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/m² [IQR, 0.4-1.1 L/min/ m²] vs 0.4 L/min/m² [IQR, 0.1-0.6 L/min/m²]; 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/m²/beat vs 2.3 ± 1.6 g-m/m2/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 ± 7.1 mm 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.