Usefulness of brachial artery reactivity to isometric handgrip exercise in identifying patients at risk and with coronary artery disease

The change in brachial artery (BA) diameter after release of an occluding cuff has been used as a measure of endothelial function, to characterize atherosclerotic risk factors, and as a surrogate marker for coronary artery disease (CAD). We compared the change in BA diameter to isometric handgrip (IHG) with the occlusion release method to determine if a physiologic stress could be used to distinguish patients at risk and with CAD. BA diameter was measured by ultrasound during and after IHG, and after occlusion release in 93 subjects. At 120 seconds after release of IHG, BA diameter increased by 9.99 ± 8.3% (p <0.001) in 26 average-risk patients, increased 1.84 ± 5.7% in 37 high-risk patients, and decreased 3.9 ± 5.6% in 30 patients with CAD (p = 0.0001 for trend and p <0.01 between groups). There was a good correlation between change in BA diameter to IHG and occlusion release (r = 0.763 and p = 0.0001). The capacity for IHG and BA occlusion to characterize subjects by group was comparable with the exception of high-risk patients versus patients with CAD (80.5% for IHG vs 71.6% for occlusion and release, p = 0.086). BA response to IHG may be useful for identifying risk factors, patients at risk and with preclinical CAD, and the assessment of treatment strategies.