Risk of gastrointestinal bleeding with direct oral anticoagulants: a systematic review and network meta-analysis

Anti-thrombotic Effects Mediated by a Novel Dual-Target Peptide Inhibiting Both Platelet Aggregation and Thrombin Activity without Causing Bleeding

BACKGROUND

 Classical anticoagulants and antiplatelets are associated with high frequencies of bleeding complications or treatment failure when used as single agents. Thrombin plays an important role in the blood coagulation system. GP IIb/IIIa is the central receptor of platelets, which can recognize the Arg-Gly-Asp (RGD) sequence and activate platelets.

MATERIAL AND METHODS

 Molecular simulation and homology modeling were performed to design a novel dual-target anticoagulant short peptide (PTIP ). The activities of PTIP on coagulation and platelet in vitro were analyzed. The antithrombotic activity of PTIP was determined by pulmonary thromboembolism model, ferric chloride injury model and arteriovenous bypass thrombosis model. Bleeding effect and toxicity of PTIP were evaluated.

RESULTS

 We have constructed a novel dual-target peptide (PTIP) based on the direct thrombin inhibitor peptide (DTIP). PTIP was expressed at high levels in Pichia pastoris. PTIP interfered with thrombin-mediated coagulation and ADP-induced platelet aggregation in vitro. When injected intravenously or subcutaneously, PTIP showed potent and dose-dependent extension of aPTT and PT which were similar to DTIP; but only PTIP was capable of inhibiting platelet aggregation. PTIP (1.0 mg/kg) decelerated thrombosis formation in venous and arterial vessels induced by FeCl3 injury. PTIP (1.0 mg/kg) also prevented deep venous thrombosis and increased the survival rate associated with pulmonary thromboembolism. And PTIP effectively reduced thrombus length in arteriovenous bypass thrombosis model. Moreover, the antithrombotic dose of PTIP could not induce bleeding.

CONCLUSION

 These data establish that PTIP represents a novel antithrombotic agent whose effects involve both inhibition of platelet activation and reduction of fibrin generation. And PTIP not only can be used in venous thrombosis and arterial thrombosis, it can also replace the combined treatment of antiplatelet and anticoagulant drugs in thrombotic diseases.

Do Proton Pump Inhibitors Reduce Upper Gastrointestinal Bleeding in Older Patients with Atrial Fibrillation Treated with Oral Anticoagulants? A Nationwide Cohort Study in France

BACKGROUND

Proton pump inhibitors (PPIs) are largely used in older adults and data are needed in off-label indications, such as the prevention of upper gastrointestinal bleeding (UGIB) in patients receiving oral anticoagulants (OACs). This study aimed to assess whether PPIs reduce the risk of UGIB in patients initiating oral anticoagulation.

METHODS

We conducted a longitudinal study based on the French national health database. The study population included 109,693 patients aged 75-110 years with a diagnosis of atrial fibrillation who initiated OACs [vitamin K antagonist (VKA) or direct OAC (DOAC)] between 2012 and 2016. We used multivariable Cox models weighted by inverse of probability of treatment to estimate the adjusted hazard ratio (aHR) of UGIB between PPI users and nonusers over a 6- and 12-month follow-up.

RESULTS

PPI users represented 23% of the study population (28% among VKA initiators and 17% among DOAC initiators). The mean age (83 ± 5.3 years) and proportion of women (near 60%) were similar between groups. The risk of UGIB in the first 6 months after initiation of OAC decreased by 20% in PPI users compared with PPI nonusers [aHR6 months = 0.80, 95% confidence interval (CI) 0.65-0.98], but was not significantly modified when the follow-up was extended to 12 months (aHR12 months = 0.90, 95% CI 0.76-1.07), with a stronger effect among patients treated with vitamin K antagonists (aHR6 months = 0.73, 95% CI 0.58-0.93; aHR12 months = 0.81, 95% CI 0.67-0.99).

CONCLUSIONS

This study suggests that PPIs were associated with reduced risk of gastrointestinal bleeding after initiation of oral anticoagulation in older patients with atrial fibrillation, particularly within 6 months after initiation of an antivitamin K antagonist.

Anticoagulant in atrial fibrillation patients with prior intracranial haemorrhage: a meta-analysis

BACKGROUND

The benefit of resuming anticoagulation in atrial fibrillation (AF) patients with prior intracranial haemorrhage (ICH) and which anticoagulant to choose are controversial.

SUMMARY OF REVIEW

PubMed, Embase, Web of Science and the Cochrane Library were searched from their inception until 13 February 2022. Thirteen eligible articles (17 600 participants) were collected, including 11 real-world studies (n=17 296) and 2 randomised controlled trials (RCTs) (n=304). Compared with no anticoagulants, oral anticoagulation (OAC) was not associated with an increased risk of ICH recurrence (HR 0.85 (95% CI 0.57 to 1.25), p=0.41), but with a significantly increased risk of major bleeding (HR 1.66 (95% CI 1.20 to 2.30), p<0.01). Meanwhile, OAC was associated with a reduced risk of ischaemic stroke/systemic thromboembolism (IS/SE) (HR 0.54 (95% CI 0.42 to 0.70), p<0.01) and all-cause death (HR 0.38 (95% CI 0.28 to 0.52), p<0.01) compared with no anticoagulants. Furthermore, compared with warfarin, non-vitamin K antagonist oral anticoagulants (NOACs) were associated with a significant reduction of ICH recurrence (HR 0.64 (95% CI 0.49 to 0.85), p<0.01), while the risk of IS/SE and all-cause mortality were comparable between warfarin and NOACs.

