Autoimmune disorders and venous thromboembolism: a report from the COMMAND VTE Registry
Authors: Yamashita Y , Morimoto T , Kimura T ,   the COMMAND VTE Registry Investigators
Published: October 2021

Abstract

Background/Introduction
Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT), is a major health problem in the world. Several studies reported that autoimmune disorder is one of important risk factors for development of VTE. Furthermore, autoimmune disorder is thought to be a relatively strong risk factor for VTE recurrence, and extended anticoagulation therapy are recommended for prevention of VTE recurrence in patients with autoimmune disorders. However, it remains controversial whether patients with autoimmune disorders have higher risk for clinical events after VTE than those without.

Purpose
We sought to evaluate the clinical characteristics, management strategies, and long-term outcomes of patients with autoimmune disorders after excluding patients with active cancer in a large observational database in Japan.

Methods
The COMMAND VTE Registry is a multicenter registry enrolling 3027 consecutive patients with acute symptomatic VTE. After excluding patients with active cancer, the current study population consisted of 2332 patients, who were divided into 2 groups: patients with autoimmune disorders and those without. We estimated the cumulative incidences of the clinical outcomes. To adjust for the clinically relevant confounders, we used the multivariable Cox proportional hazard model to estimate the hazard ratio (HR) and their 95% confidence interval (CI) for the risk of patients with autoimmune disorders relative to those without for the clinical outcome measures. Furthermore, we added corticosteroids use at discharge to explore the effect of corticosteroids use.

Results
There were 188 patients (8.1%) with autoimmune disorders and 2144 patients (92%) without autoimmune disorders. Patients with autoimmune disorders were more often women (74%), and more often received corticosteroids at discharge (69%). The discontinuation rate of anticoagulation therapy was not significantly different between patients with autoimmune disorders and those without (38.0% vs. 39.7% at 3-year, P=0.35). The cumulative 5-year incidences of recurrent VTE and major bleeding were significantly higher in patients with autoimmune disorders than in those without (recurrent VTE: 14.3% vs. 8.3%, P=0.01; major bleeding: 14.9% vs. 8.8%, P=0.02). Even after adjusting confounders of patient characteristic, the excess risk of patients with autoimmune disorders relative to those without remained significant for recurrent VTE (HR 1.81, 95% CI 1.08–2.88, P=0.03) and major bleeding (HR 1.70, 95% CI 1.05–2.63, P=0.03). However, after adjusting for corticosteroids use at discharge, the excess risk was no longer significant for recurrent VTE (HR 1.42, 95% CI 0.75–2.61, P=0.27) nor major bleeding (HR 1.53, 95% CI 0.84–2.69, P=0.16).

Conclusions
Patients with autoimmune disorders had a higher risk for recurrent VTE and major bleeding than those without, and the excess risk could at least partly be attributable to corticosteroids use.

Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): Research Institute for Production Development, Mitsubishi Tanabe Pharma Corporation