Phd in ANGIO-CARDIO-THORACIC PATHOPHYSIOLOGY AND IMAGING

Thesis title: La trombectomia percutanea nel trattamento dell’embolia polmonare massiva e sub-massiva

Background. Acute pulmonary embolism (PE) remains a leading cause of cardiovascular morbidity and mortality. Systemic thrombolysis has long been the treatment of choice for high risk of hemodynamical instability, but pose the risk of bleeding complications such as intracranial haemorrhage (ICH), and not all patients are eligible to receive it. Over the past decade, catheter-directed therapies (CDT) and large-bore mechanical thrombectomy (MT) have emerged as alternatives to systemic thrombolysis, aiming to rapidly unload the right ventricle (RV) while limiting bleeding risk. Objective. To evaluate the effectiveness and safety of percutaneous MT for the treatment of intermediate- and high-risk acute PE; to explore the landscape of recent clinical trials and registries and analyse the performance of the different devices available for MT; to develop an hospital practice for MT in PE with a structured multidisciplinary pathway. Methods. We conducted a review of recent evidence concerning MT evaluating the performances of different devices. We conducted a single-centre analysis of consecutive adults with acute PE managed according to a PERT-guided algorithm, which consist in intra-hospital guidelines with the formalization of a multidisciplinary Pulmonary Embolism Response Team (PERT). Patients with intermediate- or high-risk PE underwent percutaneous MT with large-bore aspiration catheters in the period 2021-2025. The primary efficacy endpoint was early RV afterload reduction, assessed by change in RV/LV diameter ratio and haemodynamic surrogates (pulmonary artery pressures, cardiac index, total pulmonary vascular resistance) within 24–48 hours. Safety endpoints included major bleeding (including ICH), haemodynamic deterioration/bailout therapy, and all-cause mortality through 30 days. Results. MT produced a rapid and clinically meaningful improvement in RV function and pulmonary haemodynamics, with consistent reductions in RV/LV ratio and pulmonary artery pressures and a fall in calculated afterload. The bleeding profile was favourable: no major bleeding nor ICH were reported. 2 major device-related complications occurred, including 1 death, possibly explained by the high degree of High Risk patients treated (80%). These findings align with contemporary evidence regarding MT and compare favourably with thrombolysis and pharmaco-mechanical CDT. Conclusions. In a real-world, PERT-driven workflow, percutaneous MT offers fast RV unloading for selected intermediate- and high-risk PE patients. The observed haemodynamic and clinical gains are concordant with recent prospective studies and support MT as a front-line reperfusion option when rapid thrombus removal and bleeding avoidance are priorities. Limitations of the study are slow development of a meaningful hospital practice with low population of study, and lack of longer-term outcomes (functional capacity, quality of life, and chronic thromboembolic sequelae).