Table 6. Comparisons of differences of treatment protocols and clinical outcomes between our study and other clinical trials.

	Our study	SEATTLE II	ULTIMA	PERFECT
Case number	N = 42	N = 150	N = 59	N = 101
Study design	Single-center, retrospective, observational study	Multicenter, prospective, clinical trial	Multicenter, prospective, randomized controlled trial	Multicenter, prospective, registry
Enrolled criteria	Both intermediate- and high-risk PE	Both massive and submassive PE	Only intermediate-risk PE	Both massive and submassive PE
Treatment arm	Only USAT	Only USAT	USAT vs. heparin	USAT vs. CDT
t-PA dosage	44.54 ± 20.55 mg	24 mg	10-20 mg	28 ± 11 mg
PASP baseline	60.36 ± 15.32 mmHg	51.4 ± 16 mmHg	52.0 ± 11.5 mmHg	49.83 ± 11.14 mmHg
PASP post-USAT	42.61 ± 14.89 mmHg	37.5 ± 11.9 mmHg	39.7 ± 10.3 mmHg	36.07 ± 9.62 mmHg
Severe bleeding	21.43%	1.3%	0%	0%

CDT, catheter-directed thrombolysis; PASP, pulmonary artery systolic pressure; PE, pulmonary embolism; t-PA, tissue plasminogen activator; USAT, ultrasound-assisted catheter-directed thrombolysis.