Effects of rivaroxaban and warfarin on the risk of gastrointestinal bleeding and intracranial hemorrhage in patients with atrial fibrillation: Systematic review and meta-analysis

Trends in prescribing and outcomes in obese versus non-obese patients receiving rivaroxaban therapy: an observational study using real-world data

PURPOSE

To investigate real-world prescribing trends and clinical outcomes based on body mass index (BMI) categorization in patients who received rivaroxaban therapy.

METHODS

This was a retrospective cohort study involving all patients who received rivaroxaban therapy across all Hamad Medical Corporation (HMC) hospitals from 2015 to 2020.

RESULTS

The number of patients initiated on rivaroxaban therapy significantly increased from 152 (3.3%) in 2015 to 1342 (28.9%) in 2020 (p <0.001). Within BMI categories, a similar increasing trend was observed in underweight, normal, and overweight patients, while from 2018 to 2020, there was a decreasing trend in rivaroxaban prescribing in all obese classes. The prevalence rate of all-cause mortality differed significantly between the BMI groups, with the highest mortality being among morbidly obese patients (BMI ≥ 40 kg/m2) (p< 0.001). On the other hand, no significant differences were found between the BMI groups in terms of bleeding, pulmonary embolism, deep vein thrombosis and stroke incidences. Multivariate logistic regression analyses showed that the likelihood of all-cause mortality was significantly higher in overweight and all categories of obese patients compared to underweight patients: overweight (OR: 5.3, 95% CI: 2.3-11.9, p< 0.001); obese class 1 (OR: 5.4, 95% CI: 2.3 - 12.2, p< 0.001); obese class 2 (OR: 6.5, 95% CI: 2.7 - 15.6, p< 0.001); and obese class 3 (OR: 3.7, 95% CI: 1.6 - 8.7, p = 0.003).

CONCLUSIONS

Rivaroxaban prescribing has significantly increased over the years across general population, with a noticeable decline in obese population during the last few years (from 2018 onwards). Furthermore, an appreciable association was evident between all-cause mortality and BMI of these patients.

Effectiveness and Safety of Non-Vitamin K Oral Anticoagulants versus Warfarin in Patients with Atrial Fibrillation and Previous Stroke: A Systematic Review and Meta-Analysis

INTRODUCTION

Current evidence regarding the clinical outcomes of non-vitamin K oral anticoagulants (NOACs) versus warfarin in patients with atrial fibrillation (AF) and previous stroke is inconclusive, especially in patients with previous intracranial haemorrhage (ICrH). We aim to undertake a systematic review and meta-analysis assessing the effectiveness and safety of NOACs versus warfarin in AF patients with a history of stroke.

METHODS

We searched studies published up to December 10, 2022, on PubMed, Medline, Embase, and Cochrane Central Register of Controlled Trials. Studies on adults with AF and previous ischaemic stroke (IS) or IrCH receiving either NOACs or warfarin and capturing outcome events (thromboembolic events, ICrH, and all-cause mortality) were eligible for inclusion.

RESULTS

Six randomized controlled trials (RCTs) (including 19,489 patients with previous IS) and fifteen observational studies (including 132,575 patients with previous IS and 13,068 patients with previous ICrH) were included. RCT data showed that compared with warfarin, NOACs were associated with a significant reduction in thromboembolic events (odds ratio [OR]: 0.85, 95% confidence interval [CI]: 0.75-0.96), ICrH (OR: 0.57, 95% CI: 0.36-0.90), and all-cause mortality (OR: 0.88, 95% CI: 0.80-0.98). In analysing observational studies, similar results were retrieved. Moreover, patients with previous ICrH had a lower OR on thromboembolic events than those with IS (OR: 0.66, 95% CI: 0.46-0.95 vs. OR: 0.80, 95% CI: 0.70-0.93) in the comparison between NOACs and warfarin.

CONCLUSIONS

Observational data showed that in AF patients with previous stroke, NOACs showed better clinical performance compared to warfarin and the benefits of NOACs were more pronounced in patients with previous IrCH versus those with IS. RCT data also showed NOACs are superior to warfarin. However, current RCTs only included AF patients who survived an IS, and further large RCTs focused on patients with previous ICrH are warranted.

Comparison of bleeding risk scores and evaluation of major bleeding predictive factors in patients with major bleeding due to vitamin K antagonist use

Background

Major bleeding in the treatment of atrial fibrillation is closely associated with an increased risk of death and major adverse outcomes in both the short and long term, but all bleeding events are associated with a reduced quality of life. Bleeding events are also known to reduce medication adherence. In this sense, bleeding risk scores are important tools to help predict major bleeding. However, it is not clear which scoring system is superior.

Aim

In this study, our aim was to compare bleeding risk scores and to examine the factors associated with bleeding in patients with major bleeding while using vitamin K antagonists.

Methods

In this retrospective and single-center study, scoring, laboratory and demographic data were analyzed with SPSS 20.0 statistical program.

