Acute Venous and Arterial Thromboembolic Events in Patients with Monoclonal Gammopathy of Undetermined Significance: A Nation Wide Analysis

Abstract

Introduction: Monoclonal Gammopathy of Undetermined Significance (MGUS) is a premalignant plasma cell disorder. It is found in over 3% of patients who are 50 years of age or older (Kyle et al., 2006). MGUS is usually asymptomatic; however, it carries an increased risk of certain comorbidities. Some literature suggests an increased risk of venous and arterial thromboembolism in MGUS patients. We sought to examine this relationship using data from the National Inpatient Sample (NIS). Methods: We conducted a cross-sectional study using data from the NIS from the year 2016. We evaluated the frequencies of composite venous and composite arterial thromboembolism outcomes in adult patients with MGUS compared with those who had no history of the disease. IBM SPSS 26.0 was used for analysis. We constructed several logistic regression models to adjust for common confounding variables, including age, sex, race, and expected primary payer. Adjusted odds ratios and confidence intervals were calculated for each composite and component variable. Chi-square tests were used for comparing categorical variables. Results: We identified a total of 8500 patients with the diagnosis of MGUS. Among patients with MGUS, 135 patients (1.6%) had the primary diagnosis of a venous thromboembolic event. These included 55 patients (0.65%) who had acute deep vein thromboembolic events and 80 patients (0.94%) who had pulmonary embolism. Also, 374 patients (4.4%) had the primary diagnosis of an arterial thromboembolic event. These arterial events were divided into 3 categories as follows: 171 discharges (2.01%) were acute thrombo-embolic cardiac events, 190 discharges (2.24%) were acute cerebrovascular ischemic events, and 13 discharges (0.15%) with other arterial thromboembolic events. Patients with MGUS had an increased risk of the composite venous thromboembolism outcome (adjusted odds ratio [OR] 1.271, 95% CI 1.069-1.512). Analysis of the individual components showed a significant increase in the risk of acute deep vein thrombosis (adjusted OR 1.366, 95% CI 1.047-1.782) but failed to show a significant association with the risk of pulmonary embolism (adjusted OR 1.207, 95% CI 0.962-1.513). On the other hand, we found a reduced risk of composite arterial thromboembolism outcome in patients with MGUS (adjusted OR 0.617, 95% CI 0.555-0.685). Individual components analysis showed a reduction in the risk of acute thromboembolic cardiac events (adjusted OR 0.636, 95% CI 0.546-741) and acute ischemic cerebrovascular events (adjusted OR 0.595, 95% CI 0.514-689), but no significant difference was noted in the third group which included other arterial thromboembolic events (adjusted OR 1.343, 95% CI 0.779-2.317). Conclusion: Patients with MGUS had increased odds of developing acute venous thromboembolism, especially deep vein thrombosis, when compared to patients who had no history of MGUS. Interestingly, MGUS patients had reduced odds of developing acute cardiac and cerebrovascular arterial thromboembolic events. More research is required to assess the optimal approach for venous thromboembolism prophylaxis in MGUS patients.