CONCLUSIONS

For patients with AF with prior ICH, OAC is associated with a significant reduction in IS/SE and all-cause mortality without increasing ICH recurrence, but may increase major bleeding risk. Compared with warfarin, NOACs had a better safety profile and comparable efficacy. Further larger RCTs are warranted to validate these findings.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Use of non-vitamin K antagonists oral anticoagulants in atrial fibrillation patients on dialysis

Background

Non-vitamin K antagonist oral anticoagulants (NOACs) showed a benefit-risk profile superior to that of warfarin in atrial fibrillation (AF) patients with mild to moderate chronic kidney disease. However, the effectiveness and safety of NOACs in AF patients with end-stage renal disease (ESRD) on dialysis remain unclear. Therefore, we performed a meta-analysis regarding the effect of NOACs vs. warfarin in AF patients undergoing dialysis.

Methods

A search of the Pubmed and EMBASE databases until November 2021 was performed. Adjusted risk ratios (RRs) and 95%confidence intervals (CIs) were pooled by a random-effects model with an inverse variance method.

Results

Six studies involving 3,744 NOAC- and 26,973 warfarin- users were deemed to meet the criteria. In the pooled analysis, the use of mixed NOACs had similar incidences of effectiveness and safety outcomes compared with warfarin use. And factor Xa inhibitors (rivaroxaban or apixaban) did not have significantly better effectiveness than warfarin. For the safety outcomes, the use of factor Xa inhibitors was associated with a reduced risk of gastrointestinal bleeding (RR = 0.81, 95% CI 0.70–0.95), but not major bleeding and intracranial bleeding.

Conclusion

Compared with warfarin, the use of NOACs, especially factor Xa inhibitors (rivaroxaban or apixaban), showed at least similar effectiveness and safety outcomes in AF patients on dialysis.

Consensus document of the Spanish Society of Digestives Diseases and the Spanish Society of Thrombosis and Haemostasis on massive nonvariceal gastrointestinal bleeding and direct-acting oral anticoagulants

INTRODUCTION

there is limited experience and understanding of massive nonvariceal gastrointestinal bleeding during therapy with direct-acting oral anticoagulants.

OBJECTIVES

to provide evidenced-based definitions and recommendations.

METHODS

a consensus document developed by the Spanish Society of Digestives Diseases and the Spanish Society of Thrombosis and Haemostasis using modified Delphi methodology. A panel was set up of 24 gastroenterologists with experience in gastrointestinal bleeding, and consensus building was assessed over three rounds. Final recommendations are based on a systematic review of the literature using the GRADE system.

RESULTS

panelist agreement was 91.53 % for all 30 items as a group, a percentage that was improved during rounds 2 and 3 for items where clinical experience is lower. Explicit disagreement was only 1.25 %. A definition of massive nonvariceal gastrointestinal bleeding in patients on direct-acting oral anticoagulants was established, and recommendations to optimize this condition's management were developed.

CONCLUSION

the approach to these critically ill patients must be multidisciplinary and protocolized, optimizing decisions for an early identification of the condition and patient stabilization according to the tenets of damage control resuscitation. Thus, consideration must be given to immediate anticoagulation reversal, preferentially with specific antidotes (idarucizumab for dabigatran and andexanet alfa for direct factor Xa inhibitors); hemostatic resuscitation, and bleeding point identification and management.

Clinical features of obscure gastrointestinal bleeding undergoing capsule endoscopy: A retrospective cohort study

Background

Capsule endoscopy has been widely used to investigate obscure gastrointestinal bleeding (OGIB) in the small intestine since its approval in 2001. However, the clinical features of OGIB remain unclear.

Aim

We retrospectively examined the clinical features and risk factors of OGIB in patients who underwent capsule endoscopy in our hospital.

Methods

We included 420 of the 431 patients who underwent capsule endoscopy from June 2014 to May 2021, in whom the small intestine could be observed. We retrospectively compared the clinical features and treatment of OGIB cases, with or without active small bowel bleeding (n = 173), with other cases (n = 247). Patient sex, age, diabetes mellitus, and heart failure histories were matched for the analysis.

Results

The male/female ratio was 247/173 and the average age was 51.54 years. In multivariate analysis, the use of direct oral anticoagulants was significant (P = 0.016), and vascular lesions (P = 0.018) were observed in OGIB cases. When OGIB cases with and without active small bowel bleeding were compared, serum albumin level was lower in cases with active bleeding (P = 0.031). When treatment of OGIB cases were compared, those without vascular lesions could be treated conservatively (P = 0.0047). In the 1:1 propensity score matching analysis, serum creatinine level was elevated in cases of active bleeding (P = 0.029), and cases without vascular lesions were treated conservatively (P = 0.010).

Conclusions

Use of direct oral anticoagulants is frequently associated with OGIB. OGIB patients without vascular lesions may be treated conservatively.

Editor's Choice - Severe Bleeding Risks of Direct Oral Anticoagulants in the Prevention and Treatment of Venous Thromboembolism: A Network Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

The aim of this study was to determine the severe bleeding safety of direct oral anticoagulants (DOACs) for the prevention and treatment of venous thromboembolism (VTE).

