Deciding When to Anticoagulate Patients with Isolated Subsegmental Pulmonary Embolism
We commend Duffett et al for their comprehensive, contemporary review of the diagnosis and management of pulmonary embolism (1). We know of no more accessible survey of the topic and consider it valuable reading for clinicians and aspiring pulmonary embolism researchers.
We took particular interest in their discussion of isolated subsegmental pulmonary embolism. The review addresses two clinically pressing questions: (a) Are positive findings on computed tomography pulmonary angiography diagnostically reliable? (b) If reliable, is anticoagulation warranted in those without concomitant deep vein thrombosis? On this second point, the authors suggest that, absent active malignancy or high-risk features (e.g., poor cardiopulmonary reserve), such patients may safely forgo anticoagulation and be monitored with serial leg ultrasonography (1).
While we agree in principle, we think that the anticoagulation decision is more nuanced, given the recognized evidence gap (2). Others have posited that idiopathic clot and marked symptoms may tip the scale toward anticoagulation (3), as could an increased predicted risk of recurrence, as in patients with a history of venous thromboembolism (4). A high bleeding risk, on the other hand, as indicated by an elevated HAS-BLED score, for example, might favor surveillance. Not to be forgotten in this deliberation to administer or withhold anticoagulation is the patient’s perspective. This can be elicited from a shared decision-making conversation that ensures their understanding of the options and attends to their values and preferences (5). The CHEST guideline concurs (4). Shared decision-making is of paramount importance in situations like this of suspected clinical equipoise (6).
1. Duffett L, Castellucci LA, Forgie MA. Pulmonary embolism: update on management and controversies. BMJ 2020;370:m2177. doi: 10.1136/bmj.m2177
2. Konstantinides SV, Meyer G, Becattini C, et al; ESC Scientific Document Group. 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;41(4):543-603. doi: 10.1093/eurheartj/ehz405
3. Moores LK. Are we overtreating isolated subsegmental pulmonary embolism?: First do no harm. JAMA Intern Med 2018;178(9):1274-1275. doi: 10.1001/jamainternmed.2018.2970
4. Kearon C, Akl EA, Ornelas J, et al. Antithrombotic Therapy for VTE Disease: CHEST Guideline and Expert Panel Report. Chest 2016;149(2):315-352. doi: 10.1016/j.chest.2015.11.026
5. Barry MJ, Edgman-Levitan S. Shared decision making—pinnacle of patient-centered care. N Engl J Med 2012;366(9):780-1. doi: 10.1056/NEJMp1109283
6. Hess EP, Hollander JE, Schaffer JT, et al. Shared decision making in patients with low risk chest pain: prospective randomized pragmatic trial. BMJ 2016;355:i6165. doi: 10.1136/bmj.i6165.
Competing interests: No competing interests