November 6, 2020
SUNSET sPE Trial Compares Standard Versus Ultrasound-Assisted Thrombolysis to Treat Submassive Pulmonary Embolism
November 6, 2020—The multicenter, randomized SUNSET sPE trial investigated ultrasound-assisted catheter-directed thrombolysis (USAT) compared with standard catheter-direct thrombolysis (SCDT) in treating submassive pulmonary embolism (sPE). Findings showed that patients undergoing USAT treatment had similar reduction of pulmonary arterial thrombus compared to SCDT using comparable mean lytic dose and duration of lysis.
The results were presented by Efthymios Avgerinos, MD, in a late-breaking clinical trials session at VIVA 2020, the Vascular InterVentional Advances annual meeting held as a virtual congress November 6-8, 2020.
According to the VIVA announcement, SUNSET sPE randomized 81 adults with acute sPE 1:1 to USAT (n = 39) or SCDT (n = 41), who were available for analysis. Thrombolysis dose and duration were left to the operators’ discretion.
The primary outcome was 48-hour clearance of pulmonary thrombus assessed by pre- and postprocedure CTA using a refined Miller score. Secondary outcomes included right to left ventricular (RV/LV) ratio improvement, intensive care unit (ICU), bleeding, and other serious adverse events.
At VIVA 2020, Dr. Avgerinos reported the following for the USAT group versus the SCDT group:
- Mean total dose of alteplase was 19 ± 7 mg versus 18 ± 7 mg (P = .53)
- Mean duration of alteplase infusion was 14 ± 6 hours versus 14 ± 5 hours (P = .99)
- Mean reduction of raw pulmonary thrombus score was 31 ± 4 at baseline to 22 ± 7 (P < .001) versus 33 ± 4 to 23 ± 7 (P < .001); the difference between the groups was not significant (P = .76)
- Obstruction index reduction was similar, 21% versus 22% (P = .77)
- Mean difference in RV/LV ratio from baseline to 48 hours was 1.54 ± 0.3 to 0.37 ± 0.34 versus 1.69 ± 0.44 to 0.59 ± 0.42 (P = .01).
Additionally, there was no RV/LV ratio improvement in five USAT patients and three SCDT patients. Major bleeding occurred in two patients—one stroke with hemianopia and one vaginal bleed requiring transfusion, both in the USAT group. The average ICU stay for the entire cohort was 3.2 ± 6.3 and was similar between groups, noted the VIVA 2020 announcement.