(P-610) Short-term Incidence of Thrombotic Events in Patients Who Were Treated with Factor Xa Inhibitors and Hospitalized for Bleeding

Background: There is a lack of data on the short-term risk of thrombotic events following hospitalization for major bleeding in patients who are treated with Factor Xa inhibitors.

Objectives: To estimate 30-day incidence of thrombotic events in patients who were hospitalized for major bleeding while being treated with Factor Xa inhibitors.

Methods: The U.S. claims database of Decision Resources Group was used to identify patients who were at least 18 years old, treated with Factor Xa inhibitors such as rivaroxaban, apixaban, edoxaban and enoxaparin, and hospitalized for major bleeding in 2019. National Drug Codes were used to identify Factor Xa inhibitors in pharmacy claims and ICD diagnosis codes were used to ascertain bleeding events. Thrombotic events of deep vein thrombosis (DVT), pulmonary embolism (PE), ischemic stroke (IS), transient ischemic attack (TIA), acute myocardial infarction (AMI) and arterial systemic embolism (ASE) that occurred within 30 days following the date of the index bleeding hospitalization were identified using ICD diagnosis codes. For each type of thrombotic event, the overall and age/sex stratified incidence proportions were calculated. In a secondary analysis, only thrombotic events that occurred in an inpatient or emergency room setting were included.

Results: A total of 49,576 patients were identified in this study, 51.3% (n=25,430) were male and 81.2% (n=40,245) were at least 60 years old. The 30-day incidence was 12.1% for DVT, 10.8% for PE, 7.9% for IS, 2.1% for TIA, 5.4% for AMI, 1.3% for ASE. Incidence of each type of thrombotic event was similar between male and female patients. For DVT and PE, the incidence was higher in the younger age groups. However, for IS and AMI, the incidence was higher in the older age groups. For TIA and ASE, the incidence was similar across all age groups. When the analysis was limited to events that occurred in an inpatient or emergency room setting, the incidence was 9.0% for DVT, 8.4% for PE, 5.4% for IS, 1.4% for TIA, 4.3% for AMI, and 0.9% for ASE; and similar patterns in event frequencies by sex and age were observed.

Conclusions: Our study estimated the 30-day incidence of thrombotic events in patients who were treated with Factor Xa inhibitors and were hospitalized for bleeding events. Such background incidence data could be used as benchmarks when studying the risk of thrombotic events in patients who are similar to those included in our study.