Question under study: To investigate the effectiveness of a single adjusted dose of oral vitamin K to temporarily reverse oral anticoagulation with phenprocoumon (Marcoumar) for heart catheterisation.
Methods: Patients under stable oral anticoagulation with phenprocoumon routinely scheduled for heart catheterizstion were given a single adjusted dose of oral vitamin K a day prior to the intervention. The customary anticoagulation scheme was kept unchanged with the exception of taking the double usual dose of phenprocoumon the evening after the intervention. The primary outcome was the achieved international normalised ratio (INR) immediately before the intervention. Secondary outcomes were the INR after one and four weeks, changes in phenprocoumon and coagulation factors II and VII and adverse events.
Results: 38 patients at a median age of 71 (63-74) years scheduled for heart catheterisation were included. The median INR changed from 2.2 (1.9-2.6) the day before to 1.5 (1.4-1.7) immediately before the intervention. An INR < or =1.5 respectively < or =1.8 was achieved in 61% and 95% of the patients. The INR values after one respectively four weeks were comparable to preintervention values. No thromboembolic or bleeding adverse events occurred during the study.
Conclusion: A single adjusted oral dose of vitamin K given a day prior to heart catheterisation combined with a doubled phenprocoumon dose on the procedure day seems to be an easy applicable, safe and effective way to temporary reverse oral anticoagulation with phenprocoumon.