Postthrombotic Syndrome and Chronic Pulmonary Embolism after Obstetric Venous Thromboembolism.

OBJECTIVE: While the majority of venous thromboembolism (VTE) during pregnancy events resolve with anticoagulation, long-term complications may occur including (1) postthrombotic syndrome and (2) chronic pulmonary embolism. The objective of this study was to determine risk of these two complications. STUDY DESIGN: A retrospective cohort study using the MarketScan databases was performed on deliveries from 2008 to 2014. We identified women aged 15 to 54 years diagnosed with acute VTE during pregnancy, the delivery hospitalization, or ≤60 days postpartum who received at least one prescription postpartum for anticoagulants. Risks of (1) chronic PE and (2) postthrombotic syndrome were evaluated for women at 6, 12, 24, and 60 months after delivery hospitalization through 2017 via the International Classification of Diseases, 9th/10th Revision, Clinical Modification codes. RESULTS: Of 4,267 of 4,128,900 pregnancies complicated by VTE, the majority had DVT alone (61.8%, n = 2,637), while 25.8% had PE alone (n = 1,103) and 12.4% (n = 527) had both DVT and PE. Of the entire cohort, 3,328 retained insurance coverage at 6 months, 2,823 at 12 months, 2,161 at 24 months, and 831 at 60 months. Restricted to DVT, risk of postthrombotic syndrome was 0.7% at 6 months (n = 17), 1.1% at 12 months (n = 22), 1.7% at 24 months (n = 26), and 2.7% at 60 months (n = 16). Among women with PE diagnoses, the risk of chronic PE was 2.4% at 6 months (n = 30), 3.3% at 12 months (n = 36), 4.2% at 24 months (n = 36), and 7.2% at 60 months (n = 24). CONCLUSION: In comparison to the general population, the risk of postthrombotic syndrome was lower. In comparison, the risk of chronic PE was similar to the estimates in the general population at comparable time points after PE events. For women with obstetric PE, it may be appropriate to be vigilant for findings and symptoms associated with chronic PE. KEY POINTS: · Risk of postthrombotic syndrome after obstetric deep vein thrombosis is low.. · Risk of chronic pulmonary embolism may approximate that in the general population.. · Overall risk of chronic complications after obstetric VTE was relatively low..

Trends in Venous Thromboembolism and Associated Risk Factors During Delivery Hospitalizations From 2000 to 2018.

OBJECTIVE: To characterize trends in and risk factors for venous thromboembolism (VTE) during delivery hospitalizations in the United States. METHODS: The 2000-2018 National Inpatient Sample was used for this repeated cross-sectional analysis. Venous thromboembolism (including deep vein thrombosis [DVT] and pulmonary embolism) during delivery hospitalizations for women aged 15 to 54 years was determined by year. Temporal trends in VTE were characterized using joinpoint regression with estimates presented as the average annual percent change. Temporal trends in common VTE risk factors were also analyzed. The proportion of vaginal and cesarean deliveries by year that had VTE risk factors was determined, and average annual percent changes with 95% CIs were calculated. The relationship between risk factors and the likelihood of VTE events was determined with adjusted and unadjusted logistic regression models. RESULTS: Of 73,109,789 delivery hospitalizations, 48,546 VTE events occurred (6.6/10,000 deliveries), including 37,312 DVT diagnoses and 12,487 pulmonary embolism diagnoses. Rates increased significantly for vaginal (average annual percent change 2.5%, 95% CI 1.5-3.5%) but not for cesarean delivery hospitalizations (average annual percent change 0.3%, 95% CI -1.0 to 1.6%) over the study period. Pulmonary embolism increased for both vaginal delivery (average annual percent change 8.7%, 95% CI 6.0-11.5%) and cesarean delivery (average annual percent change 4.9%, 95% CI 3.6-6.2%). The proportion of cesarean deliveries with at least one VTE risk factor increased from 27.2% in 2000 to 43.6% in 2018 (average annual percent change 2.6%, 95% CI 2.2-3.1%) and for vaginal deliveries, from 17.7% to 31.4% (average annual percent change 3.4%, 95% CI 2.3-4.4%). The 5.9% of deliveries with at least two VTE risk factor diagnoses accounted for 25.4% of VTE diagnoses. Factors with the highest VTE risk included transfusion (adjusted odds ratio [aOR] 4.1, 95% CI 3.7-4.5), infection (aOR 5.8, 95% CI 5.3-6.3), history of VTE (aOR 7.2, 95% CI 6.2-8.4), and thrombophilias (aOR 9.6, 95% CI 8.5-11.0). CONCLUSION: Both risk factors for VTE and rate of pulmonary embolism increased over the study period. Deep vein thrombosis increased during vaginal delivery hospitalizations but not during cesarean delivery hospitalizations.

Receipt of anticoagulation after venous thromboembolism diagnoses during delivery hospitalizations.

INTRODUCTION: Obstetric venous thromboembolism (VTE) is a leading cause of maternal mortality. While hospital discharge data provide a readily accessible means of studying this relatively rare outcome, diagnosis codes are of limited validity. Prior studies have demonstrated that VTE billing codes may be subject to misclassification and false positives and overestimate obstetric VTE risk. Given the public health significance of accurately estimating obstetric VTE, the purpose of this study was to determine to what degree patients received anticoagulants after discharge from a delivery hospitalization associated with an acute VTE diagnosis as pharmacy claims may more accurately assess the incidence of obstetric VTE. STUDY DESIGN: A retrospective cohort study using the MarketScan database was performed using 2008-2014 claims data. We identified women 15-54 years of age diagnosed with acute VTE during a delivery hospitalization. We determined the proportion of women with VTE that received anticoagulants within 60 days of delivery discharge. Only women with ≥60 days of pharmacy benefits after discharge were included. Receipt of low molecular weight and unfractionated heparin, warfarin, and Xa inhibitors was ascertained. Receipt of anticoagulants was analyzed individually based on diagnoses for deep vein thrombosis (DVT), pulmonary embolism (PE), or both. The Chi-square test was performed for categorical comparisons. RESULTS: Of 2,664,951 delivery hospitalizations, 2112 women had a diagnosis of VTE (0.08%) including 236 women with PE alone, 1760 women with DVT alone, and 116 women with both DVT and PE. Of these women, 51.3% (95% CI 49.2-53.4%) received an anticoagulant including 49.5% of women with DVT (95% CI 47.2-51.8%), 50.0% of women with PE (95% CI 43.7-56.3%), and 81.9% of women with both DVT and PE (95% CI 73.9-87.9%). CONCLUSION: This analysis of pharmacy claims found that estimates for the proportion of deliveries with acute VTE diagnoses that subsequently received anticoagulants was similar to chart-confirmed VTE, albeit in a large population. In addition to previous studies comparing database claims to chart review that showed that the prevalence of VTE was grossly overestimated, these findings support that the proportion of cases with VTE during delivery hospitalization may be approximately half that ascertained with billing codes.