Patients who experienced one of the following occurrences in the index leg between the 6 month and 24 month post-randomization follow-up visits, inclusive: 1) Villalta score of 5 or greater; 2) leg ulcer; or 3) late endovascular procedure performed to treat severe venous disease. The Villalta scale ranges from 0-33 points, with higher scores being worse.

Change from baseline in RV diameter/LV diameter ratio was determined by contrast-enhanced chest computed tomography (CT) within 48 +/- 6 hours after initiating ultrasound-accelerated catheter-directed fibrinolysis.

Bleeding adverse events were graded (severe or life-threatening, moderate or mild bleeding) according to the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) classification. The participant incidence of major bleeding events was defined as GUSTO moderate and severe events occurring within 72 hours after starting the ultrasound-accelerated catheter-directed fibrinolysis procedure. Mild: Does not meet criteria for moderate or severe; Moderate: Requires transfusion - No hemodynamic compromise; and Severe: Bleeding causes hemodynamic compromise and required intervention or intracranial hemorrhage. A summary of serious and all other non-serious adverse events regardless of causality is located in the Reported Adverse Events module.