Pulmonary embolism (PE) is the third most common cardiovascular disease in the United States. In 1999, 140,000 individuals were discharged from the hospital with an acute PE diagnosis with an incidence estimated at 1 case per 1,000 persons per year. This results in 200,000-300,000 hospitalizations per year with a prevalence estimated at 1 percent. PE is the underlying cause of death in 10 to 34 percent of these cases. Overall mortality ranges from 3.5 to 25 percent and can be as high as 31 to 58 percent when the shock state is present. Pulmonary embolism is unsuspected in 70 percent of the patients who die from it. Early recognition is crucial as 65 percent of people will die within the first hour of presentation and almost 93 percent will pass away in the first two and a half hours.
Early, safe, and accurate diagnosis is crucial, and one of our founding experts, Kenneth Leeper, MD, was a key leader in some of the largest studies performed on this topic. He was an investigator of all of the NHLBI sponsored Prospective Investigations of Pulmonary Embolism Diagnosis (PIOPED) studies. These studies evaluated the accuracy of the ventilation/perfusion scan (PIOPED I), computed tomography angiography of the chest (PIOPED II), and currently magnetic resonance angiography of the chest (PIOPED III) for the diagnosis and exclusion of PE. Alvaro Velasquez, MD has studied VTE and VTE prophylaxis in the ICU setting with a focus on the effectiveness of pharmacologic VTE prophylaxis according to current consensus guidelines. In one study, he demonstrated that LMWH had a more predictable achievement of prophylactic range anti-Xa levels when compared with UFH.