Abstract
The optimal treatment strategy for patients with acute intermediate-high-risk pulmonary embolism (PE) remains uncertain. This randomized clinical trial (PRETHA) aimed to evaluate the efficacy and safety of percutaneous reperfusion therapies-trans-catheter thrombectomy and trans-catheter thrombolysis-compared with standard anticoagulation therapy. In this single-center, prospective trial conducted between April 2020 and April 2022, 39 patients with acute intermediate-high-risk PE were randomly assigned (1:1:1) to receive trans-catheter thrombectomy, trans-catheter thrombolysis, or conservative medical therapy with anticoagulation. Echocardiographic, hemodynamic, and biomarker parameters were assessed at baseline, 48 h, and at 1-, 6-, and 12-month follow-up. At 48 h, both interventional groups demonstrated significant improvement in right ventricular (RV) function and pulmonary pressures. The RV/LV ratio decreased by 0.3 (95% CI: 0.13-0.69; p < 0.0002) in the thrombectomy group and by 0.4 (95% CI: 0.12-0.96; p < 0.0002) in the thrombolysis group. Noninvasively measured systolic pulmonary artery pressure decreased by 29% in the thrombectomy group and by 39% in the thrombolysis group (both p < 0.001). Significant reductions in direct systolic and mean pulmonary artery pressures were also observed (p = 0.0002). However, at longer (1 to 12 months) follow-up, all three treatment groups represent similar positive changes of echocardiographic parameters and cardio-specific biomarkers independent of the treatment tactic chosen in the acute period. Functional capacity and quality of life were superior in the interventional groups compared with anticoagulation alone. The incidence of adverse events was highest in the thrombolysis group (38%), whereas thrombectomy and medical therapy demonstrated more favorable safety profiles. Percutaneous reperfusion therapies were associated with earlier improvements in hemodynamic and functional surrogate parameters compared with anticoagulation alone; however, at 1-year follow-up, echocardiographic measures and biomarkers of cardiac function were similar across all treatment groups. These findings should be interpreted as mechanistic and hypothesis-generating.