Previous studies demonstrated that ventricular response to stress cardiovascular magnetic resonance (CMR) is frequently abnormal in patients with a systemic right ventricle (RV). However, the clinical implications of these findings remained unknown. We sought to evaluate whether abnormal response to stress CMR predicts adverse outcome in patients with a systemic RV.Thirty-nine adult patients (54% male; mean age 26, range 18-65 years) with a systemic RV underwent stress CMR to determine the response of RV volumes and ejection fraction (EF). During follow-up, cardiac events, defined as hospitalization for heart failure, cardiac surgery, aborted cardiac arrest, or death, were recorded. The prognostic value of an abnormal response to stress, defined as lack of a decrease in RV end-systolic volume (ESV) or lack of an increase in RV EF, was assessed.We frequently observed an abnormal response to stress, as RV ESV did not decrease in 17 patients (44%), and RV EF did not increase in 15 patients (38%). After a mean follow-up period of 8.1 years, 8 (21%) patients had reached the composite end point. The inability to decrease RV ESV during stress was predictive for cardiac events with a hazard ratio of 2.3 (95% CI 1.19-88.72, P = .034), as was the inability to increase RV EF with a hazard ratio of 2.3 (95% CI 1.31-81.59, P = .027).Stress CMR potentially has important prognostic value in patients with a systemic RV. Patients with a systemic RV who show abnormal cardiac response to stress have a substantially higher risk of adverse outcome.