithrombotic therapy in patients with UGIB was higher in pandemic period (24.39% versus 13.8%). Unadjusted mortality was 12.21%, similar with patients with no antithrombotic treatment but age-adjusted mortality was 9.62% (28% lower). The rate of endoscopy was similar but fewer therapeutic procedures were required. Mean Hb level was 10% lower, and more than 60% of patients required blood transfusion.

CONCLUSION

Mortality was similar compared with patients with no antithrombotic therapy, fewer therapeutic endoscopies were performed and similar rebleeding rate and emergency surgery were noted. Hb level was 10% lower and a higher proportion of patients required blood transfusions. Mortality was higher in DOAC treatment group compared with VKA patients but with no statistical significance. The rate of upper gastrointestinal bleeding in Covid-19 positive hospitalized cases was 0.58%. The mortality risk in multivariate analysis was associated with GB score, with no endoscopy performed, with obscure and variceal bleeding and with LMWH versus VKA therapy.

Comparison of real-world clinical and economic outcomes in patients receiving oral anticoagulants: A retrospective claims analysis

BACKGROUND: Direct oral anticoagulants (DOACs) have become widely used for the prevention of stroke in nonvalvular atrial fibrillation (AF) and for the treatment of venous thromboembolism (VTE). Warfarin, the standard of care prior to DOACs, requires monitoring and dose adjustment to ensure patients remain appropriately anticoagulated. DOACs do not require monitoring but are significantly more expensive. We sought to examine real-world effectiveness and costs of DOACs and warfarin in patients with AF and VTE. OBJECTIVE: To examine clinical and economic outcomes. The clinical objectives were to determine the bleeding and thrombotic event rates associated with DOACs vs warfarin. The economic objectives were to determine the cost associated with these events, as well as the all-cause medical and pharmacy costs associated with DOACs vs warfarin. METHODS: This analysis was an observational, propensity-matched comparison of retrospective medical and pharmacy claims data for members enrolled in an integrated health plan between October 1, 2015, and September 30, 2020. Members who were older than 18 years of age with at least 1 30-day supply of warfarin or a DOAC filled within 30 days of a new diagnosis of VTE or nonvalvular AF were eligible for the analysis. Cox hazard ratios were used to compare differences in clinical outcomes, where paired t-tests were used to evaluate economic outcomes. RESULTS: After matching, there were 893 patients in each group. Among matched members, warfarin was associated with increased risk of nonmajor bleeds relative to apixaban (hazard ratio [HR] = 1.526; P = 0.0048) and increased risk of pulmonary embolism relative to both DOACs (apixaban: HR = 1.941 [P = 0.0328]; rivaroxaban: HR = 1.833 [P = 0.0489]). No statistically significant difference was observed in hospitalizations or in length of stay between warfarin and either DOAC. The difference-in-difference (DID) in total costs of care per member per month for apixaban and rivaroxaban relative to warfarin were $801.64 (P = 0.0178) and $534.23 (P = 0.0998) more, respectively. DID in VTE-related cost for apixaban was $177.09 less, relative to warfarin (P = 0.0098). DID in all-cause pharmacy costs for apixaban and rivaroxaban relative to warfarin were $342.47 (P < 0.0001) and $386.42 (P < 0.001) more, respectively. CONCLUSIONS: Warfarin use was associated with a significant decrease in total cost of care despite a significant increase in VTE-related costs vs apixaban. Warfarin was also associated with a significant increase in other nonmajor bleeds relative to apixaban, as well as a significant increase in pulmonary embolism relative to both DOACs. Warfarin was associated with a significant reduction in all-cause pharmacy cost compared with either DOAC. DISCLOSURES: The authors of this study have nothing to disclose.

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.

A Historical Perspective on the Reversal of Anticoagulants

There has been a landmark shift in the last several decades in the management and prevention of thromboembolic events. From the discovery of parenteral and oral agents requiring frequent monitoring as early as 1914, to the development of direct oral anticoagulants (DOACs) that do not require monitoring or dose adjustment in the late 20th century, great advances have been achieved. Despite the advent of these newer agents, bleeding continues to be a key complication, affecting 2 to 4% of DOAC-treated patients per year. Bleeding is associated with substantial morbidity and mortality. Although specific reversal agents for DOACs have lagged the release of these agents, idarucizumab and andexanet alfa are now available as antagonists. However, the efficacy of these reversal agents is uncertain, and complications, including thrombosis, have not been adequately explored. As such, guidelines continue to advise the use of nonspecific prohemostatic agents for patients requiring reversal of the anticoagulant effect of these drugs. As the indications for DOACs and the overall prevalence of their use expand, there is an unmet need for further studies to determine the efficacy of specific compared with nonspecific pro-hemostatic reversal agents. In this review, we will discuss the evidence behind specific and nonspecific reversal agents for both parenteral and oral anticoagulants.

Assessment of knowledge and practice of cardiovascular nurses regarding warfarin

BACKGROUND

Despite new anticoagulants' developments, warfarin is still one of the most commonly used medicines, particularly in the cardiovascular system. One of the significant challenges with warfarin is the prevalence of dangerous side effects such as bleeding and drug and food interactions, which can negatively affect patients if not adequately controlled. As health-care team members, nurses have a crucial role in prescribing this medicine and educating patients. In this regard, this study was conducted to determine the knowledge and practice of nurses working in the cardiovascular wards regarding warfarin.

MATERIALS AND METHODS

In this cross-sectional, descriptive study, knowledge and practice of 239 nurses working in the cardiovascular wards of teaching hospitals affiliated to Iran University of Medical Sciences have been investigated using European Cardiovascular Nurses Knowledge questionnaire on anticoagulants and the checklist for high-risk drugs safety instructions. The sampling was performed through the stratified sampling method with proportional allocation. Data were analyzed using the SPSS software version 16 through descriptive and inferential statistics (independent t-test, one-way analysis of variance, and Pearson correlation coefficient) (Inc., Chicago, IL, USA).

RESULTS

The mean scores of knowledge (18.51 ± 3.87) and practice (10.53 ± 2.12) were slightly higher than the median, and the lowest mean score was related to knowledge on drug interactions (7.62). The practice had a statistically significant relationship with knowledge (P < 0.001). Regarding demographic variables, there was a statistically significant relationship between nurses' knowledge and the education level (P = 0.009) and nurses' practice and age (P = 0.022), work experience (P = 0.032), and work experience in cardiovascular wards (P = 0.036).

CONCLUSIONS

Based on the findings of this study, the knowledge of nurses working in the cardiovascular wards about warfarin was not sufficient, and their practice was of poor quality. Nurses' lack of knowledge and improper practice can jeopardize drug safety in patients and cause serious side effects such as bleeding. Proper training of nursing students and nurses about warfarin as a high-risk drug, its side effects, and drug-food interactions, and the emphasis on patient education in patients receiving this medicine can effectively reduce the incidence of side effects.

Concurrent Use of Oral Anticoagulants and Sulfonylureas in Individuals With Type 2 Diabetes and Risk of Hypoglycemia: A UK Population-Based Cohort Study

Objective

To investigate the association of concurrent use of oral anticoagulants (OACs) and sulfonylureas and the risk of hypoglycemia in individuals with type 2 diabetes mellitus (T2DM).

