A medical device comprising a coating thereon comprising a biocompatible polymer and heparin is provided herein. Heparin is coupled with the biocompatible polymer via a spacer having a grouping that renders a binding site of the heparin molecule accessible by a binding protein. The medical device can be implanted in a human being for the treatment of a disease such as atherosclerosis, thrombosis, restenosis, hemorrhage, vascular dissection or perforation, vascular aneurysm, vulnerable plaque, chronic total occlusion, claudication, anastomotic proliferation for vein and artificial grafts, bile duct obstruction, ureter obstruction, tumor obstruction, or combinations thereof.