626 - Progressive Right Ventricular Recovery After Mechanical Thrombectomy in Pulmonary Embolism: A Longitudinal Analysis

Purpose: To evaluate longitudinal changes in right ventricular function after catheter-directed mechanical thrombectomy in the setting of acute pulmonary embolism (PE).

Materials and Methods: A retrospective review was conducted of patients who underwent catheter-directed mechanical thrombectomy for acute PE at a single institution between November 2019 and June 2023 (n=268). Among these, 53 patients with available sequential echocardiograms during one week before, one month after and beyond one month after thrombectomy were selected for analysis. Evaluated parameters were Tricuspid Annular Plane Systolic Excursion (TAPSE), RV systolic pressure (RVSP), RV free wall systolic maximum velocity (RVFW S’ Vmax), RV early diastolic basal diameter (RVD1), and severities of RV dilation, systolic dysfunction, and tricuspid regurgitation (TR). An independent cardiologist reviewed all echocardiograms. Repeated measures ANOVA was used for statistical analysis. P< 0.05 was considered significant.

Results: Median age was 61 years; 57% were female. Prior PE or deep vein thrombosis (DVT) was present in 21%, and 43% had concurrent DVT. Median systolic/diastolic [mean] pulmonary artery pressures (PAP) decreased from 45/20 [31] mmHg to 32/14 [21] mmHg after thrombectomy. Median echocardiographic follow-up time was 3 months. PE severity was low/ intermediate-low, intermediate-high and high-risk in 11%, 64% and 25% of the patients, respectively. Pre-, one-month and beyond-one-month post-thrombectomy RV indices were as follows: TAPSE: 1.7, 2.2 and 2.4 mm, RVD1: 44, 39 and 36 mm, RVSP: 43, 34 and 27 mmHg, RVFW S’ Vmax: 104, 124 and 122 mm/s. Moderate-to-severe RV dilation: 48%, 15% and 4%, moderate-to-severe RV systolic dysfunction: 58%, 18% and 2% and moderate-to-severe TR: 14%, 4% and 0% (p< 0.001 for all).

Conclusion: Catheter-directed mechanical thrombectomy significantly improves RV function and functional TR severity, with continued improvement observed beyond one-month post-procedure.