Background/Purpose:

Venous thromboembolism (VTE) contributes significantly to in-hospital morbidity and mortality. Previous studies have suggested that certain vasculitides, including granulomatosis with polyangiitis (GPA) and giant cell arteritis (GCA) are associated with increased risk of VTE. However, there is mixed evidence in the literature about the risk of VTE in patients with polyarteritis nodosa (PAN) and Takayasu’s arteritis (TA). Some of these studies were limited by not adjusting for common cofounders, in this case VTE risk factors. We sought to explore the association of VTE as primary reason for hospitalization in patients with GPA, GCA, PAN and TA using a national inpatient database.

Methods:

We conducted a retrospective cross-sectional study using the National Inpatient Sample (NIS) database for the year 2014. Diagnoses were identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Patients with a principal admission diagnosis of VTE and a secondary diagnosis of GPA, GCA, PAN and TA were included in the study. There were no exclusion criteria. Univariate and multivariate logistic regression models were used to adjust for potential confounders.
In this study, we adjusted for age, gender, race, length of stay and selected common risk factors for VTE such as active smoking, cancer, heart failure, stroke, sepsis, thrombophilia, obesity, nephrotic syndrome, inflammatory bowel disease, pregnancy, postpartum and long bone fracture.

Results:

A total of 287,790 hospitalizations with a principal diagnosis of VTE were identified. Among this cohort, the number of hospitalizations with a secondary diagnosis of GPA, GCA, PAN and TA were 11,285, 16,480, 4,450 and 1,350, respectively. The unadjusted OR for a principal diagnosis of VTE and a secondary diagnosis of any of these four vasculitis reached statistical significance for GPA (OR 2.76, 95% CI 2.10 – 3.64, p < 0.001), GCA (OR 2.45, 95% CI 1.91 – 3.13, P < 0.001), PAN (OR 1.81, 95% CI 1.04 – 3.13, p = 0.035). There was no difference for TA (OR 2.30, 95% CI 0.95 – 5.56, p = 0.065). When adjusting for confounding variables, there was statistical significance for GPA (OR 2.54, 95% CI 1.90 – 3.40, p < 0.001), GCA (OR 1.53, 95% CI 1.18 – 1.98, p = 0.001) and TA (OR 2.46, 95% CI 1.01 – 5.97, p = 0.047), though not for PAN (OR 1.47, 95% CI 0.83 – 2.60, p = 0.183).

Conclusion:

Our study suggests that GPA and GCA are independently associated with increased risk of hospitalizations for VTE, which is consistent with previously published studies in the literature. We found that PAN is associated with increased risk of VTE hospitalizations but is not considered an independent risk factor, which confers a possible explanation for the conflicting results in previous investigations. TA was associated with an increased risk of VTE after adjusting for confounders. Further studies are needed to clarify these relationships further.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/risk-of-hospitalizations-for-venous-thromboembolism-among-patients-with-selected-systemic-vasculitides-a-nationwide-analysis/