Mahe, Guillaume

Background Lower extremity peripheral arterial disease (PAD) is a common medical condition causing substantial morbidity. Limited data exist on whether discrepancies in PAD prevalence exist between the lower extremities using resting ankle-brachial indices (ABIs) and postexercise pressures. Objective We predicted the prevalence of PAD between the lower extremities. Methods and Results Consecutive patients who had undergone a noninvasive arterial lower extremity study at Mayo Clinic, Rochester, MN, between January 1996 and December 2012 with suspected PAD were retrospectively reviewed. We identified 12,312 consecutive patients who underwent an arterial lower extremity and an exercise treadmill study. Prevalence of PAD was assessed at rest and after exercise using two criteria: a resting ABI ≤ 0.90 and a postexercise pressure decrease of > 30 mm Hg. Mean age was 67 ± 12 years and there were 4,780 (39%) women studied. At rest, we found a higher prevalence of PAD on the left extremity (27.4%) compared with the right (24.6%) (p < 0.0001). After exercise, we found a higher prevalence of PAD on the right extremity (25.1%) compared with the left (19.0%) (p < 0.0001). These discrepancies between the prevalence of PAD at rest and after exercise were present in women and men. Conclusion Using validated criteria of a resting ABI of ≤ 0.90 and postexercise ankle pressure decrease > 30 mm Hg, our results suggest that there is a significantly higher prevalence of PAD in the left lower extremity at rest, in contrast to a greater prevalence of abnormal postexercise testing in the right lower extremity. The reason(s) of these discrepancies remain to be studied.

Proximal claudication is secondary to ischemia caused by peripheral artery disease (PAD), whereas proximal pseudo-claudication is secondary to other disease processes such as hip arthritis, spinal stenosis, neuropathy, and so forth. The differentiation between the two can be challenging. Exercise transcutaneous oxygen pressure measurement (exercise-TcPO 2 ) allows noninvasive detection of flow-reducing lesions in the proximal arteries and tributaries of the lower extremity arterial tree. We present the first case report in the United States using an exercise-TcPO 2 algorithm. A 71-year-old diabetic patient with proximal left-sided and right-calf claudication with indeterminate ankle-brachial indices underwent an exercise-TcPO 2 study before and after endovascular intervention. Four TcPO 2 probes were placed: one at chest level (reference probe), one on each buttock, and one on the symptomatic calf. The Delta from Resting Oxygen Pressure (DROP) index was calculated at each probe site using a previously validated protocol. Proximal left- and right-calf ischemia were confirmed by the initial exercise-TcPO 2 , and, after endovascular treatment of the left iliac artery lesion, improvements in proximal exercise-TcPO 2 values were found. These data suggest that exercise-TcPO 2 can be useful in PAD evaluation in patients with non-compressible arteries and/or proximal claudication.