Unfractionated heparin remains a common choice for hospitalized pulmonary embolism patients, even with guidelines recommending low-molecular-weight heparin, due to physician agnosticism toward anticoagulant choice and institutional culture, according to a recent study.
A qualitative study examined factors influencing the initial anticoagulant choice among hospitalized patients with acute pulmonary embolism (PE). The study explored barriers and facilitators to guideline-concordant anticoagulation, focusing on low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH).
Published in JAMA Network Open, the study included 46 U.S.-based physicians from emergency medicine (54.3%), hospital medicine (37.0%), and interventional specialties (8.7%). Participants, with a median age of 43 years (interquartile range [IQR], 36–50), were selected using maximum variation sampling to reflect diverse institutional and individual practice characteristics. Interviews were conducted between February 1 and June 3, 2024, using a semistructured guide informed by the Consolidated Framework for Implementation Research and Theoretical Domains Framework. Each interview, lasting a median of 29 minutes (IQR, 25–32), was recorded, transcribed, and analyzed through reflexive thematic analysis.
The findings highlighted recurring themes influencing anticoagulant selection, including indifference toward choice, therapeutic inertia, institutional culture, and misperceptions about pharmacologic properties. Many participants perceived LMWH and UFH as similar in efficacy and risk, except for UFH's "quick off" pharmacokinetics. Institutional norms and training practices perpetuated UFH use despite evidence of its resource intensity and unpredictability. Only 26% of patients treated with UFH achieved therapeutic levels within 24 hours, aligning with previous studies demonstrating increased bleeding risk compared with LMWH.
Therapeutic momentum emerged as a key factor, with initial anticoagulant decisions frequently carried through hospitalization. Emergency physicians often deferred decisions to hospitalists, while hospitalists rarely transitioned patients from UFH to LMWH or direct oral anticoagulants until discharge. Fear of decompensation and misconceptions about anticoagulation's role in catheter-directed treatments further reinforced UFH use. Interventionalists, however, reported no contraindications to LMWH for these procedures.
The study found that addressing barriers to guideline-concordant anticoagulation may require interventions focused on decision-making at admission. Behavioral nudges, institutional guidelines, and multidisciplinary collaboration could help support evidence-based practices, while addressing therapeutic inertia and institutional culture may improve adherence to guidelines and patient outcomes.
Full disclosures can be found in the published study.