Birth of PERT: Systematic Approach to Acute PE

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pert-group.jpg - PERT Group
Upper row (left to right): Moshe Vardi, MD, Harvard Clinical Research Institute; Richard N. Channick, MD, Director of Pulmonary Hypertension and Thromboendarterectomy Program; Kenneth Rosenfield, MD, Section Head, Vascular Medicine and Intervention. Lower row (left to right): Janet McClintic, MHA, Administrative Manager, Heart Center; Maryfran Hughes, RN, MSN, Nursing Director, Emergency Services; Christopher Kabrhel, MD, MPH, Emergency Medicine. Not Pictured from PERT Team: Joshua N. Baker, MD; Thoralf M. Sundt III, MD. Michael Jaff, DO
Source: Massachusetts General Hospital

Due to a lack of clarity and uniformity in how to proceed with vulnerable massive and submassive pulmonary embolism, one Boston provider is taking steps to standardize care across specialties in lieu of guidelines, as well as accrue data to develop a better evidence base for more informed decisions in the future.

Challenges

Pulmonary embolism (PE)—the sudden blockage of an artery in the lung—and deep vein thrombosis (DVT)—a blood clot generally occurring in the legs—constitute the two categories of venous thromboembolism (VTE). Acute PE can occur rapidly and unpredictably. Approximately 150,000 U.S. patients per year are diagnosed with acute PE, resulting in thousands of deaths annually from massive PE (Arch Intern Med 2003;163:1213-1219). The estimated annual incidence of PE is 23 to 69 cases per 100,000 persons with hospitalizations resulting in 676,700 inpatient days (Vital Health Stat 13 2005;(158):1-199).

However, these patients first must be diagnosed before they can be treated, which is particularly important in a population that has a mortality rate as high as 25 to 30 percent if left untreated (Arch Intern Med 2001;161[1]:92-97). This rate has resulted in its reputation as a “silent killer,” causing more than 100,000 U.S. deaths each year, estimates the American College of Cardiology (ACC).

“PE is not immediately recognizable through a clear set of symptoms, so even experienced medical personnel don’t always identify it as the potential diagnosis,” says Kenneth Rosenfield, MD, section head for vascular medicine and intervention within the cardiology department at Massachusetts General Hospital (MGH) in Boston. “Also, the signs are subtle; thus, it is often referred to as ‘the great masquerader,’ since it may mimic many other illnesses.”

The most common symptoms are shortness of breath, chest pain and a cough (that may produce bloody sputum), sweating and lightheadedness or fainting. Other signs can include wheezing, leg swelling (typically in one leg only), clammy or bluish-colored skin, rapid or irregular heartbeat and weak pulse. These symptoms can easily be confused and diagnosed as another condition.

Another challenge to standardizing care for the appropriate diagnosis and treatment of acute PE is that no one specialty “owns” this disease state. What compounds this problem is that PE can present in a multitude of venues—intraoperatively, post-operatively or when the patient presents to the emergency room (ER). “There are multiple specialists, including in trauma, orthopedics, gynecology, surgery, cardiology and cardiac surgery, pulmonary, and hematology, who all approach this disease differently and see it from their own perspective,” says Rosenfield.  

Michael R. Jaff, DO, medical director of the vascular center at MGH, adds, “Internists like me who don’t perform procedures might consider medical therapy the appropriate first step, whereas cardiac surgeons who have been trained to perform acute pulmonary thromboendarterectomy or embolectomy might go with that first.” He adds that patients who present with submassive PE “don’t look so bad, particularly when they are lying down. It has a lot to do it with how patients present and how sick they actually look.”

One final challenge is the discrepancy of care depending on which specialist accepts responsibility for a patient because there is no defined algorithm to optimally treat him or her. “PE has been treated in an unstructured, disparate manner,” says Joshua N. Baker, MD, cardiac surgeon at MGH.

Jaff chalks up some of the disparity in care delivery to the plethora of “very confusing” literature. For instance, he says it’s unclear whether intervention offers any real advantage over standard anticoagulation for submassive PE. He adds that the literature is lacking because of the paucity of controlled studies; furthermore, many published studies were sponsored by industry, with companies trying to get