A multinational observational cohort study in hospitalized medical patients of practices in prevention of venous thromboembolism and clinical outcomes: findings of the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE)

Abstract number: P1438

Anderson^* F. A., Decousus† H., Bergmann‡ J.F., Chong§ C., Froehlich¶ J., Johnson†† J., Kakkar^** A., Merli‡‡ G., Monreal§§ M., Pavanello*⁰ R., Pini** M., Piovella*† F., Spyropoulos*‡ A., Turpie*§ A.G.G., Tapson*¶ V., Zotz*†† R.

^{** *}Center for Outcomes Research, University of Massac, USA †Centre Hospitalier Universitaire de Bellevue, France *¶Duke University Medical Center, USA ‡Hôpital Lariboisiere Clinique Therapeutique, France *§Hamilton Health Sciences General Hospital, Canada *⁰Hospital do Coracao Clinica Medica, Brazil *†Italy ††Jefferson Antithrombotic Therapy, USA *‡Lovelace Medical Center, USA **Ospedale di Fidenza Medicina Interna, Italy §§Spain §St. George Hospital, Australia *††Universitätsklinikum Düsseldorf Institut für Hämos, Germany ¶University of Massachusetts Medical Center, USA

Background  

Acutely ill medical patients are at significant risk from venous thromboembolism (VTE). However, clinical practices in providing VTE prophylaxis for patients hospitalized with acute medical illnesses are unknown. IMPROVE is a prospective cohort study designed to (1) assess routine clinical practices in providing VTE prophylaxis in acutely ill medical patients; and (2) test predictive models of the relationship between patient characteristics, prophylaxis use and key clinical endpoints.

Methods  

Patient recruitment began in July 2002. Patients, >=18 years old, hospitalized for >=3 days with an acute medical illness are enrolled consecutively. Exclusion criteria are therapeutic anti-thrombotic agents or thrombolytics at admission; major surgery or trauma during 3 months prior to admission; and VTE treatment within 24 h of admission. Standard case report forms are used to record data at hospital discharge and 3 months after discharge. Data is sent to a central data-coordination center and subjected to quality control and audit. A central adjudication committee reviews key clinical endpoints, including type and duration of VTE prophylaxis, death, symptomatic VTE, and bleeding.

Results  

To date, 403 patients have been enrolled at 9 hospitals in 6 countries, with 3-month follow-up data on 245 patients (61%). Of enrolled patients, 52% were female, mean age was 69.0 ± 18.4 years, mean length of hospital stay was 11.5 ± 9.3 days, mean weight was 70.3 ± 19.2 kg, and 54% were immobile for >= 3 days (median length of immobility 10 days). VTE prophylaxis (>= 1 type) was received by 30% of patients in hospital. The most common types of VTE prophylaxis were low-molecular-weight heparin (16%), unfractionated heparin (9%) and intermittent calf compression (4%). Prophylaxis was continued after discharge in 3% of patients. 11% of patients died in hospital and an additional 14% died within 3-months after hospital discharge. Although no patient underwent an autopsy, pulmonary embolism was the suspected cause of death in one patient who died after discharge. Key clinical endpoints are shown in Table 1.

Conclusion  

Most acutely ill medical patients did not receive VTE prophylaxis during hospitalization, including 43% of patients who developed clinically recognized VTE in hospital and 66% who developed VTE within 3-months after discharge. Substantial additional data from all 21 participating hospitals in 10 countries are expected to be available for this presentation.

Table 1  Key clinical endpoints