METHODS

PubMed, EMBASE, Web of Science, and the Cochrane Library databases were searched up to 6 January 2021. The incidence of severe bleeding (major, gastrointestinal [GI], intracranial, and fatal) was investigated. Using frequentist network meta-analysis, interventions that were not compared directly could be compared indirectly by the 95% confidence interval (CI), making the search results more intuitive. Based on surface under the cumulative ranking curves (SUCRA), the relative ranking probability of each group was generated.

RESULTS

Thirty-one randomised controlled trials (76 641 patients) were included. For the treatment of VTE, the risk of major bleeding with apixaban was significantly lower than dabigatran (odds ratio [OR] 2.10, 95% CI 1.07 - 4.12) and edoxaban (OR 2.64, 95% CI 1.36 - 5.15). The safety of the drugs was ranked from highest to lowest as follows: major bleeding: apixaban (SUCRA 98.0), rivaroxaban (SUCRA 69.6), dabigatran (SUCRA 50.7), edoxaban (SUCRA 26.5), and vitamin K antagonists (VKAs; SUCRA 5.1); GI bleeding: apixaban (SUCRA 80.7), rivaroxaban (SUCRA 66.8), edoxaban (SUCRA 62.3), VKAs (SUCRA 34.4), and dabigatran (SUCRA 5.8); intracranial bleeding: rivaroxaban (SUCRA 74.4), edoxaban (SUCRA 70.4), dabigatran (SUCRA 58.2), apixaban (SUCRA 44.4), and VKAs (SUCRA 5.6); fatal bleeding: edoxaban (SUCRA 82.7), rivaroxaban (SUCRA 59.2), dabigatran (SUCRA 48.6), apixaban (SUCRA 43.0), and VKAs (SUCRA 16.3). For the prevention of VTE, the risk of major bleeding with apixaban was significantly lower than rivaroxaban (OR 2.14, 95% CI 1.02 - 4.52). Among the four types of bleeding, apixaban had the lowest bleeding risk among DOACs (major bleeding: SUCRA 81.6; GI bleeding: SUCRA 75.4; intracranial bleeding: SUCRA 64.1; fatal bleeding: SUCRA 73.6).

CONCLUSIONS

For the treatment of VTE, in terms of major bleeding and GI bleeding, apixaban had the lowest bleeding risk; in terms of intracranial bleeding, rivaroxaban had the lowest bleeding risk; in terms of fatal bleeding, edoxaban had the lowest bleeding risk. For the prevention of VTE, apixaban had the lowest bleeding risk.

Design and fabrication of r-hirudin loaded dissolving microneedle patch for minimally invasive and long-term treatment of thromboembolic disease

Cardiovascular disease is the leading cause of global mortality, with anticoagulant therapy being the main prevention and treatment strategy. Recombinant hirudin (r-hirudin) is a direct thrombin inhibitor that can potentially prevent thrombosis via subcutaneous (SC) and intravenous (IV) administration, but there is a risk of haemorrhage via SC and IV. Thus, microneedle (MN) provides painless and sanitary alternatives to syringes and oral administration. However, the current technological process for the micro mould is complicated and expensive. The micro mould obtained via three-dimensional (3D) printing is expected to save time and cost, as well as provide a diverse range of MNs. Therefore, we explored a method for MNs array model production based on 3D printing and translate it to micro mould that can be used for fabrication of dissolving MNs patch. The results show that r-hirudin-loaded and hyaluronic acid (HA)-based MNs can achieve transdermal drug delivery and exhibit significant potential in the prevention of thromboembolic disease without bleeding in animal models. These results indicate that based on 3D printing technology, MNs combined with r-hirudin are expected to achieve diverse customizable MNs and thus realize personalized transdermal anticoagulant delivery for minimally invasive and long-term treatment of thrombotic disease.

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.

Neurologists' attitudes and options for anticoagulation therapy in central China

AIMS

We aim to find out the factors affecting the use of anticoagulants and the intensity of their choices, and to establish a basis for improving neurologists' effective implementation of the guidelines.

METHODS

A cross-sectional study is conducted in Hubei province in central China. Each neurologist completes a standard-structured anonymous questionnaire through face-to-face interviews. The problems include the attitude and options about anticoagulant therapy.

RESULTS

A total of 611 neurologists from 38 hospitals respond to this survey. For the best treatment of atrial fibrillation, more than 80% of physicians choose anticoagulant therapy. For patients with atrial fibrillation and cerebral infarction, physicians think that Warfarin is the preferred drug as high as 93.8%. Among the anticoagulant drugs ever used by clinicians, the use rate of Warfarin is 93.8%, but the use rate of direct oral anticoagulants is insufficient. The use of direct oral anticoagulants is related to the educational level and the geographical location of the hospital. Bleeding risk is the first reason influencing clinicians' choice of Warfarin, accounts for 88.9%. 97.7% of the clinicians recommend patients with Warfarin to regularly monitor the INR, but the frequency of monitoring is inconsistent. Clinicians have a high willingness to learn about AF, but the proportion of hospitals that carry out appropriate training is low.

CONCLUSIONS

There are still some gaps with the guidelines on the choice of anticoagulant drugs. Neurologists have positive attitude towards anticoagulant therapy and a strong willingness to learn, but the corresponding training is lacking. Continuous professional training is necessary.

Comparative data on left atrial appendage occlusion efficacy and clinical outcomes by age group in the Amplatzer™ Amulet™ Occluder Observational Study

AIMS

Left atrial appendage occlusion (LAAO) may be considered for patients with non-valvular atrial fibrillation (NVAF) and a relative/formal contraindication to anticoagulation. This study aimed to summarize the impact of aging on LAAO outcomes at short and long-term follow-up.

