Abstract Number: PB2394
Meeting: ISTH 2020 Congress
Theme: Venous Thromboembolism and Cardioembolism » VTE Treatment
Background: Delayed initiation of anticoagulation for acute venous thromboembolism (VTE) is associated with increased risk of thrombus propagation, embolization and death. Identification and analysis of reasons for anticoagulation delay (AD) are important safety measures.
Aims: Describe barriers to initiation of anticoagulation and outcomes of patient with AD for over 24 hours.
Methods: Consecutive patients enrolled in the Mayo Clinic VTE Registry between March 2013 and November 2019 with acute VTE were followed prospectively. Patient outcomes were assessed in person, by mailed questionnaire, or scripted phone interview. Outcomes were reported at 90 days.
Results: Of the 2355 patients enrolled, 92 (3.9%) experienced AD of >24h. Among the AD group, the mean time to anticoagulation initiation was 7.6±10.4 days, and median of 4 days. Patients with AD more often had thrombosis at an unusual location (38% vs. 9.7% p< 0.001) and were more likely to have a provoked VTE (p=0.01) due to cancer or immobility (Table 1).
Most common reasons for AD (Table 2) were waiting for expert opinion, proximity to surgery, recent bleeding, thrombocytopenia, and missed diagnosis. AD could have been avoided in 60% (access, workflow, misdiagnosis and education).
In patients with 3 months of follow up (n=86), patients with AD had higher frequency of VTE recurrence (5.8% vs. 1.7% p=0.006) and clinically relevant non-major bleeding (CRNMB) (7.0% vs. 2.9% p=0.03) compared to the patients with immediate onset of anticoagulation. There was no difference in mortality (9.3% vs 5.1% p=0.09) or major bleeding (5.8% vs. 2.7% p=0.08). After adjusting for age and cancer, differences remained significant for recurrence (p=0.02) and CRNMB (p=0.04) and not significant for mortality or major bleeding.
Variable | No delay (n=2017) | Anticoagulation Delayed (n=86) | p value |
Age, mean (±SD) | 61.0 (14.4) | 62.4 (13.0) | 0.39 |
Female gender, n (%) | 878 (43.6) | 35 (40.7) | 0.60 |
Lower extremity DVT and/or PE, n (%) | 1676 (83.1) | 47 (54.7) | <0.001 |
Upper extremity DVT, n (%) | 209 (10.4) | 13 (15.1) | 0.16 |
Atypical location, n (%) | 195 (9.7) | 32 (37.2) | <0.001 |
Provoked, n (%) | 1620 (80.4) | 79 (91.9) | 0.03 |
Recurrence at 90 days | 34 (1.7) | 5 (5.8) | 0.006 |
Major bleeding at 90 days | 54 (2.7) | 5 (5.8) | 0.08 |
CRNMB at 90 days | 58 (2.9) | 6 (7.0) | 0.03 |
[Table 1. Demographics and outcomes in patients with 3 months of follow up. ]
Reason for AD (n=92) | n (%) |
Deferred decision to expert consult | 36 (39.1) |
Recent or upcoming procedure | 14 (15.2) |
Current or recent bleeding | 11(12.0) |
Thrombocytopenia | 9 (9.8) |
Missed diagnosis of VTE | 6 (6.5) |
Logistics (Insurance, availability, etc.) | 5 (5.4) |
Patient choice | 4 (4.3) |
No reason documented | 7 (7.6) |
[Table 2. Reasons for delay in initiation of anticoagulation in 92 patients.]
Conclusions: AD was associated with worse clinical outcomes. Although uncommon, most delays could have been avoided. Most AD happened in patients with thrombus in unusual locations, reflecting current confusion regarding management for VTE of these locations.
To cite this abstract in AMA style:
Brunton NE, Wysokinski WE, Hodges DO, Vlazny DT, Houghton DE, Casanegra A. Reasons and Associated Outcomes in Delayed Anticoagulation in Venous Thromboembolism [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/reasons-and-associated-outcomes-in-delayed-anticoagulation-in-venous-thromboembolism/. Accessed April 18, 2024.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/reasons-and-associated-outcomes-in-delayed-anticoagulation-in-venous-thromboembolism/