Acute mechanical prosthetic valve thrombosis after initiating oral anticoagulation therapy. Is bridging anticoagulation with heparin required?

• Published in: Interactive cardiovascular and thoracic surgery 2009-10, Vol.9 (4), p.685-687
• Main Authors: Charokopos, Nicholas, Antonitsis, Polychronis, Artemiou, Panagiotis, Rouska, Efthymia, Foroulis, Christophoros, Papakonstantinou, Christos
• Format: Article
• Language: English
• Subjects: Acenocoumarol - administration & dosage; Acenocoumarol - adverse effects; Acute Disease; Adult; Anticoagulants - administration & dosage; Anticoagulants - adverse effects; Aortic Valve Insufficiency - etiology; Aortic Valve Insufficiency - surgery; Endocarditis - complications; Fibrinolytic Agents - administration & dosage; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation - adverse effects; Heart Valve Prosthesis Implantation - instrumentation; Heparin - administration & dosage; Heparin - adverse effects; Humans; Male; Medication Adherence; Thrombolytic Therapy; Thrombosis - drug therapy; Thrombosis - etiology; Thrombosis - prevention & control; Tissue Plasminogen Activator - administration & dosage; Treatment Outcome; Warfarin - administration & dosage; Warfarin - adverse effects
• ISSN: 1569-9293; 1569-9285
• DOI: 10.1510/icvts.2009.208587

Department of Thoracic and Cardiovascular Surgery, AHEPA University Hospital, Thessaloniki, Greece *Corresponding author. Sakellaridi 25, 542 48 Thessaloniki, Greece. Tel.: [phone]; fax: [phone]. E-mail address : antonits{at}otenet.gr (P. Antonitsis). Prosthetic valve thrombosis (PVT) represents a serious and potentially lethal complication. It can be attributed more frequently to inadequate anticoagulant therapy. We present a case of acute aortic mechanical valve thrombosis six months after implantation. The patient discontinued oral anticoagulation after being discharged following the primary operation. Two days after reinitiating warfarin as an outpatient, he developed acute valve thrombosis presenting with symptoms and signs of cardiac failure. He was managed with intravenous thrombolysis with a recombinant plasminogen activator which resulted in immediate resolution of thrombus and clinical improvement. A paradox procoagulant effect of warfarin is evident on the first one or two days after initiation of therapy. A ‘bridging’ protocol with unfractionated or low molecular weight heparin (LMWH) should be considered, according to recently published guidelines, until warfarin reaches therapeutic levels and exerts an antithrombotic effect. Key Words: Aortic valve; Mechanical valve; Anticoagulation; Thrombosis; Embolism