METHODS AND RESULTS

We compared subjects aged <70, ≥70 and <80, and ≥80 years old in the prospective, multicentre Amplatzer™ Amulet™ Occluder Observational Study (Abbott, Plymouth, MN, USA). Serious adverse events (SAEs) were reported from implant through a 2-year post-LAAO visit and adjudicated by an independent clinical events committee. Overall, 1088 subjects were prospectively enrolled. There were 265 subjects (24.4%) <70 years old, 491 subjects (45.1%) ≥70 and <80 years old, and 332 subjects (30.5%) ≥80 years old, with the majority (≥80%) being contraindicated to anticoagulation. As expected, CHA2DS2-VASc and HAS-BLED Scores increased with age. Implant success was high (≥98.5%) across all groups, and the proportion of subjects with a procedure- or device-related SAE was similar between groups. At follow-up, the observed ischaemic stroke rate was not significantly different between groups, and corresponding risk reductions were 62, 56, and 85% when compared with predicted rates for subjects <70, ≥70 and <80, and ≥80 years old, respectively. Major bleeding and mortality rates increased with age, while the incidence of device-related thrombus tended to increase with age.

CONCLUSIONS

Despite the increased risk for ischaemic stroke with increasing age in AF patients, LAAO reduced the risk for ischaemic stroke compared with the predicted rate across all age groups without differences in procedural SAEs.

Clinical history and gastrointestinal bleeding in patients taking oral anticoagulants

BACKGROUND

Common risk factors for gastrointestinal bleeding (GIB) are advanced age and the use of antiplatelet or anticoagulants drugs for the prevention of cardiovascular diseases.

METHODS

In this prospective real-world observational study, oral anticoagulated patients were recruited and followed between June 2013 and December 2019. The primary end-point was to evaluate a possible relationship between bleeding events and patients' clinical history of gastrointestinal disease prior to the start of the therapy. The secondary end-points were time of GIB appearance and the percentage of idiopathic or provoked events, i.e., bleeding due to a gastrointestinal disease. In case of GIB event all the patients were studied by means of endoscopic procedures. Cox regression was used to calculate the relative hazard ratios (HRs) of GIB for each considered clinical variable.

RESULTS

734 patients on both VKAs or DOACs were studied. Overall, 46 hemorrhagic events were recorded: 6 were major bleeding (0.42/100 patient-years) while 43 were clinically relevant non major bleeding (2.8/100 patient-years). The Cox regression analysis did not show any relationships among GIB and the variables considered.

CONCLUSION

The patients' clinical history is neither a predictor for GIB bleeding nor a guide to the choice of the oral anticoagulant to be administered. Routinely applying bleeding risk screening, such as occult blood in the stool, should be added to the periodic laboratory checks for early recognition of patients at higher risk of GIB.

Incidence and Mortality Related to Gastrointestinal Bleeding, and the Effect of Tranexamic Acid on Gastrointestinal Bleeding

Background

Gastrointestinal bleeding is a common and potentially life-threatening condition. The incidence of gastrointestinal bleeding has not decreased despite new prophylaxis and treatments. Ulcer is still one of the most common etiologies for upper gastrointestinal bleeding. It is routinely treated with proton pump inhibitors (PPIs) and endoscopic interventions, sometimes endovascular procedures, and rarely today, open surgery with suture to stop the bleeding. The fibrinolytic tranexamic acid (TXA) has a role in bleeding treatment, and is routinely used for example within trauma care, postpartum bleeding and orthopedic surgery. The aim of this study is to assess the incidence of gastrointestinal bleeding. A further aim was to investigate if TXA has any role in medical treatment of gastrointestinal bleeding today.

Methods

We performed a retrospective cohort study with a review of medical records, involving patients with clinical signs of gastrointestinal bleeding and endoscopically verified ulcers between the years of 2010 and 2016 at the University Hospital of Linkoping, Sweden. The cities of Motala and Linkoping have the primary acute admissions at this Hospital.

Results

We found in total 1,331 patients with gastrointestinal bleeding. The overall incidence for patients with gastrointestinal bleeding was 98.6 (98.6/100,000 inhabitants and year). For those with endoscopically verified ulcer (386 patients), the incidence for peptic ulcer was 28.6/100,000/year. In the group with endoscopically verified ulcer, 25 patients died, giving the 30-day mortality of 6.4%. TXA is still used for treatment of bleeding ulcers. We had two groups, those with and without TXA treatment. They were equal in age, gender and comorbidity. Clinically we saw no major differences in respect to hemodynamic stability. There were more patients with overt bleeding symptoms in the TXA group. We also saw more patients in need of intensive care in the TXA group.

Conclusions

The incidence of gastrointestinal bleeding has not significantly decreased during the last years. There was no significant positive effect of TXA in patients with upper gastrointestinal bleeding in this study. The difference between the two groups is probably more a question of whom we treat with TXA (e.g., the patients in worse condition or at higher risk) than a difference in drug effect. It is time to quit with TXA treatment in all patients with gastrointestinal bleeding, even those at intensive care unit (ICU).

Review Article: Gastrointestinal Bleeding Risk with Direct Oral Anticoagulants

PURPOSE

Although direct oral anticoagulants (DOACs) are associated with an overall favourable safety profile, the risk of gastrointestinal bleeding with DOACs compared with vitamin K antagonists (VKAs) remains controversial. Accordingly, we aimed to provide a focused overview of the risk of gastrointestinal bleeding associated with dabigatran, rivaroxaban, apixaban and edoxaban and its management.

