Potential role of systemic thrombolysis in acute submassive intermediate risk pulmonary embolism: review and future perspectives.

Submassive (intermediate risk) pulmonary embolism (PE) continues to be a significantly morbid disease process that remains unrecognized, inadequately risk stratified and suboptimally treated. Appropriate early clinical and imaging-based risk stratification represents the cornerstone for adequate therapeutic decision making, particularly for the selection of candidates who may benefit the most from systemic thrombolysis. The relevance of estimating clinical prognostic scores, in combination with imaging data, for accurate assessment of right ventricular function and laboratory biomarkers, indicative of myocardial injury for identification of normotensive patients at intermediate risk for an adverse short-term outcome are emphasized in this review. Recent clinical trials have demonstrated improvement in hemodynamics and mortality with the use of systemic thrombolysis among intermediate risk patients; however, it came at the cost of a significantly increased risk of major bleeding. Catheter-based therapies have garnered considerable clinical interest in recent years; of particular note is the ultrasound accelerated catheter-directed thrombolysis which has emerged as a novel and attractive alternative therapeutic modality with an increasing number of single center studies and ongoing randomized trials. Our review focuses on the major trials and studies involved in submassive PE in the recent literature including the role of thrombolytic therapy. We include major trials with reasonable sample size and extensive review of the potential side effects, such as major bleeding.