Related Experiment Video
Updated: Jun 26, 2025

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Factor XI as a new target for prevention of thromboembolism in cardiovascular disease: a meta-analysis of randomized
Ahmed E Ali1,2, Mohamed K Awad3, Karim Ali4,2
1Department of Medicine, Mayo Clinic, Rochester, MN, USA.
Abstract:
Anticoagulant therapy is a mainstay in the management of patients with cardiovascular disease. The use of conventional anticoagulants carries potential side effects, mainly bleeding. Drugs targeting Factor XI (FXI) have been investigated in randomized controlled trials as a new option with more favorable outcomes. A comprehensive literature search was conducted to identify relevant studies comparing FXI inhibitors to placebo or standard therapy. The primary outcomes were incidence of all bleeding events, major bleeding, and thromboembolism. Secondary outcomes included incidence of all adverse events (AE), serious AE, and all-cause mortality. A total of 11 studies involving 10,536 patients were included. FXI inhibitors were associated with a trend toward reduction of bleeding events and incidence of thromboembolism compared to the control group (placebo/standard therapy). There was no statistically significant difference between both groups in terms of adverse events and all-cause mortality. When compared to enoxaparin, FXI inhibitors significantly reduced the risk of bleeding events (RR = 0.42, 95% CI: 0.23-0.76, P = 0.004) and thromboembolism (RR = 0.59, 95% CI: 0.44-0.77, P = 0.001). On the other hand, when compared to DOACs, FXI inhibitors were associated with a significant reduction in bleeding events but not thromboembolism. Whereas, compared to placebo, FXI inhibitors did not increase the risk of bleeding events, adverse events, or all-cause mortality (P > 0.05). FXI inhibitors could be a safer and more potent option for prevention of thromboembolism than conventional therapy.
Insights
New Factor XI (FXI) inhibitors show promise in reducing bleeding and thromboembolism compared to conventional anticoagulants. These FXI drugs may offer a safer, more effective option for cardiovascular disease patients.
Area of Science:
- Cardiovascular Medicine
- Pharmacology
- Thrombosis Research
Background:
- Anticoagulant therapy is crucial for cardiovascular disease (CVD) management.
- Conventional anticoagulants pose risks, primarily bleeding.
- Factor XI (FXI) inhibitors represent a novel therapeutic class under investigation.
Purpose of the Study:
- To evaluate the efficacy and safety of FXI inhibitors compared to placebo or standard anticoagulation.
- To assess FXI inhibitors' impact on bleeding events and thromboembolic risk.
- To analyze FXI inhibitors' effect on adverse events and mortality.
Main Methods:
- A comprehensive literature search identified 11 randomized controlled trials.
- 10,536 patients were included in the meta-analysis.
- Primary outcomes: bleeding incidence and thromboembolism. Secondary outcomes: adverse events and mortality.
Main Results:
- FXI inhibitors demonstrated a trend toward reduced bleeding and thromboembolism versus controls.
- Significant reductions in bleeding (RR=0.42) and thromboembolism (RR=0.59) were observed compared to enoxaparin.
- Compared to DOACs, FXI inhibitors significantly reduced bleeding but not thromboembolism.
Conclusions:
- FXI inhibitors show potential as a safer alternative to conventional anticoagulants.
- They may offer improved efficacy in preventing thromboembolism with reduced bleeding risk.
- Further research is warranted to fully elucidate the role of FXI inhibitors in anticoagulation.
Related Concept Videos
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Clot Retraction and Fibrinolysis
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which...
Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
Coagulation
During the coagulation phase, clotting factors, or procoagulants, play a vital role in initiating and progressing the coagulation cascade. This cascade is a series of reactions...
Disorders of Hemostasis
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.

