Abstract 18303: Characteristics of Clinical Studies Evaluating Thrombolysis and Novel Catheter-Based Interventions for Pulmonary Embolism

Abstract

Introduction: Novel treatment approaches for pulmonary embolism (PE) including catheter directed thrombolysis (CDT), percutaneous thrombectomy (PT), and systemic thrombolysis (ST) are under investigation. However, characteristics of studies of these interventions are not well described. We sought to evaluate the state of studies pertaining to advanced PE therapies. Methods: The ClinicalTrials.gov (CTG) database was queried using search terms specific to advanced therapies and PE between January 1, 2000, and June 30, 2022, with unrelated, withdrawn, and terminated studies excluded. Advanced therapies were defined as studies evaluating either systemic thrombolysis, CDT, and/or PT. Geographic data from enrollment was gathered using zip codes of study sites. Descriptive characteristics related to studies were explored, and ANOVA was used to compare mean trial enrollment between interventions. Results: Of 700 total results, our search yielded 56 eligible studies (8.0%) investigating advanced PE therapies, among which 39.3% studies evaluated CDT, 32.1% evaluated ST, and 28.6% evaluated MT. Most studies were interventional (76.7%) rather than observational (23.3%). The primary study endpoint was most commonly a surrogate endpoint (60.7%), with mortality (5.4%) or a composite including mortality (21.4%), or other endpoints (12.5%) were less frequent (Figure). Mean enrollment was 206.4 in ST, 101.5 in CDT, and 103.7 in PT studies, with no significant difference in study size between intervention type (p=0.207). The USA was the most frequent trial sponsor (41.1%), and within the USA, trial sites were most commonly in large, urban areas and demonstrated geographic variation. Conclusion In conclusion, there is a paucity of studies evaluating advanced therapies for PE with substantial heterogeneity in design and geography. These data highlight the need for further high-quality studies to inform clinical decision making for the treatment of PE.