Important informations

Review on the state of current knowledge on pulmonary embolism published in New England Journal of Medicine (NEJM)

The special feature, co-authored by Dr. Susan R. Kahn and Dr. Kerstin de Wit, aims to help front line clinicians better diagnose, treat, and manage a common condition with many repercussions and the potential to be fatal for patients.

Pulmonary embolism (PE) is the most dangerous, and potentially life-threatening, form of venous thromboembolism (VTE), in which a blood clot develops in a large vein. PE occurs when a blood clot travels from the legs to the lungs, causing an individual to experience stabbing chest pains, coughing, difficulty breathing, and a rapid pulse. This affects an average of 30,000 Canadian each year.

“While PE is a common condition, it is often misdiagnosed and underdiagnosed as knowing which diagnostic test to use and when is a major challenge,” says Dr. Susan R. Kahn, Senior Investigator in the Centre for Clinical Epidemiology of the Lady Davis Institute at the Jewish General Hospital (JGH), Director of the JGH Centre of Excellence in Thrombosis and Anticoagulation Care (CETAC), and Canada Research Chair in Venous Thromboembolism, lead author of the article. “In practice, it may be diagnosed as some other problem, such as pneumonia, or physicians might not think the patient could have PE and do a proper diagnostic test.”

Recovery from PE is associated with complications such as bleeding due to anticoagulant treatment, recurrent VTE, chronic thromboembolic pulmonary hypertension, and long-term psychological distress. Furthermore, Dr. Kahn’s team previously showed that approximately half the patients who receive a diagnosis of PE have functional and exercise limitations one year later (known as post–pulmonary-embolism syndrome), and the health-related quality of life for patients with a history of PE is poor, making the timely diagnosis and expert management of PE crucial.

Dr. Kahn and co-author Dr. Kerstin de Wit, a venous thrombosis and emergency medicine physician and researcher based at the Kingston Health Sciences Centre, provide a clinical overview of what is currently known about PE, its diagnosis, treatment, management, and patient follow-up, using a case vignette.

The article contains many practical points for clinicians, highlighting that:

  • PE is a common diagnosis with many repercussions, which has the potential to be fatal if not recognized and treated appropriately. Untreated PE has a mortality rate approaching 20%;
  • It is very important for physicians to be familiar with one diagnostic approach, to know it very well, and to use it systematically;
  • Initial treatment is guided by classification of the pulmonary embolism as high-risk, intermediate-risk, or low-risk;
  • Treatment modalities and duration vary depending on patients’ medical conditions and characteristics (i.e. cancer, advanced kidney or liver disease, pregnant women, etc.)

The article reviews the latest research, existing clinical practice guidelines and presents the main areas of uncertainty that need to be addressed to ensure the optimal care and management of patients with or at risk of PE.

“Whether a particular direct oral anticoagulant – the standard of care – is preferable for the treatment of PE is not known at this point,” Dr. Kahn exemplifies. “That is why we are currently enrolling patients from CETAC in ongoing randomized trials that are assessing apixaban as compared with rivaroxaban for the initial treatment of patients with venous thromboembolism.”

Dr. de Wit will address another area of uncertainty by leading in Canada an important multinational, randomized, controlled trial to assess the efficacy and safety of a therapy involving a reduced dose of thrombolytic medication in patients with intermediate-risk acute PE. This trial will start in a few months and will be conducted at the Jewish General Hospital/Lady Davis Institute as well.

“The good news is that blood clots are preventable and treatable if discovered early,” says Dr. Kahn. “Although there are many risk factors, with proper attention to prevention and treatment, we can reduce the incidence and recurrence of VTE and its complications, such as PE.” This emphasizes the importance of concerted efforts to guide and train physicians— especially those working in high-risk settings such as primary care offices, emergency rooms, inpatient medical and surgical wards and intensive care units—and to educate the public at large and patients to ensure early diagnosis.