Comparison of leg loader and treadmill exercise for evaluating patients with peripheral artery disease

The exercise ankle-brachial index (ABI) helps diagnose lower extremity peripheral artery disease (PAD). Patients with comorbidities may be unable to perform treadmill exercise, the most common stress loading test. While the active pedal plantar flexion (APP) test using the leg loader, simple and easy stress loading device, could be an alternative, there are no data comparing the leg loader and treadmill exercise. Therefore, we aimed to compare APP using the leg loader and treadmill exercise to evaluate PAD. A total of 27 patients (54 limbs) diagnosed with PAD with intermittent claudication and considered for angiography and/or endovascular treatment were recruited prospectively, and both the leg loader and treadmill were performed. There was a strong correlation (r = 0.925, p < 0.001) between the leg loader ABI and treadmill ABI; however, the decrease rate of the leg loader ABI was significantly less than that of treadmill ABI (14.0% [5.6, 30.1] vs. 25.8% [6.1, 53.1], p < 0.001). The number of patients who terminated the exercise prematurely due to dyspnea was four during the treadmill and zero during the leg loader. There was a good correlation between the leg loader ABI and treadmill ABI. Although leg loader, a simple, safe, and easy method, could be an alternative to diagnose PAD, further studies are needed to evaluate the diagnostic value of the leg loader in patients with borderline ABI or those unable to perform the treadmill.