Pearls and Oy-sters: A Patient on Lecanemab Newly Diagnosed With Atrial Fibrillation.

A 77-year-old woman with a medical history of amnestic mild cognitive impairment on lecanemab presented to the hospital with new onset shortness of breath. ECG revealed new diagnosis of atrial fibrillation with rapid ventricular response. Considering the patient's risk factors with a CHADS-VASc score of 6, the patient would warrant use of anticoagulation, with the caveat that this is currently not recommended with use of lecanemab. In this case, we describe the management dilemma posed by new diagnosis of atrial fibrillation using anti-amyloid immunotherapies and suggest possible solutions in this unique population.