Gender Related Differences in Gastrointestinal Bleeding With Oral Anticoagulation in Atrial Fibrillation

Sex-specific comparative outcomes between oral anticoagulants in patients with atrial fibrillation: a systematic review and meta-analysis

AIMS

Women with atrial fibrillation (AF) are under-represented in randomised controlled trials (RCTs) of direct oral anticoagulants (DOACs). This systematic review and meta-analysis of RCTs and observational studies examined sex-specific outcomes of DOACs in AF.

METHODS

PubMed, Embase, Web of Science and Cochrane Library were searched from January 2008 to November 2022. Sex-specific comparative outcomes of stroke/systemic embolism (SE), major bleeding, intracranial haemorrhage (ICH) and gastrointestinal bleeding (GIB) between oral anticoagulants were pooled using random effects models. P values for interaction were calculated to examine differences in results between sexes. RCTs and observational studies were meta-analysed separately.

RESULTS

5 RCTs and 33 observational studies were included, totalling 1 085 931 women and 1 387 123 men. Meta-analyses showed that for both sexes, DOAC versus warfarin was generally associated with lower risk of stroke/SE, major bleeding and ICH; in DOAC-DOAC comparisons, rivaroxaban versus dabigatran had higher GIB risk. The only sex-specific difference observed was that when compared with warfarin, women had higher GIB risk with rivaroxaban (women: pooled risk ratio (pRR)=1.34, 95% CI=1.18 to 1.51; men: pRR=0.97, 95% CI=0.85 to 1.10; p value for interaction (p for interaction)<0.001) and possibly dabigatran (women: pRR=1.25, 95% CI=0.92 to 1.70; men: pRR=0.83, 95% CI=0.72 to 0.97; p-for-interaction=0.02). The sex difference in GIB remained for rivaroxaban when a Bonferroni-corrected significance level was used (α=0.003). No sex-specific GIB data for apixaban and edoxaban was available for the meta-analysis.

CONCLUSIONS

For both sexes, DOACs generally demonstrated favourable effectiveness and safety over warfarin. However, observational data suggested that women may have higher GIB risk with rivaroxaban and possibly dabigatran than warfarin. Further studies are warranted to verify our findings and elucidate sex-specific GIB risk with apixaban and edoxaban, of which the data is currently lacking.

PROSPERO REGISTRATION NUMBER

CRD42022325027.

Head-to-head ex vivo comparison of clinically used direct anticoagulant drugs

An imbalance in coagulation is associated with cardiovascular events. For prevention and treatment, anticoagulants, currently mainly xabans and gatrans, are used. The purpose of the present study was to provide a head-to-head comparison since there are no studies directly evaluating these novel anticoagulants. An additional aim was to find whether selected anthropological and biochemical factors can affect their anticoagulant properties as they are used in fixed doses. In this cross-sectional study, blood from 50 generally healthy donors was collected, and coagulation responses to dabigatran, argatroban, rivaroxaban, and apixaban, at a concentration of 1 μM, were analyzed. Heparin was used as a positive control. Prothrombin time (PT) expressed as international normalized ratio (INR) and activated partial thromboplastin time (aPTT) were measured and compared. Rivaroxaban was the most active according to PT/INR while argatroban according to aPTT. The ex vivo anticoagulant effect measured by INR correlated inversely with body mass index (BMI) in all four anticoagulants tested. Shortening of aPTT was associated with higher cholesterol and triglyceride levels. No sex-related differences were observed in response to the anticoagulant treatments. As this was an ex vivo study and pharmacokinetic factors were not included, the influence of BMI is of high therapeutic importance.

Risk factors for anticoagulant-associated gastrointestinal hemorrhage: a systematic review and meta-analysis

BACKGROUND/AIMS

There may be many predictors of anticoagulation-related gastrointestinal bleeding (GIB), but until now, systematic reviews and assessments of the certainty of the evidence have not been published. We conducted a systematic review to identify all risk factors for anticoagulant-associated GIB to inform risk prediction in the management of anticoagulation- related GIB.

METHODS

A systematic review and meta-analysis were conducted to search PubMed, EMBASE, Web of Science, and Cochrane Library databases (from inception through January 21, 2022) using the following search terms: anticoagulants, heparin, warfarin, dabigatran, rivaroxaban, apixaban, DOACs, gastrointestinal hemorrhage, risk factors. According to inclusion and exclusion criteria, studies of risk factors for anticoagulation-related GIB were identified. Risk factors for anticoagulant-associated GIB were used as the outcome index of this review.

RESULTS

We included 34 studies in our analysis. For anticoagulant-associated GIB, moderate-certainty evidence showed a probable association with older age, kidney disease, concomitant use of aspirin, concomitant use of the antiplatelet agent, heart failure, myocardial infarction, hematochezia, renal failure, coronary artery disease, helicobacter pylori infection, social risk factors, alcohol use, smoking, anemia, history of sleep apnea, chronic obstructive pulmonary disease, international normalized ratio (INR), obesity et al. Some of these factors are not included in current GIB risk prediction models. such as anemia, co-administration of gemfibrozil, co-administration of verapamil or diltiazem, INR, heart failure, myocardial infarction, etc.

CONCLUSION

The study found that anemia, co-administration of gemfibrozil, co-administration of verapamil or diltiazem, INR, heart failure, myocardial infarction et al. were associated with anticoagulation-related GIB, and these factors were not in the existing prediction models. This study informs risk prediction for anticoagulant-associated GIB, it also informs guidelines for GIB prevention and future research.

Sex disparities in left ventricular assist device implantation outcomes: A systematic review and meta-analysis of over 50 000 patients

BACKGROUND

Left ventricular assist devices (LVAD) represent an important therapeutic option for patients progressing to end-stage heart failure. Women have been historically underrepresented in LVAD studies, and have been reported to have worse outcomes despite technological optimisation. We aimed to systematically explore the evidence on sex disparities in the use and outcomes of LVAD implantation.

METHODS

A systematic database search with meta-analysis was conducted of comparative original articles of men versus women undergoing LVAD implantation, in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to July 2022. Primary outcomes were stroke (haemorrhagic and ischaemic) and early/overall mortality. Secondary outcomes were LVAD thrombosis, right VAD implantation, major bleeding, kidney dysfunction, and device/driveline infection.

RESULTS

Our search yielded 137 relevant studies, including 22 meeting the inclusion criteria with a total of 53 227 patients (24.2% women). Overall mortality was higher in women (odds ratio [OR] 1.35, 95% confidence interval [CI] 1.05-1.62, p = 0.02), as was overall stroke (OR 1.32, 95%CI 1.06-1.66, p = 0.01), including ischemic (OR 1.80, 95%CI 1.22-2.64, p = 0.003) and haemorrhagic (OR 1.72, 95%CI 1.09-2.70, p = 0.02). Women had more frequent right VAD implantation (OR 2.11, 95%CI 1.24-3.57, p = 0.006) and major bleeding (OR 1.40, 95%CI 1.06-1.85, p = 0.02). Kidney dysfunction, LVAD thrombosis, and device/driveline infections were comparable between sexes.

CONCLUSIONS

Our analysis suggests that women face a greater risk of adverse events and mortality post-LVAD implantation. Although the mechanisms remain unclear, the difference in outcomes is thought to be multifactorial. Further research, that includes comprehensive pre-operative characteristics and post-operative outcomes, is encouraged.