BACKGROUND Dabigatran etexilate, a direct thrombin inhibitor and new oral anticoagulant (NOAC), has been shown to effectively prevent thromboembolic events in patients with atrial fibrillation (AF). However, there is a paucity of data on the antithrombotic efficacy and safety of dabigatran in the resolution of left atrial appendage (LAA) thrombi in AF patients.~OBJECTIVE The primary objective of the RE-LATED trial is to assess whether treatment with dabigatran results in a faster complete LAA thrombus resolution as compared to vitamin-K antagonist phenprocoumon. Secondary objectives are to assess the impact of dabigatran on complete LAA thrombus resolution rate during treatment of 6 weeks, and change in LAA thrombus volume under treatment. Furthermore, this study aims to assess and compare safety and tolerability of dabigatran vs. phenprocoumon.~METHODS The study is designed as a prospective, multicenter, randomized, open-label, controlled, explorative, blinded endpoint (PROBE) trial. Patients with AF and left atrial appendage thrombus confirmed by transesophageal echocardiography (TEE) will be randomized to receive either dabigatran (150 mg bid) or phenprocoumon (INR 2-3) for the resolution of LAA thrombus formation for at least 21 days. Thrombus resolution will be determined by TEE 3 weeks after treatment initiation and subsequently at week 4 and 6, if the primary study endpoint (LAA thrombus resolution) has not yet been achieved. A total of 110 patients are planned to get randomized.~CLINICAL CONTEXT This is the first controlled trial that investigates the safety and efficacy of a NOAC for the resolution of a LAA thrombus in patients with AF.
The primary objective of this study is to assess whether Dabigatran leads to a faster complete left atrial appendage (LAA) thrombus resolution as compared to Phenprocoumon. The secondary objectives of this trial are to assess the impact of Dabigatran versus Phenprocoumon on complete LAA thrombus resolution rate until week 6 and change in LAA thrombus volume under treatment as well as to assess and compare safety and tolerability of both drugs. A total of 110 patients with atrial fibrillation and LAA thrombus will be randomized to receive either Dabigatran (150 mg bid) or Phenprocoumon (INR 2-3) for a least three weeks. Thrombus resolution will be determined by transoesophageal echocardiography (TEE) 3 weeks after start of study treatment and subsequently at week 4 and 6 if necessary, i.e. LAA thrombus has not yet resolved. The study is terminated for each patient with the resolution of the LAA thrombus. For those patients whose thrombus still exists after 6 weeks treatment, the study is also terminated. Further treatments will be decided at the discretion of the treating physician.