Continuous low-dose thrombolysis in patients with intermediate-high risk pulmonary embolism: A retrospective analysis.

Acute pulmonary embolism (PE) is a life-threating condition with high morbidity and mortality. While current guidelines recommend systemic thrombolysis for patients with high-risk PE and anticoagulation in those with low-risk PE, full dose systemic thrombolytic therapy is not recommended in patients with intermediate risk since the bleeding risk may outweigh the therapeutic benefits [ 1 Konstantinides S.V. Meyer G. Becattini C. Bueno H. Geersing G.J. Harjola V.P. UA 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS): The Task Force for the diagnosis and management of acute pulmonary embolism of the European Society of Cardiology (ESC). Eur. Heart J. 2020; 41 (21. Januar): 543-603 Crossref PubMed Scopus (1627) Google Scholar , 2 Meyer G. Vicaut E. Danays T. Agnelli G. Becattini C. Beyer-Westendorf J. UA Fibrinolysis for patients with intermediate-risk pulmonary embolism. N Engl J Med. 2014; 370 (10. April): 1402-1411 Crossref PubMed Scopus (989) Google Scholar ]. However, intermediate-high risk PE is associated with severe clinical symptoms and relevant mortality risk despite optimal anticoagulation. Reduced-dose regimens of systemic thrombolysis were introduced to reduce the risk of bleeding while effectively treating PE and showed promising results in several studies with small patient cohorts [ 3 Sharifi M. Bay C. Skrocki L. Rahimi F. Mehdipour M. “MOPETT” Investigators. Moderate pulmonary embolism treated with thrombolysis (from the "MOPETT" Trial). Am. J. Cardiol. 2013; 111 (15. Januar): 273-277 Abstract Full Text Full Text PDF PubMed Scopus (413) Google Scholar , 4 Sharifi M. Bay C. Mehdipour M. Sharifi J. TORPEDO InvestigatorsThrombus Obliteration by Rapid Percutaneous Endovenous Intervention in Deep Venous Occlusion (TORPEDO) trial: midterm results. J Endovasc Ther. 2012; 19: 273-280 Crossref PubMed Scopus (85) Google Scholar , 5 Enden T. Kløw N.E. Sandvik L. Slagsvold C.E. Ghanima W. Hafsahl G. UA Catheter-directed thrombolysis vs. anticoagulant therapy alone in deep vein thrombosis: results of an open randomized, controlled trial reporting on short-term patency. J. Thromb. Haemost. 2009; 7: 1268-1275 Abstract Full Text Full Text PDF PubMed Scopus (231) Google Scholar , 6 Piazza G. Hohlfelder B. Jaff M.R. Ouriel K. Engelhardt T.C. Sterling K.M. UA A prospective, single-arm, multicenter trial of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis for acute massive and submassive pulmonary embolism: the SEATTLE II study. JACC Cardiovasc Interv. 2015; 8 (24. August): 1382-1392 Crossref PubMed Scopus (537) Google Scholar ]. In this retrospective observational study, we aimed to investigate the feasibility of prolonged systemic low-dose application of recombinant tissue plasminogen activator (rt-PA) in patients with intermediate-high risk PE, and the effects of this approach on patients' symptoms, echocardiographic parameters, and clinical outcomes.