2935 Thrombolysis in intermediate high-risk pulmonary embolism: a tertiary care versus district general hospital emergency department experience

<h3>Aims and Objectives</h3> Intermediate high-risk pulmonary embolism (IHPE) management is challenging in the emergency department (ED). Though systemic thrombolysis (ST) improves outcomes, up to 12% of patients develop major bleeding. Interventional reperfusion techniques (IRP) are only available in tertiary-care hospitals (TCH). We therefore sought to understand how ST and referrals for IRP are used at TCH and district-general hospitals (DGH) for IHPEs. <h3>Method and Design</h3> We performed a retrospective cohort study at one TCH (Hospital-A) and two DGH EDs (Hospitals-B, C) between 11/2019 and 10/2023. We pulled all positive PE diagnoses from computed tomography pulmonary angiogram (CTPA) reports and patient data from the medical record. Eligible patients had right heart strain on CTPA or echocardiography, elevated troponin-T, and systolic blood pressure ≥90mmHg. Chi-Squared tests were used to assess primary outcome to compare the proportion of ST, half-dose-ST (50mg alteplase), and IRP-referrals at each hospital; and secondary outcomes (vasopressor-use, haemodynamic instability, ITU-admission, survival-to-discharge, hospital length-of-stay (LOS), any bleeding and major bleeding) in patients receiving full-dose-ST Vs anticoagulation-only (AC) and half-dose-ST vs. AC aggregating data from all sites. <h3>Results and Conclusion</h3> 11,033 CTPAs were performed, 1,514 were positive for PE, and 290 (19%) met our definition of IHPE (120-A, 84-B, 86-C). Hospital-B had a higher rate of ST compared to hospitals-A and C (29% vs. 15% &amp; 15%, p=0.035). Half-dose-ST was used in 59% of hospital-A, 77% hospital-B and 92% hospital-C patients receiving ST (p=0.12). There was no difference in IRP-referrals (27%-A, 33%-B, 19%-C; p=0.089). Full-dose-ST was associated with greater vasopressor-use, haemodynamic instability, ITU-admission, any and major bleeding compared to AC patients with no difference in survival-to-discharge and LOS. Half-dose-ST had higher rates of ITU-admission compared to AC but no other differences in secondary outcomes. DGHs have equal or greater utilization of ST compared to TCHs. Half-dose-ST appears to be a safe option for reperfusion in hospitals with limited IRP availability.