METHODS

We reviewed published studies reporting on DOACs with gastrointestinal bleeding as an outcome, including randomised controlled trials (RCTs), retrospective database studies and large-scale prospective cohort studies.

RESULTS

Cumulative evidence confirms no notable difference in major gastrointestinal bleeding risk between DOACs and VKAs. Moreover, gastrointestinal bleeding in DOAC-treated patients seems less severe and requires less intensive management. The main cause of upper gastrointestinal bleeding in DOAC-treated patients appears to be gastroduodenal ulcers, whereas lower gastrointestinal bleedings are mainly due to diverticula followed by angiodysplasia and haemorrhoids. The lack of head-to-head RCTs with DOACs precludes drawing conclusions on the DOAC with the lowest gastrointestinal bleeding risk. Prescribing physicians should be aware of risk factors for DOAC-related gastrointestinal bleeding (e.g. age > 65, heavy alcohol use, uncontrolled hypertension, hepatic or renal dysfunction, active cancer, anaemia) and adopt preventive measures accordingly. Management of DOAC-associated major gastrointestinal bleeding involves temporary discontinuation of the DOAC, investigation of the bleeding source and treatment of bleeding with fluid resuscitation combined with transfusion and endoscopic haemostasis.

CONCLUSION

DOACs as a class do not increase the risk of major gastrointestinal bleeding compared to VKAs, which supports their continued use for different anticoagulant indications.

Dabigatran activates inflammation resolution by promoting fibrinogen-like protein 2 shedding and RvD5n-3 DPA production

Rationale: The interaction between coagulation and inflammation resolution remains elusive. We recently highlighted a link between fibrinogen-like protein 2 (Fgl2) and a specialized pro-resolving mediator (SPM)-n-3 docosapentaenoic acid-derived resolvin D5 (RvD5_{n-3 DPA}) in sepsis. This study aimed to investigate the functions of commonly used anticoagulants warfarin, dabigatran and heparin in regulating inflammation resolution.

Methods: Peripheral blood was collected from clinical sepsis patients and healthy control for the determination of indicated indexes. Mouse sepsis models of zymosan-induced peritonitis and cecal ligation and puncture (CLP) were employed for the measurement of inflammation- and coagulation-related indexes. Western-blotting, ELISA and flow cytometry were applied to assess proteins. UPLC-MS/MS was used to evaluate lipid metabolites.

Results: Here we report that the transmembrane Fgl2 (mFgl2) was positively associated with coagulation, while soluble Fgl2 (sFgl2) level correlated with the enhanced number of peripheral blood mononuclear cells in the sepsis patients. The anticoagulants dabigatran and warfarin attenuated zymosan-induced peritonitis, which was not shared by heparin, while only dabigatran significantly improved sepsis survival in the CLP sepsis mouse model. Although these anticoagulants consistently inhibited pro-inflammatory mediators including prostaglandin E₂ and leukotriene B₄, only dabigatran increased sFgl2 at both the initiation and resolution phases of inflammation. Mechanistically, dabigatran elicited the shedding of sFgl2 via prothrombin-related metalloproteases, thereby enhanced the subsequent biosynthesis of RvD5_{n-3 DPA}via STAT6-ALOX15 axis. Blocking metalloproteases or ALOX15 significantly impaired dabigatran-enhanced macrophage efferocytosis in vitro, as well as delayed the dabigatran-accelerated inflammation resolution in vivo.

Conclusions: Our findings identify the dual anti-inflammatory and pro-resolving actions of dabigatran, through promoting sFgl2-triggered RvD5_{n-3 DPA} production, which has important implications for promoting tissue homeostasis of sepsis.

Direct oral anticoagulants for unusual-site venous thromboembolism

Direct oral anticoagulants (DOACs) are currently the preferred oral anticoagulant treatment for most of the patients with deep vein thrombosis of the lower extremities and/or pulmonary embolism. DOACs have several advantages over vitamin K antagonists, such as availability of fixed dosages, fewer drug interactions, faster onset of action, shorter half-life, and lower risk of major and intracranial bleeding. Although the evidence on the use of DOACs in patients with unusual-site venous thromboembolism (VTE) is limited to a few, small randomized controlled trials, these drugs are increasingly used in clinical practice, and several observational cohort studies have been published recently. This narrative review will describe the latest evidence for the use of the DOACs in patients with thrombosis in atypical locations (splanchnic, cerebral, upper extremity, ovarian, and renal vein thrombosis) and will provide some practical advice for their use in patients with unusual-site VTE.

Non-Vitamin K Antagonist Oral Anticoagulants in Patients With Atrial Fibrillation and Prior Gastrointestinal Bleeding

BACKGROUND AND PURPOSE

Limited data support the benefits of non-vitamin K oral anticoagulants (NOACs) among atrial fibrillation patients with prior gastrointestinal bleeding (GIB). We aimed to evaluate the effectiveness and safety of NOACs compared with those of warfarin among atrial fibrillation patients with prior GIB.

METHODS

Oral anticoagulant-naive individuals with atrial fibrillation and prior GIB between January 2010 and April 2018 were identified from the Korean claims database. NOAC users were compared with warfarin users by balancing covariates using the inverse probability of treatment weighting method. The primary outcomes were ischemic stroke, major bleeding, and the composite outcome (combined ischemic stroke and major bleeding). Fatal events from each outcome were evaluated as secondary outcomes.

