Does direct oral anticoagulant lead-in dosing following initial parenteral therapy affect clinical outcomes in acute venous thromboembolism?: A retrospective cohort study.

INTRODUCTION

Initiation of direct oral anticoagulants (DOAC) for the management of venous thromboembolism (VTE) typically includes a lead-in dosing phase. However, some patients may receive a shortened course due to comorbid conditions and/or numerous days of parenteral therapy. Limited data exist on the outcomes of an abbreviated lead-in therapy regimen.

AIM: To investigate the clinical outcomes of patients receiving abbreviated versus standard/non-abbreviated DOAC lead-in regimens following parenteral anticoagulation therapy for VTE.

METHOD: We conducted a retrospective cohort study including adults (≥ 18 years of age) who were admitted for acute VTE between 04/01/2019 and 12/31/2023 and received ≥ 24 h of parenteral anticoagulation before being transitioned to a DOAC with abbreviated versus non-abbreviated DOAC lead-in dose. The primary outcome was death or readmission from a thrombotic event within 30 days of discharge. Data were presented using descriptive statistics, logistic regression, and time-to-event analysis.

RESULTS

Across 590 patients, the median (IQR) age was 67 (58-76) years and 280 (47.5%) were female. Over half had a pulmonary embolism (54.9%; N = 324), 21.0% (N = 124) had a deep vein thrombosis, and the remainder experienced a combination. Most patients received the non-abbreviated lead-in dose (83.2%; N = 491). When compared to the non-abbreviated cohort, a higher proportion of those who received an abbreviated lead-in therapy had prior VTE and heart failure. There were no significant associations between an abbreviated lead-in dose and the primary outcome (aOR 0.44; 95% CI 0.13-1.52; P = 0.20). Bleeding events were also similar between the abbreviated and non-abbreviated dose cohorts at the longest follow-up (3.0%, N = 3 vs. 2.9%, N = 14; P = 0.92; aOR 0.82; 95% CI 0.22-3.1; P = 0.77) and within 30 days of DOAC initiation (HR 1.24; 95% CI 0.26-5.82; P = 0.79).

CONCLUSION

An abbreviated DOAC lead-in therapy was not associated with short-term mortality, readmission due to recurrent thrombosis, or bleeding. Further prospective studies are needed to confirm these findings and provide insights into more personalized regimens.