 Peripheral arterial disease involving the lower limbs is becoming an increasingly important health issue which places considerable burden on individuals, communities and health care resources. PAD affects an estimated 27 million adults 55 years of age in Europe and North America 1. The prevalence of PAD in Asia is expected to be similar and is likely to rise as the Chinese population ages. Intermittent claudication affects most patients with PAD. Although IC is not limb-threatening, the loss of walking ability and the experience of pain with ambulation can cause significant social, leisure, and occupational impairment in many patients 2-4. The decreased QoL experienced in patients with IC is on par with other cardiovascular diseases such as heart failure and heart attack. More alarmingly, physical disability is associated with higher risk of death among PAD patients. For these reasons and because patients are chronically disabled, the treatment of IC has increasingly become a major clinical focus in cardiovascular research. 