<<forEachTiddler where 'tiddler.tags.contains(context.inTiddler.title)' sortBy tiddler.title ascending write '"*[["+tiddler.title+"]]\n"'>> <<tiddler AutoRefresh with: force>> most common valves to replace - aortic and mitral either biological (bioprosthetic) or mechanical. ''Biological (bioprosthetic) valves'' Usually bovine or porcine in origin Major disadvantage - structural deterioration and calcification over time. older patients ( > 65y aortic, > 70y mitral) receive a bioprosthetic valve Long-term anticoagulation not usually needed. Warfarin for first 3/12 then Low-dose aspirin ''Mechanical valves'' most common - bileaflet valve. Ball-and-cage valves are rarely used nowadays Mechanical valves have a low failure rate Major disadvantage - increased risk of thrombosis meaning long-term anticoagulation Aspirin as well unless contraindication. Target INR - aortic: 2.0-3.0, mitral: 2.5-3.5 2008 NICE guidelines for prophylaxis of endocarditis - antibiotics not needed for common procedures eg dental