Samantha Ables, MSc Candidate (Translational Medicine)
During last week’s Medical Ground Rounds, we had the pleasure of hearing from Dr. Kerstin de Wit about the diagnosis and treatment of pulmonary embolism (PE). PE occurs when a blood clot breaks loose and becomes trapped in the blood vessels of the lungs.1 This can cause breathlessness, fatigue, feeling faint, chest pain, and other symptoms.2 Globally, PE is the third most common cause of cardiovascular death.2
PE is notoriously difficult to diagnose, as its symptoms are non-specific.3 Dr. de Wit’s research aims to make PE testing in the emergency department (ED) simpler and more accurate. Her team conducted a qualitative study to better understand how physicians test for PE. Many ED physicians are anxious about missing a PE, which is a barrier to using evidence-based guidelines for PE testing.4
There are numerous validated clinical probability tools, in addition to blood work and imaging, which can test for PE.5 Physicians must decide which tests to use and how to weigh the results of each test.5 A computed tomography (CT) scan of the lung’s blood vessels is often thought to be the gold standard for PE testing.4,6 However, CT has a 1/20 false positive rate for PE diagnosis and exposes patients to radiation.6 Other tests for PE include clinical probability tools, which determine a patient’s risk of PE, and the D-dimer test.3 This test shows the level of a protein fragment created when a blood clot dissolves, which is elevated in PE.3,5 Evidence-based guidelines support using a clinical probability tool and D-dimer test to rule out PE in low-risk patients, reducing the use of CT.4 However, ED physicians may be very worried about PE and choose a CT over these tests.4,7
Dr. de Wit’s most recent study implemented a standard PE testing protocol in a Canadian ED to determine whether this would simplify PE testing and safely diagnose patients.8 For all potential PE patients, a D-dimer test would be ordered. D-dimer <500ng/mL ruled out PE and meant no further testing was required, while patients with a higher D-dimer received a CT.9 This protocol increased testing for PE and adherence to evidence-based guidelines.8 Additionally, CT scans were reduced while the incidence of PE diagnosis increased, indicating this protocol did not miss PE cases.7-9 Building on this success, Dr. de Wit aims to refine this protocol with additional criteria. Her study highlights the importance of translational research. Previous research created validated diagnostic tests and evidence-based guidelines for PE testing, but these were underutilized by physicians diagnosing PE in the ED.3-5,7 Dr. de Wit’s research bridges this gap by bringing evidence-based guidelines to ED physicians in a straightforward protocol for PE testing.8
Once PE is diagnosed, the patient and physician must decide on treatment. The optimal treatment for PE depends on risk level and the patient’s individual situation.5 Newer PE medications, direct oral anticoagulants (DOACs), allow patients to be treated at home, which increases patient satisfaction.10,11 To be safely treated at home, patients are required to have support at home, a low risk of bleeding, and the financial means to afford DOACs.11 Additionally, patients must have access to follow-up appointments with a physician.11 During the patient’s initial ED visit, they may be stressed and overwhelmed, and thus need further support from a physician to answer their questions.12 At the follow-up appointment, a physician can explain PE, their prognosis, and provide instructions for their medication.11,13 Dr. de Wit established such an outpatient thrombosis clinic in Kingston. She stressed the importance of physician-patient communication during PE diagnosis and treatment, as physicians’ anxiety about diagnosing PE may transfer to patients, causing lasting psychological distress.13 Physicians can mitigate this by using lay terms to explain PE, taking the time to answer patient questions, and adopting a calm demeanor.12 High quality communication helps patients understand their diagnosis and treatment options, allowing them to fully participate in decision making.14
Following Grand Rounds, the translational medicine (TMED) graduate students were fortunate to continue learning about this topic from Dr. de Wit. We discussed the potential for educational campaigns to increase the public’s understanding of PE,15 as well as the vital role of pharmacists in helping PE patients understand their treatment and follow their medication instructions.16 Finally, Dr. de Wit outlined her education and career path, including extensive research training and an active research program. She left the us with insightful advice for students just beginning the journey into research: success in research often takes time and patience, but researchers who persevere can make a difference.
On behalf of the TMED students, I would like to thank Dr. de Wit for presenting at Grand Rounds, further discussing this topic with us, and illustrating the importance of translational research.
