Warfarin still offers benefits after traumatic brain injury

In spite of increased bleeding risks, resumption of anticoagulant therapy was beneficial to patients following a traumatic brain injury, according to an article published in the August issue of JAMA: Internal Medicine.

Reviewing data from Medicare databases between May 2006 and December 2009, the research team led by Jennifer Albrecht, PhD, of the University of Maryland School of Pharmacy in Baltimore, followed the outcomes of 10,782 traumatic brain injury patients to determine whether they were at greater risk for adverse events. All were prescribed warfarin in the month prior to the traumatic brain event.

Among those patients, 46 percent used warfarin for some amount of time by three months after discharge and 53 percent used warfarin for some length of time by six months. At 12 months, 55 percent of patients had at one time used warfarin following their brain injury. Other anticoagulant use increased slightly over the same period in time.

In the 12-month period, warfarin users experienced an unadjusted annualized rate of thrombolytic events of 113.5 per 1,000, while those who were not on warfarin experienced a rate of 155.9 per 1,000. Hemorrhagic events occurred at a rate of 119.8 per 1,000 patients using warfarin vs 85.7 per 1,000 in patients not using warfarin.

The research team noted that the data may be skewed due to lack of information about anticoagulant prescriptions for patients who were released to skilled nursing facilities.

However, Albrecht et al found that patients who didn’t return to anticoagulants had a longer hospital stay and were more likely to be discharged to a nursing facility. They suggested this may have had more to do the severity of the traumatic brain injury.

They also noted that pre-injury, in patients with atrial fibrillation (AF), anticoagulation therapy was underutilized: Of the patients followed, 82 percent had AF and only 55 percent of participants resumed a minimum of a month of use of warfarin in the year that followed their injury. They also noted that while there was an elevated risk for hemorrhagic events following traumatic brain injury with warfarin, patients appeared to have a decreased risk of stroke.

“Results from this study suggest that despite increased risk of hemorrhage, there is a benefit for most patients receiving anticoagulation therapy, in terms of reduction of risk in stroke, from warfarin therapy resumption following discharge after hospitalization for TBI [traumatic brain injury],” Albrecht et al wrote. They suggested that more information was needed to determine if warfarin therapy would be beneficial to patients who were discharged to skilled nursing facilities, as it constitutes gap in knowledge about anticoagulation therapy after a traumatic brain injury.