History of traumatic brain injury (TBI) increases the risk for cardiovascular disease (CVD) among United States (US) veterans of the post 9/11 era, according to study findings published in JAMA Neurology.
Among US veterans deployed to Iraq and Afghanistan, sustaining a TBI has been common. Previous research suggests that TBI increases the risk for CVD, but this has been mostly limited to cerebrovascular outcomes. For this study, researchers sought to assess the long-term cardiovascular risks associated with TBI history and severity.
Researchers conducted a retrospective cohort study from October 1, 1999 to September 30, 2016 with follow-up until December 31, 2018. The researchers included data from the US Department of Veterans Affairs and the Department of Defense from the Long-term Impact of Military-Relevant Brain Injury Consortium–Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC). They were a total of 1,559,928 veterans — 301,169 (88.1% men) with a history of TBI and 1,258,759 (80.4% men) without history of TBI. Most of these participants (67.8%) were young (<35 years old) at the study’s start. They were followed for an average of 7.3 years.
The researchers analyzed the incidence of CVD using ICD-9 and ICD-10 codes, comparing participants in both the TBI and non-TBI groups.
The primary outcome was CVD, a composite of coronary artery disease, stroke, peripheral artery disease, and CVD death. Veterans had to have either 1 inpatient diagnosis or 2 outpatient diagnoses (at least 7 days apart) for any of these disorders to be diagnosed with CVD. Secondary outcomes included individual components of the composite score.
Following analysis, the researchers confirmed a correlation between CVD and TBI. Veterans with a history of mild TBI (hazard ratio [HR]: 1.62; 95% CI, 1.58-1.66; P <.001), moderate to severe TBI (HR: 2.63; 95% CI, 2.51-2.76; P <.001), and penetrating TBI (HR: 4.60; 95% CI, 4.26-4.96; P <.001) all demonstrated increased risk for CVD compared with veterans without TBI history.
Veterans with mild and moderate to severe TBI demonstrated a significantly higher risk for CVD death compared with veterans without TBI (HR: 1.26; 95% CI, 1.12- 1.42; P <.001 and HR: 1.69; 95% CI, 1.37- 2.08; P <.001, respectively). Those with penetrating TBI did not share this outcome (P =.50).
“Results…suggest that US veterans with a TBI history were more likely to develop CVD [cardiovascular disease] compared with veterans without a TBI history,” the researchers stated. “Given the relatively young age of the cohort, these results suggest that there may be an increased burden of CVD as these veterans age and develop other CVD risk factors.”
Study limitations included potential biases, lack of access to data from private healthcare system databases, lack of generalizability outside of the predominantly White, male, US veteran population, and potential coding errors regarding cardiovascular diagnoses.
Disclosures: Some study authors declared conflicts of interest. Please see the original reference for a full list of authors’ disclosures.
Stewart IJ, Amuan ME, Wang CP, et al. Association between traumatic brain injury and subsequent cardiovascular disease among post-9/11-era veterans. JAMA Neurol. Published online September 6, 2022. doi:10.1001/jamaneurol.2022.2682