GI Bleeding Risk of DOACs Versus Warfarin: Is Newer Better?

Construction of a risk scoring system using clinical factors and RYR2 polymorphisms for bleeding complications in patients on direct oral anticoagulants

Introduction: Bleeding is one of the most undesirable complications of direct oral anticoagulants (DOACs). While the ryanodine receptor (RYR2) has been related to cardiac diseases, research on bleeding complications is lacking. This study aimed to elucidate the association between RYR2 and bleeding risk to develop the risk scoring system in patients treated with DOACs. Methods: This study was a retrospective analysis of prospectively collected samples. We selected ten SNPs within the RYR2 gene, and two models were constructed (Model I: demographic factors only, Model II: demographic and genetic factors) in multivariable analysis. Independent risk factors for bleeding were used to develop a risk scoring system. Results: A total of 447 patients were included, and 49 experienced either major bleeding or clinically relevant non-major bleeding. In Model I, patients using rivaroxaban and experiencing anemia exhibited an increased bleeding risk after adjusting for covariates. Upon incorporating genetic factors into Model I, a significant association with bleeding was also observed in cases of overdosing on DOACs and in patients with a creatinine clearance (CrCl) < 30 mL/min, in addition to rivaroxaban and anemia (Model II). Among genetic factors, RYR2 rs12594 GG, rs17682073 AA, rs3766871 GG, and rs6678625 T alleles were associated with bleeding complications. The area under the receiver operating characteristic curve (AUROC) of Model I was 0.670, whereas that of Model II increased to 0.803, demonstrating better performance with the inclusion of genetic factors. Using the significant variables in Model II, a risk scoring system was constructed. The predicted bleeding risks for scores of 0, 1-2, 3-4, 5-6, 7-8, and 9-10 points were 0%, 1.2%, 4.6%, 15.7%, 41.7%, and 73.3%, respectively. Conclusion: This study revealed an association between RYR2 and bleeding complications among patients taking DOACs and established a risk scoring system to support individualized DOAC treatment for these patients.

Direct oral anticoagulants are associated with potentially bleeding lesions in suspected mid-gastrointestinal bleeding

BACKGROUND AND AIM

Direct oral anticoagulants (DOACs) became a widespread alternative in anticoagulant therapy. Nevertheless, concerns are raised about their safety, with increased gastrointestinal bleeding rates being described. There are scarce studies regarding DOACs effect on small-bowel capsule endoscopy (SBCE) findings. We aimed to assess if the detection of lesions with high bleeding potential on SBCE was significantly different in patients treated with DOACs when compared to non-anticoagulated patients and to patients anticoagulated with other agents.

METHODS

Cohort study including consecutive patients who underwent SBCE for suspected mid-gastrointestinal bleeding (MGIB) in 2019 and 2020.

RESULTS

From 148 patients, 38 (25.7%) were anticoagulated, of which 26 (68.4%) with DOACs. P2 lesions were detected in 36.5% (n = 54) of the patients. These lesions were more frequently detected in patients under DOACs treatment when compared to non-anticoagulated patients (69.2% vs. 29.1%; p=.001), and also when compared to patients treated with other anticoagulants (69.2% vs. 33.3%; p=.037). No differences in P2 lesions detection were observed between patients treated with other anticoagulants and non-anticoagulated patients (33.3% vs. 29.1%; p=.747). In multivariate analysis, DOACs usage was significantly associated with higher detection rates of P2 lesions on SBCE, when adjusted for classical risk factors for MGIB (OR: 3.38; 95%CI = 1.23-9.26; p=.018).

CONCLUSIONS

Despite their undeniable cardiovascular benefits and easy applicability, DOACs should still be considered with caution. These drugs were significantly associated with higher risk of potentially bleeding lesions on SBCE when compared to other anticoagulants and represent an independent risk factor for MGIB when adjusted for other variables.

Apixaban vs. Warfarin in Atrial Fibrillation Patients With Chronic Kidney Disease

Background and Objectives: Real-world evidence of apixaban treatment in patients with chronic kidney disease remains scarce. This study aimed to compare the relative risk of stroke or systemic embolism (SE) and major bleeding between apixaban and warfarin in atrial fibrillation (AF) patients with different degrees of kidney function.

Design, Setting, Participants, and Measurements: We evaluated newly diagnosed AF patients between 2004 and 2018, who were receiving apixaban or warfarin. Electronic medical record data were collected from a large healthcare delivery network in Taiwan. The outcomes of hospitalization for stroke/SE and major bleeding were compared with propensity-score matched apixaban and warfarin cohorts. Stratified analyses according to initial apixaban dose (standard dose of 10 mg/day vs. lower dose of 2.5–5.0 mg/day) and baseline estimated glomerular filtration rate were performed.

Results: Each cohort involved 1,625 matched patients. Apixaban was significantly associated with a lower risk of stroke/SE (adjusted hazard ratio [aHR]: 0.74; 95% confidence interval [CI]:0.57–0.97; p = 0.03). The risk of major bleeding was not increased whether in standard doses (aHR: 0.66; 95% CI: 0.45–0.96; p = 0.03) or reduced doses (aHR, 0.84; 95% CI, 0.63–1.12; p = 0.23) of apixaban. Regarding kidney function, apixaban reduced the risk of stroke/SE by 37% in those with an eGFR of <30 ml/min/1.73 m² (aHR: 0.63; 95% CI: 0.40–0.98; p = 0.04).

