Impact of Undertreated Antithrombotic Therapy on Adverse Patient Outcomes: A Scientific Statement From the American Heart Association.

Antithrombotic therapy undertreatment includes omission, nonadherence, underdosing, and clinical circumstances that result in subtherapeutic antithrombotic levels. Antithrombotic undertreatment has profound implications for patient safety, public health, and healthcare costs. Due to deviation from evidence-based clinical practice, misperceptions of bleeding versus thrombotic risk, and inequities in healthcare access, many patients with atrial fibrillation, venous thromboembolism, or peripheral artery disease remain untreated or receive suboptimal anticoagulant dosing. Antithrombotic undertreatment has been shown to increase rates of ischemic stroke, systemic embolism, recurrent thrombosis, and mortality. Real-world data continue to highlight substantial gaps in care, which appear to be magnified in patients with inequity in social determinants of health. The emergence of antithrombotic stewardship, in concert with growing bodies of literature on antithrombotic agent underdosing, represents a transformative opportunity to address these gaps through structured, interprofessional, and evidence-based approaches. Through interdisciplinary collaboration, healthcare professionals are well positioned to enhance patient health and safety by recognizing and recommitting to reducing antithrombotic undertreatment.