ABSTRACT
Pulmonary embolism (PE) secondary to deep venous thrombosis (DVT) is estimated to occur at an incidence rate of 69 cases per 100,000 and a prevalence rate of 3.5 cases per 1000 hospital admissions (1,2). The three-month mortality following PE was reported at 17.4% in the International Cooperative Pulmonary Embolism Registry, and in the Management Strategy and Prognosis of Pulmonary Embolism Registry the mortality rate rose to 31% in those patients with hemodynamic instability (3,4). The size of the embolus does not seem to affect outcome. Massive PE, as defined by angiographic pulmonary artery obstruction 50% or obstruction of two or more lobar arteries, is not associated with increased mortality unless accompanied by hemodynamic instability (5). A subset of the hemodynamically stable group with right ventricular dysfunction, however, may be at increased risk of death (6).
