Dabigatran Versus Warfarin After Bioprosthesis Valve Replacement for the Management of Atrial Fibrillation Postoperatively: DAWA Pilot Study

Abstract

ObjectivesDabigatran is a direct thrombin inhibitor shown to be an effective alternative to warfarin in patients with non-valvular atrial fibrillation (AF). We evaluated the use of dabigatran in patients with bioprosthetic mitral and/or aortic valve replacement and AF.MethodsWe selected 34 and randomized 27 patients in a 1:1 ratio to receive dabigatran or warfarin. The primary endpoint was the presence of a new intracardiac thrombus at 90 days, by transesophageal echocardiogram (TEE). Secondary endpoints included the development of dense spontaneous echo contrast (SEC) and incidence of stroke (ischemic or hemorrhagic), myocardium infarction, valve thrombosis and peripheral embolic events.ResultsThe trial was terminated prematurely because of low enrollment. There were 27 patients in total: 15 patients placed in the dabigatran group and 12 in the warfarin group. After 90 days, one patient (8.3 %) in the warfarin group and none in the dabigatran group had developed a new intracardiac thrombus. In the dabigatran group, two patients (13.3 %) developed dense SEC versus one patient (8.3 %) in the warfarin group. In the warfarin group, one patient (8.3 %) presented ischemic stroke, and none did in the dabigatran group. We observed no cases of hemorrhagic stroke, valve thrombosis, embolic events or myocardial infarction in either group throughout the study. However, one patient (6.7 %) in the dabigatran group had a fully recovered transient ischemic attack and one patient in the warfarin group died of heart failure.ConclusionsThe use of dabigatran appears to be similar to warfarin in preventing the formation of intracardiac thrombus.Trial RegistrationClinicaltrials.gov NCT01868243.

Nonvitamin K Antagonist Oral Anticoagulants Use in Patients with Atrial Fibrillation and Bioprosthetic Heart Valves/Prior Surgical Valve Repair: A Multicenter Clinical Practice Experience

“…16 In a recent phase II, prospective, open-label, randomized, pilot study, Durães et al evaluated the use of dabigatran 110 mg BID versus warfarin in 27 patients with bioprosthetic mitral and/or aortic valve replacement and AF postoperatively. 17 The trial was prematurely terminated because of low enrollment; however, the efficacy of dabigatran appears to be similar to warfarin in preventing the formation of intracardiac thrombus in patients after mitral and/or aortic bioprosthesis valve replacement and with documented AF postoperatively. In the clinical practice setting, there is only a retrospective single-center cohort study performed on 73 AF patients with bioprosthetic heart valve implantation on NOAC therapy.…”

Direct oral anticoagulant use in nonvalvular atrial fibrillation with valvular heart disease: a systematic review

“…Duräes and colleagues most recently observed the effects of dabigatran compared with warfarin after bioprosthetic valve replacement, a population not originally included in the RE‐LY trial . The primary endpoint was intracardiac thrombus at 90 days by transesophageal echocardiography.…”

“…Utilization of DOACs in the setting of bioprosthetic valves should be determined on a patient‐specific basis based on the limited patient populations studied currently. Although preliminary results with dabigatran are promising, other studies are needed to validate these findings due to the premature termination . In the ARISTOTLE study, outcomes of apixaban with bioprosthetic valves should be viewed as hypothesis generating, given the small number of bioprosthetic valve patients included in the original trial .…”

Antithrombotic Therapy in Atrial Fibrillation Associated with Valvular Heart Disease: Executive Summary of a Joint Consensus Document from the European Heart Rhythm Association (EHRA) and European Society of Cardiology Working Group on Thrombosis, Endorsed by the ESC Working Group on Valvular Heart Disease, Cardiac Arrhythmia Society of Southern Africa (CASSA), Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), South African Heart (SA Heart) Association and Sociedad Latinoamericana de E

“…31 One small pilot study compared dabigatran versus warfarin after bioprosthesis valve replacement for the management of AF postoperatively (DAWA pilot study), but small numbers preclude definitive conclusions. 32 Recent small studies also suggest that NOACs can be a reasonable alternative to VKA in patients with AF and remote bioprosthetic valve implantation; 22,33 however, larger studies are needed to define the safety and efficacy profile. Data on thromboprophylaxis in patients with AF and TAVI, which is actually the insertion of a bioprosthesis, are preliminary 34 and discussed in section 'Antithrombotic Therapy in Patients with AF Undergoing TAVI or Left Atrial Appendage Occlusion'.…”