title: Randomised comparison of two intensities of oral anticoagulant therapy after tissue heart valve replacement.
abstract: After tissue heart valve replacement 108 patients were randomised to standard anticoagulant control with rabbit brain thromboplastin (Dade C reagent, therapeutic range 18-24 s; international normalised ratio 2.5-40) and 102 to a less intensive regimen controlled with human brain thromboplastin (Manchester Comparative Reagent, therapeutic range 26-30 s; INR 2.0-2.25). Treatment was continued for three months, outcome measures being major or minor embolism or haemorrhage. 2 patients in each group had major embolic events and 11 in each group had minor embolic events. The 95% confidence intervals on the differences are -3.4% to 3.2% for major embolism and -9.3% to 8.2% for minor embolism. Haemorrhagic complications were significantly more frequent with standard treatment (15 patients) than with the less intensive regimen (6 patients); and of the 5 patients with major haemorrhagic complications, all were in the standard treatment group, again a significant difference. The less intensive regimen is thus no less effective and safer than standard anticoagulant therapy in patients with tissue heart valve replacement.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage* / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000209:etiology; D002986:Clinical Trials as Topic; D004341:Drug Evaluation; D004617:Embolism / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D005260:Female; D006351:Heart Valves / Q000637:transplantation*; D006470:Hemorrhage / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D011517:Prothrombin Time; D011897:Random Allocation; D014859:Warfarin / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin