Direct Oral Anticoagulants in the Treatment of Venous Thromboembolism: Use in Patients with Advanced Renal Impairment, Obesity, or Other Weight-Related Special Populations

A real-world exploration into clinical outcomes of direct oral anticoagulant therapy in people with chronic kidney disease: a large hospital-based study

BACKGROUND

There is limited evidence to support definite clinical outcomes of direct oral anticoagulant (DOAC) therapy in chronic kidney disease (CKD). By identifying the important variables associated with clinical outcomes following DOAC administration in patients in different stages of CKD, this study aims to assess this evidence gap.

METHODS

An anonymised dataset comprising 97,413 patients receiving DOAC therapy in a tertiary health setting was systematically extracted from the multidimensional electronic health records and prepared for analysis. Machine learning classifiers were applied to the prepared dataset to select the important features which informed covariate selection in multivariate logistic regression analysis.

RESULTS

For both CKD and non-CKD DOAC users, features such as length of stay, treatment days, and age were ranked highest for relevance to adverse outcomes like death and stroke. Patients with Stage 3a CKD had significantly higher odds of ischaemic stroke (OR 2.45, 95% Cl: 2.10-2.86; p = 0.001) and lower odds of all-cause mortality (OR 0.87, 95% Cl: 0.79-0.95; p = 0.001) on apixaban therapy. In patients with CKD (Stage 5) receiving apixaban, the odds of death were significantly lowered (OR 0.28, 95% Cl: 0.14-0.58; p = 0.001), while the effect on ischaemic stroke was insignificant.

CONCLUSIONS

A positive effect of DOAC therapy was observed in advanced CKD. Key factors influencing clinical outcomes following DOAC administration in patients in different stages of CKD were identified. These are crucial for designing more advanced studies to explore safer and more effective DOAC therapy for the population.

Efficacy, safety, and feasibility of Apixaban for postoperative venous thromboembolism prophylaxis following open gynecologic cancer surgery at a comprehensive cancer center

OBJECTIVES

To evaluate safety, efficacy, and feasibility of apixaban for postoperative venous thromboembolism (VTE) prophylaxis following open gynecologic cancer surgery at a comprehensive cancer center.

METHODS

This retrospective, cohort study included patients with gynecologic cancer who underwent open surgery between 3/2021 and 3/2023 and received 28-day postoperative VTE prophylaxis. Patients on therapeutic anticoagulation preoperatively were excluded. Predictors of 90- and 30-day VTE and 30-day bleeding events were determined using multivariable logistic regression, adjusting for known confounders.

RESULTS

452 patients were included in the cohort: 348 received apixaban and 104 received enoxaparin. Those who received enoxaparin were more likely to be American Society of Anesthesiologists class III/IV (compared to I/II) (p = 0.033), current or former smokers (p = 0.012) and have a higher BMI (p < 0.001), Charlson Comorbidity Index (p = 0.005), and age (p = 0.046). 30-day VTE rate was significantly lower in the apixaban group (0.6%) compared to the enoxaparin group (6.2%) (adjusted OR 0.13, 95% CI 0.03-0.56; p = 0.006). 90-day VTE rate was 2.7% and 6.2% in the apixaban and enoxaparin groups, respectively (adjusted OR 0.85, 95% CI 0.38-1.92; p = 0.704). Major bleeding complications (2.4% vs. 2.0%) and minor bleeding complications (0.9% vs. 3.0%) were similar in the apixaban and enoxaparin groups, respectively, on multivariate analyses. The median patient out of pocket cost was $10 (IQR 0.0-40.0) for apixaban and $20 (IQR 3.7-67.7) for enoxaparin (p = 0.001).

CONCLUSIONS

Our findings along with previously published data suggest that apixaban should be considered the standard of care for VTE prophylaxis in patients undergoing open surgery for gynecologic malignancies.

Antiplatelet Aggregation Properties of Cirsilineol: A Novel Inhibitor of Blood Coagulation Factor Xa

A small natural substance called cirsilineol (CSL), which was discovered in the plant Artemisia vestita, is lethal to many cancer cells and has antioxidant, anticancer, and antibacterial properties. Here, we investigated the underlying mechanisms of the antithrombotic action of CSL. We demonstrated that CSL has antithrombotic efficacy comparable to rivaroxaban, a direct blood coagulation factor Xa (FXa) inhibitor employed as a positive control, in inhibiting the enzymatic activity of FXa and the platelet aggregation induced by adenosine diphosphate (ADP) and U46619, a thromboxane A2 analog. The expression of P-selectin, the phosphorylation of myristoylated alanine-rich C kinase substrate by U46619 or ADP, and the activation of PAC-1 in platelets were inhibited by CSL. Nitric oxide production was increased by CSL in ADP- or U46619-treated human umbilical vein endothelial cells (HUVECs), although excessive endothelin-1 secretion was suppressed. CSL demonstrated strong anticoagulant and antithrombotic effects in a mouse model of arterial and pulmonary thrombosis. Our findings suggest that CSL is a potential pharmacological candidate for a novel class of anti-FXa and antiplatelet medications.