Objective: To determine the safety of regadenoson for vasodilation in cardiac MRI stress tests to detect myocardial ischemia. Material and methods: We retrospectively analyzed cardiac MRI studies done in 120 patients (mean age, 67 11.6 years; 88 men) with suspected ischemic heart disease or known coronary disease who had clinical indications for cardiac MRI stress tests. All studies were done on a 1.5 T scanner (MAGNETOM Aera, Siemens Healthineers) using regadenoson (5 ml, 0.4 mg) for vasodilation. We recorded cardiovascular risk factors, medications, and indications for the test as well as vital signs at rest and under stress and the symptoms and adverse effects induced by the drug. Results: No symptoms developed in 52.6% of patients. The most common symptoms were central chest pain (25%) and dyspnea (12%). At peak stress, the mean increase in heart rate was 23.9 + 11.4 beats per minute and the mean decreases in systolic and diastolic blood pressure were 7.1+18.8 mmHg and 5.3 9.2 mmHg, respectively (p '0.O01). The response to regadenoson was less pronounced in obese and diabetic patients. The increase in heart rate was greater in symptomatic patients (27.4 11.2 bpm vs. 20.6 + 10.7 bpm in asymptomatic patients, p =0.001). No severe adverse effects were observed. Conclusion: Regadenoson is welt tolerated and can be safety used for cardiac MRI stress tests. 0Z0/9 SERAM. Published by Elsevier Espana, S.L.U. All rights reserved.