DIrect Oral Anticoagulation and mechaNical Aortic Valve

DIAMOND study is a national, multicentre, randomized, parallel-group, open label study in patients (aged ≥18 years) with mechanical aortic valve at least 7 days after cardiac surgery.Experimental group:Patients treated with apixaban 5 mg twice daily (BID)Active Comparator group:Patients treated with warfarin with an objective of INR target of 2.5 (range: 2.0-3.0)The Primary objective is To demonstrate that antithrombotic treatment with apixaban is non-inferior to warfarin (INR target range 2.0 - 3.0) in patients with mechanical heart valve implanted in the aortic position for at least 7 days for the primary net clinical benefit endpoint of ischemic outcomes (death, myocardial infarction, stroke, systemic embolism and valve thrombosis) and bleeding (ISTH major and non-major clinically relevant bleeding).

Inclusion Criteria:Male or female ≥18 years of agePrior implantation of a mechanical prosthetic bileaflet valve in the aortic position at least 7 daysParticipants currently receiving anticoagulation and who can receive warfarin with a target INR= 2.0 to 3.0 or apixabanPatients affiliated to social securityPatient able to give free, informed and written consentExclusion Criteria:Any cardiac surgery in the 7 days prior to enrollmentMechanical valve in any position other than aortic valve.Old aortic mechanical valves such as Starr-Edwards, Omniscience, Björk- Shiley or other tilting-disc valvesAny major bleeding in the three months (90 days) prior to enrollment.Active bleeding or high risk of bleeding after cardiac surgery (i.e. hemopericardium) according to investigatorsNeed to be on dual antiplatelet therapy (aspirin >100 mg daily and a P2Y12 inhibitor, i.e. clopidogrel, ticagrelor, prasugrel).Known hypersensitivity or other contraindications to apixaban (hepatic disease associated with coagulopathy and clinically relevant bleeding risk).Creatinine clearance <30 mL/min (Cockcroft) or patients requiring apixaban dose reduction.Known hypersensitivity or other contraindications to warfarin (severe hepaticinsufficiency, malignant hypertension, pregnancy,breastfeeding, treatment with high dose of aspirin, miconazole, phenylbutazone or milepertuis).Need of heparin or low molecular weight heparin and known hypersensitivity or other contraindications to these drugs specially heparin-induced thrombocytopeniaIschemic stroke or intracranial hemorrhage within 1 month.Active endocarditis at the time of screening for enrollment.Women of childbearing potential without efficient contraception, pregnant or breastfeeding women.Concomitant combined strong P-gp and CYP3A4 inducers or inhibitors.History of non-compliance with recommended monthly INR testingParticipation in another interventional studyActive cancer or life expectancy less than 3 yearsPersons deprived of their liberty by judicial or administrative decision