Research Design and Methods

A retrospective cohort study was conducted between 2001 and 2017 using electronic primary healthcare data from the IQVIA Medical Research Data (IMRD) that incorporates data supplied by The Health Improvement Network (THIN), a propriety database of Cegedim SA. Individuals with T2DM who received OAC prescription and sulfonylureas were included. We compared the risk of hypoglycemia with sulfonylureas and OACs using propensity score matching and Cox regression.

Results

109,040 individuals using warfarin and sulfonylureas and 77,296 using direct oral anticoagulants (DOACs) and sulfonylureas were identified and included. There were 285 hypoglycemia events in the warfarin with sulfonylureas group (incidence rate = 17.8 per 1,000 person-years), while in the sulfonylureas only, 304 hypoglycemia events were observed (incidence rate = 14.4 per 1,000 person-years). There were 14 hypoglycemic events in the DOACs with sulfonylureas group (incidence rates = 14.8 per 1,000 person-years), while in the sulfonylureas alone group, 60 hypoglycemia events were observed (incidence rate =23.7 per 1,000 person-years). Concurrent use of warfarin and sulfonylureas was associated with increased risk of hypoglycemia compared with sulfonylureas alone (HR 1.38; 95% CI 1.10-1.75). However, we found no evidence of an association between concurrent use of DOACs and sulfonylureas and risk of hypoglycemia (HR 0.54; 95% CI, 0.27-1.10) when compared with sulfonylureas only.

Conclusions

We provide real-world evidence of possible drug-drug interactions between warfarin and sulfonylureas. The decision to prescribe warfarin with coexistent sulfonylureas to individuals with T2DM should be carefully evaluated in the context of other risk factors of hypoglycemia, and availability of alternative medications.

Stroke Prevention in Atrial Fibrillation: A Scientific Statement of JACC: Asia (Part 2)

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with substantial increases in the risk for stroke and systemic thromboembolism. With the successful introduction of the first non-vitamin K antagonistdirect oral anticoagulant agent (NOAC) in 2009, the role of vitamin K antagonists has been replaced in most clinical settings except in a few conditions for which NOACs are contraindicated. Data for the use of NOACs in different clinical scenarios have been accumulating in the past decade, and a more sophisticated strategy for patients with AF is now warranted. JACC: Asia recently appointed a working group to summarize the most updated information regarding stroke prevention in AF. The aim of this statement is to provide possible treatment options in daily practice. Local availability, cost, and patient comorbidities should also be considered. Final decisions may still need to be individualized and based on clinicians' discretion. This is part 2 of the statement.

Clinical outcomes of gastrointestinal bleeding management during anticoagulation therapy

Background

Acute gastrointestinal (GI) bleeding is not an uncommon complication of oral anticoagulation (OAC) therapy that requires medication cessation. However, drug cessation may cause fatal stroke or systemic embolization in patients at high thromboembolic risk. Here we sought to find an appropriate anticoagulation cessation strategy in cases of GI bleeding during OAC therapy.

Methods

This single-center retrospective cohort analysis was performed between 2010 and 2018. Patients were enrolled if the following three consecutive conditions were met: 1) electrocardiography electrocardiography-proven atrial fibrillation; 2) OAC therapy; and 3) GI bleeding. We divided the drug cessation strategy into the continuation and discontinuation groups. During 1-year follow-up, the rates of major thromboembolic and rebleeding events were calculated.

Results

One hundred and forty-six patients (continuation [n = 54] vs. discontinuation [n = 92] group) were enrolled. Patients in the discontinuation group were more likely to be older (69.8 ± 9.0 yrs vs. 74.9 ± 8.9 yrs, p = 0.001), while patients in the continuation group were more likely to have undergone cardiac valve surgery (51.9% vs. 20.7%, p<0.001). The presence of a mechanical mitral valve was a determinant of continuation strategy (38.9% vs. 7.5%, p<0.001). However, the mean CHA₂DS₂-VASc (3.4±1.3 vs. 4.1±1.6, p = 0.010) and Glasgow-Blatchford (8.0±2.4 vs. 8.9±2.5, p = 0.037) scores were higher in the discontinuation group.

Two major embolic strokes occurred in each group (3.7% vs. 2.2%, p = 0.585). Four of 54 (7.4%) and five of 92 (5.4%) patients had rebleeding events during follow-up (p = 0.632). One embolic event in the continuation group and one rebleeding event in the discontinuation group were fatal. The Glasgow-Blatchford score was a predictor of 1-year rebleeding events (odds ratio [OR], 1.36; 95% confidence interval [CI], 0.68–2.20; p = 0.028). The high CHA₂DS₂-VASc score showed a strong trend (OR, 1.71; 95% CI, 0.92–3.20; p = 0.089) in 1-year thromboembolic events.

Conclusion

No single risk factor or drug cessation strategy was attributed to adverse clinical events after GI bleeding. The risk of future thrombotic or rebleeding events should be individualized and controlled for based on a pre-existing stratification system.

Cutaneous Ulcer Caused by Apixaban Treatment Is Resolved after Replacement with Dabigatran

Nowadays, novel oral anticoagulants (NOACs) have shown improved safety profile and efficacy compared to vitamin K antagonists in the prevention of thromboembolic events occurring during different pathological conditions. However, there are concerns and safety issues, mostly related to adverse events following interactions with other drugs, in real-world practice. We report the case of an 83-year-old woman who developed a non-bleeding leg ulcer not caused by trauma or other evident pathological conditions after 10 days of treatment with apixaban 5 mg/q.d. She was switched from apixaban to dabigatran and the leg ulcer rapidly improved and completely cicatrized in 40 days. The resolution of the ulcer and the toleration of dabigatran therapy suggest an apixaban-specific reaction; however, the pathological mechanism of ulcer onset is currently unclear. Careful evaluation of hospital databases of Molise region (Southern Italy) hospitals identified two similar cases between 2019 and 2021. These cases underline the necessity of careful post-marketing surveillance, considering the rapidly increasing number of patients treated with NOACs and patient’s risk factors such as old age, high polypharmacy rate, co-morbidities, and peculiar genetic background related to NOACs pharmacokinetic features.

Role of Direct Oral Anticoagulants for Post-operative Venous Thromboembolism Prophylaxis

Venous thromboembolism (VTE) is one of the leading causes of post-operative morbidity and mortality. Over previous decades, heparin and warfarin were the predominant therapeutic options for post-operative thromboprophylaxis. However, their use is limited by drawbacks including a narrow therapeutic range, numerous food and drug interactions, and the need for regular monitoring for dose adjustments. Recently, direct oral anticoagulants (DOACs), such as dabigatran etexilate (a direct thrombin inhibitor) and apixaban, rivaroxaban and edoxaban (direct factor Xa inhibitors), have been developed to overcome these issues. DOACs have shown promising results in Phase III clinical trials for post-operative VTE prophylaxis. This review summarises the pharmacological profile of DOACs and highlights the use of DOACs in post-operative VTE prophylaxis based on the available clinical trial data.