RESULTS

A total of 42 048 patients were included (24 781 in the NOAC group and 17 267 in the warfarin group). The mean time from prior GIB to the initiation of oral anticoagulant was 3.1±2.6 years. After inverse probability of treatment weighting, baseline characteristics were balanced between the two groups (mean age, 72 years; men, 56.8%; and mean CHA₂DS₂-VASc score, 3.7). Lower risks of ischemic stroke, major bleeding, and the composite outcome were associated with NOAC use than with warfarin use (weighted hazard ratio, 0.608 [95% CI, 0.543-0.680]; hazard ratio, 0.731 [95% CI, 0.642-0.832]; and hazard ratio, 0.661 [95% CI, 0.606-0.721], respectively). For all secondary outcomes, NOACs showed greater risk reductions compared with warfarin.

CONCLUSIONS

NOACs were associated with lower risks of ischemic stroke and major bleeding than warfarin among atrial fibrillation patients with prior GIB.

Rectus sheath hematoma in patients receiving subcutaneous enoxaparin: A case series of five patients

Physicians must acknowledge the potential risk of RSH with enoxaparin. Switching home anticoagulation by enoxaparin upon hospital admission is common, but it may put patients at higher risk for RSH. Management guidelines are needed in this setting.

Comparing Major Bleeding Risk in Outpatients With Atrial Fibrillation or Flutter by Oral Anticoagulant Type (from the National Cardiovascular Disease Registry's Practice Innovation and Clinical Excellence Registry)

Direct oral anticoagulants (DOACs) have a favorable bleeding risk profile in patients with atrial fibrillation (AF). However, the safety of individual DOACs relative to warfarin for specific bleeding outcomes is less certain. We identified 423,450 patients with AF between 2013 to 2015 in the NCDR PINNACLE national ambulatory registry matched to the Centers for Medicare and Medicaid Services database. Outcomes included time to first major bleed, intracranial hemorrhage (ICH), major gastrointestinal bleed (GIB), or other major bleed. We estimated the association of OAC with bleeding using Cox proportional hazard models. The median duration of follow-up was 1.4 years. OACs were used in 64% of AF patients (66% warfarin, 15% rivaroxaban, 12% dabigatran, and 7% apixaban). A major bleeding event occurred in 6.9% of patients. Compared with warfarin users, fewer patients experienced ICH with the use of rivaroxaban (HR 0.73; 95% CI 0.64 to 0.84), dabigatran (HR 0.56; 95% CI 0.48 to 0.65), and apixaban (HR 0.70; 95% CI 0.55 to 0.90). The risk of major GIB was higher in rivaroxaban users (HR 1.20; 95% CI 1.12 to 1.27), and lower in dabigatran (HR 0.88; 95% CI 0.82 to 0.95) and apixaban (HR 0.84; 95% CI 0.74 to 0.95) users. For any DOAC versus warfarin, age (≥75 or <75 years) interacted with major bleeding (HR 0.93 vs 0.78; p <0.001), GIB (HR 1.10 vs 0.82; p <0.001), and other major bleeding (HR 0.93 vs 0.80; p <0.001). In conclusion, our results suggest that the safety of DOACs is superior to warfarin in AF patients, except with rivaroxaban and GIB. Age ≥75 years attenuated the relative safety benefits of DOACs.

Risk of Major Gastrointestinal Bleeding With New vs Conventional Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

There is controversy over whether use of non-vitamin K antagonist oral anticoagulants (NOACs) associates with increased risk of major gastrointestinal bleeding (GIB) compared with conventional therapies (such as vitamin K antagonists or anti-platelet agents). We performed a systematic review and meta-analysis of data from randomized controlled trials and high-quality real-world studies.

METHODS

We performed a systematic search of the MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov Website databases (through Oct 12, 2018) for randomized controlled trials and high-quality real-world studies that reported major GIB events in patients given NOACs or conventional therapy. Relative risks (RRs) for randomized controlled trials and adjusted hazard ratios (aHRs) for real-world studies were calculated separately using random-effects models.

RESULTS

We analyzed data from 43 randomized controlled trials (183,752 patients) and 41 real-world studies (1,879,428 patients). The pooled major rates of GIB for patients on NOACs (1.19%) vs conventional treatment (0.92%) did not differ significantly (RR from randomized controlled trials, 1.09; 95% CI, 0.91-1.31 and aHR from real-world studies, 1.02; 95% CI, 0.94-1.10; Pinteraction=.52). Rivaroxaban, but not other NOACs, was associated with an increased risk for major GIB (RR from randomized controlled trials, 1.39; 95% CI, 1.17-1.65 and aHR from real-world studies, 1.14; 95% CI, 1.04-1.23; Pinteraction = .06). Analyses of subgroups, such as patients with different indications, dosage, or follow-up time, did not significantly affect results. Meta-regression analysis failed to detect any potential confounding to impact the primacy outcome.

CONCLUSIONS

In a systematic review and meta-analysis of data from randomized controlled trials and real-world studies, we confirmed that there is no significant difference in risk of major GIB between patients receiving NOACs vs conventional treatment. Rivaroxaban users had a 39% increase in risk for major GIB.

Differences In Gastrointestinal Safety Profiles Among Novel Oral Anticoagulants: Evidence From A Network Meta-Analysis

Background

There is no consensus at present regarding the differences in the risk of GI bleeding across various NOAC regimens. Therefore, we performed a network meta-analysis to compare the risk of gastrointestinal bleeding after different NOAC regimens.

