CARDIAC-FM: A Multimodal Foundation Model for Cardiovascular Risk Prediction Using ECG and Cardiac MRI. - Li F; Li S; Qian Y; Chen B; Brody JA; Yogeswaran V; Wiggins KL; Sitlani CM; Bis JC; Shojaie A; Longstreth WT Jr; Psaty BM; et al. (MedRxiv : the preprint server for health sciences, 2026)