Investigation into the Cost-Effectiveness of Extended Posttraumatic Thromboprophylaxis

BACKGROUND

Severely injured patients are at particularly high risk for venous thromboembolism (VTE). Although thromboprophylaxis (PPX) is employed during the inpatient period, patients may continue to be at high risk after discharge. Comparative evidence from surgical subspecialities (eg oncology) reveals benefits of postdischarge (ie extended) PPX. We hypothesized that an extended, postinjury oral thromboprophylaxis regimen would be cost-effective.

STUDY DESIGN

A cost-utility model compared no PPX with a 30-day course of apixaban, dabigatran, enoxaparin, fondaparinux, or rivaroxaban in trauma patients. Immediate events including deep venous thrombosis, pulmonary embolus, or bleeding within 30 days of injury were modeled in a decision tree with patients entering a Markov process to account for sequelae of VTE, including postthrombotic syndrome and chronic thromboembolic pulmonary hypertension. Effectiveness was measured in quality-adjusted life years. One-way and probabilistic sensitivity analyses were performed to identify conditions under which the preferred PPX strategy changed.

RESULTS

Rivaroxaban was the dominant strategy (ie less costly and more effective) compared with no PPX or alternative regimens, delivering 30.21 quality-adjusted life years for $404,546.38. One-way sensitivity analyses demonstrated robust preference for rivaroxaban. When examining only patients with moderate-high or high VTE Risk Assessment Profile scores, rivaroxaban remained the preferred strategy. Probabilistic sensitivity analysis demonstrated a preference for rivaroxaban in 100% of cases at a standard willingness-to-pay threshold of $100,000/quality-adjusted life year.

CONCLUSIONS

A 30-day course of rivaroxaban is a cost-effective extended thromboprophylaxis strategy in trauma patients in this theoretical study. Prospective studies of postdischarge thromboprophylaxis to prevent postinjury VTE are warranted.

Association of Direct Oral Anticoagulants (DOACs) and Warfarin With Haemorrhagic Risk by Applying Correspondence Analysis to Data From the Italian Pharmacovigilance Database - A Case Study

Introduction: Post-marketing data on the risks associated with direct oral anticoagulants (DOACs) are conflicting and only few studies evaluated a comparison between each different DOAC. Real-world data from pharmacovigilance databases can help to better define the safety profile of each DOAC and warfarin. However, Correspondence Analysis (CA) could represent a useful tool in this context. Objective: In the attempt to assess the usefulness of CA as a signal detection pharmacovigilance tool, we applied this method to the Italian Pharmacovigilance Database (RNF, Rete Nazionale di Farmacovigilanza), by comparing with disproportionality analysis on warfarin and DOACs. Methods: Study based on AEs sent to RNF by Campania Region from 2008 to 2021, in which warfarin, dabigatran, apixaban, edoxaban or rivaroxaban were reported as suspected drug. AEs were clustered into three Standardized MedDRA Queries (SMQs): Central Nervous System Haemorrhages and Conditions (CNSH), GastroIntestinal Perforation, Ulceration, Obstruction or Haemorrhages (GIPUOH) and other Haemorrhages (HH). Non-haemorrhagic AEs were included in a fourth cluster (nHH). Results: We retrieved 1,161 reports: 41.5% are associated to warfarin, 21.0% to dabigatran, 17.8% to rivaroxaban, 13.9% to apixaban and 5.8% to edoxaban. No significant differences in age distribution were observed. Results of CA showed that dabigatran and warfarin have the highest contribution (44.910 and 47.656, respectively) to the inertia of Dimension 1 as well as apixaban and dabigatran to the inertia of Dimension 2 (53.768 and 30.488, respectively). Edoxaban and rivaroxaban showed a negligible total contribution. CA biplot showed positive associations between warfarin and HH, apixaban and CNSH and dabigatran and nHH. Conclusion: Results seem to confirm that DOACs are not interchangeable. Apixaban was surprisingly associated with a higher risk of cerebral haemorrhage. As expected, our data support the better safety profile of DOACs than warfarin in terms of skin and respiratory tract hemorrhagic risks. Finally, we showed how CA could play a complementary role in analyzing data from pharmacovigilance databases.

Patient-specific and healthcare real-world costs of atrial fibrillation in individuals treated with direct oral anticoagulant agents or warfarin

BACKGROUND

Anticoagulant therapies are used to prevent atrial fibrillation-related strokes, with warfarin and direct oral anticoagulant (DOAC) the most common. In this study, we incorporate direct health care costs, drug costs, travel costs, and lost working and leisure time costs to estimate the total costs of the two therapies.

METHODS

This retrospective study used individual-level patient data from 4000 atrial fibrillation (AF) patients from North Karelia, Finland. Real-world data on healthcare use was obtained from the regional patient information system and data on reimbursed travel costs from the database of the Social Insurance Institution of Finland. The costs of the therapies were estimated between June 2017 and May 2018. Using a Geographical Information System (GIS), we estimated travel time and costs for each journey related to anticoagulant therapies. We ultimately applied therapy and travel costs to a cost model to reflect real-world expenditures.

RESULTS

The costs of anticoagulant therapies were calculated from the standpoint of patient and the healthcare service when considering all costs from AF-related healthcare visits, including major complications arising from atrial fibrillation. On average, the annual cost per patient for healthcare in the form of public expenditure was higher when using DOAC therapy than warfarin therapy (average cost = € 927 vs. € 805). Additionally, the average annual cost for patients was also higher with DOAC therapy (average cost = € 406.5 vs. € 296.7). In warfarin therapy, patients had considerable more travel and time costs due the different implementation practices of therapies.

CONCLUSION

The results indicated that DOAC therapy had higher costs over warfarin from the perspectives of the patient and healthcare service in the study area on average. Currently, the cost of the DOAC drug is the largest determinator of total therapy costs from both perspectives. Despite slightly higher costs, the patients on DOAC therapy experienced less AF-related complications during the study period.

Evidence of the Different Associations of Prognostic Factors With Censoring Across Treatment Groups and Impact on Censoring Weight Model Specification: The Example of Anticoagulation in Atrial Fibrillation

Inverse probability of censoring weights (IPCWs) may reduce selection bias due to informative censoring in longitudinal studies. However, in studies with an active comparator, the associations between predictors and censoring may differ across treatment groups. We used the clinical example of anticoagulation treatment with warfarin or a direct oral anticoagulant (DOAC) in atrial fibrillation to illustrate this. The cohort of individuals initiating an oral anticoagulant during 2010-2016 was identified from the Régie de l'assurance maladie du Québec (RAMQ) databases. The parameter of interest was the hazard ratio (HR) of the composite of stroke, major bleeding, myocardial infarction, or death associated with continuous use of warfarin versus DOACs. Two strategies for the specification of the model for estimation of censoring weights were explored: exposure-unstratified and exposure-stratified. The HR associated with continuous treatment with warfarin versus DOACs adjusted with exposure-stratified IPCWs was 1.26 (95% confidence interval: 1.20, 1.33). Using exposure-unstratified IPCWs, the HR differed by 15% in favor of DOACs (1.41, 95% confidence interval: 1.34, 1.48). Not accounting for the different associations between the predictors and informative censoring across exposure groups may lead to misspecification of censoring weights and biased estimate on comparative effectiveness and safety.

