The YEARS Algorithm & Diagnosing Pulmonary Embolism in Pregnancy

This month JC will be discussing the diagnosis of PE in pregnancy. PE is the seventh leading cause of maternal mortality and accounts for 9 percent of maternal deaths. That stated, in the United States, VTE is fairly rare, diagnosed in 1 in 500 to 2000 pregnancies (absolute incidence; 0.025 to 0.1 percent) however, our risk tolerance for missing a VTE in a pregnant patient is very low. Because of this, many patients presenting to the ED with any clinical suspicion of PE are likely to undergo CTA with inherent risks to mother and fetus. Risk stratification tools such as the Wells, Geneva and YEARS scores were derived in non-pregnant patients which limits their applicability as a screening tool. In addition, d-dimer thresholds have been derived in non-pregnant patients as well and levels are known to be elevated as a pregnancy progresses which also limits its applicability. Having a tool that is highly sensitive screening tool could help to reduce unnecessary CTA’s and potential harms. The attached articles may provide some evidence to help mitigate overuse of CTA and VQ scans however, is the quality of data reported sufficient to be considered practice changing?

van der Hulle et al, Simplified diagnostic management of suspected pulmonary embolism (the YEARS study): a prospective, multicentre, cohort study.  Lancet. 2017 Jul 15;390(10091):289-297. Appraisal

Righini M. et al, Diagnosis of Pulmonary Embolism During Pregnancy: A Multicenter Prospective Management Outcome Study. Ann Intern Med. 2018 Dec 4;169(11):766-773. Appraisal

 van der Pol LM et al, Pregnancy-Adapted YEARS Algorithm for Diagnosis of Suspected Pulmonary Embolism. N Engl J Med. 2019 Mar 21;380(12):1139-1149. Appraisal

 ACOG Practice Bulletin No. 196: Thromboembolism in Pregnancy.Obstet Gynecol. 2018 Jul;132(1):e1-e17