The First Registry: Follow-up in Rivaroxaban Patients in the Setting of Venous Thromboembolism

The direct oral anticoagulants (DOACs) are revolutionising the management of acute venous thromboembolism (VTE). Although favourable short term outcomes have been demonstrated with these agents, there is a growing need to improve our understanding of biological and clinical predictors of longer-term outcomes with all DOACs. In addition to reducing the need for dual anticoagulant coverage, the use of oral rivaroxaban, has accelerated the implementation of outpatient and early discharge treatment protocols for VTE, in particular for pulmonary embolism (PE).

Although clinical trials provide evidence of efficacy and safety, there is a need for ongoing assessment of outcomes in unselected populations treated in routine 'real-world' clinical practice. As for most drugs, conditions requiring special attention include advanced age, impaired renal or liver function, extremes of body weight, presence of multiple co-morbidities, and the need for concomitant therapies. Such conditions commonly co-exist, particularly in elderly patients. In clinical practice patients aged 80 years or older and requiring anticoagulation are becoming increasingly common. In addition, trials do not report long-term adverse outcomes after VTE; aside from bleeding, currently there are no long-term data that assess the impact of the DOACs as part of a single-drug treatment algorithm on long-term recurrence.

The FIRST registry will assess long-term outcomes of patients with acute VTE treated with rivaroxaban from diagnosis - our hypothesis is that the long-term outcomes for such patients will be favourable due to consistent anticoagulation intensity, particularly during the acute phase of thrombosis. There are currently no data describing post-thrombotic syndrome (PTS) or chronic thromboembolic pulmonary hypertension (CTEPH) incidence rates in patients treated with DOACs. Patients enrolled onto the FIRST registry will be followed up for five years with primary end-points defined as incidence of long-term sequelae (PTS and CTEPH, defined clinically) and secondary endpoints including recurrence, bleeding and anticoagulation related satisfaction and adherence scores. Analysis of these data may also contribute to improved risk stratification strategies to identify patients who have the greatest risk of adverse bleeding events, recurrence and long-term VTE-related morbidity. Recruitment is currently underway at 20 UK hospitals, with a target of 1500 patients, to be achieved by summer 2017.