Incidence and risk factors for venous thromboembolism during an acute attack in patients with neuromyelitis optica spectrum disorders

Background: Neuromyelitis optica spectrum disorders (NMOSD) patients may be at increased risk of venous thromboembolism (VTE) during the acute attack, but evidence is limited. Objective: To investigate the incidence of venous thromboembolism (VTE) in Neuromyelitis optica spectrum disorders (NMOSD) patients with an acute attack and to identify the potential risk factors for the development of VTE. Methods: We conducted a retrospective study of NMOSD patients with an acute attack between January 1, 2015, and June 31, 2021. Diagnosis of DVT or PE was objectively confirmed by doppler ultrasound or computed tomographic pulmonary angiography (CTPA) during their acute hospital stay. Results: We identified 184 attacks in 128 NMOSD patients with the mean age of 46.9 years at the time of the attack and female predominance (152/184, 83.2%). VTE occurred in 22 (12.0%) attacks. Among the 22 attacks, 20 presented with transverse myelitis (TM), 1 cerebral syndrome (CS), and 1 simultaneous TM and brainstem syndrome (BS). Multivariable logistic regression analysis showed that advanced age [odds ratio (OR) = 1.08, 95% confidence interval (CI) = 1.04-1.12, p = 0.000], Nadir Expanded Disability Status Scale (EDSS)> 6.5(OR = 3.39, 95% CI = 1.22-10.10, p = 0.029) and intravenous immunoglobulin (IVIG) treatment (OR = 3.21, 95% CI = 1.15-8.91, p = 0.025) were independent risk factors for the development of VTE in the total NMOSD cohort. In the subgroup analysis of the NMOSD patients with TM, age at attack (OR = 1.07, 95% CI = 1.03-1.11, p = 0.002) and IVIG treatment (OR = 4.23, 95% CI = 1.44-12.45, p = 0.009) were independent risk factors for the development of VTE in the total NMOSD cohort, but Nadir EDSS > 6.5 was not an independent risk factor. Conclusions: VTE is a frequent complication in NMOSD patients, especially in patients with TM. Advanced age and IVIG are independent risk factors for VTE. Immobilization is an independent risk factor for VTE in the total NMOSD cohort but not in the subgroup analysis of the patients with TM.

Automated summary

VTE is a common complication in NMOSD patients, especially in those with TM. Advanced age and IVIG treatment are independent risk factors for VTE. Immobilization is also a risk factor for VTE in the total NMOSD cohort.