D-dimer Response to Thrombolysis vs. Anticoagulation in Acute Pulmonary Embolism: An Observational Study

Abstract The utility of D-dimer as a dynamic biomarker for treatment response in pulmonary embolism (PE) remains unclear. This study compares changes in D-dimer and their relation to right ventricular (RV) recovery in PE patients treated with thrombolysis with alteplase (tPA) versus anticoagulation with heparin. We retrospectively analyzed 62 patients with acute PE treated with either tPA or heparin. All patients had baseline and 24-hour follow-up laboratories and echocardiography. RV function improvement was defined as a ≥15% change in tricuspid regurgitation maximum velocity (TRmax), tricuspid annular plane systolic excursion (TAPSE), right ventricle to left ventricle diameter ratio (RV/LV), and peak systolic velocity of the tricuspid annulus (S'). D-dimer levels increased significantly in the tPA group (median 2.40 to 20.0 µg/mL, p < 0.001) and decreased in the heparin group (2.42 to 1.65 µg/mL, p < 0.001). Troponin I decreased significantly after tPA but not with heparin. RV function improved in 61% of tPA patients versus 7% in the heparin group (p < 0.001) and was associated with changes in D-dimer and troponin I. In a subset of patients, follow-up computed tomography pulmonary angiography (CTPA) showed clot reduction in 90% of tPA-treated patients, compared with none in the heparin group. In the tPA group 30-day mortality was lower (9% versus 17%), although the difference was not statistically significant. tPA treatment is associated with increase in D-dimer levels, reduction in troponin I, and greater RV recovery. D-dimer may serve as a useful real-time biomarker for therapeutic response and possibly prognosis in acute PE.