References
- 2021. Pulmonary Embolism Recovery: your questions answered. Healthline. https://www.healthline.com/health/pulmonary-embolism-recovery#outlook
- Konstantinides SV, Meyer G, Becattini C, et al. 2019 ESC guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS). Eur Heart J. 2020 Jan 21;41(4):543-603.
- Hamad, M., Bhatia, P., Ellidir, E., Abdelaziz, M., & Connolly, V. (2011). Diagnostic approach to pulmonary embolism and lessons from a busy acute assessment unit in the UK. Breathe, 7(4), 315-323. DOI: 10.1183/20734735.020210
- Zarabi, S., Chan, T. M., Mercuri, M., … de Wit, K. (2021). Physician choices in pulmonary embolism testing. CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 193(2), E38–E46. https://doi.org/10.1503/cmaj.201639
- Hunt, J. M., & Bull, T. M. (2011). Clinical review of pulmonary embolism: diagnosis, prognosis, and treatment. The Medical clinics of North America, 95(6), 1203–1222. https://doi.org/10.1016/j.mcna.2011.08.003
- Stein, P. D., Fowler, S. E., Goodman, L. R., et al. (2006). Multidetector computed tomography for acute pulmonary embolism. The New England journal of medicine, 354(22), 2317–2327. https://doi.org/10.1056/NEJMoa052367
- Kline, J. A., Garrett, J. S., Sarmiento, E. J., Strachan, C. C., & Courtney, D. M. (2020). Over-Testing for Suspected Pulmonary Embolism in American Emergency Departments: The Continuing Epidemic. Circulation. Cardiovascular quality and outcomes, 13(1), e005753. https://doi.org/10.1161/CIRCOUTCOMES.119.005753
- Germini, F., … de Wit, K. (2022) Submitted abstract.
- Raja, A. S., Greenberg, J. O., Qaseem, A., et al. (2015). Evaluation of Patients With Suspected Acute Pulmonary Embolism: Best Practice Advice From the Clinical Guidelines Committee of the American College of Physicians. Annals of internal medicine, 163(9), 701–711. https://doi.org/10.7326/M14-1772
- 2022. Managing pulmonary embolism in primary care feasible for some patients. Healthday. https://consumer.healthday.com/primary-care-management-of-pulmonary-emb…
- Kabrhel, C., Vinson, D. R., Mitchell, A. M., Rosovsky, R. P., Chang, A. M., Hernandez-Nino, J., & Wolf, S. J. (2021). A clinical decision framework to guide the outpatient treatment of emergency department patients diagnosed with acute pulmonary embolism or deep vein thrombosis: Results from a multidisciplinary consensus panel. Journal of the American College of Emergency Physicians open, 2(6), e12588. https://doi.org/10.1002/emp2.12588
- Hernandez-Nino, J., Thomas, M., Alexander, A. B., Ott, M. A., & Kline, J. A. (2022). Communication at diagnosis of venous thromboembolism: Lasting impact of verbal and nonverbal provider communication on patients. Research and practice in thrombosis and haemostasis, 6(1), e12647. https://doi.org/10.1002/rth2.12647
- Noble, S., Lewis, R., Whithers, J., Lewis, S., & Bennett, P. (2014). Long-term psychological consequences of symptomatic pulmonary embolism: a qualitative study. BMJ open, 4(4), e004561. https://doi.org/10.1136/bmjopen-2013-004561
- Ubel, P. A., Scherr, K. A., & Fagerlin, A. (2017). Empowerment Failure: How Shortcomings in Physician Communication Unwittingly Undermine Patient Autonomy. The American journal of bioethics, 17(11), 31–39. https://doi.org/10.1080/15265161.2017.1378753
- C-L-O-T-S national awareness campaign. 2019. Thrombosis Canada. https://thrombosiscanada.ca/c-l-o-t-s-national-awareness-campaign/
- Groth, Acquisto, N. M., Wright, C., Marinescu, M., McNitt, S., Goldenberg, I., & Cameron, S. J. (2021). Pharmacists as members of an interdisciplinary pulmonary embolism response team. JAACP : Journal of the American College of Clinical Pharmacy. Https://doi.org/10.1002/jac5.1569