First-Ever AHA/ACC Pulmonary Embolism Guideline Introduces Five-Category Severity System

Approximately 470,000 people are hospitalized in the United States each year with acute pulmonary embolism - a blood clot that typically forms in a deep vein of the leg or pelvis, migrates through the heart, and lodges in an artery in the lungs. About 1 in 5 patients with high-risk PE die. Until now, no dedicated clinical practice guideline existed to help clinicians systematically navigate diagnosis and treatment decisions.

The American Heart Association and the American College of Cardiology have changed that. Published simultaneously in Circulation and JACC, the 2026 joint guideline offers the most comprehensive evidence-based framework for acute PE management yet produced, incorporating advances in imaging, anticoagulation, and interventional treatments that have emerged over the past decade.

"There have been significant advances in the understanding of pulmonary embolism and treatments to effectively manage this condition," said guideline chair Mark A. Creager, MD, a professor of medicine at Dartmouth's Geisel School of Medicine. "This guideline is a road map to help clinicians navigate these advances for the safest and most effective approaches to care."

Five Categories, Five Treatment Paths

The centerpiece of the guideline is a new Acute PE Clinical Category system that classifies patients into five groups - A through E - based on symptom severity and risk for adverse outcomes. The categories are designed to match treatment intensity to clinical need.

Patients in Categories A and B have no or mild symptoms and a low probability of serious complications. These patients often can be safely sent home from the emergency department and managed as outpatients, avoiding a hospital stay and its associated risks.

Categories C through E encompass patients with more severe symptoms, including those showing signs of right heart strain, hemodynamic instability, or cardiovascular collapse. These patients require hospitalization. Those in Categories D and E may need the most aggressive interventions: intravenous or catheter-based clot-dissolving drugs, catheter-based mechanical clot removal, or surgical extraction of the clot.

The classification system also acknowledges that treatment decisions depend on what resources are available locally - a tertiary center with an experienced interventional radiology team can offer options that a rural community hospital cannot. The guideline provides recommendations calibrated to different care settings.

Who Is at Risk, and How Doctors Recognize It

PE is frequently misdiagnosed or diagnosed late because its symptoms - shortness of breath, chest pain, rapid heartbeat, dizziness, and fainting - overlap with many other conditions. The guideline identifies factors that raise the probability of PE, including major surgery, hospitalization, prolonged immobility, pregnancy and the postpartum period within six weeks of delivery, oral contraceptive use, obesity defined by a BMI of 30 or above, smoking, cancer, thrombophilias, and age over 40.

For patients with low or intermediate clinical probability - below 50% - the first recommended test is a blood D-dimer measurement. D-dimer is a protein fragment released when the body dissolves a blood clot; normal levels effectively rule out PE. Elevated D-dimer, or high clinical probability without testing, indicates the need for imaging.

Computed tomography pulmonary angiography (CTPA) is the standard imaging test. It is highly accurate, widely available in emergency settings, and can directly visualize the location and size of a clot. Patients who cannot receive the iodine-based contrast dye used in CTPA - due to allergy or kidney concerns - should receive a nuclear lung scan instead.

Treatment Preferences: DOACs Over Warfarin

Anticoagulation remains the cornerstone of PE treatment. The guideline recommends direct oral anticoagulants (DOACs) - specifically rivaroxaban, apixaban, edoxaban, or dabigatran - over older vitamin K antagonists such as warfarin for most patients. DOACs are easier to use, carry a lower risk of major bleeding, and do not require the frequent blood monitoring that warfarin demands.

The exception is pregnancy. DOACs are not recommended during pregnancy due to potential fetal risks. Low-molecular-weight heparin or unfractionated heparin are safe alternatives for pregnant patients with acute PE.

Follow-Up Beyond the Acute Event

The guideline includes detailed follow-up recommendations, recognizing that PE is not always a discrete event with a clear endpoint. All patients should have contact within one week of hospital discharge. A clinic visit should occur by three months after diagnosis to assess anticoagulation duration and check for ongoing symptoms.

For at least one year, patients should be screened at every visit for signs of chronic thromboembolic pulmonary disease - a condition in which persistent clots obstruct lung arteries long-term, potentially leading to pulmonary hypertension and right-sided heart failure. Patients on anticoagulants beyond three to six months should have the risks and benefits periodically reassessed.

The guideline also addresses psychological aftermath. Depression, anxiety, and post-traumatic stress disorder are common following acute PE, and the guideline recommends screening for these conditions and evaluating quality of life as part of routine follow-up care.

The guideline was developed by the AHA and ACC Joint Committee on Clinical Practice Guidelines and endorsed by eight additional healthcare organizations, including the American College of Emergency Physicians, the Society of Interventional Radiology, and the Society of Hospital Medicine.