Trends and Outcomes of Deep Vein Thrombosis in Multiple Myeloma and Monoclonal Gammopathy of Undetermined Significance: A National Inpatient Sample (NIS) Analysis
Authors: Gaddam Mrunanjali , Sinha Samridhi , Iqbal Rabia , Jayakumar Jayalekshmi , Sanka Sujana , Kavuri Swathi , Colon Ramos Ana , Singh Surbhi , Atluri Sobha , Koifman Michelle , Quadri Kalimullah , Ullah Asmat 
Published: December 2024

Introduction:
In general, patients with Multiple Myeloma (MM) are at higher risk of developing deep vein thrombosis (DVT), mainly when treated with immunomodulatory agents. In addition, Monoclonal gammopathy of undetermined significance (MGUS), a premalignant clonal plasma cell or lymphoplasmacytic proliferative disorder, can also increase the risk of developing deep vein thrombosis. The risk is attributed to several factors, including increased levels of circulating paraproteins, reduced mobility due to bone involvement and use of immunomodulatory drugs. Understanding the trends in DVT incidence in these populations can improve clinical practice and patient management. It is essential to have a thorough understanding of the potential outcomes of deep venous thrombosis, such as pulmonary embolism, chronic venous insufficiency, leg ulcers, and post-thrombotic syndrome, so as to make informed clinical decisions and optimize patient care strategies.
Objective: To analyze the trends in the incidence of DVT and its outcomes in patients with MM and MGUS from 2018 to 2020 using the National Inpatient Sample (NIS) database.
Methods:
We queried the National Inpatient Sample database from 2018 - 2020 to identify adult hospitalizations (age &gt; 18) with a primary diagnosis of MM and MGUS using appropriate ICD 10 codes. This population was further stratified based on concomitant DVT. We compared the all-cause in-hospital mortality, length of hospital stay (LOS), and total costs in patients admitted with MM and MGUS with DVT and compared to those without DVT. Categorical variables were compared using the chi-square test and continuous variables with the t-test. Multivariate regression analysis was further performed to study the impact of DVT on complications and mortality after adjusting for relevant confounders.
Results:
Among 354,810 Multiple Myeloma (MM) hospitalizations and 148,940 Monoclonal Gammopathy of undetermined significance (MGUS) hospitalizations, DVT was diagnosed in 2.01 % (N=7120) of MM Hospitalizations and 1.82 % (N=2705) of MGUS Hospitalizations. In-hospital mortality was significantly higher in both MM (OR 1.36; P =0.005) and MGUS (OR 1.48; P&lt;0.05) populations with DVT compared to those without DVT. Multivariate regression analysis revealed that DVT presence increased the chance of mortality among both MM (OR 1.32; P 0.014) and MGUS (OR 1.49; P 0.048) Hospitalizations. DVT also significantly impacted secondary outcomes such as Pulmonary Embolism (PE), Chronic venous insufficiency (CVI), Leg Ulcers (LU) and Post Thrombotic Syndrome (PTS) in both MM and MGUS populations. However, no statistically significant differences were found in the odds of Leg ulcers in the MM Group. DVT was also associated with longer LOS (mean 10.35 days Vs 7.13 in MM; mean 10.83 days Vs 6.63 in MGUS) and higher total hospital costs ($133,062$ Vs $86,671in MM; $123,086 Vs $75,826 in MGUS) in both MM and MGUS groups compared to those without DVT.
Conclusion:
The incidence of DVT in patients with Multiple Myeloma (MM) and Monoclonal gammopathy of undetermined significance (MGUS) showed an increasing trend. The increase was more pronounced in the MM population than in the MGUS population. DVT is an independent risk factor for in-patient mortality, the longer length of stay, and the total cost in both MM and MGUS patients. Understanding these elements is crucial in this vulnerable cohort for improving patient outcomes and tailoring treatments effectively.