External validation of venous thromboembolism risk prediction models in patients with multiple myeloma in a community setting: A retrospective cohort study.

Abstract

e20027 Background: Newly diagnosed Multiple Myeloma (MM) patients have a 10 to 20 times higher risk of developing venous thromboembolism (VTE) than the general population. Three risk prediction models have been recently established to ascertain the degree of VTE risk: SAVED (Surgery, Asian race, VTE history, Elderly and Dexamethasone), IMPEDE VTE (Immunomodulatory drugs (IMiD), BMI, Pelvic fracture, Erythropoietin stimulating agent, Dexamethasone/Doxorubicin, Asian Ethnicity, VTE history, Tunneled line, Existing thromboprophylaxis) and PRISM scores (Prior VTE, Race, IMiD, Surgery, Metaphase Cytogenetics). Our primary objective was to assess the external validity of three VTE risk prediction models in a community hospital setting. Methods: All consecutive newly diagnosed MM treated at Saint Vincent Hospital from 1/1/2012 to 12/22/2022 were included in our analysis. Patients receiving therapeutic anticoagulation for other indications or a diagnosis of VTE within 6 months prior to MM diagnosis were excluded. Variables were collected by retrospective chart review at the time of MM treatment initiation. Model discrimination was assessed by calculating the area under the receiver operating characteristic curve (AUROC). Logistic regression was used to calculate the odds ratio (OR) of VTE occurrence with candidate variables in the risk prediction model. Results: The 160 patients with newly diagnosed MM and available data on VTE occurrence were included. The median age of our cohort at treatment initiation was 74 years (range 31-96); 55% were male, and 75% were Caucasians. IMiD-based induction regimen was used in 68.1 % of patients. The median SAVED score was 1 (IQR:0-2), IMPEDE VTE was 4 (IQR: 2-6), and PRISM score was 2 (IQR: 0-2). The most common thromboprophylactic agent used was aspirin (53.8%). The median time to VTE from induction was 4.8 months. The cumulative incidence of VTE at 12 months was 13.1%. Each 1-point increase in the score was associated with a significantly higher chance of VTE occurrence across all three models (Table). Factors significantly associated with the development of VTE were prior VTE history (OR:2.28, 95% CI:1.31-3.97,p = 0.003) and age greater than 80 years (OR:4.03, 95% CI:1.47-11.02,p = 0.006). Conclusions: Our findings suggest that all three PRISM (AUROC = 0.70), SAVED (AUROC = 0.72), and IMPEDE VTE (AUROC = 0.73) scores could statistically predict VTE outcomes in our patient population. The inclusion of more parameters in the IMPEDE VTE score may have led to its outperformance in risk stratification. [Table: see text]