Impact of thrombectomy on outcomes according to haemodynamic status in acute pulmonary embolism

The clinical benefit of mechanical thrombectomy (MT) in acute pulmonary embolism (PE) remains uncertain, particularly across different haemodynamic profiles due to the challenges in accurately assessing the patient risk. This study aimed to evaluate the association between MT and in-hospital outcomes stratified by Shock Index (SI). Methods: A retrospective cohort of 208 patients hospitalised with PE between 2019 and 2025 was analysed. SI was categorised as ≤1 for haemodynamically stable patients and >1 for unstable ones. The evaluated outcomes included in-hospital mortality, PE-related readmission, bleeding (any and major), and a composite endpoint of death or PE readmission. Associations between MT and outcomes were assessed using Fisher’s exact test and multivariable logistic regresion adjusted for simplified PESI and vasopressor use. Results: In the stable group (SI ≤1), MT showed a non-significant trend towards lower mortality (6.8% vs 1.9%; OR 0.30 [95% CI 0.07–1.23], p = 0.09) without increasing the risk of bleeding. Conversely, in the unstable group (SI >1), MT was associated with a significant reduction in in-hospital mortality (45% vs 19%; adjusted OR 0.28 [0.09–0.88], p = 0.028) and in the composite outcome of death or PE readmission (52% vs 25%; adjusted OR 0.32 [0.11–0.94], p = 0.039). No significant differences were observed in bleeding events (any or major) between groups. Conclusions: Mechanical thrombectomy was associated with a significant survival benefit in patients with Shock Index >1, without an increase in haemorrhagic complications. However, among haemodynamically stable patients, MT showed a protective trend that did not reach statistical significance. These findings suggest that thrombectomy may improve outcomes in intermediate–high-risk PE when accompanied by an elevated Shock Index, nevertheless not in those with SI <1 despite being classified within the same clinical risk category.