Results

The mean age of a total of 1434 patients included in our study was 68.2 ± 11.3 years, range was 39-93 years and 769 (53.6%) of these patients were male. Of 588 patients with major bleeding, 93 (15.8%) had intracranial hemorrhage. Logistic regression analysis comparing the scoring systems among themselves revealed that the GARFIELD-AF scoring system had a predictive effect on major bleeding independent of the effect of other scoring systems (OR: 1.532, 95% CI 1.348-1.741, p < 0.001). The area under the curve (AUC) for GARFIELD-AF was 0.690 (0.662-0.718) as a result of the ROC analysis considering the best cut-off point of 3.2% calculated for 2 years. AUC 0.659 (0.630-0.687) for HAS-BLED, AUC 0.636 (0.606-0.665) for ORBIT and AUC 0.611 (0.5810.642) for ATRIA. When we compare the patient group with the control group, it can be said that intracranial hemorrhage occurred independently of INR and TTR values, unlike in the major bleeding group (p:0.129, p:0.545).

Conclusion

In patients using vitamin K antagonists for atrial fibrillation, the GARFIELD-AF risk score was found to be superior to important bleeding risk scores such as HAS-BLED, ORBIT and ATRIA in terms of predicting major bleeding. It is an important result that intracranial hemorrhages, which have a special place among major hemorrhages, were independent of INR and TTR levels. It is noteworthy that 8.2% of patients with major bleeding had a history of minor bleeding in the last year.

XGBoost-based machine learning test improves the accuracy of hemorrhage prediction among geriatric patients with long-term administration of rivaroxaban

BACKGROUND

Hemorrhage is a potential and serious adverse drug reaction, especially for geriatric patients with long-term administration of rivaroxaban. It is essential to establish an effective model for predicting bleeding events, which could improve the safety of rivaroxaban use in clinical practice.

METHODS

The hemorrhage information of 798 geriatric patients (over the age of 70 years) who needed long-term administration of rivaroxaban for anticoagulation therapy was constantly tracked and recorded through a well-established clinical follow-up system. Relying on the 27 collected clinical indicators of these patients, conventional logistic regression analysis, random forest and XGBoost-based machine learning approaches were applied to analyze the hemorrhagic risk factors and establish the corresponding prediction models. Furthermore, the performance of the models was tested and compared by the area under curve (AUC) of the receiver operating characteristic (ROC) curve.

RESULTS

A total of 112 patients (14.0%) had bleeding adverse events after treatment with rivaroxaban for more than 3 months. Among them, 96 patients had gastrointestinal and intracranial hemorrhage during treatment, which accounted for 83.18% of the total hemorrhagic events. The logistic regression, random forest and XGBoost models were established with AUCs of 0.679, 0.672 and 0.776, respectively. The XGBoost model showed the best predictive performance in terms of discrimination, accuracy and calibration among all the models.

CONCLUSION

An XGBoost-based model with good discrimination and accuracy was built to predict the hemorrhage risk of rivaroxaban, which will facilitate individualized treatment for geriatric patients.

Atraumatic Splenic Rupture: A Notable Complication of Rivaroxaban Use

Direct oral anticoagulants (DOACs) are well known to be associated with bleeding complications. However, little is known about their association with atraumatic splenic rupture, a potentially fatal condition. We present the case of a 73-year-old female with paroxysmal atrial fibrillation managed with rivaroxaban who developed a spontaneous atraumatic splenic rupture. This highlights the importance of recognizing this complication in patients without previous risk factors, such as abdominal trauma or infiltrative splenic disease, who are under anticoagulation with DOACs. There is a strong need for further research on this complication's underlying mechanism and management.

Local Ancestry-Informed Candidate Pathway Analysis of Warfarin Stable Dose in Latino Populations

Accuracy of warfarin dose prediction algorithms may be improved by including data from diverse populations in genetic studies of dose variability. Here, we surveyed single nucleotide polymorphisms in vitamin K-related genetic pathways for association with warfarin dose requirements in two admixed Latino populations in standard-principal component adjusted and contemporary-local ancestry adjusted regression models. A total of five variants from vitamin K-related genes/pathways were associated with warfarin dose in both cohorts (P < 0.0125) in standard models. Local ancestry-adjusted analysis unveiled 35 associated variants with absolute effects ranging from β = 9.04 ( ±2.23) to 39.18 ( ±10.89) per ancestral allele in the discovery cohort and β = 6.47 (± 2.02) to 17.82 (± 6.83) in the replication cohort. Importantly, we demonstrate the technical validity of the Tractor model in cohorts with admixed ancestry from three founder populations and bring attention to the technical hurdles obstructing the inclusion of diverse, especially admixed, populations in pharmacogenomic research.

