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

Abstract

Abstract. Ribeiro A, Lindmarker P, Johnsson H, Juhlin-Dannfelt A, Jorfeldt L (Karolinska Hospital, Karolinska Institute, Stockholm, Sweden). Pulmonary embolism: a follow-up study of the relation between the degree of right ventricle overload and the extent of perfusion defects. J Intern Med 1999; 245: 601]610.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.

Reperfusion after pulmonary embolism - long-term follow-up, risk factors, clinical impact

“…The likely explanation may lie in the fact that ageing leads to degenerative involutional changes of the vessel walls and of the endothelium in the pulmonary bloodstream, resulting in lower production of vasodilating agents such as prostaglandins and nitrous oxide. Greater PE severity (in our patient group, intermediate or high risk PE) was proved to be a significant risk factor in several studies 7,12 and is related to the fact that clinically more serious PEs are associated with a greater degree of obstruction of the pulmonary bloodstream, which is in itself a well-known predictor of perfusion disorders 6,9 . In our study, interestingly, we found that increased hemoglobin levels are another significant risk factor of incomplete reperfusion.…”

“…The reported rate of complete reperfusion 6-12 months after PE ranges from 33 to 81%, absence of any reperfusion is found in 3-16% (ref. 6,7,11 ). The wide range of results may be due to methodological issues -different patient classification, study period or different diagnostic methods (CT AG or VP scintigraphy).…”

“…[6][7][8][9] ) or presence of central thrombi during initial CT scan 10 . Various studies highlight mostly the following clinical risk factors: Personal history of cardiovascular disease 9 or of thromboembolic disease (OR 2.06 -2.6) (ref.…”

“…The only known long-term complication of PE is chronic thromboembolic pulmonary hypertension (CTEPH), which occurs in 2-3% of patients within two years of PE (ref. [2][3][4][5][6] ). The outlook in remaining PE patients is good, providing they receive appropriate treatment, and most of them (over 75%) survive in the long-term without any impact on their condition or quality of life.…”

“…The most commonly reported risk factors of incomplete reperfusion traditionally include the severity of the initial PE expressed as the obstruction index [6][7][8][9] , presence of central emboli and right ventricular enlargement on the initial CT scan 10 . The aim of our multicentric study was prospective monitoring of the reperfusion of the pulmonary arteries after the first pulmonary embolism event and correlating the results of such monitoring to laboratory results taken at the time of the initial PE and to clinical risk factors.…”