Most Post-VTE Anticoagulant Regimens Exceed Guideline-Recommended Duration

Geoffrey Barnes, MD, MSc

A quality improvement initiative based in Michigan suggests most patients with provoked venous thromboembolism (VTE) receive anticoagulation therapy for longer than the guideline-directed duration of 3 months.

An analysis of data from the Michigan Anticoagulation Quality Improvement Initiative (MAQI²) registry, results of the study provide evidence indicating the majority of patients receiving anticoagulation therapy following provoked VTE received anticoagulant therapies beyond 120 days, with warfarin users having a median length of treatment of 142 days and DOAC users having a mean length of treatment of 180 days.

“In our cohort of patients with provoked VTE, most patients received anticoagulation for longer than the guideline‐recommended 3 months. This demonstrates a potential opportunity to improve care delivery and reduce anticoagulant‐associated bleeding risk,” wrote investigators.

Anticoagulation has undergone major changes in the last 20 years. With these rapid advances in therapeutics and treatment strategies, optimal dissemination of evidence-based guideline recommendations from major professional bodies has become essential. To better understand how guideline recommendations are adopted in real-world settings, a team led by Geoffrey Barnes, MD, MSc, of the Michigan Medicine Frankel Cardiovascular Center, sought to leverage the MAQI² registry to examine contemporary trends in long-term anticoagulation among those with provoked VTE compared against the recommendations set forth in the American College of Chest Physicians (ACCP) guidelines. Formed in 2008 with the aim of improving safety, quality of care, and outcomes of patients requiring anticoagulation, the MAQI² registry collects data related to patients requiring long-term anticoagulation from 6 centers in Michigan.

Using the registry, investigators obtained data related to 474 patients on warfarin and 302 patients on direct oral anticoagulants (DOACs) who were receiving anticoagulation for a primary indication of provoked VTE from 2008-2020 for inclusion in the current study. Investigators pointed out age, race, and insurance status were similar between the treatment arms, but a greater proportion of patients with Medicaid received DOACs compared with warfarin. Investigators also pointed out a greater proportion of those receiving DOACs were women (70.2% vs 55.5%, P <.001).

For the purpose of analysis, duration of treatment was categorized as less than 80 days, 80-120 days, or more than 120 days. Investigators defined the appropriate length of treatment as 80-120 days to account for variable clinic vista scheduling. Investigators also noted patients were further classified based on whether they were prescribed warfarin or DOACs.

Upon analysis, results indicated the median length of treatment for patients receiving warfarin was 142 (91-234) days and the median length of treatment with DOACs was 180 (101-360) days. Using multivariable logistic regression, investigators identified recurrent VTE (odds ratio [OR], 2.75 [95% CI, 1.67-4.53]), history of myocardial infarction (OR, 3.92 [95% CI, 1.32-1.7]), and DOAC use rather than warfarin use (OR, 2.22 [95% CI, 1.59-3.08]) were all independently associated with prolonged anticoagulation.

“This study identifies a group of patients with provoked VTE who were more likely to receive prolonged anticoagulation and may be at increased risk of anticoagulant‐related bleeding complications,” investigators added. “Further study will be necessary to investigate how the duration of anticoagulation therapy changes with evolving guidelines and increasingly widespread DOAC use.”

This study, “Length of Anticoagulation in Provoked Venous Thromboembolism: A Multicenter Study of How Real‐World Practice Mirrors Guideline Recommendations,” was published in the Journal of the American Heart Association.