Jonathan D. Marmur, MD is an interventional cardiologist and academic physician who recently joined NYC Health + Hospitals/Mount Sinai-Elmhurst as Chair of Cardiology. He previously served for more than two decades at SUNY Downstate Health Sciences University, where he held multiple leadership roles including Professor of Medicine, Chief of Cardiology, Director of the Cardiac Catheterization Laboratory, and Fellowship Director for both general and interventional cardiology.

Dr. Marmur is nationally recognized for his work in complex coronary intervention, cardiovascular education, and translational research. Over his career, he has mentored more than 70 interventional cardiologists and played a central role in building regional referral networks serving communities across Brooklyn. His research has spanned vascular biology, thrombosis, and genomics, including collaborative work leading to novel cardiovascular biomarkers and the establishment of the Downstate Cath Lab GeneBank.

Dr. Marmur completed his medical training at Laval University in Quebec, Canada, with postgraduate training at McGill University, the University of Toronto, and the Mount Sinai Medical Center in New York.