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.