APEX accepts coronary angiogram frames in DICOM format or as key still images. The agent processes multi-view angiograms and performs frame-level analysis — no manual pre-processing or annotation required. Each detected lesion is linked back to the specific source frame so the interventionalist can pull up the underlying image and verify the finding directly.

A two-stage AI detection pipeline localizes each lesion by vessel and segment, classifies severity as a percentage with a confidence score, and automatically flags lesions above the SYNTAX threshold as CABG-favoring.

The agent maps each detected lesion to the 25-segment SYNTAX scoring system using the ARCADE-trained vessel segmentation model. Lesion weights are summed per the standard SYNTAX II algorithm and returned as a composite score with an intermediate or high complexity classification. A score above 22 favors CABG under both ACC/AHA and ESC guidelines — and this finding feeds directly into the Guideline Agent's recommendation.