Contrary to previous studies, only 1 in 100 patients with pulmonary embolism die in emergency departments, but more standardized treatment, including earlier use of anticoagulants, is needed, according to the initial report of the EMPEROR study in the Feb. 8, 2011, issue of the Journal of the American College of Cardiology.
Of the 20 patients in this study whose death was due to PE, only 3 received anticoagulant treatment before a diagnosis was confirmed, even though previous studies have shown that delays in starting anticoagulants can be fatal. Only another 3 of the 20 patients received fibrinolytic therapy in the emergency department, the Emergency Medicine Pulmonary Embolism in the Real World Registry (EMPEROR) researchers found.
Dr. Charles V. Pollack of Pennsylvania Hospital, Philadelphia, and colleagues created the national, prospective, multicenter, observational registry to establish more definitive signs and symptoms of PE, compare treatment strategies, and measure use of risk stratification methods, frequency of empiric anticoagulation use, and rates of major hemorrhage and death. Earlier registries of patients with PE have not provided specific data about race or ethnicity, risk stratification methods, or the frequency of anticoagulant use in the emergency department.
Between Jan. 1, 2005, and Dec. 29, 2008, the researchers enrolled 2,408 patients from 22 emergency departments, 1,880 of whom had confirmed PE (J. Am. Coll. Cardiol. 2011;57:700-6).
Systemic non–vitamin K–dependent anticoagulation was initiated in the ED in 1,593 (84%) patients, but only 173 (9%) received heparin of any type before the results of diagnostic imaging were available and 33 (1.7%) received a fibrinolytic agent.
While other registries show a mortality of 10%-15%, only 20 of the 1,880 patients (1%) in this study died as a direct result of the embolism, with 0.2% mortality from hemorrhage. At 30 days, patients whose acute PE was diagnosed in emergency departments had an all-cause mortality of 5.4%. The lower mortality in this report may reflect the fact that the registry included only outpatients who experienced PE and that this population was younger and less ill than those in other registries, the researchers said.
Of the 1,880 patients with confirmed PE, 1,654 (88%) were diagnosed based on CT pulmonary angiogram, 91 (5%) on formal pulmonary angiography, 82 (4%) on ventilation-perfusion scan, 51 (3%) on deep vein thrombosis with appropriate PE symptoms, and 2 (0.1%) on pulmonary MRI.
The mean age was 57 years, with one-third past age 65; 53% of the patients were women, and 68% were white. The racial and ethnic distribution of patients with PE closely parallels that of all patients who present to emergency departments.
The most common presenting signs and symptoms of PE were dyspnea at rest (50%), pleuritic chest pain (39%), dyspnea with exertion (27%), extremity swelling suggestive of deep vein thrombosis (24%), and syncope (5%).
The most common comorbidities that could represent potential risk factors for PE were hypertension (46%), obesity (27%), recent hospitalization (24%), and active malignancy (22%). Based on the absence of any predefined risk factors for PE, 312 (16.6%) of the 1,880 patients were considered to have idiopathic PE.
Most patients (79%) diagnosed with PE in the ED lived independently, while 11.6% reported generalized immobility.
The low rate of early treatment found by the study "suggested that empiric anticoagulation in patients with suspected PE should be instituted more often in the ED and that timely, therapeutic anticoagulation should be administered after the diagnosis is confirmed," the researchers wrote. "Future treatment studies of PE conducted in U.S. EDs should focus on accelerating the time frame of administration of systemic anticoagulation and fibrinolysis to patients with evidence of severe PE."
Several coauthors disclosed consulting relationships with and/or funding from a wide range of pharmaceutical companies that make anticoagulant agents.