Major gastrointestinal bleeding risk with direct oral anticoagulants: Does type and dose matter? - A systematic review and network meta-analysis

The relative risk of major gastrointestinal bleeding (GIB) among different direct oral anticoagulants (DOACs) is debatable. Randomized controlled trials (RCTs) comparing DOACs with each other are lacking. We performed network meta-analysis to assess whether the risk of major GIB differs based on type and dose of DOAC. Literature search of PubMed, EMBASE and Cochrane databases from inception to August 2019, limited to English publications, was conducted to identify RCTs comparing DOACs with warfarin or enoxaparin for any indication. Primary outcome of interest was major GIB risk. We used frequentist network meta-analysis through the random-effects model to compare DOACs with each other and DOACs by dose to isolate the impact on major GIB. Twenty-eight RCTs, including 139 587 patients receiving six anticoagulants, were selected. The risk of major GIB for DOACs was equal to warfarin. Comparison of DOACs with each other did not show risk differences. After accounting for dose, rivaroxaban 20 mg, dabigatran 300 mg and edoxaban 60 mg daily had 47, 40 and 22% higher rates of major GIB versus warfarin, respectively. Apixaban 5 mg twice daily had lower major GIB compared to dabigatran 300 mg (OR, 0.63; 95% CI, 0.44-0.88) and rivaroxaban 20 mg (OR, 0.60; 95% CI, 0.43-0.83) daily. Heterogeneity was low, and the model was consistent without publication bias (Egger's test: P = 0.079). All RCTs were high-quality with low risk of bias. DOACs at standard dose, except apixaban, had a higher risk of major GIB compared to warfarin. Apixaban had a lower rate of major GIB compared to dabigatran and rivaroxaban.

Gastrointestinal Bleeding: a Cardiologist's Point of View

Oral anticoagulant therapy is widely used in different patients for the prevention and treatment of thromboembolic events: in atrial fibrillation, deep vein thrombosis/pulmonary embolism, acute coronary syndrome, in the early postoperative period after orthopedic surgery. Nowadays it is possible to use vitamin K antagonists (warfarin) as well as direct oral anticoagulants (DOAC): dabigatran, rivaroxaban, apixaban and edoxaban. The mai complication of any anticoagulant therapy is bleeding (gastrointestinal, intracranial, etc.), which seriously limits its usage. In this review the incidence of gastrointestinal bleeding (GIB) associated with oral anticoagulants intake was analyzed according to the results of both large randomized and postregistration trials. Furthermore, the effect of age on the risk of GIB development is discussed, and also aspects of the pathophysiology of gastrointestinal mucosa lesions in patients taking DOAC are considered.

Rivaroxaban Is Associated With Higher Rates of Gastrointestinal Bleeding Than Other Direct Oral Anticoagulants : A Nationwide Propensity Score-Weighted Study

BACKGROUND

Gastrointestinal bleeding (GIB) rates for direct oral anticoagulants (DOACs) and warfarin have been extensively compared. However, population-based studies comparing GIB rates among different DOACs are limited.

OBJECTIVE

To compare rates of GIB among apixaban, dabigatran, and rivaroxaban.

DESIGN

Nationwide population-based cohort study.

SETTING

Landspítali-The National University Hospital of Iceland and the 4 regional hospitals in Iceland.

PATIENTS

New users of apixaban, dabigatran, and rivaroxaban from 2014 to 2019.

MEASUREMENTS

Rates of GIB were compared using inverse probability weighting, Kaplan-Meier survival estimates, and Cox regression.

RESULTS

In total, 2157 patients receiving apixaban, 494 patients receiving dabigatran, and 3217 patients receiving rivaroxaban were compared. For all patients, rivaroxaban had higher overall rates of GIB (3.2 vs. 2.5 events per 100 person-years; hazard ratio [HR], 1.42 [95% CI, 1.04 to 1.93]) and major GIB (1.9 vs. 1.4 events per 100 person-years; HR, 1.50 [CI, 1.00 to 2.24]) compared with apixaban. Rivaroxaban also had higher GIB rates than dabigatran, with similar point estimates, although the CIs were wider and included the possibility of a null effect. When only patients with atrial fibrillation were included, rivaroxaban was associated with higher rates of overall GIB than apixaban (HR, 1.40 [CI, 1.01 to 1.94]) or dabigatran (HR, 2.04 [CI, 1.17 to 3.55]). Dabigatran was associated with lower rates of upper GIB than rivaroxaban in both analyses.

LIMITATIONS

Unmeasured confounding and small subgroup analyses.

CONCLUSION

Rivaroxaban was associated with higher GIB rates than apixaban and dabigatran regardless of treatment indication.

PRIMARY FUNDING SOURCE

Icelandic Centre for Research and Landspítali-The National University Hospital of Iceland.

The Role of Thromboxane in the Course and Treatment of Ischemic Stroke: Review

Cardiovascular diseases are currently among the leading causes of morbidity and mortality in many developed countries. They are distinguished by chronic and latent development, a course with stages of worsening of symptoms and a period of improvement, and a constant potential threat to life. One of the most important disorders in cardiovascular disease is ischemic stroke. The causes of ischemic stroke can be divided into non-modifiable and modifiable causes. One treatment modality from a neurological point of view is acetylsalicylic acid (ASA), which blocks cyclooxygenase and, thus, thromboxane synthesis. The legitimacy of its administration does not raise any doubts in the case of the acute phase of stroke in patients in whom thrombolytic treatment cannot be initiated. The measurement of thromboxane B2 (TxB2) in serum (a stable metabolic product of TxA2) is the only test that measures the effect of aspirin on the activity of COX-1 in platelets. Measurement of thromboxane B2 may be a potential biomarker of vascular disease risk in patients treated with aspirin. The aim of this study is to present the role of thromboxane B2 in ischemic stroke and to present effective therapies for the treatment of ischemic stroke. Scientific articles from the PubMed database were used for the work, which were selected on the basis of a search for “thromboxane and stroke”. Subsequently, a restriction was introduced for works older than 10 years, those concerning animals, and those without full text access. Ultimately, 58 articles were selected. It was shown that a high concentration of TXB2 may be a risk factor for ischemic stroke or ischemic heart disease. However, there is insufficient evidence to suggest that thromboxane could be used in clinical practice as a marker of ischemic stroke. The inclusion of ASA in the prevention of stroke has a beneficial effect that is associated with the effect on thromboxane. However, its insufficient power in 25% or even 50% of the population should be taken into account. An alternative and/or additional therapy could be a selective antagonist of the thromboxane receptor. Thromboxane A2 production is inhibited by estrogen; therefore, the risk of CVD after the menopause and among men is higher. More research is needed in this area.

Major bleeding in users of direct oral anticoagulants in atrial fibrillation: A pooled analysis of results from multiple population-based cohort studies

OBJECTIVE

To establish the risk of major bleeding in direct oral anticoagulant (DOAC) users (overall and by class) versus vitamin K antagonist (VKA) users, using health care databases from four European countries and six provinces in Canada.

