The association of acute exercise-induced ischaemia with systemic vasodilator function in patients with peripheral arterial disease

Patients with peripheral arterial disease (PAD) frequently experience ischaemic attacks of the affected tissues during exercise. The present study assesses the association of transient exercise-induced leg ischaemia with vasodilator function of the clinically unaffected brachial artery over the course of 4 hours. Thirty male patients with symptomatic PAD and 14 age- and sex-matched healthy controls were included in the study. They performed a treadmill exercise until intolerable exercise-induced ischaemic pain occurred in the affected lower extremity, or for at most 10 min. Flow-mediated dilation (FMD) of the brachial artery was measured at baseline, 30 minutes, 2 hours and 4 hours after exercise. Baseline FMD values were significantly diminished in patients (7.03 +/- 1.99% vs 8.22 +/- 1.60% in controls, p = 0.009). A significant decrease in FMD was observed in patients after exercise (at 30 minutes: 3.92 +/- 1.78% vs 7.03 +/- 1.99% at baseline, p < 0.001; at 2 hours: 6.36 +/- 2.12% vs 7.03 +/- 1.99% at baseline, p = 0.005), followed by a gradual return to its baseline value, whereas FMD in controls non-significantly increased after exercise. The difference in the pattern of FMD change over time between patients and controls was significant (p < 0.001). This study shows that in PAD patients ischaemia during intermittent claudication is related to a transitory functional deterioration of the distant arteries. This indicates the harmful systemic effects of repeated ischaemic attacks during exercise and might explain the generalized and advanced nature of atherosclerotic disease in PAD patients.