Catheter based thrombectomy in pulmonary embolism and its role on oxidative stress

Abstract Background/Introduction Catheter based thrombectomy (CBT) has emerged as an effective and potentially safe therapy option for deteriorating patients with intermediate- or high-risk pulmonary embolism (PE). In recent years, a linkage between mitochondrial dysfunction, inflammation, oxidative stress and acute PE was reported. Purpose We aimed to evaluate the in-hospital course in patients treated with CBT as well as oxidative stress and inflammation before and after CBT. Methods We prospectively included consecutive patients with intermediate- or high-risk PE treated with CBT in our university medical center from September 2023 to October 2024. Catheter based thrombus aspiration with the FlowTriever® system (INARI Medical) was used. We investigated the in-hospital course of clinical and hemodynamic parameters (in-hospital death, ICU admission, bleeding, length of stay) as well as markers of oxidative stress and inflammation by dot blot analysis of 3-nitrotyrosine (3-NT)-, malondialdehyde (MDA)- and 4-hydroxynonenal (4-HNE)-positive proteins, and interleukin-6 in plasma samples. Results Overall, 26 patients (median age 60 years, 42% women) were included. The median length of stay in the hospital was 8 days (IQR 5-15). All patients had a PE response team (PERT) treatment decision. All patients received unfractionated heparin in adjunction to CBT. Procedural characteristics included a median duration of 88 minutes (IQR 80-114). Clinical and hemodynamic parameters before and after the procedure demonstrated a significant decrease in mPAP from 26mmHg to 18mmHg (p0.001) and in respiratory rate from 20 per minute to 16 per minute (p=0.045). There were no recorded interventional complications or bleeding event, while one patients (4.7%) suffered from recurrent PE necessitating rescue systemic thrombolysis with consecutive death. Levels of MDA, 3-NT, 4-HNE and IL-6 were elevated before thrombectomy in patients with PE by 22% (Standard error of the mean SEM 3%; p=0.009), 33% (SEM 7%%; p=0.003), 35% (SEM 11%; P0.001) and 55% (SEM 6%%; p0.001), respectively, compared to healthy controls (Figure 1). After thrombectomy (3 and 24 hours later), all of these markers showed a time-dependent trend of decrease, partially on the level of healthy controls. Conclusion CBT may offer a potential therapeutic advantage for PE patients with contraindications to thrombolysis and patients with persisting or deteriorating clinical course, while showing a favorable hemodynamic and safety profile. Additionally, oxidative stress and inflammation markers decline rapidly 3 and 24 hours after interventions on the level of healthy controls. Randomized controlled trials are much needed to establish the indications for use of these novel modalities and comparing different reperfusion strategies comparing levels of oxidative stress as well as inflammation and its possible long-term effects.