International normalized ratio for the guidance of warfarin treatment in elderly patients after cardiac valve replacement.

Thus far, the target value for international normalized ratio (INR) has remained to be determined. The current study aimed to further explore the INR value of the anti-coagulation drug warfarin after cardiac valve replacement. The clinical data of 213 patients who underwent cardiac valve replacement at Linyi Central Hospital (Linyi, China) between January 2010 and May 2013 were retrospectively analyzed.