Efficacy and Safety of Systemic Thrombolysis and Catheter-Directed Therapy in Pulmonary Embolism: A Narrative Review.

Pulmonary embolism (PE) is the third most frequent cause of acute cardiovascular presentation after myocardial infarction and stroke. The treatment approach for PE consists of hemodynamic and respiratory support, anticoagulation, reperfusion treatment, and vena cava filters. Reperfusion treatment consists of systemic thrombolysis (recombinant tissue-type plasminogen activator, streptokinase, and urokinase); percutaneous catheter-directed therapy (CDT); and surgical embolectomy. CDT is an emerging treatment, with most data derived from randomized controlled trials (RCTs) or case series. Currently, there is a lack of data on clinical efficacy and safety outcomes and a lack of large studies that directly compare CDT with systemic thrombolysis or surgical embolectomy.  This narrative review aims to explore the efficacy and safety of systemic thrombolysis and CDT in pulmonary embolism.  Clinical trials have studied CDT for more than a decade now and have shown that CDT improves the post-procedural right ventricular (RV)/left ventricular (LV) ratio and has a reduced rate of bleeding episodes and all-cause mortality. However, there is a lack of large prospective RCTs studying the effects of CDT in intermediate-high-risk PE patients to determine which patients from this sub-group require CDT both in terms of improving short-term mortality risk and long-term morbidity (such as chronic thromboembolic pulmonary hypertension (CTEPH) and post-PE syndrome). Future clinical trials need to focus on identifying which patient groups will benefit from CDT over anticoagulation and if there are any advantages of using the EkoSonic endovascular system (EKOS) (ultrasound (US)-assisted CDT) over standard CDT. In addition, the scientific community needs to study the healthcare costs of CDT over traditional treatment, which is relevant for public health systems such as the National Health Service (NHS). Lastly, we need standardized guidelines for the use of thrombectomy systems since pulmonary embolism is a complex disease requiring a multifaceted and nuanced treatment approach.