Study protocol for the dabigatran, apixaban, rivaroxaban, edoxaban, warfarin comparative effectiveness research study

Comparison of bleeding and ischemic events with apixaban vs. rivaroxaban in triple antithrombotic therapy regimens

OBJECTIVE

To compare the risk of readmissions for major bleeding within one year between apixaban and rivaroxaban as a component of triple antithrombotic therapy.

METHODS

This study was a multicenter, retrospective cohort study conducted at two academic medical centers in the Western New York and New York City region between July 1, 2011 and September 25, 2019. Adult patients were included if they were diagnosed with atrial fibrillation or venous thromboembolism and discharged on new triple antithrombotic therapy. The primary outcome compared the rates of 1-year readmission for major bleeding between apixaban and rivaroxaban groups. Secondary outcomes included rate of ischemic outcomes. Time to event analysis was determined with a Kaplan-Meier plot and Cox proportional hazard ratios (HR).

RESULTS

A total of 378 patients were included in the study, 212 in the apixaban group and 166 in the rivaroxaban group. Within 1 year, readmission for major bleeding events occurred in six (2.8%) patients in the apixaban group and four (2.4%) patients in the rivaroxaban group ( P  = 1.000). After adjustment, the major bleeding event rate was not statistically significantly different between apixaban and rivaroxaban [adjusted hazard ratio (aHR) 0.68, 95% confidence interval (CI) 0.12-3.77; P  = 0.6624]. Higher albumin levels were identified to be protective against major bleeding related readmission events (aHR 0.18, 95% CI 0.05-0.63; P  = 0.0072). The ischemic outcome occurred in seven (3.3%) patients in the apixaban group and three (1.8%) in the rivaroxaban group ( P  = 0.7368).

CONCLUSION

Use of apixaban or rivaroxaban in a triple antithrombotic regimen was not associated with bleeding or ischemic outcomes.

New generation oral anticoagulant apixaban enhances embryo implantation by increasing integrin β3 expression in rats: A pilot study

OBJECTIVE

The first aim of this study was to investigate the effect of apixaban on endometrial receptivity via immunohistochemical investigation of integrin β3 expression in pregnant rats. The second aim was to compare the endometrial effects of both subcutaneous and oral anticoagulant drugs in terms of integrin β3 expressions.

METHODS

A total of 24 rats were selected for this study and divided into three equal groups as control, enoxaparin and apixaban groups. Subcutaneous enoxaparin and oral apixaban were applied for 15 days starting on the first day of pregnancy. On the 15th day of pregnancy, all rats were killed by cervical dislocation, and uterine horns, including pregnancy materials, were investigated for pregnancy success and endometrial receptivity by using immunohistochemical integrin β3 staining.

RESULTS

Living, viable fetuses were higher in the apixaban group compared to the control group (p=0.037). Intensity and universality of immunohistochemical staining of integrin β3 for endometrial stroma were detected statistically higher in the apixaban group than the other groups. (p=0.009 for intensity, p=0.014 for universality). Endometrial epithelial and myometrial integrin β3 expression were detected to be identical between the groups (p=0.3).

CONCLUSIONS

Apixaban enhances endometrial receptivity via increasing integrin β3 expression in rats. This result can lead to further studies to be done in the future.

Introducing Volume 7 of the Journal of Comparative Effectiveness Research

Welcome to the seventh volume of the Journal of Comparative Effectiveness Research. It is great to start the year with a look back at some of our successes from 2017, as well as a look forward to the content of this issue and beyond.