Methods

PubMed, Cochrane, Web of Science, Clinicaltrial.gov and Clinicaltrialresults.org were searched for randomized controlled trials (RCTs) assessing gastrointestinal bleeding of all NOAC regimens from inception to January 2018. The primary endpoint was major gastrointestinal (MGI) bleeding. The meta-regression was performed to access the association between the MGI bleeding events and mortality. The network meta-analysis was carried out with the Bayesian random-effect model.

Results

A total of 25 RCTs, including 139,392 patients, were identified. Meta-regression analysis showed that MGI bleeding was correlated with fatal bleeding events (odds ratios [OR], 1.76; 95% confidence interval [CI], 1.13-2.77], P=0.015). The network meta-analysis results showed that compared to the conventional regimens, rivaroxaban was associated with increased risk of MGI bleeding (OR, 1.37; 95% credible interval [CrI], 1.00-1.85), but not the apixaban (OR, 0.77; 95% CrI, 0.53-1.07]), edoxaban (OR, 0.86; 95%CrI, 0.52-1.18) and dabigatran etexilate (OR, 1.22; 95% CrI, 0.82-1.69). Compared to rivaroxaban, apixaban (OR, 0.56; 95% CrI, 0.35-0.88) and edoxaban (OR, 0.62; 95% CrI, 0.35-0.96) showed a significantly lower risk of MGI bleeding. Apixaban had the highest probability of being the safest option with regard to the risk of MGI bleeding (89.1%), followed by edoxaban (77.4%), conventional therapy (51.4%), dabigatran etexilate (23.8%) and rivaroxaban (8.3%).

Conclusion

The risk of GI bleeding significantly varies among different NOAC regimens, and evidence shows that apixaban and edoxaban had the most favorable MGI bleeding safety profile, while rivaroxaban and dabigatran etexilate were the least safe.

Clinical and endoscopic features of severe acute gastrointestinal bleeding in elderly patients treated with direct oral anticoagulants: a multicentre study

BACKGROUND

The aim of the study was to describe the clinical and endoscopic characteristics and management of severe acute gastrointestinal (GI) bleeding in patients treated with direct oral anticoagulants (DOACs).

METHODS

Patients hospitalized for severe GI bleeding under DOAC therapy were identified in 36 centres between June 2013 and March 2016. Clinical outcomes including re-bleeding, major cerebral and cardiovascular events or all-cause mortality were assessed initially and 30 days after admission.

RESULTS

A total of 59 patients with anonymized detailed endoscopy reports for severe GI bleeding were considered. Mean age was 79.3 ± 10.0 years and 61.3% of patients were men. Patients had histories of hypertension (65.6%), heart failure (29.5%), coronary artery disease (27.9%), stroke (19.7%) and peripheral vascular disease (36.1%). Life-threatening bleeding was observed in 42.6%. Mean number of packed red blood cells transfused was 3.4 (range 1-31). Aetiology of bleeding (identified in 66.2% of cases) was peptic gastroduodenal ulcers (22%), diverticula (11.9%), angiodysplasia (8.5%), colorectal neoplasia (5.1%) and anorectal causes (5.1%). Endoscopic haemostasis was performed in 37.7% of patients. A low haemoglobin level was predictive of life-threatening bleeding and death in multivariate analysis. All-cause mortality rate at day 30 was 11.8%.

CONCLUSIONS

In this cohort of elderly patients with multiple comorbidities treated with DOACs, the main cause of severe acute GI bleeding was peptic gastroduodenal ulcer and mortality was high.

Mortality rate and risk factors for gastrointestinal bleeding in elderly patients

BACKGROUND

Gastrointestinal bleeding (GIB) is burdened by high mortality rate that increases with aging. Elderly patients may be exposed to multiple risk factors for GIB. We aimed at defining the impact of GIB in elderly patients.

METHODS

Since 2008, samples of elderly patients (age ≥ 65 years) with multimorbidity admitted to 101 internal medicine wards across Italy have been prospectively enrolled and followed-up (REPOSI registry). Diagnoses of GIB, length of stay (LOS), mortality rate, and possible risk factors, including drugs, index of comorbidity (Cumulative Illness Rating Scale [CIRS]), polypharmacy, and chronic diseases were assessed. Adjusted multivariate logistic regression models were computed.

RESULTS

3872 patients were included (mean age 79 ± 7.5 years, F:M ratio 1.1:1). GIB was reported in 120 patients (mean age 79.6 ± 7.3 years, F:M 0.9:1), with a crude prevalence of 3.1%. Upper GIB occurred in 72 patients (mean age 79.3 ± 7.6 years, F:M 0.8:1), lower GIB in 51 patients (mean age 79.4 ± 7.1 years, F:M 0.9:1), and both upper/lower GIB in 3 patients. Hemorrhagic gastritis/duodenitis and colonic diverticular disease were the most common causes. The LOS of patients with GIB was 11.7 ± 8.1 days, with a 3.3% in-hospital and a 9.4% 3-month mortality rates. Liver cirrhosis (OR 5.64; CI 2.51-12.65), non-ASA antiplatelet agents (OR 2.70; CI 1.23-5.90), and CIRS index of comorbidity >3 (OR 2.41; CI 1.16-4.98) were associated with GIB (p < 0.05).

CONCLUSIONS

A high index of comorbidity is associated with high odds of GIB in elderly patients. The use of non-ASA antiplatelet agents should be discussed in patients with multimorbidity.

