AHA/ACC PE algorithm thread

A pulmonary embolism is a blood clot in the lungs, and the new American Heart Association and American College of Cardiology guideline says the first job is deciding who needs imaging and who does not. (ahajournals.org) The multisociety guideline was published online February 19, 2026, in *Circulation* and the *Journal of the American College of Cardiology* for adults age 18 and older with acute pulmonary embolism. It was developed with emergency medicine, chest medicine, hospital medicine, interventional radiology, vascular medicine, and other groups. (ahajournals.org) For people with suspected pulmonary embolism, the guideline starts with clinical probability, which is a bedside estimate of how likely the clot is before any scan. In adults with low or intermediate probability, an age-adjusted D-dimer blood test below the cutoff can rule out pulmonary embolism without imaging. (professional.heart.org) That age-adjusted cutoff is age times 10 micrograms per liter for fibrinogen equivalent unit assays in patients older than 50, with the standard 500 micrograms per liter cutoff used up to age 50. The guideline also cites the YEARS pathway, which combines a short clinical checklist with D-dimer testing in low- and intermediate-probability patients. (professional.heart.org) (ahajournals.org) The document adds a new five-level severity framework after pulmonary embolism is found, labeled categories A through E. Those categories run from subclinical disease to cardiopulmonary failure and are meant to standardize prognosis and treatment decisions. (professional.heart.org) Patients in category C, D, or E — including those with elevated biomarkers, right-ventricular strain, incipient cardiopulmonary failure, or persistent low blood pressure — should be hospitalized, according to the guideline summary. Low-risk patients can be identified with tools including Hestia, the Pulmonary Embolism Severity Index, or the simplified Pulmonary Embolism Severity Index. (professional.heart.org 1) (professional.heart.org 2) The push to avoid unnecessary scans comes after years of concern about low-yield computed tomography pulmonary angiography in emergency departments. A 2020 American Heart Association outcomes study found a pooled pulmonary embolism yield of 3.1% from computed tomography pulmonary angiography across 27 emergency departments. (ahajournals.org) The guideline’s treatment section also favors direct oral anticoagulants over vitamin K antagonists for eligible patients, unless there is a contraindication. That recommendation is paired with the new diagnostic pathway so clinicians move from suspicion, to testing, to treatment with fewer unnecessary scans. (professional.heart.org) The document is the first de novo American Heart Association and American College of Cardiology guideline focused on acute pulmonary embolism in adults. Its diagnostic message is simple in practice: estimate risk first, use D-dimer when risk is not high, and reserve imaging for the patients who still need it. (acc.org)