Quality of vitamin K antagonist treatment during the last year of life

Limited data exist on the quality of anticoagulation in patients approaching the end of life. This study evaluated vitamin K antagonist (VKA) anticoagulation control during the last year of life, using nationwide data from Statistics Netherlands, linked to anticoagulation clinics' data and the Netherlands Cancer Registry. We included prevalent VKA users who were hospitalized with a severe medical condition and died between January 1, 2013, and December 31, 2019. Anticoagulation control was assessed using time in therapeutic range (TTR), time above therapeutic range (TAR), and time below therapeutic range (TBR) and the international normalized ratio (INR) variance growth rate (VGR), which reflects INR variability. Anticoagulation control was examined by two approaches: (1) over four intervals (0-12 months, 0-9 months, 0-6 months, and 0-3 months preceding death), and (2) in 3-month intervals (9-12, 6-9, 3-6, and 0-3 months before death) to describe temporal changes. Among 6874 VKA users in their last year of life (median age 82 [Interquartile range: 76-87] years, 46.9% female), the most prevalent severe medical conditions were heart disease (60.4%), cancer (16.2%), and hip fracture (15.2%). As death approached, TTR and TBR decreased, while TAR and mean VGR increased, particularly in the last 3 months of life. This decline was more pronounced in cancer patients and acenocoumarol users. In conclusion, the quality of VKA anticoagulation declined in the last year of life in severely ill patients, marked by reduced TTR and increased TAR and VGR, suggesting an increased bleeding risk. These findings highlight the importance of reassessing VKA use and considering discontinuation in patients approaching the end of life.