Background: No-React treatment is known to render tissues resistant to calcific degeneration and to reduce early inflammatory response. No-React bovine internal mammary artery (NR-IMA) is available for restricted use in Europe. In this first study, our aim was to use magnetic resonance imaging (MRI) to investigate the clinical performance and patency rates of this conduit. Methods: Seven patients received 8 grafts with NR-IMA. Approval from the Medical Devices Agency of the United Kingdom was obtained for use of this material. One patient needed salvage coronary artery bypass grafting (CABG). Graft patency was investigated with cardiac MRI. One patient was excluded from the MRI study because of the presence of intracerebral metal clips. The mean follow-up period was 2.5 years with a range of 1 to 4.5 years. Results: There was no mortality in this group. After treatment 6 patients were asymptomatic, and 1 patient had class II anginal symptoms. Four (57%) of the 7 NR-IMA grafts remained patent. The longest patency was 4.5 years in a patient who underwent salvage CABG. Other associated grafts in this cohort of patients were 5 left internal mammary arteries (all patent), 1 radial artery graft (patent), and 7 saphenous vein grafts (4 [57%] of 7 patent). There were no occluded NR-IMA grafts in a patient with patent vein grafts. Conclusion: We concluded that at 2.5 year follow-up, NR-IMA had a patency rate of 57% (4 of 7 cases). This rate matched the vein graft patency rate in this cohort of patients. With the longest patency of 4.5 years, use of NR-IMA seems to hold promise for the future.