Paradoxical venous thromboembolism in immune thrombocytopenia : A national study of mortality,anticoagulation gaps and racial disparities

Abstract Background: Immune thrombocytopenia (ITP) is an acquired autoimmune disorder charcahterized by isolated thrombocytopenia in the absence of other underlying causes.It affects an estimated of 3.3 per 100,000 adults annually in the United States,with a higher incidence in women and older adults.Although traditionally associated with bleeding,paradoxical thrombotic events -particularly Venous thromboembolism including deep vein thrombosis (DVT) and pulmonary embolism (PE) are increasingly recognised.Clinical management of VTE in ITP remains complex,requiring a balance between thrombosis prevention and bleeding risk.Despite increased awareness,national data on VTE outcomes and anticoagulation practices in hospitalized ITP patients are limited. Methods: We conducted a retrospective cross-sectional analysis using the 2022 National Inpatient Sample (NIS) . Adult hospitalizations with a primary or secondary diagnosis of ITP wereidentified using ICD-10-CM code D69.3.Venous thrombolembolism,including DVT and pulmonary embolism (PE),identified using validated ICD-10-CM codes (e.g.I26.x,I82.4x,I82.6x).Anticoagulation use was identified using code Z79.01. We extracted patient level variables including age,sex,race,insurance and hospital charachteristics.Primary outcomes were in hospital mortality,length of stay (LOS) and total hospital charges (TOCH). Descriptive statistics were calculated using chi-square and t-tests.Multivariate logistic regression models identified independent predictors of VTE,mortality and bleeding.Adjusted odd ratios (aORs) with 95% confidence intervals (CI) were reported.Analysis were conducted using Stata/SE19.due to the NIS 2022 redesign,discharge weights were not applied. Results: Among 12,214 adult hospitalizations with ITP, 5.2% developed VTE.Compared to those without VTE,affected patients had significantally Higher in hospital mortality (10.6% vs 4.4%,p<0.001) Higher Length of stay (12.7 vs 6.4,p<0.001%) Greater hospital charges ($226,552 vs $198,080,p,0.001%) On multivariate analysis VTE was independently associated with increased mortality (aOR 2.44; 95% CI :1.62-3.67,p <0.001%) Female sex (aOR 1.24; p =0.009%) was a predictor of VTE Hispanic patients had significantly lower odds of VTE comapred to White patients (aOR 0.33; 95% CI : 0.22-0.51;p <0.001%) Among patients with ITP and VTE : Only 21.9% received anticoagulation Bleeding occurs in 0.7% of anticoagulated vs3.8% of non-anticoagulated patients Anticoagulation was not significantally associated with increased bleeding risk (aOR 0.19; p = 0.11) Conclusions Venous thromboembolism is a clinically significant complication in hospitalised patientswith ITP,associated with higher mortality and resource utilisation.Despite this anticoagulation was administed in fewer than one in four patients and was not associated with increased bleeding.These findings support a more individualized,evidence -based approach to anticoagulation in ITP.Continued evaluation of sociodemographic and treatment related factors is essential to optimize outcomes. National guidelines are warranted to address the complex thrombotic and hemorrhagic risks in this unique patient population.