METHODS

A retrospective cohort study was performed according to a similar protocol. First-users of VKAs or DOACs with a diagnosis of non-valvular atrial fibrillation (NVAF) were included. The main outcome of interest was major bleeding and secondary outcomes included gastrointestinal (GI) bleeding and intracranial haemorrhage (ICH). Incidence rates of events per 1000 person years were calculated. Hazard ratios (HRs) and 95% confidence intervals (95% CI) were estimated using a Cox proportional hazard regression model. Exposure and confounders were measured and analysed in a time-dependant way. Risk estimates were pooled using a random effect model.

RESULTS

421 523 patients were included. The risk of major bleeding for the group of DOACs compared to VKAs showed a pooled HR of 0.94 (95% CI: 0.87-1.02). Rivaroxaban showed a modestly increased risk (HR 1.11, 95% CI: 1.06-1.16). Apixaban and dabigatran showed a decreased risk of respectively HR 0.76 (95% CI: 0.69-0.84) and HR 0.85 (95% CI: 0.75-0.96).

CONCLUSIONS

This study confirms that the risk of major bleeding of DOACs compared to VKAs is not increased when combining all DOACs. However, we observed a modest higher risk of major bleeding for rivaroxaban, whereas for apixaban and dabigatran lower risks of major bleeding were observed compared to VKAs.

RHEDAR study: Determination of the risk of gastrointestinal hemorrhage in treatment with dabigatran, acenocoumarol and rivaroxaban

BACKGROUND AND AIM

Atrial fibrillation is a major cause of death and disability due to stroke. Vitamin K antagonist drugs are effective for prevention, but they have a narrow therapeutic range and multiple pharmacological interactions. In recent years, new therapeutic alternatives have been searched to minimize complications. The main objective is to evaluate the risk of gastrointestinal bleeding in anticoagulated patients and compare the classic treatment with new anticoagulants.

METHODS

We conducted a retrospective cohort study to determine the risk of gastrointestinal bleeding in patients treated with acenocoumarol/dabigatran/rivaroxaban, between 2012 and 2016. We compared the classic with the new anticoagulant group, and a multivariate logistic regression analysis was used to determinate the risk factors of gastrointestinal bleeding.

RESULTS

A total of 1213 patients were selected, 52.7% male patients, a mean age of 72.6 years old (± 14.563). 73.6% had atrial fibrilation. 14.5% of patients used acetylsalicylic acid, and 4% clopidogrel. 67.2% had a high-risk CHADS-2 Score, and 36.9% a high-risk HAS-BLED Score. We determined a 5.6% (68) of gastrointestinal bleeding, without differences according to anticoagulant used. The multivariate model showed a greater risk for digestive hemorrhage in patients with a previous hemorrhagic event (odds ratio [OR] = 2.422 95% confidence interval [CI]: 1.101-5.327) and the concomitant therapy with clopidogrel (OR = 2.373 95% CI: 0.996-5.652).

CONCLUSIONS

No differences were found in the risk of gastrointestinal bleeding between the different anticoagulants. A previous gastrointestinal bleeding were considered independent risk factor. The HAS-BLED score should be taken into account to make clinical decisions about to prescribe anticoagulant treatment.

Severe gastrointestinal bleeding in patients with atrial fibrillation receiving oral anticoagulants (based on REGistry of long-term AnTithrombotic TherApy – REGATTA)

Background. The rate of major bleeding in patients with atrial fibrillation receiving oral anticoagulants is 25% per year. Gastrointestinal bleedings are at least a half of major hemorrhagic complications. Currently, there is no optimal scale to calculate the risk of bleeding, and therefore the search for clinical predictors of gastrointestinal bleeding remains relevant. Aim. To assess the frequency and structure of large gastrointestinal bleeding, as well as to identify clinical predictors of their development based on long-term prospective observation of patients with atrial fibrillation receiving oral anticoagulants. Materials and methods. Data were obtained from single center prospective REGistry of long-term AnTithrombotic TherApy (REGATTA NCT043447187). Investigation based on a 20-year follow-up with 510 patients with atrial fibrillation with a high thromboembolic risk (median CHA2DS2-VASc was 4 points). The REGATTA registry assessed the frequency and structure of major gastrointestinal bleeding. Predictors of the development of 32 large gastrointestinal bleeding were identified based on the analysis of pairs with univariate and multivariate analyses. Results. The frequency of major gastrointestinal bleeding in patients with atrial fibrillation receiving oral anticoagulants at 1 year was 1.42 per 100 patients; the predominant localization was upper gastrointestinal tract. Predictors of the development of major gastrointestinal bleeding according to multiple regression data analysis were hemoglobin level 14.55 g/dL, body mass index 28.4 kg/m2, gastrointestinal ulcer or erosive lesion and major hemorrhagic complications in history of disease. In 1/2 cases the sourse of bleeding remained unclear. Conclusion. Searching for clinical predictors of gastrointestinal bleeding can identify patients receiving oral anticoagulants who is need of intensive monitoring risk factors to prevent the development of life-threatening bleeding and to provide with adequate anticoagulant therapy.

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).

Bleeding Events in Patients 75 Years of Age and Older Under Long-term Anticoagulant Therapy: A Real-life Study

OBJECTIVE

To investigate the risk of bleeding events in older patients under oral anticoagulant with a 4-year survey of a catchment area with 197,722 inhabitants of whom 15,267 were on warfarin and 10,397 on direct oral anticoagulants (DOACs).

METHODS

Patients presented to the Emergency Department with major bleeding were enrolled and stratified according to age ≥75 years and ongoing warfarin or DOACs. Primary endpoint was 1-month death.

RESULTS

Out of 1919 major bleeding, those of patients ≥75 years of age were 1127 (59%) versus 792 (41%) <75 years of age, P < 0.0001. In patients ≥75 years of age, brain hemorrhage accounted for 612 (54%) patients, gastrointestinal hemorrhage for 301 (27%), hematuria for 104 (9%), and other hemorrhage for 108 (10%). In patients ≥75 years of age, those on warfarin accounted for 175 versus 53 on DOACs, without difference of Charlson Comorbidity Index (5.25 ± 1.92 versus 5.09 ± 1.61; P = 0.5824). One-month death in patients ≥75 of age versus <75 years of age accounted for 77 (4.0%) versus 20 (1.0%); P < 0.0001. One-month death in patients ≥75 of age on DOACs was very low, without difference versus <75 years and within DOACs. Among DOACs, absolute bleeding events showed differences as follows: 3 bleeding events for edoxaban versus 21 for dabigatran; P < 0.001; versus 16 for rivaroxaban, P = 0.006; and versus 13 for apixaban, P = 0.02.

CONCLUSIONS

Major bleeding and 1-month death accounted for higher percentage in patients ≥75 years of age and in patients receiving warfarin. Among DOACs, edoxaban presented the lowest absolute rate of hemorrhage among the 4 available DOACs, without difference in mortality.

Cinacalcet and gastrointestinal bleeding risk in patients receiving hemodialysis

PURPOSE

Secondary hyperparathyroidism (SHPT) is common among dialysis patients, and calcimimetics are a mainstay of treatment. This study assessed whether cinacalcet use is associated with gastrointestinal bleeding in a large hemodialysis cohort.

