Poor control of warfarin treatment (TTR60 ≤40%) was associated with a significantly higher risk of intracranial hemorrhage compared to optimal control (TTR60 >80%), with an adjusted HR of 2.16.
Cohort (n=53,953)
Yes
Does poor quality of warfarin treatment (low TTR60) increase the risk of intracranial hemorrhage in patients with atrial fibrillation?
In patients with atrial fibrillation, poor control of warfarin therapy (TTR60 ≤40%) is associated with a more than twofold increased risk of both traumatic and non-traumatic intracranial hemorrhage compared to excellent control.
Hazard Ratio: 2.16 (95% CI 1.83–2.54)
Absolute Event Rate: 1.35% vs 0.62%
p-value: p=<0.001
BACKGROUND: Intracranial hemorrhage (ICH) is a devastating complication of oral anticoagulation. The aim of this study was to describe the spectrum of ICH and to evaluate the association of warfarin control with the risk of ICH in a nationwide cohort of unselected atrial fibrillation (AF) patients. METHODS AND RESULTS: The FinWAF is a retrospective registry-linkage study. Data were collected from several nationwide Finnish health-care registers and laboratory databases. The primary outcome was any ICH (traumatic or non-traumatic). The quality of warfarin therapy was assessed continuously by calculating the time in therapeutic range in a 60-day window (TTR60). Adjusted Cox proportional hazard models were used. A total of 53,953 patients were included (53% men; mean age, 73 years; mean follow-up, 2.94 years; mean TTR, 63%). In 129,684 patient-years, 1,196 patients had ICH (non-traumatic, 53.5%; traumatic, 43.6%; traumatic subdural, 38.6%); crude annual rate, 0.92%; 95% CI: 0.87-0.98). A lower TTR60 was significantly associated with higher risk of ICH (TTR60 ≤40% vs. TTR60 >80%; adjusted hazard ratio, 2.16; 95% CI: 1.83-2.54). Other variables independently associated with ICH included age >65 years, previous stroke, male sex, low hemoglobin, thrombocytopenia, elevated alanine aminotransferase, and previous bleeding other than ICH. CONCLUSIONS: Poor control of warfarin treatment was associated with elevated risk of ICH. Approximately half of the ICH were traumatic, mainly subdural.
Tiili et al. (2019) conducted a cohort in Atrial Fibrillation (n=53,953). Poor quality of warfarin therapy (TTR60 ≤40%) vs. Optimal quality of warfarin therapy (TTR60 >80%) was evaluated on Any intracranial hemorrhage (traumatic or non-traumatic) (HR 2.16, 95% CI 1.83-2.54, p=<0.001). Poor control of warfarin treatment (TTR60 ≤40%) was associated with a significantly higher risk of intracranial hemorrhage compared to optimal control (TTR60 >80%), with an adjusted HR of 2.16.