Pulmonary embolism: a follow-up study of the relation between the degree of right ventricle overload and the extent of perfusion defects.

Abstract

To describe the course of changes in perfusion lung scintigraphy (LS) after acute pulmonary embolism (PE) and test the hypothesis that patients with persistent pulmonary hypertension (PH)/right ventricle (RV) dysfunction after acute PE can be differentiated from those without through larger perfusion defects (PDf) on LS. Design. Prospective, one-year follow-up study with repeated LS and echocardiography-Doppler investigations. Single centre, University Hospital. Patients with clinical suspicion of acute PE with a diagnosis confirmed by LS and/or pulmonary angiography and able to undergo repeated investigations. Of the 78 patients included, a six-week follow-up was completed in 67 and a one-year follow-up in 64. Time course of PDf in relation to time course of pulmonary artery systolic pressure (PAsP) and RV function. Initially, PDf decreased exponentially, until the beginning of a stable phase, which was achieved within 54 days for 90% of the patients and within 148 days for all. The temporal relation for the regress of PDf and decrease in PAsP was loose. Patients with persistent PDf suffered PH/RV dysfunction more often than those without. However, the variability in the degree of haemodynamic changes for a given extent of PDf was large. After acute PE, LS is of use for the identification of the group of patients that may have persistent PH/RV dysfunction. However. since the identification of individual patients is uncertain, LS cannot replace echocardiography-Doppler in the identification of persistent PH/RV dysfunction after acute PE.