METHODS

A linked database of clinical records and medical claims for patients receiving hemodialysis in a large dialysis organization, 2007-2010, was used. A nested case-control study was performed among patients aged ≥18 years who had received hemodialysis for ≥90 days, had Medicare Parts A, B, and D coverage for ≥1 year, and had clinical evidence of SHPT (parathyroid hormone >300 pg/mL). Cases were those who experienced death or hospitalization caused by gastrointestinal bleeding. Each case was matched to up to four controls. Exposure was measured by any cinacalcet use, current use, past use, cumulative exposure days, and cumulative dosage. Conditional logistic models were used to assess the association.

RESULTS

Of 48 437 patients included, 2570 experienced gastrointestinal bleeding events (2498 non-fatal, 72 fatal), and 2465 (2397 non-fatal, 68 fatal) were matched to 9500 controls; 17.2% of cases and 15.8% of controls had cinacalcet exposure and 11.1% of both cases and controls had current use. The adjusted odds ratios (95% CI) of gastrointestinal bleeding for any use, current use, and past use of cinacalcet were 1.04 (0.91-1.19), 0.97 (0.83-1.13), and 1.22 (0.99-1.50), respectively, with no use as the reference.

CONCLUSION

The results do not suggest an elevated risk of gastrointestinal bleeding resulting in hospitalization or death for hemodialysis patients exposed to cinacalcet.

Oral Anticoagulants for Nonvalvular Atrial Fibrillation in Patients With High Risk of Gastrointestinal Bleeding

IMPORTANCE

Many patients with nonvalvular atrial fibrillation (NVAF) are at a high risk of gastrointestinal (GI) bleeding due to conditions including older age; stage III to V chronic kidney disease (CKD); HAS-BLED (hypertension, kidney or liver disease, stroke history, prior bleeding, unstable international normalized ratio, age >65, drug or alcohol use) score of 3 or greater; corticosteroid, antiplatelet or nonsteroidal anti-inflammatory drug (NSAID) use; or GI conditions.

OBJECTIVE

To compare the risk of stroke and/or systemic embolism (SE) and major bleeding (MB) among patients with NVAF and high risk of GI bleeding who received non-vitamin K antagonist oral anticoagulants (NOACs) vs those who received warfarin.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included patients with NVAF who were 75 years and older; had stage III to V CKD; had an HAS-BLED score of 3 or greater; used corticosteroids, antiplatelets, or NSAIDs; or had GI conditions. Data were collected from the Centers for Medicare & Medicaid Services and 4 commercial insurance databases between January 1, 2012, and September 30, 2015. Data analysis was conducted from January 2012 to September 2015.

EXPOSURES

New prescription for apixaban, dabigatran, rivaroxaban, or warfarin between January 1, 2013, and September 30, 2015 (identification period).

MAIN OUTCOMES AND MEASURES

Six propensity score-matched cohorts were created to compare between study drugs. For the primary objective, Cox models were used to estimate stroke and/or SE and MB hazard ratios (HRs).

RESULTS

A total of 381 054 patients (187 489 [49.2%] women) with NVAF and at least 1 high-risk GI bleeding factor were identified (HAS-BLED score ≥3: 284 527 [74.7%]; aged ≥75 years: 252 835 [66.4%]; corticosteroid, antiplatelet, or NSAID therapy: 107 675 [28.3%]; prior GI bleeding conditions: 74 818 [19.6%]; and stage III-V CKD: 56 892 [14.9%]). All NOACs were associated with a lower risk of stroke and/or SE vs warfarin (apixaban: HR, 0.60; 95% CI, 0.52-0.68; dabigatran: HR, 0.75; 95% CI, 0.64-0.88; rivaroxaban: HR, 0.79; 95% CI, 0.73-0.86). Compared with warfarin, apixaban and dabigatran were associated with a lower risk of MB (apixaban: HR, 0.59; 95% CI, 0.56-0.63; dabigatran: HR, 0.78; 95% CI, 0.70-0.86), while rivaroxaban was associated with a higher risk (HR, 1.11; 95% CI, 1.05-1.16).

CONCLUSIONS AND RELEVANCE

In this study of patients with NVAF and high risk of GI bleed, NOACs were associated with lower rates of stroke and/or SE, but NOACs had varying risks of MB compared with warfarin. These results may help inform treatment options in this patient population.

Gastrointestinal Bleeding and Direct Oral Anticoagulants among Patients with Atrial Fibrillation: Risk, Prevention, Management, and Quality of Life

A significant problem for patients undergoing oral anticoagulation therapy is gastrointestinal bleeding (GIB), a problem that has become increasingly urgent following the introduction of direct oral anticoagulants (DOACs). Furthermore, in recent years a greater focus has been placed on the quality of life (QOL) of patients on long-term oral anticoagulant therapy, which necessitates changes in lifestyle, as well as posing an increased risk of bleeding without producing objective symptomatic relief. Here, we examine current evidence linked to GIB associated with oral anticoagulants, with a focus on randomized control trials, meta-analyses, and postmarketing observational studies. Rivaroxaban and dabigatran (especially the 150-mg bis-in-die dose) appeared to be linked to an increased risk of GIB. The risk of GIB was also greater when edoxaban was used, although this was dependent on the dose. Apixaban did not pose a higher risk of GIB in comparison with warfarin. We provided a summary of current knowledge regarding GIB risk factors for individual anticoagulants, prevention strategies that lower the risk of GIB and management of DOAC therapy after a GIB episode.

Adverse Events Associated With the Addition of Aspirin to Direct Oral Anticoagulant Therapy Without a Clear Indication

IMPORTANCE

It is unclear how many patients treated with a direct oral anticoagulant (DOAC) are using concomitant acetylsalicylic acid (ASA, or aspirin) and how this affects clinical outcomes.

OBJECTIVE

To evaluate the frequency and outcomes of prescription of concomitant ASA and DOAC therapy for patients with atrial fibrillation (AF) or venous thromboembolic disease (VTE).

DESIGN, SETTING, AND PARTICIPANTS

This registry-based cohort study took place at 4 anticoagulation clinics in Michigan from January 2015 to December 2019. Eligible participants were adults undergoing treatment with a DOAC for AF or VTE, without a recent myocardial infarction (MI) or history of heart valve replacement, with at least 3 months of follow-up.

EXPOSURES

Use of ASA concomitant with DOAC therapy.

MAIN OUTCOMES AND MEASURES

Rates of bleeding (any, nonmajor, major), rates of thrombosis (stroke, VTE, MI), emergency department visits, hospitalizations, and death.

