Outcomes following catheter-directed therapy for intermediate-high risk acute pulmonary embolism

Abstract Background Intermediate-high risk acute pulmonary embolism (PE) managed with anticoagulation is associated with a 30-day mortality risk of up to 10%. Catheter-directed therapies (CDT) have emerged as a treatment option for such patients (Figure 1). Options include catheter-directed thrombolysis and mechanical thrombectomy (MT), with limited studies demonstrating procedural safety and low early mortality rates. However, there have been no large trials comparing CDT to standard medical therapy. The aim of this retrospective observational single-centre study was to assess mortality and length of in-patient stay following admission with intermediate-high risk acute PE treated with either medical therapy or CDT. Methods A total of 476 patients treated for intermediate-high risk acute PE at our institution between 2018 and January 2025 were included in this study: (i) 175 patients treated with CDT based on clinical decision - 115 with catheter-directed thrombolysis (EKOS - between July 2018 and July 2023) and 60 with MT (FlowTriever - between January 2023 and January 2025); (ii) 301 patients who met criteria for intermediate-high risk PE (RV:LV ratio 1 and positive troponin) and were medically managed; these patients were retrospectively identified from 2,448 consecutive positive CT pulmonary angiogram scans performed between July 2018 and July 2023. Similar proportions of patients were managed medically (95/301, 32%) and using EKOS (37/115, 32%) during the first year of the Covid-19 pandemic in the UK (March 2020-March 2021). Results Patients treated with CDT were younger (EKOS 66 years (51-76), MT 57 years (44-73), medical therapy 76 years (64-85), p0.001) but more unwell due to PE (initial heart rate: EKOS 111 +/- 21bpm, MT 113 +/- 21bpm, medical therapy 97 +/- 22bpm, p0.001; lactate: EKOS 2.20 (1.58 - 3.25), MT 2.50 (1.70 - 3.00), medical therapy 1.81 (1.25 - 2.64), p=0.001). There was no difference in PESI score between groups, but CDT treated patients had higher BOVA and POPE risk scores (Table 1). Patients were followed up for up to 2 years following acute PE diagnosis.. All-cause mortality was lower with CDT compared to medical therapy (EKOS vs medical therapy hazard ratio (HR) 0.48 (p=0.002), MT vs medical therapy HR 0.29 (p=0.007), Figure 2) even when adjusted for age, serum lactate and Covid-19 pandemic (EKOS vs medical therapy HR 0.57 (p=0.04), MT vs medical therapy HR 0.27 (p=0.03)). There was no difference in mortality between EKOS and MT. Overall length of in-patient stay was shorter for patients treated with CDT (EKOS 5 days (3-9), MT 5 days (3-8), medical therapy 7 days (4-15), p0.01). Conclusions In real-world clinical practice, CDT in selected patients with intermediate-high risk acute PE is associated with low all-cause mortality and short in-patient hospital stay. Patients with acute PE who were clinically selected for CDT were younger but more clinically unwell.