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

Abstract

OBJECTIVES: 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. SETTING: Single centre, University Hospital. SUBJECTS: 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. MAIN OUTCOME MEASURES: Time course of PDf in relation to time course of pulmonary artery systolic pressure (PAsP) and RV function. RESULTS: 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. CONCLUSIONS: 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.