The SYMPTOMS - SYstematic Elderly Medical Patients Thromboprophylaxis: Efficacy on Symptomatic OutcoMeS - Study
Status:
Recruiting
Trial end date:
2022-12-01
Target enrollment:
Participant gender:
Summary
Venous thromboembolism (VTE) is a frequent condition, affecting 1.8 per 1,000 people every
year. Admission to hospital is one of the main risk factors for VTE, and could account for up
to 20% of all VTE, making VTE prevention in admitted patients an appealing option to reduce
VTE global burden.
The landmark MEDENOX trial and others demonstrated the efficacy of low molecular weight
heparins (LMWH) in reducing a composite outcome of symptomatic and asymptomatic events, the
latter accounting for the vast majority of events.
Publication of these trials led to the implementation of thromboprophylaxis policies in
hospitals, which acceptance has been variable. More recently, the use of thromboprophylaxis
has been challenged after the publication of 1) a negative trial that used 'death from any
cause' as main outcome, 2) a systematic review showing the lack of a clear efficacy on the
risk of pulmonary embolism or death, 3) negative trials using new oral anticoagulants, 4) the
last version of the American College of Chest Physicians Guidelines, focusing on symptomatic
events only, downgraded its recommendation for thromboprophylaxis in medical patients to a 1B
recommendation, restricting its use to patients 'at increased risk of thrombosis' and
recommending against the use of thromboprophylaxis in patients at low risk of thrombosis,
patients bleeding or at high risk of bleeding.
However, a limitation of this interpretation of the data is that in most trials, patients
with screened asymptomatic events were treated with anticoagulants, preventing the occurrence
of symptomatic events during follow-up. Moreover, subgroup analyses showed that elderly
patients were at high risk of thrombosis in these trials, and that LMWH could be particularly
efficient in this subgroup of patients. Conversely, their risk of bleeding is also higher
than in younger patients and the current trials were not powered to detect a difference in
the bleeding risk between groups. Finally, the diagnostic and therapeutic management of VTE
is more challenging in the elderly. Therefore, we planned a randomized controlled trial on
the efficacy of LMWH for the prevention of symptomatic VTE in elderly patients.