The Adverse Events and Hemodynamic Effects of Adenosine-Based Cardiac MRI

Objective: We wanted to prospectively assess the adverse events and hemodynamic effects associated with an intravenous adenosine infusion in patients with suspected or known coronary artery disease and who were undergoing cardiac MRI. Materials and Methods: One hundred and sixty-eight patients ($64{\pm}9$ years) received adenosine (140${\mu}g$/kg/min) during cardiac MRI. Before and during the administration, the heart rate, systemic blood pressure, and oxygen saturation were monitored using a MRI-compatible system. We documented any signs and symptoms of potential adverse events. Results: In total, 47 out of 168 patients (28%) experienced adverse effects, which were mostly mild or moderate. In 13 patients (8%), the adenosine infusion was discontinued due to intolerable dyspnea or chest pain. No high grade atrioventricular block, bronchospasm or other life-threatening adverse events occurred. The hemodynamic measurements showed a significant increase in the heart rate during adenosine infusion ($69.3{\pm}11.7$ versus $82.4{\pm}13.0$ beats/min, respectively; p < 0.001). A significant but clinically irrelevant increase in oxygen saturation occurred during adenosine infusion ($96{\pm}1.9$% versus $97{\pm}1.3$%, respectively; p < 0.001). The blood pressure did not significantly change during adenosine infusion (systolic: $142.8{\pm}24.0$ versus $140.9{\pm}25.7$ mmHg; diastolic: $80.2{\pm}12.5$ mmHg versus $78.9{\pm}15.6$, respectively). Conclusion: This study confirms the safety of adenosine infusion during cardiac MRI. A considerable proportion of all patients will experience minor adverse effects and some patients will not tolerate adenosine infusion. However, all adverse events can be successfully managed by a radiologist. The increased heart rate during adenosine infusion highlights the need to individually adjust the settings according to the patient, e.g., the number of slices of myocardial perfusion imaging.