D3.291 - Hereditary angioedema with normal C1Inh and PLG mutation treated with tranexamic acid : Beware of the risk of thrombosis
Background
The anti-fibrinolytic, tranexamic acid (TA) can be proposed as a long term prophylaxis for hereditary angioedema (HAE), and seems to be specifically efficient for HAE with plasminogen gene mutation (HAE-PLG), a subset of HAE with normal C1Inh (HAE-nC1INH). Although TA is usually well tolerated in patients without any thromboembolic risk factors,we report here 4 cases of thrombosis following the use of TA in HAE-PLG patients
Method
retrospective study based on clinical data from the French HAE-nC1INH registry.
Results
Of the 28 HAE-PLG patients recorded in France in December 2024, 20 were symptomatic and 10 were receiving long term prophylaxis, including 7 with TA. Of these, 4 have developed venous or arterial thrombotic complications. All patients received a usual dosage of 2 to 3 g/d of TA. For all patients, TA was totally effective in preventing AE: the frequency decreased from an average of 2 attacks per month before TA, to 0 attacks per month during TA.
|
Age (years) and sex at time of thrombotic event |
Cardiovascular risk factors and history |
Antiplatelet aggregation therapy prior to TA initiation |
Duration of TA treatment prior to thrombotic event |
Cardio vascular events |
|
Woman, 73 |
Hypertension Diabetes |
No |
1 year |
Stroke |
|
Woman, 95
|
Diabetes |
Yes (during 25 years) |
5 years |
Heart attack |
|
Man, 70 |
Ischemic heart disease |
Yes (during 13 years) |
1 year |
Deep Venous thrombosis New episode of coronary ischemia |
|
Man, 67 |
Peripheral arteriel disease |
Yes (during 11 years) |
1 year |
Deep Venous thrombosis |
Conclusion
The HAE-PLG patients who developed thrombotic events on AT were all elderly (over 65) and had cardiovascular history and risk factors. For 3 of them, the thrombotic event occurred within a year of the introduction of AT, despite prior antiplatelet aggregation. Four out of 7 (57%) of HAE-PLG patients taking TA had a thrombotic episode. TA administration should be avoided in patients with risk factors or a history of cardiovascular disease. This also raises the question of the role of the PLG mutation in this increased vascular risk.
