MARCUS: An agentic, multimodal vision-language model for cardiac diagnosis and management. - Jack W. O'Sullivan; Mohammad Asadi; Lennart Elbe; Akshay Chaudhari; Tahoura Nedaee; Francois Haddad; Michael Salerno; Li Fei-Fei 001; Ehsan Adeli-Mosabbeb; Rima Arnaout; Euan A. Ashley (CoRR, 2026)