Early Versus Late Resumption of Anticoagulation in Patients With Both High Thrombosis Risk and Major HEmoRrhage

Overview

In patients with a high thromboembolic risk, withdrawing anticoagulant treatment is recommended in some situations, including when major hæmorrhage occurs. But withdrawing treatment can be risky. In patients on a curative dose of anticoagulant medicine, treatment withdrawal heightens the risk of thromboembolic events occurring, with potentially major consequences. For instance, mechanical valve thrombosis is fatal in 15% of patients. Resumption of anticoagulation is therefore critical in patients at high risk for thromboembolic events. However, in these patients having presented major hæmorrhage, resumption of anticoagulation heightens the risk of hæmorrhage recurrence. This risk is even higher when the original hæmorrhage was not accessible via surgical, endoscopic or endoluminal hemostasis. As far as investigators know, there is no data in the literature to rely on when the major hæmorrhage is not accessible via hemostatic intervention and the risk of thrombosis is high. When confronted with patients who need anticoagulation but have a high risk of hæmorrhage recurrence, the question of when treatment should be resumed has not been resolved. This is why investigators propose to conduct a randomised comparative study to evaluate two treatment strategies - early resumption (H48 to H72) versus late resumption (H120 to H144) of anticoagulation. MAIN OBJECTIVE: The main objective of the present study is to evaluate in terms of bleeding risk, thrombosis risk and mortality at one month, the effect of early vs. late resumption of anticoagulation in patients having presented with serious hæmorrhage while on curative-dose anticoagulants and facing a high thromboembolic risk.

STUDY DESIGN: This is a comparative, randomised, open study assessing after 1 month and 3 months the effect of early (H48 to 72) versus late (H120 to 144) resumption of anticoagulation in patients presenting with serious bleeding while on anticoagulants (excluding intracerebral bleeding) and with a thromboembolic risk evaluated as high (except mitral prostheses). The accumulated frequency of major hæmorrhage, thromboembolic events and deaths should be 26% in case of early resumption and 15% in case of late resumption, i.e. a relative risk reduction of 43%. Based on this hypothesis, to obtain 80% power with two-sided α being 5%, each group should include 208 patients, for a total of 416 patients. EVALUATION CRITERIA: The main criteria in this study will be the accumulated one-month incidence of hæmorrhage recurrence, thromboembolic complications and deaths. It is a combined criterion associating: * Fatal hæmorrhage proven by autopsy or sudden deaths in a clinical context strongly suggestive of hæmorrhage * Fatal thromboembolic events proven by autopsy or imagery or sudden deaths in a clinical context strongly suggestive of thrombosis * Any clinically significant hæmorrhage leading to temporary (\> 24 hours) or permanent withdrawal of anticoagulant treatment * Any symptomatic thromboembolic event in any territory, proven by imagery or surgery These events will be validated by a committee for the validation of critical events blind to the date of anticoagulant treatment resumption. The secondary evaluation criteria will be symptomatic hæmorrhages, fatal or not, symptomatic thromboembolic incidents, fatal or not, and mortality at 1 month and 3 mont