Comparison of adenosine echocardiography, with and without isometric handgrip, to exercise echocardiography in the detection of ischemia in patients with coronary artery disease.
This study was undertaken to evaluate whether adenosine echocardiography is comparable to exercise echocardiography in the detection of ischemia in patients with suspected coronary artery disease and to assess whether the addition of handgrip exercise to adenosine enhances the induction of ischemia in these patients. Accordingly, 67 patients with suspected or known coronary artery disease referred for exercise testing underwent adenosine, adenosine with handgrip, and post-treadmill exercise echocardiography. A maximal adenosine infusion dose of 170 micrograms/kg/min was used. Images at baseline and during each of the three stress modalities were digitized in a quad-screen format, randomized, and blinded as to the stage and mode of intervention for nonbiased interpretation. An ischemic response was defined as a new or worsening wall motion abnormality. Ischemia was detected by exercise echocardiography (n = 20) more often than by adenosine echocardiography alone (n = 11; p = 0.039) but similarly to adenosine plus handgrip (n = 16; difference not significant). Exact agreement in individual response between exercise adenosine echocardiography was seen in 51 (80%) of 64 patients and increased to 88% between exercise and adenosine plus handgrip. In the patients who underwent angiography (n = 45), the sensitivity for coronary artery disease (n = 33) was 87% for adenosine, 91% for adenosine plus handgrip, and 93% for exercise echocardiography. The respective sensitivities decreased to 64%, 81%, and 89% in patients without previous myocardial infarction. Specificity was 91% for adenosine with or without handgrip and 82% for exercise echocardiography. Image quality during adenosine with and without handgrip was superior to that during exercise (p < 0.01). Thus in patients with coronary artery disease able to exercise, exercise echocardiography induces ischemia more frequently than does adenosine echocardiography alone. The addition of handgrip exercise to adenosine infusion enhances the detection of ischemia without reducing specificity or image quality and is recommended when adenosine echocardiography is used as a pharmacologic stress test.