Evolving paradigm of thrombolysis in pulmonary embolism: Comprehensive review of clinical manifestations, indications, recent advances and guideline

Table 2 Ultrasound-assisted catheter-directed thrombolysis use in patients with intermediate or high-risk proximal pulmonary embolism

Study	Ultima[32]	Seattle II[33]	Optalyse[34]
Aim of the study	The aim of the study was to investigate whether ultrasound-assisted catheter-directed thrombolysis (USAT) is superior to anticoagulation alone in the reversal of RV dilatation in intermediate-risk patients	To evaluate the safety and efficacy of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis	To determine the lowest optimal tissue plasminogen activator (tPA) dose and delivery duration using ultrasound-facilitated catheter-directed thrombolysis (USCDT) for the treatment of acute intermediate-risk (sub-massive) PE
Study design	Two arms	Single arm	Single arm
Single-center/multi-center	Multi-center	Multi-center	Multi-center
Completed/ongoing	Completed	Completed	Completed
Year of publication	2014	2015	2018
Primary endpoint	The difference in the RV/LV ratio at 24 h	The difference in RV/LV ratio at 48 h and bleeding at 72 h	reduction in RV/LV ratio on CT imaging at 48 h
Total number of patients	59	150	101
Mean age of patients	63 +/- 14	59	60
% of males	47%	48.7	53
Drug used	UFH and USAT VS UFH alone	t-PA	t-PA and heparin
Results	The mean difference in RV/LV ratio from baseline to 24 h was 0.30 ± 0.20 vs 0.03 ± 0.16 (P < 0.001), respectively	The mean RV/LV diameter ratio decreased from baseline to 48 h post-procedure (1.55 vs 1.13; mean difference, -0.42; P < 0.0001)	Improvements in RV/LV ratio were as follows: Arm 1 (4 mg/lung/2 h), 0.40 (24%; P = 0.0001); arm 2 (4 mg/lung/4 h), 0.35 (22.6%; P = 0.0001); arm 3 (6 mg/lung/6 h), 0.42 (26.3%; P = 0.0001); and arm 4 (12 mg/lung/6 h), 0.48 (25.5%; P = 0.0001)
Adverse effects	4 minor bleedings. No major bleeding	17 major bleeding events within 30 d of the procedure observed in 15 patients (10%). One of these major bleeding events was a GUSTO severe/life-threatening hemorrhage (a right groin vascular access site hematoma with transient hypotension requiring vasopressor support). The remainder (94%) were GUSTO moderate bleeds, 3 of which were related to vascular access	4 patients had a total of 5 major bleeding events

CT: Computed tomography; DVT: Deep vein thrombosis; PE: Pulmonary embolism; RV: Right ventricle; LV: Left ventricular; t-PA: Tissue-plasminogen activator.