Selection of Specific Aptamer against Rivaroxaban and Utilization for Label-Free Electrochemical Aptasensing Using Gold Nanoparticles: First Announcement and Application for Clinical Sample Analysis

For the first time, a novel aptamer was designed and utilized for the selective detection of rivaroxaban (RIV) using the integration of bioinformatics with biosensing technology. The selected aptamer with the sequence 5'-TAG GGA AGA GAA GGA CAT ATG ATG ACT CAC AAC TGG ACG AAC GTA CTT ATC CCC CCC AAT CAC TAG TGA ATT-3' displayed a high binding affinity to RIV and had an efficient ability to discriminate RIV from similar molecular structures. A novel label-free electrochemical aptasensor was designed and fabricated through the conjugation of a thiolated aptamer with Au nanoparticles (Au-NPs). Then, the aptasensor was successfully applied for the quantitative determination of RIV in human plasma and exhaled breath condensate (EBC) samples with limits of detection (LODs) of 14.08 and 6.03 nM, respectively. These valuable results provide ample evidence of the green electrogeneration of AuNPs on the surface of electrodes and their interaction with loaded aptamers (based on Au-S binding) towards the sensitive and selective monitoring of RIV in human plasma and EBC samples. This bio-assay is an alternative approach for the clinical analysis of RIV and has improved specificity and affinity. As far as we know, this is the first time that an electrochemical aptasensor has been verified for the recognition of RIV and that allows for the easy, fast, and precise screening of RIV in biological samples.

Spontaneous epidural hematoma induced by rivaroxaban: A case report and review of the literature

Background:

Trauma is the most frequent reason for epidural bleeding. However, numerous investigation had discovered that anticoagulants such as rivaroxaban could cause epidural hematoma. Here, we present a case of epidural hematoma in young man who got rivaroxaban as treatment of deep vein thrombosis.

Case Description:

A 27-year-old male with a history of deep vein thrombosis and one month of rivaroxaban medication presented with seizure and loss of consciousness following a severe headache. A CT scan of the head revealed epidural bleeding, and emergency blood clot removal was performed. As a reversal, prothrombin complex was utilized.

Conclusion:

Rivaroxaban has the potential to cause an epidural hemorrhage. Reversal anticoagulant should be administered before doing emergency surgery.

Changes in primary care management of atrial fibrillation patients following the shift from warfarin to non-vitamin K antagonist oral anticoagulants: a Norwegian population based study

Background

To assess baseline characteristics, drug utilisation and healthcare use for oral anticoagulants (OACs) following the introduction of non-vitamin K antagonist oral anticoagulants among patients with atrial fibrillation in primary care in Norway.

Methods

In this retrospective longitudinal cohort study, 92,936 patients with atrial fibrillation were identified from the Norwegian Primary Care Registry between 2010 and 2018. Linking to the Norwegian Prescription Database, we identified 64,112 patients (69.0%) treated with OACs and 28,824 (31%) who were untreated. Participants were followed until 15 May 2019, death, or loss to follow-up, whichever came first. For each OAC, predictors of initiation were assessed by modelling the probability of initiating the OAC using logistic regression, and predictors of the first switch after index date were assessed using multivariable Cox proportional hazards models. The numbers of primary care visits per quarter by index OAC were plotted and analysed with negative binomial regression analyses offset for the log of days at risk.

Results

Patients treated with OACs were older, had more comorbidities, and higher CHA₂DS₂-VASc scores than untreated patients. However, the mean CHA₂DS₂-VASc in the non-OAC group was 1.58 for men and 3.13 for women, suggesting an indication for OAC therapy. The percentage of patients with atrial fibrillation initiating OACs increased from 59% in 2010 to 79% in 2018. Non-vitamin K antagonist oral anticoagulant use increased throughout the study period to 95% of new OAC-treated patients in 2018, and switches from warfarin to non-vitamin K antagonist oral anticoagulants were common. The persistence of OAC treatment was > 60% after four years, with greatest persistence for apixaban. Patients treated with non-vitamin K antagonist oral anticoagulants had fewer primary care visits compared with those treated with warfarin (incidence rate ratio: 0.73, 95% confidence interval 0.71 to 0.75).

Conclusion

In this Norwegian primary care study, we found that the shift from warfarin to non-vitamin K antagonist oral anticoagulants was successful with 95% use in patients initiating OACs in 2018, and associated with fewer general practitioner visits. Persistence with OACs was high, particularly for apixaban. However, many patients eligible for treatment with OACs remained untreated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-022-01824-6.

A proposal for managing bleeding in patients on therapeutic factor XI(a) inhibitors

Several drugs that reduce functional levels of the plasma protease zymogen factor XI (FXI), or that inhibit its activated form (FXIa), are being evaluated as treatments to prevent thrombosis. Based on the observation that individuals with inherited FXI deficiency have a relatively mild bleeding disorder, it is anticipated that therapeutic FXI(a) inhibitors will have a smaller impact on hemostasis than anticoagulants targeting thrombin or factor Xa. However, even if FXI(a) inhibitors are determined to be safer than currently used anticoagulants, some patients on these drugs will experience abnormal bleeding or require emergent surgery. Strategies for dealing with such situations are required. Treatment with antifibrinolytic agents and low doses of recombinant factor VIIa effectively prevent abnormal bleeding in FXI-deficient patients with alloantibody inhibitors to FXI who undergo surgery. We propose that a similar strategy can be used for patients on therapeutic FXI(a) inhibitors who are bleeding or require invasive procedures.