Changing Treatment Patterns in Patients With Venous Thromboembolism in Taiwan

Dynamic Patterns and Persistence of Anticoagulation Therapy in Patients with Venous Thromboembolism in South Korea: A Nationwide Cohort Study

BACKGROUND

 Venous thromboembolism (VTE) is associated with increased morbidity, mortality, and health care expenditure. However, the comprehensive utilization of anticoagulation therapy in patients with VTE, especially regarding active cancer, in real-world practice remains unclear.

OBJECTIVE

 To describe the prescription, persistence, and patterns of anticoagulation therapy among patients with VTE stratified according to active cancer.

METHODS

 Using Korean nationwide claims data, we identified an incident, treatment-naïve cohort of patients with VTE from 2013 to 2019 and classified them according to the presence/absence of active cancer. We explored the secular trends, treatment patterns (e.g., discontinuation, interruption, and switch), and persistence of anticoagulation therapy.

RESULTS

 There were 48,504 and 7,255 patients without and with active cancer, respectively. Non-vitamin K antagonist oral anticoagulants (NOACs) were the most common anticoagulant in both groups (65.1 and 57.9%, respectively). The prescription of NOACs increased steeply over time, regardless of active cancer, whereas parenteral anticoagulants (PACs) plateaued and warfarin decreased sharply. A heterogeneous pattern was observed between the groups without and with active cancer (3-month persistence was 60.8, 62.9, 57.2, and 3.4%, respectively; 6-month persistence was 42.3, 33.5, 25.9, and 1.2% vs. 9.9%). Median durations of continuous anticoagulant therapy for warfarin, NOAC, and PAC were 183, 147, and 3 days in nonactive cancer patients, and 121, 117, and 44 days in active cancer patients.

CONCLUSION

 Our findings suggest that there were substantial differences in persistence, patterns, and patient characteristics of anticoagulant therapy based on index anticoagulant and active cancer.

Epidemiology and Treatment Patterns of Venous Thromboembolism: an Observational Study of Nationwide Time-Series Trends in Japan

INTRODUCTION

Previous studies on anticoagulation treatment trends have mostly focused on hospitalized patients. This study aimed to clarify the treatment status of patients with venous thromboembolism (VTE) in Japan from 2011 to 2018, including outpatients, and to assess adherence with current guidelines.

METHODS

Data of inpatients and outpatients who were treated for VTE were extracted from a nationwide claims database (Medical Data Vision Co., Ltd., Tokyo, Japan) and analyzed.

RESULTS

The study included 79,330 patients with VTE; half were diagnosed during hospitalization for diseases other than VTE. The proportion of outpatient treatment increased significantly from 2015 to 2018 (Cochran-Armitage trend test, P < 0.0001), while 80% were anticoagulated in hospital after pulmonary embolism (PE) diagnosis. The proportion of patients with VTE treated as outpatients was no lower than the proportion of inpatients, even in the presence of active cancer, and there were no clear differences in anticoagulant choices. Treatment with direct oral anticoagulants (DOACs) did not always include the recommended initial intensification therapy. There was wide variation in the duration of DOAC treatment and the median duration of use was shorter than that recommended in VTE treatment guidelines.

CONCLUSION

While the gradual increase in VTE outpatient treatment appears to be in line with guideline recommendations, PE outpatient treatment could be further facilitated. The large proportion of patients diagnosed with VTE during hospitalization for other conditions suggests the importance of further utilizing in-hospital manuals for thrombosis prevention. The presence or absence of cancer did not appear to affect the basic treatment strategy of anticoagulation for VTE. Future studies are expected to better define the characteristics of patients who can be safely and effectively treated in an outpatient setting, and to examine whether anticoagulation for a shorter treatment period than recommended by the guidelines or DOAC therapy without initial intensification would improve patient outcomes.

A Comparison among Nonvitamin K Antagonist Oral Anticoagulants in Asian Patients with Venous Thromboembolism: A Multi-Institutional Study

The comparison of clinical effectiveness and safety across different nonvitamin K antagonist direct oral anticoagulants (DOACs) in Asian patients with venous thromboembolism (VTE) remains unclear. Therefore, we assessed the real-world benefits of different DOACs in these patients. A cohort of 1480 patients with VTE were identified from the Chang Gung Research Database between 1 January 2012, and 31 December 2019. The composite outcomes of recurrent VTE and major bleeding were evaluated for four DOACs. The composite outcomes of recurrent VTE and major bleeding occurred in 9.06%, 9.80%, 8.61%, and 10.86% of the apixaban, dabigatran, edoxaban, and rivaroxaban groups, respectively, within 12 months of treatment initiation. The risk of the composite outcomes was similar in the rivaroxaban group and the apixaban, dabigatran, and edoxaban groups, with a subdistribution hazard ratio (SHR) of 0.80 (95% CI, 0.49-1.29), 0.81 (95% CI, 0.34-1.95), and 0.76 (95% CI, 0.42-1.39), respectively. No significant differences in the rates of recurrent VTE or major bleeding were observed between the rivaroxaban and other DOAC groups at the 12-month follow-up. According to real-world practice in Asian patients with VTE, the DOAC type was not associated with the differences in the risk of recurrent VTE or major bleeding within 12 months of treatment initiation.

An engineered factor Va prevents bleeding induced by direct-acting oral anticoagulants by different mechanisms

Control of bleeding with direct-acting oral anticoagulants (DOACs) remains an unmet clinical need. Activated superFactor V (superFVa) is an engineered activated protein C (APC)-resistant FVa variant with enhanced procoagulant activity resulting from an A2/A3 domain disulfide bond and was studied here for control of DOAC-induced bleeding. SuperFVa reversed bleeding induced by FXa inhibitors (rivaroxaban, apixaban), and the FIIa inhibitor dabigatran in BalbC mice. The blocking anti-protein C and APC [(A)PC] antibody SPC-54 also reduced FXa inhibitor induced bleeding similar to superFVa, whereas dabigatran-induced bleeding was not affected. This indicated that sufficient APC was generated to contribute to bleeding in the presence of FXa inhibitors, but not in the presence of dabigatran, suggesting that mechanisms contributing to bleeding differed for FXa and FIIa inhibitors. Despite different mechanisms contributing to bleeding, superFVa effectively reduced bleeding for all DOACs, indicating the versatility of superFVa's properties that contribute to its universal prohemostatic effects for DOAC associated bleeding. Supported by thrombin generation assays on endothelial cells in normal plasma spiked with DOACs and patient plasma anticoagulated with DOACs, 3 complementary mechanisms were identified by which superFVa achieved DOAC class-independent prohemostatic efficiency. These mechanisms are resistance to inactivation by APC, overcoming the FV activation threshold, and maximizing the efficiency of the prothrombinase complex when the available FXa is increased by FVIIa-based prohemostatics. In summary, it is this versatility of superFVa that delineates it from other prohemostatic agents as a promising class-independent rescue agent in bleeding situations associated with DOACs.