Early Versus Delayed Use of Ultrasound-Assisted Catheter-Directed Thrombolysis in Patients With Acute Submassive Pulmonary Embolism

Objectives. The effect of early vs delayed use of ultrasound-assisted catheter-directed thrombolysis (USAT) on invasive hemodynamics and in-hospital outcomes in patients with acute submassive pulmonary embolism (PE) is not well known. Methods. We evaluated 41 patients with submassive PE to study the association of early USAT [<= 24 hours; n = 21] vs delayed USAT [>24 hours; n = 20] with change in invasive hemodynamic measures from pre USAT to post USAT. Results. Significantly greater improvement was observed in the early USAT group compared to the delayed group for median cardiac index [0.6 L,/min/m(2) [IQR, 0.4-11 L/min/m(2)] vs 0.4 L/min/m(2) [IQR, 0.1-0.6 Li/min/m(2)]; P=.03], median pulmonary vascular resistance [3.4 Wood units [IQR, 2.5-4.1 Wood units] vs 0.5 Wood units [IQR, 0.2-1.3 Wood units]; P<.001), and mean right ventricular stroke work index [3.5 +/- 2.0 g-m/m(2)/beat vs 23 +/- 1.6 g-m/m(2)/ beat: P=.04]. Although not statistically significant, a trend in favor of early treatment was found for improvement in mean right ventricle to left ventricle diameter ratio [0.38 +/- 0.17 vs 0.33 +/- 0.21; P=.40], mean pulmonary artery pressure [8.4 +/- 7.1mm Hg vs 5.3 +/- 5.2 mm Hg; P=.13], and median pulmonary artery pulsatility index [1.14[IQR, 2.01-0.45] vs 0.65 [IQR, 0.22-1.78]; P=.49]. The mean postprocedural length of stay was significantly lower in the early-USAT group [6.0 +/- 2.7 days vs 10.1 +/- 7.0 days; P=.02]. Three patients experienced moderate bleeding [2 patients in the early-USAT group and 1 patient in the delayed-USAT group] and no major bleeds or in-hospital mortality occurred. Conclusion. Early USAT was associated with greater improvement in pulmonary hemodynamics and shorter postprocedural length of stay compared with delayed USAT in patients with acute submassive PE.