By examining the physiology of patients who exercised under a magnetic resonance imaging scanner (MRI), doctors at the University of Virginia Health System have devised a new test to diagnose and follow peripheral arterial disease. This test shows promise in helping drug companies test new PAD medications and, perhaps in the near future, may give doctors the ability to tell which patients are at risk for developing PAD-related complications and require stenting, bypass surgery or even amputation of a leg.
A UVa cardiologist, Dr. Christopher Kramer, and his colleagues, measured how fast the leg muscles of patients with PAD, and people without PAD, recovered a phosphorus substance called phosphocreatine (PCr), the major energy "store" in muscle cells. Tests at UVa on 20 patients with mild to moderate PAD and 14 people without PAD, showed that the median time to recover phosphocreatine at the end of exercise in PAD patients was three times slower, 91 seconds in the PAD group versus 35 seconds in the normal group.
"Not only is this a good test that can discriminate patients with PAD from those without the disease," Kramer said, "but a longer exercise time was a marker of worse outcomes in PAD patients. Those patients with events, including amputations and surgery, had a longer recovery time." Kramer's findings are published in the June 6 issue of the Journal of the American College of Cardiology found on the web at: http://www.cardiosource.com/jacc/index.asp