Risk for stroke significantly elevated for veterans with all levels of TBI, including mild
By Sravya Valiveti. This article was initially published in our Concussion Update newsletter; please consider subscribing.
A study published by Andrea Schneider et al. in the American Heart Association journal Stroke highlights how a prior history of traumatic brain injury is strongly associated with long-term stroke risk among US military veterans. Based on previous research, TBI is highly prevalent among military veterans. Those with prior TBI are at an increased long-term risk for stroke; in this study, stroke risk was found to be the highest in the first year following a TBI diagnosis and remained elevated for more than ten years post-TBI diagnosis. Veterans with TBI were found to be 1.69 times more likely to be at risk for any stroke compared to veterans without TBI; while the risk was highest in the first year post-TBI diagnosis, this risk remained elevated for 10+ years. Veterans with a mild TBI had a risk ratio of 1.47 times, and veterans with moderate, severe, or penetrating injuries had double the risk.
The researchers wanted to explore the risk for stroke among diverse populations as well as further assess the long-term impact of TBI and how that might correlate to differences in age, sex, race, ethnicity, and time since the patients’ TBI diagnosis. This was a large-scale retrospective study looking at veterans “receiving healthcare in the Veterans Health Administration system” between 2002 and 2019. The study groups included 306,796 veterans with TBI and 306,796 veterans without TBI who were matched on age, sex, race, and ethnicity. The subjects were 18+, with a mean age of 50 years, and 25% were of non-White race and ethnicity. TBI was found to be more strongly associated with hemorrhagic stroke than ischemic stroke, as well as “associations of TBI with stroke were stronger among older compared to younger individuals and were weaker among Black veterans compared to other races and ethnicities.”
Those who were younger and non-Hispanic Black had a lower risk for any stroke compared to those who were older. Additionally, a key finding from the study showed that “4.7% of the veterans with prior diagnosis of TBI developed a stroke over a median follow-up period of 5.2 years”.
The study limitations, mentioned in a Neurology Advisor article, include the lack of study participants outside of the VA healthcare system and the “lack of generalizability to populations other than veterans and men.” This study not only corroborates previous research on the link between TBI and long-term stroke risk but also highlights that US veterans are at a heightened risk for developing stroke in the years following a TBI diagnosis. The researchers suggest that this is a key demographic to target with regard to primary preventive stroke strategies, which thus warrants close monitoring among veterans with prior TBI.