Impact of an abbreviated adenosine protocol incorporating adjunctive treadmill exercise on adverse effects and image quality in patients undergoing stress myocardial perfusion imaging

Background. Limited data are available about the effects of adjunctive treadmill exercise on adverse effects and the image quality of adenosine perfusion imaging. This study compared the incidence of adverse effects and image quality between standard 6-minute adenosine perfusion imaging and a stress test incorporating a 4-minute adenosine infusion with low-level treadmill exercise. Methods and Results. Nineteen patients underwent both a 6-minute adenosine technetium-99m sestamibi single photon emission computed tomography (SPECT) imaging study and a 4-minute adenosine Tc-99m sestamibi SPECT study with 6 minutes of simultaneous low-level treadmill exercise. Symptoms were recorded at 1-minute intervals during the stress and recovery periods. Heart-to-liver and heart-to-lung count ratios were determined from anterior planar images. More adverse effects were experienced during the standard adenosine study than during the adenosine study with low-level exercise (2.7 ± 1.4 vs 1.4 ± 1.1, P = .0003). The duration adverse effects were experienced was longer during the standard 6-minute adenosine protocol (6.6 ± 2.1 minutes vs 3.2 ± 2.8 minutes, P<.0001). Additionally, the symptom-severity scores were higher with the standard adenosine study (15.5 ± 9.8 vs 4.5 ± 5.1, P<.0001). The heart-to-liver ratios were noted to be higher in the 4-minute adenosine protocol with low-level exercise (1.0 ± 0.3 vs 0.6 ± 0.2, P = .0003). Conclusions. In comparison with standard 6-minute adenosine perfusion imaging, a protocol incorporating a 4-minute adenosine infusion with low-level treadmill exercise results in a marked reduction in the quantity and severity of adverse effects and an improvement in image quality.