RESULTS

Of the study cohort of 3280 patients (1673 [51.0%] men; mean [SD] age 68.2 [13.3] years), 1107 (33.8%) patients without a clear indication for ASA were being treated with DOACs and ASA. Two propensity score-matched cohorts, each with 1047 patients, were analyzed (DOAC plus ASA and DOAC only). Patients were followed up for a mean (SD) of 20.9 (19.0) months. Patients taking DOAC and ASA experienced more bleeding events compared with DOAC monotherapy (26.0 bleeds vs 31.6 bleeds per 100 patient years, P = .01). Specifically, patients undergoing combination therapy had significantly higher rates of nonmajor bleeding (26.1 bleeds vs 21.7 bleeds per 100 patient years, P = .02) compared with DOAC monotherapy. Major bleeding rates were similar between the 2 cohorts. Thrombotic event rates were also similar between the cohorts (2.5 events vs 2.3 events per 100 patient years for patients treated with DOAC and ASA compared with DOAC monotherapy, P = .80). Patients were more often hospitalized while undergoing combination therapy (9.1 vs 6.5 admissions per 100 patient years, P = .02).

CONCLUSION AND RELEVANCE

Nearly one-third of patients with AF and/or VTE who were treated with a DOAC received ASA without a clear indication. Compared with DOAC monotherapy, concurrent DOAC and ASA use was associated with increased bleeding and hospitalizations but similar observed thrombosis rate. Future research should identify and deprescribe ASA for patients when the risk exceeds the anticipated benefit.

Dose specific effectiveness and safety of DOACs in patients with non-valvular atrial fibrillation: A Canadian retrospective cohort study

BACKGROUND

Direct oral anticoagulants (DOACs) have been proven to be effective and safe for prevention of ischemic stroke and systemic embolism in patients with non-valvular atrial fibrillation (NVAF). However, suboptimal adherence, variable dosing and use in patient populations that otherwise would have been excluded from clinical trials may impact the efficacy and safety profile of DOACs in a routine care setting. We compared stroke, bleeding, and mortality rates on and off therapy for standard and low-dose DOACs (apixaban, rivaroxaban, dabigatran) versus warfarin in a Canadian cohort. We also assessed persistence of DOACs compared to warfarin.

METHODS

We conducted six 1-1 propensity-score matched retrospective cohort analyses using Quebec health administrative databases (2011-2017). NVAF patients (≥18 years) covered by the public medication insurance plan entered the cohort on the first OAC dispensation date. We excluded those with OAC use in the previous year or stroke or bleeding diagnoses in the previous two years. Follow-up ended at death, March 2017 or end of medication coverage by the public plan. Time-dependent Cox regression was applied.

RESULTS

We evaluated 10,893 patients initiated on apixaban (7206 standard, 3687 low-dose), 10,190 on rivaroxaban (7396 standard, 2794 low-dose), 5884 on dabigatran (2756 standard, 3128 low-dose), and propensity score-matched warfarin users. Across standard-dose DOACs, compared to warfarin, stroke risks were similar; bleeding risks were lower with apixaban (hazard ratio 0.63; 95% confidence interval 0.52-0.77) and dabigatran (0.47; 0.35-0.64) but not rivaroxaban (0.93; 0.79-1.10); death risks were lower with all DOACs. For low-dose DOACs, rivaroxaban demonstrated higher stroke (1.79; 1.21-2.64) and bleeding risks (1.37; 1.09-1.73); other agents had stroke risks similar to warfarin and bleeding risks lower than warfarin; only low-dose dabigatran had lower death risk (0.59; 0.52-0.68). Treatment discontinuation was lower with DOACs versus warfarin with the exception of low-dose rivaroxaban. The risks of stroke were 2-4 folds higher during time off any OAC versus time on warfarin. The risks of death were higher, while the risks of bleeding were generally lower during times off any OAC.

CONCLUSIONS

Standard-dose DOACs had similar stroke, better persistence and mortality profiles than warfarin. Only standard dose apixaban and dabigatran had better bleeding profiles than warfarin. Low-dose rivaroxaban had worse persistence, stroke and bleeding profiles than warfarin, while low-dose apixaban and dabigatran had similar stroke and better bleeding profiles. Real-world use of DOACs may explain some of the differences observed in Canadian routine care versus the phase III clinical trials.

Comparative Effectiveness of Machine Learning Approaches for Predicting Gastrointestinal Bleeds in Patients Receiving Antithrombotic Treatment

IMPORTANCE

Anticipating the risk of gastrointestinal bleeding (GIB) when initiating antithrombotic treatment (oral antiplatelets or anticoagulants) is limited by existing risk prediction models. Machine learning algorithms may result in superior predictive models to aid in clinical decision-making.

OBJECTIVE

To compare the performance of 3 machine learning approaches with the commonly used HAS-BLED (hypertension, abnormal kidney and liver function, stroke, bleeding, labile international normalized ratio, older age, and drug or alcohol use) risk score in predicting antithrombotic-related GIB.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cross-sectional study used data from the OptumLabs Data Warehouse, which contains medical and pharmacy claims on privately insured patients and Medicare Advantage enrollees in the US. The study cohort included patients 18 years or older with a history of atrial fibrillation, ischemic heart disease, or venous thromboembolism who were prescribed oral anticoagulant and/or thienopyridine antiplatelet agents between January 1, 2016, and December 31, 2019.

EXPOSURES

A cohort of patients prescribed oral anticoagulant and thienopyridine antiplatelet agents was divided into development and validation cohorts based on date of index prescription. The development cohort was used to train 3 machine learning models to predict GIB at 6 and 12 months: regularized Cox proportional hazards regression (RegCox), random survival forests (RSF), and extreme gradient boosting (XGBoost).

MAIN OUTCOMES AND MEASURES

The performance of the models for predicting GIB in the validation cohort, evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive predictive value, and prediction density plots. Relative importance scores were used to identify the variables that were most influential in the top-performing machine learning model.

RESULTS

In the entire study cohort of 306 463 patients, 166 177 (54.2%) were male, 193 648 (63.2%) were White, the mean (SD) age was 69.0 (12.6) years, and 12 322 (4.0%) had experienced a GIB. In the validation data set, the HAS-BLED model had an AUC of 0.60 for predicting GIB at 6 months and 0.59 at 12 months. The RegCox model performed the best in the validation set, with an AUC of 0.67 at 6 months and 0.66 at 12 months. XGBoost was similar, with AUCs of 0.67 at 6 months and 0.66 at 12 months, whereas for RSF, AUCs were 0.62 at 6 months and 0.60 at 12 months. The variables with the highest importance scores in the RegCox model were prior GI bleed (importance score, 0.72); atrial fibrillation, ischemic heart disease, and venous thromboembolism combined (importance score, 0.38); and use of gastroprotective agents (importance score, 0.32).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, the machine learning models examined showed similar performance in identifying patients at high risk for GIB after being prescribed antithrombotic agents. Two models (RegCox and XGBoost) performed modestly better than the HAS-BLED score. A prospective evaluation of the RegCox model compared with HAS-BLED may provide a better understanding of the clinical impact of improved performance.

The risk of gastrointestinal hemorrhage with non-vitamin K antagonist oral anticoagulants: A network meta-analysis

BACKGROUND

Non-vitamin K antagonist oral anticoagulants (NOACs) have been widely used for stroke prevention in atrial fibrillation (AF) and the treatment and prevention of venous thromboembolism. There is an issue with safety, especially in clinically relevant bleeding. We performed a network meta-analysis to evaluate the risk of major gastrointestinal (GI) bleeding associated with NOACs.

