Intracranial Hemorrhage in Atrial Fibrillation Patients During Anticoagulation With Warfarin or Dabigatran: The RE-LY Trial
Diener HC, Yang S, Connolly SJ, Wallentin L, Reilly PA, Ezekowitz MD, Yusuf S; Stroke (Apr 2012)
BACKGROUND AND PURPOSE: Intracranial hemorrhage is the most devastating complication of anticoagulation. Outcomes associated with different sites of intracranial bleeding occurring with warfarin versus dabigatran have not been defined. METHODS: Analysis of 18 113 participants with atrial fibrillation in the Randomized Evaluation of Long-term anticoagulant therapY (RE-LY) trial assigned to adjusted-dose warfarin (target international normalized ratio, 2-3) or dabigatran (150 mg or 110 mg, both twice daily). RESULTS: During a mean of 2.0 years of follow-up, 154 intracranial hemorrhages occurred in 153 participants: 46% intracerebral (49% mortality), 45% subdural (24% mortality), and 8% subarachnoid (31% mortality). The rates of intracranial hemorrhage were 0.76%, 0.31%, and 0.23% per year among those assigned to warfarin, dabigatran 150 mg, and dabigatran 110 mg, respectively (P<0.001 for either dabigatran dose versus warfarin). Fewer fatal intracranial hemorrhages occurred among those assigned dabigatran 150 mg and 110 mg (n=13 and n=11, respectively) versus warfarin (n=32; P<0.01 for both). Fewer traumatic intracranial hemorrhages occurred among those assigned to dabigatran (11 patients with each dose) compared with warfarin (24 patients; P<0.05 for both dabigatran doses versus warfarin). Independent predictors of intracranial hemorrhage were assignment to warfarin (relative risk, 2.9; P<0.001), aspirin use (relative risk, 1.6; P=0.01), age (relative risk, 1.1 per year; P<0.001), and previous stroke/transient ischemic attack (relative risk, 1.8; P=0.001). CONCLUSIONS: The clinical spectrum of intracranial hemorrhage was similar for patients given warfarin and dabigatran. Absolute rates at all sites and both fatal and traumatic intracranial hemorrhages were lower with dabigatran than with warfarin. Concomitant aspirin use was the most important modifiable independent risk factor for intracranial hemorrhage.
Comment: warfarin use by itself was more of a risk than dabagitran + asa, although the combination also increased risk. Age was not a major risk factor. Fall risk was not looked at.
Old studies that panned the use of anticoagulation in stroke, including WASID might need to be restudied, with dabagatran, since in Wasid the real problem was keeping the INR's in range. This point is likely to be incredibly controversial, yet the facts speak: dabagatran has not been studied in the group of intracranial stensosis and the results of warfarin studies cannot be generalized as is clear from this trial.