Conclusions: Compared to warfarin, apixaban is associated with a reduced risk of stroke/SE and is consistent with a subset of AF patients with eGFR <30 ml/min/1.73 m². Both standard and reduced doses of apixaban showed lower risk of major bleeding than those of warfarin.

The Watchman device for preventing stroke in patients with atrial fibrillation

ABSTRACT

Atrial fibrillation (AF) is one of the most common sustained dysrhythmias that increases in prevalence with age, and is associated with strokes that can lead to significant patient morbidity and mortality. AF prevalence is projected to double over the next 25 years, demonstrating the need for innovative and effective stroke prevention modalities. Two options are direct oral anticoagulants and left atrial appendage occlusion. This article discusses the Watchman device, a left atrial appendage occlusion device that provides an option for patients with contraindications for anticoagulation.

Major gastrointestinal bleeding and antithrombotics: Characteristics and management

BACKGROUND

There are few reports on major gastrointestinal (GI) bleeding among patients receiving an antithrombotic.

AIM

To describe clinical characteristics, bleeding locations, management and in-hospital mortality related to these events.

METHODS

Over a three-year period, we prospectively identified 1080 consecutive adult patients admitted in two tertiary care hospitals between January 1, 2013 and December 31, 2015 for major GI bleeding while receiving an antithrombotic. The bleeding events were medically validated. Clinical characteristics, causative lesions, management and fatalities were described. The distribution of antithrombotics prescribed was compared across the bleeding lesions identified.

RESULTS

Of 576 patients had symptoms of upper GI bleeding and 504 symptoms of lower GI bleeding. No cause was identified for 383 (35.5%) patients. Gastro-duodenal ulcer was the first causative lesion in the upper tract (209 out of 408) and colonic diverticulum the first causative lesion in the lower tract (120 out of 289). There was a larger proportion of direct oral anticoagulant use among patients with lower GI than among those with upper GI lesion locations (P = 0.03). There was an independent association between gastro-duodenal ulcer and antithrombotic use (P = 0.03), taking account of confounders and proton pump inhibitor co-prescription. Pair wise comparisons pointed to a difference between vitamin K antagonist, direct oral anticoagulants, and antiplatelet agents in monotherapy vs dual antiplatelet agents.

CONCLUSION

We showed a higher rate of bleeding lesion identification and suggested a different pattern of antithrombotic exposure between upper and lower GI lesion locations and between gastro-duodenal ulcer and other identified upper GI causes of bleeding. Management was similar across antithrombotics and in-hospital mortality was low (5.95%).

The gut microbes, Enterococcus and Escherichia-Shigella, affect the responses of heart valve replacement patients to the anticoagulant warfarin

Numerous algorithms based on patient genetic variants have been established with the aim of reducing the risk of GI bleeding and thromboembolism during warfarin administration. However, approximately 35 % of individual warfarin sensitivity still remains unexplained. Few of warfarin algorithms take into account gut microbiota profiles. The identification of certain microbiome will provide new targets and new strategies for reducing the risk of bleeding and thromboembolism during warfarin administration. In this study, we collected plasma and stool samples from 200 inpatients undergoing heart valve replacement (HVR), which were classified as low responder (LR), high responder (HR) and normal responder (NR). Significant differences were observed in the diversity and relative abundance of the gut microbiota among the three groups. The genus Escherichia-Shigella was enriched significantly in the LRs (P = 3.189e^-11), while the genus Enterococcus was enriched significantly in the HRs (P = 1.249e^-11). The amount of VK2 synthesized by gut microbiota in LR group was much higher than that in HR group (P = 0.005). Whole genome shotgun sequencing indicated that the relative abundance of enzymes and modules associated with VK biosynthesis was significantly higher in LRs than in HRs or NRs. The 12 microbial markers were identified through tenfold cross-validation with a random forest model. The results provided a new microbial diagnostic model that can be used to inform modulation of warfarin dosage on the basis of patient intestinal flora composition.

Preventable Cases of Oral Anticoagulant-Induced Bleeding: Data From the Spontaneous Reporting System

Background

Despite the risk of bleeding is a well-known adverse effect of oral anticoagulants, there is scarce evidence on the preventability of oral anticoagulant-induced bleedings. Therefore, we investigated the potential risk factors related to preventable cases of oral anticoagulant-induced bleedings.

Methods

We performed a study using Individual Case Safety Reports (ICSRs) with an oral anticoagulant as suspected drug among those reported through the spontaneous reporting system of Campania Region from 1 July 2012 to 31 December 2017. The P-method was used for the preventability assessment of all cases of bleeding.

Results

In total, 58 cases out of 253 (22.9%) were preventable, and the most reported suspected drug was an indirect oral anticoagulant (warfarin). Sixty-eight critical criteria for preventability were identified, all related to healthcare professionals' practices. The most detected risk factor related to healthcare professionals' practices was the labeled drug-drug interaction for both direct and indirect oral anticoagulants.

Conclusion

Our findings describe the most reported risk factors for preventability of oral anticoagulant-induced bleedings. These factors may be useful for targeting interventions to improve pharmacovigilance activities in our regional territory and to reduce the burden of medication errors and inappropriate prescription.

Colonoscopy, Polypectomy, and the Risk of Bleeding

Colonoscopy with polypectomy is the means by which the incidence of colon cancer may be reduced; however, polypectomy is not without risk. Physicians must carefully weigh the risks and benefits of colonoscopy, particularly when patients are given prescriptions for antiplatelet agents and anticoagulants. This article discusses the risks of colonoscopy and polypectomy and reviews the most recent data for managing antiplatelet agents and anticoagulants in the periendoscopic period.