Spinal Cord Injuries & Disorders Are a Risk Factor for Ischemic Stroke in US Veterans
Rafer Willenberg1, Bridget Smith2, Kevin Stroupe3, Jennifer Sippel4, Charlesnika Evans2, Zhiping Huo5, Sunil Sabharwal6
1VA Boston Healthcare System / Harvard Medical School / Spaulding Rehabilitation Network, 2Edward Hines Jr. VA Hospital / Northwestern University School of Medicine, 3Edward Hines Jr. VA Hospital / Loyola University Chicago, 4US Department of Veterans Affairs, SCI/D National Program Office, 5Edward Hines Jr. VA Hospital, 6VA Boston Healthcare System / Harvard Medical School
Objective:

We evaluated whether spinal cord injuries and disorders (SCI/D) are a risk factor for ischemic stroke in US Veterans.

Background:

Ischemic stroke risk is elevated with SCI/D based on data from Taiwan [Wu et al, Neurology. 2012;78:1051–1057].  Whether SCI/D increases ischemic stroke risk in US Veterans has been unconfirmed.

Design/Methods:

Using a retrospective dual-cohort design, adjusted stroke incidence was estimated for Veterans with and without SCI/D between fiscal years 2017-2021 using Veterans Health Administration (VHA) and Medicare utilization data. Veterans with ischemic stroke were identified using ICD-10 codes for cerebral infarction or sequalae of cerebral infarction. Veterans with prior diagnoses of ischemic stroke or sequelae were excluded. Incidence rate ratios were estimated using Poisson regression models adjusted for Veteran characteristics including common stroke risk factors, and prescriptions for stroke-prophylactic medications (antiplatelet agents, antilipid agents, and anticoagulants) immediately preceding the retrospective observation period.

Results:

Analyses included 560,314 Veterans. Adjusting for person-days in the 5-year period, 7.2% with SCI/D vs 5.7% without had a stroke [p < .001], reflecting an incidence rate ratio (IRR) of 1.27 [95%CI: 1.19 – 1.36].  Adjusting for age, sex, smoking, diabetes, hypertension, atrial fibrillation, race and ethnicity yielded a 26% higher stroke incidence with SCI/D than without [IRR 1.26, 95%CI: 1.17 – 1.35]. Further adjusting for stroke-prophylactic prescriptions yielded a 19% higher stroke incidence with SCI/D than without [IRR 1.19, 95%CI: 1.11-1.27]. Compared to controls, stroke incidence was 50% and 31% higher with high and low tetraplegia, respectively [IRR 1.50, 95%CI: 1.16 – 1.92 and IRR 1.31, 95%CI: 1.02 – 1.67]. Stroke incidence was 36% higher with non-traumatic SCI/D [IRR 1.36, 95%CI: 1.24-1.49], whereas stroke incidence with traumatic SCI was not significantly higher than controls [IRR 1.05, 95%CI: 0.95-1.17]. 

Conclusions:

SCI/D is a risk factor for ischemic stroke in US Veterans, especially for Veterans with tetraplegia and non-traumatic injuries.

10.1212/WNL.0000000000204719