We examined correlations of ischemic stroke risk with etiology, time from onset, neurologic level of injury, and common stroke risk factors for the first five years following onset of spinal cord injuries and disorders (SCI/D) in US Veterans.
SCI/D are reported to increase ischemic stroke risk in the initial years following onset, based on data from Taiwan. Whether ischemic stroke incidence is increased in the early years following SCI/D in US Veterans is unconfirmed. Further stroke risk correlations with etiology of SCI/D, level of neurologic injury, and age at SCI/D onset have not yet been reported.
A retrospective dual-cohort design with Veterans Health Administration (VHA) and Medicare utilization data was used to estimate stroke incidence for 5 years following SCI/D onset, and during 2017-2021 for controls. Incidence rate ratios (IRRs) of ischemic stroke were estimated using Poisson regression models adjusted for Veteran characteristics, common stroke risk factors (smoking, diabetes, hypertension, atrial fibrillation), and prescriptions for stroke-prophylactic medications (antiplatelet agents, antilipid agents, and anticoagulants) immediately preceding the retrospective observation period.
Analyses included 48,533 Veterans; 3,080 with SCI/D, and 45,848 controls. Adjusting for characteristics, comorbidities, stroke-prophylactic medications, and person-days in the 5-year periods, 13.3% with SCI/D vs 5.7% controls had an ischemic stroke [p < .001], reflecting an IRR of 2.33 [95%CI: 2.09 – 2.60]. Stroke IRR was highest in the first year following SCI/D onset [3.81; 95%CI: 3.20-4.54], relative to controls. Stroke IRR was elevated with both traumatic [IRR 2.36; 95%CI: 1.96 – 2.83] and non-traumatic [IRR 2.34; 95%CI: 2.06 – 2.66] SCI/D. Stroke IRR was elevated across all levels of neurologic injury.
Ischemic stroke risk is elevated in Veterans in the early years following SCI/D, and especially in the first year. Ischemic stroke risk is elevated for all neurologic levels of injury, and regardless of traumatic or non-traumatic SCI/D etiology.