Surgically treated rare intestinal bleeding due to submucosal hematoma in a patient on oral anticoagulant therapy: A case report

RATIONALE

Bleeding in the gastrointestinal tract is a common complication of oral anticoagulant therapy (AT), and it usually appears as mucosal erosion or ulcer; however, intestinal submucosal hematoma (ISH) is an uncommon cause of hemorrhage.

PATIENT CONCERNS

This report presents the case of a 70-year-old woman with acute hematochezia induced by AT. She underwent computed tomography and endoscopy.

DIAGNOSES

Colon submucosal hematoma.

INTERVENTIONS

Conservative treatment had no effect, and the patient underwent emergency surgery.

OUTCOMES

Surgical resection showed hemorrhage and necrosis in the left colon, and the patient recovered 24 hours after surgery and continued AT.

LESSONS

The present case indicates that the ISH should be kept in mind as a complication of AT. It can be managed conservatively in some stable patients, but emergency surgery may be needed in some serious situations.

A systematic review of clinicians' views and experiences of direct-acting oral anticoagulants in the management of nonvalvular atrial fibrillation

AIMS

While a plethora of systematic reviews have provided evidence of efficacy, effectiveness and safety of direct-acting oral anticoagulants (DOACs) in the management of nonvalvular atrial fibrillation, there has been little emphasis on clinicians' perspectives. This systematic review aimed to critically appraise, synthesize and present the available evidence of clinicians' views and experiences.

METHODS

Studies published in English from January 2006 to July 2017 reporting the views and/or experiences of doctors, nurses or pharmacists on any individual DOAC or as a pharmacological group were included. Studies were assessed for quality by two researchers, data extracted and findings synthesized using a narrative approach.

RESULTS

Following exclusion of duplicates, 777 titles, 394 abstracts and 196 studies were screened. Ten studies were included in the review, nine of which were quantitative (cross-sectional surveys) and one qualitative (semistructured interviews), with marked heterogeneity in outcomes reported. Studies were conducted exclusively in Europe and the USA. In those studies reporting clinician preference, DOACs were first choice over warfarin in naïve patients, based on perceptions of evidence of effectiveness equivalent or superior to warfarin and superior safety. Other advantageous factors were in those with an unstable International Normalized Ratio and likely to miss appointments. There were, however, concerns relating to management of over-anticoagulation and experiences of observed bleeding rates.

CONCLUSION

There is a limited evidence base of clinicians' perspectives of DOACs, necessitating further research, particularly given the trajectory of increased use worldwide.

Discovery of FIXa inhibitors by combination of pharmacophore modeling, molecular docking, and 3D-QSAR modeling

Human Coagulation Factor IXa (FIXa), specifically inhibited at the initiation stage of the blood coagulation cascade, is an excellent target for developing selective and safe anticoagulants. To explore this inhibitory mechanism, 86 FIXa inhibitors were selected to generate pharmacophore models and subsequently SAR models. Both best pharmacophore model and ROC curve were built through the Receptor-Ligand Pharmacophore Generation module. CoMFA model based on molecular docking and PLS factor analysis methods were developed. Model propagations values are q² = 0.709, r² = 0.949, and r²_pred = 0.905. The satisfactory q² value of 0.609, r² value of 0.962, and r²_pred value of 0.819 for CoMSIA indicated that the CoMFA and CoMSIA models are both available to predict the inhibitory activity on FIXa. On the basis of pharmacophore modeling, molecular docking, and 3D-QSAR modeling screening, six molecules are screened as potential FIXa inhibitors.

Evaluation and management of Non-variceal upper gastrointestinal bleeding

Non-variceal upper gastrointestinal bleeding continues to be an important cause of morbidity and mortality. The most common causes include peptic ulcer disease, Mallory-Weiss syndrome, erosive gastritis, duodenitis, esophagitis, malignancy, angiodysplasias and Dieulafoy's lesion. Initial assessment and early aggressive resuscitation significantly improves outcomes. Upper gastrointestinal endoscopy continues to be the gold standard for diagnosis and treatment. We present a comprehensive review of literature for the evaluation and management of non-variceal upper gastrointestinal bleeding.

Risk of gastrointestinal bleeding during anticoagulant treatment

INTRODUCTION

Gastrointestinal bleeding (GIB) is a major problem in patients on oral anticoagulation therapy. This issue has become even more pressing since the introduction of direct oral anticoagulants (DOACs) in 2009. Areas covered: Here we review current evidence related to GIB associated with oral anticoagulants, focusing on randomized controlled trials, meta-analyses, and post-marketing observational studies. Dabigatran 150 mg twice daily and rivaroxaban 20 mg once daily increase the risk of GIB compared to warfarin. The risk increase with edoxaban is dose-dependent, while apixaban shows apparently, no increased risk. We summarize what is known about GIB risk factors for individual anticoagulants, the location of GIB in patients taking these compounds, and prevention strategies that lower the risk of GIB. Expert opinion: Recently there has been an important shift in the clinical presentation of GIB. Specifically, upper GIB has decreased with the decreased incidence of peptic ulcers due to the broad use of proton pump inhibitors and the decreased prevalence of H. pylori infections. In contrast, the incidence of lower GIB has increased, due in part to colonic diverticular bleeding and angiodysplasia in the elderly. In this population, the addition of oral anticoagulation therapy, especially DOACs, seems to increase the risk of lower GIB.