Trials and Tribulations of Assessing New Imaging Protocols: Combining Vasodilator Stress With Exercise

Among all patients referred for stress myocardial perfusion imaging (MPI), a substantial proportion in contemporary practice cannot exercise. Another group of patients are those who are thought to be able to achieve an adequate workload with treadmill (or bicycle) exercise but do not achieve at least 85% of maximum predicted heart rate without developing symptoms. There has been substantial interest and literature on the adjunctive use of vasodilator stress during the same visit to generate best-quality results for patients who do not exercise adequately. Current American Society of Nuclear Cardiology Guidelines recommend the possible use of vasodilator stress agents to supplement exercise in those patients who do not achieve target heart rate. However, optimal timing of administration is not clear. Herein, we summarize literature to date on the combination of vasodilator and exercise stress testing in light of the recently published Exercise to Regadenoson in Recovery Trial (EXERRT).