Abstract Number: PB2399
Meeting: ISTH 2020 Congress
Theme: Venous Thromboembolism and Cardioembolism » VTE Treatment
Background: Outpatient treatment of patients with low-risk pulmonary embolism (PE) is recommended by the British Thoracic Society and European Society of Cardiology.1,2 However, PE treatment often takes place in hospital.
Aims: The ALPHA-PE study compared length of stay (LOS) in patients treated with anticoagulation for acute PE in hospital before and after apixaban was introduced in the UK, and total LOS (including readmissions ≤30 days of initial discharge). LOS was stratified by risk according to the simplified Pulmonary Embolism Severity Index (sPESI).
Methods: A retrospective chart review at five UK hospitals included patients aged ≥18 years, admitted with acute symptomatic PE and initiated on anticoagulation pre- and post-licensing of apixaban for treating VTE in the UK. The study used Cohort 1 before apixaban licensing (C1), 01 January to 30 June 2013 and Cohort 2 after apixaban licensing (C2), 01 January to 30 June 2017. The study was powered to detect LOS difference of ≥1.0 day between C1 and C2.
Ethical and research approvals were obtained from the Office Research Ethics Committees Northern Ireland (Reference: 17/NI/0128) and the Health Regulatory Authority (Reference: 223148). As this was a retrospective review of patient medical records without direct patient contact, informed consent was not sought.
Results: The study included 538 patients; 269 (50.0%) in Cohort 1 (C1) and 269 (50%) in Cohort 2 (C2). Mean age was 66.9 years (C1) and 64.2 years, (C2) with 51.3% male (C1) and 44.6% male (C2). Demographic and clinical characteristics were well matched between C1 and C2. Patients hospitalised with PE and treated with apixaban had shorter mean LOS of 2.7 days compared with patients on warfarin, and shorter total LOS of 2.2 days (Tables 1 and 2).
Conclusions: Patients hospitalised with PE and treated with apixaban, compared with warfarin, had shorter LOS regardless of sPESI risk profile.
| Cohort 1 (January to June 2013), n=262* | Cohort 2 (January to June 2017), n=269 | Difference in mean LOS | |
| Heparin/warfarin, n (%) | 214 (81.7) | 14 (5.2) | – |
| Apixaban, n (%) | NA | 194 (72.1) | – |
| Other anticoagulation, n (%) | 48 (28.3) | 61 (22.7) | – |
| LOS (days) – Overall, mean (SD) | 7.4 (9.4) | 4.6 (7.3) | – 2.8 |
| LOS (days) – Heparin/warfarin, mean (SD) | 7.3 (8.1) | 7.2 (6.0) | -0.1 |
| LOS (days) – Apixaban, mean (SD) | NA | 4.5 (7.8) | NA |
| Total LOS (days) – Heparin/warfarin, mean (SD) | 7.5 (8.2) | 7.2 (6.0) | -0.3 |
| Total LOS (days) – Apixaban, mean (SD) | NA | 5.0 (8.5) | NA |
| *Seven out of 269 patients were excluded from analyses: six patients who died during their hospital stay and one patient who received dabigatran etexilate. P-value <0.005 LOS: Length of stay; NA: Not applicable; SD: Standard deviation Total LOS includes readmissions within 30 days of initial discharge | |||
[Table 1. LOS and total LOS in patients hospitalised with acute symptomatic PE, by study cohort]
| sPESI risk stratification | Warfarin (n = 228) | Apixaban (n = 194) | Difference in mean LOS |
| Low risk | |||
| Total, n | 91 | 96 | – |
| LOS (days), mean (SD) | 4.7 (3.8) | 2.7 (4.3) | -.20* |
| High risk | |||
| Total, n | 122 | 91 | – |
| LOS (days), mean (SD) | 9.2 (9.6) | 6.5 (10.1) | -2.7 |
| *P-value <0.005 LOS: Length of stay; SD: standard deviation; sPESI: simplified Pulmonary Embolism Severity Index | |||
[Table 2. LOS in patients hospitalised with acute symptomatic PE, by sPESI risk stratification and anticoagulation type, Cohorts 1 and 2 combined]
To cite this abstract in AMA style:
Alikhan R, Church C, Shapiro S, Lister S, Chattree S, Smith N, Bomken C, Grundy S, Gordon J, Sugrue D, Hill N, Howard L. Apixaban versus Heparin/Warfarin Treatment in Pulmonary Embolism: Results from the UK Apixaban Length-of-Stay Pulmonary Embolism – Hospital Admissions Study (ALPHA-PE) [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/apixaban-versus-heparin-warfarin-treatment-in-pulmonary-embolism-results-from-the-uk-apixaban-length-of-stay-pulmonary-embolism-hospital-admissions-study-alpha-pe/. Accessed November 29, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/apixaban-versus-heparin-warfarin-treatment-in-pulmonary-embolism-results-from-the-uk-apixaban-length-of-stay-pulmonary-embolism-hospital-admissions-study-alpha-pe/