METHODS

Interventions were warfarin, enoxaparin, apixaban, dabigatran, edoxaban, and rivaroxaban. The primary outcome was the incidence of major GI bleeding. A subgroup analysis was performed according to the following indications: AF, deep venous thrombosis/pulmonary embolism, and postsurgical prophylaxis.

RESULTS

A total of 29 randomized controlled trials (RCTs) and 4 large observation population studies were included. Compared with warfarin, apixaban showed a decreased the risk of major GI bleeding (relative risk [RR] 0.54, 95% confidence interval [CI] 0.25-0.76), and rivaroxaban tended to increase this risk (RR 1.40, 95% CI 1.06-1.85). Dabigatran (RR 1.25, 95% CI 0.98-1.60), edoxaban (RR 1.07, 95% CI 0.69-1.65), and enoxaparin (RR 1.24, 95% CI 0.63-2.43) did not significantly increase the risk of GI bleeding than did warfarin. In the subgroup analysis, according to indications, apixaban showed a decreased risk of major GI bleeding (RR 0.50, 95% CI 0.34-0.74) than did warfarin in AF studies. Dabigatran (RR 2.36, 95% CI 1.55-3.60, and rivaroxaban (RR 1.75, 95% CI 1.10-6.41) increased the risk of major GI bleeding than did apixaban. An analysis of studies on venous thromboembolism or pulmonary embolism showed that no individual NOAC or enoxaparin was associated with an increased risk of major GI bleeding compared to warfarin.

CONCLUSION

Individual NOACs had varying profiles of GI bleeding risk. Results of analyses including only RCTs and those including both RCTs and population studies showed similar trends, but also showed several differences.

5-year outcomes from rivaroxaban therapy in atrial fibrillation: Results from the Dresden NOAC Registry

INTRODUCTION

Following successful phase-III trials, direct oral anticoagulants such as rivaroxaban have largely replaced warfarin for stroke prevention in atrial fibrillation (SPAF). However, data from randomized trials should be confirmed in unselected cohorts.

MATERIALS AND METHODS

Prospective registries can provide such data but often limit follow-up to short periods only. Extending our previously reported follow-up of 2.2 years in 1204 SPAF patients receiving rivaroxaban in the non-interventional DRESDEN NOAC REGISTRY, we now provide prospectively collected 5 years data (mean follow-up 5.5 ± 2.3 years) for this cohort.

RESULTS

Between 1 October 2011 and 31 December 2019, the combined endpoint of stroke/transient ischemic attack/systemic embolism occurred at a rate of 2.3/100 patient-years in the intention-to-treat analysis (95% confidence interval [CI] 1.9-2.7) and at 1.6/100 patient-years in the on-treatment analysis (events within 3 days after last drug intake). On-treatment rates for major or clinically relevant non-major bleeding were 3.1 and 19.6/100 patient-years, respectively. Rivaroxaban treatment discontinuation occurred in a total of 574 patients during follow-up (11.0/100 patient-years in Kaplan-Meier analysis) and 426 patient died (all-cause mortality 6.3/100 pt. years; mean time from enrolment 3.6 ± 2.1 years), of which the causes of death were reported as arterial or venous embolism for 32 patients (21 occurring after treatment discontinuation and 11 during active treatment) and as bleeding for 24 patients.

CONCLUSIONS

Our data provide reassuring long-term outcome data for an elderly, co-morbid SPAF population, especially with regard to the low rate of fatal thromboembolic and bleeding complications.

Outcomes of upper gastrointestinal bleeding are similar between direct oral anticoagulants and vitamin K antagonists

BACKGROUND

The increased risk of upper gastrointestinal bleeding (UGIB) related to direct oral anticoagulants (DOACs) as compared to vitamin K antagonists (VKA) remains debated.

AIMS

To describe the epidemiology and outcomes of UGIB in patients treated with oral anticoagulants.

METHODS

A prospective, multicentre study in French general hospitals enrolled all consecutive patients with UGIB during one year. Patients treated with oral anticoagulants were retrieved from the cohort. Main outcomes were mortality and rebleeding during the first 6 weeks and need for non-endoscopic treatment (surgery or interventional radiology).

RESULTS

Among the 2498 patients included, 475 (19%) had an oral anticoagulant, mostly with VKA (267 patients [56.2%]). Baseline characteristics were similar between the groups except for renal failure and cirrhosis that were more prevalent in the VKA group. Gastroscopy was normal in 73 patients (15.3%); peptic lesions were the main cause of UGIB (n = 233, 49%). Endoscopic treatment was performed in 128 patients (26.9%), leading to bleeding resolution in 74% (n = 95). Mortality rate at 6 weeks was 12.4% (59 patients), and was higher in the VKA group compared to DOACs (16.1% vs 7.8%, P < 0.01). By multivariate analysis, only the Charlson index ≥ 5 and UGIB occurrring in in-patients were independently associated with mortality. Rebleeding (56 patients [11.8%]) and need for non-endoscopic treatment (18 patients [3.8%]) were not associated with the type of anticoagulant.

CONCLUSION

DOACs do not alter outcomes of UGIB as compared to VKA. Comorbidities and associated treatment are the most important factors worsening the prognosis of UGIB.

Cost-Effectiveness of Direct Non-Vitamin K Oral Anticoagulants Versus Vitamin K Antagonists for the Management of Patients with Non-Valvular Atrial Fibrillation Based on Available "Real-World" Evidence: The Italian National Health System Perspective

BACKGROUND AND OBJECTIVE

The increasing availability of real-world evidence (RWE) about safety and effectiveness of direct non-vitamin K oral anticoagulants (DOACs) for the management of atrial fibrillation (AF) offers the opportunity to better understand the clinical and economic implications of DOACs versus vitamin K antagonists (VKAs). The objective of this study was to compare the economic implications of DOACs and VKAs using data from real-world evidence in patients with AF.

METHODS

A Markov model simulating the lifetime course of patients diagnosed with non-valvular AF was used to evaluate the cost-effectiveness of DOACs (i.e., rivaroxaban, dabigatran and apixaban) versus VKAs from the Italian National Health System (INHS) perspective. The model was made up of data from the literature and a meta-analysis of RWE on the incidence of stroke/systemic embolism (SE), major bleeding (MB), intracranial haemorrhage (ICH) and all-cause mortality (ACM); direct costs included drug costs, costs for drug monitoring, and management of events from official national lists. One-way and probabilistic sensitivity analyses (PSA) were used to assess the robustness of the results.

RESULTS

Results from the meta-analysis showed that apixaban had a high probability of being the most effective for stroke/SE, MB and ACM. Despite their higher acquisition costs, the cost-effectiveness analysis showed all DOACs involved a saving when compared with VKAs, with per-patient savings ranging between €4647 (rivaroxaban) to €6086 (apixaban). Moreover, all DOACs indicated a gain both in quality-adjusted life-years and life-years. According to PSA, findings related to apixaban were consistent, while for dabigatran and rivaroxaban PSA revealed a higher degree of uncertainty.

CONCLUSIONS

The beneficial effect of DOACs on containing events showed in RWE had the potential to offset drug-related costs, thus improving the sustainability of treatment for non-valvular AF in daily clinical practice.