Primary Pulmonary Embolism Research Articles

Prospective study of exogenous hormones and risk of pulmonary embolism in women

Current use of oral contraceptives (OCs) is a well-recognised risk factor for venous thrombosis and consequent pulmonary embolism (PE). Little is known about residual effects of past OC use. Furthermore, few epidemiological studies have assessed the relation between postmenopausal use of hormones and thrombotic disease. In this prospective study information was obtained through questionnaires sent every 2 years (1976-92) to 1125,93 women aged 30-55 in 1976. We excluded women with previously diagnosed cardiovascular disease or cancer in 1976 and at the beginning of each subsequent 2-year follow-up period. From self-reports and medical records, we documented 123 cases of primary PE (no identified antecedent cancer, trauma, surgery, or immobilisation). Current users of postmenopausal hormones had an increased risk of primary PE (relative risk adjusted for multiple risk factors 2.1 [95% CI 1.2-3.8]). However, past use showed no relation to PE (1.3 [0.7-2.4]). In current users of OCs the risk of primary PE was about twice that in non-users (2.2 [0.8-5.9]), but this finding was based on only five cases who were current OC users. Users of OCs in the past had no increase in risk of PE (0.8 [0.5-1.2]). These relations were consistent irrespective of cigarette-smoking status. Primary PE was uncommon in this cohort. The risk was increased by current though not past use of postmenopausal hormones or OCs.

The cost-effectiveness of diagnostic strategies in patients with suspected pulmonary embolism.

The cost-effectiveness of various diagnostic strategies in patients with clinically suspected pulmonary embolism (PE) was analysed using a modelling approach. In 451 consecutive patients with clinically suspected PE data on the performance of diagnostic tests were collected prospectively in two large teaching hospitals in Amsterdam, The Netherlands. The ventilation-perfusion lung scan was used as the primary diagnostic test in all patients. In patients with a non-diagnostic lung scan result the performance of a clinical decision rule, a D-dimer test, and ultrasonography of the leg veins was evaluated with pulmonary angiography as the gold standard. It was estimated that the strategy recommended by a 1992 Dutch consensus meeting costs about Dfl 4400 per patient and that 97.02% of the patients can be expected to survive the first 6 months after the primary PE. The nation-wide annual costs for the diagnosis and treatment of patients by this strategy were estimated at 163 million Dutch Guilders. Subsequently, the costs and effects of alternative strategies were evaluated in a modelling approach, and compared with those of the consensus strategy. One strategy was selected that produces the best results in terms of survival and leads to considerable savings as compared with the consensus strategy. In this strategy subsequently a ventilation-perfusion scan, a clinical decision rule, a D-dimer test, a pulmonary angiography and leg ultrasonography are performed. Patients with a high probability ventilation-perfusion scan, an abnormal angiography or leg ultrasound test are treated, whereas treatment is withheld in patients with a normal ventilation-perfusion scan, a normal clinical decision rule, a negative D-dimer test, a normal angiography, or a normal leg ultrasound test. This strategy will have to prove its value and usefulness in clinical practice in a subsequent prospective validation phase.

Epidemiology

Present evidence suggests that venous thromboembolism is the third most common acute cardiovascular disease after cardiac ischemic syndromes and stroke. The frequency of the diagnosis of pulmonary embolism (PE) at a given hospital greatly increases if a referral unit for PE is set up in the hospital. Pulmonary embolism is characterized by a continuous spectrum of severity, from 2 to 3 to 15 to 16 embolized pulmonary segments (over a total of 19). Morbidity from PE increases with age and male sex (males/females ratio: 1.24). In only a minority (10%) of patients with PE and/or deep-vein thrombosis (DVT), primary deficiencies of coagulation-inhibiting proteins have been shown. Primary abnormalities of the fibrinolytic system seem even more rare. On the basis of the clinical conditions preceding the embolic episode, patients may be divided into different groups: apparently primary or idiopathic PE (40%), surgery or trauma (43%), heart disease (12%), neoplastic disease (4%), and systemic disease (1%). Patients with apparently primary or idiopathic PE often develop subsequent clinically overt cancer (9.1%), whereas surgery or trauma patients rarely do (1.4%). Furthermore, the former exhibit a significantly shorter survival than the latter mostly for causes of death that reflect increased predisposition to thrombogenesis. Thus, as for DVT, it is convenient to consider a primary or idiopathic form also for PE.