Abnormal cardiovascular response to exercise in patients with peripheral arterial disease: Implications for management

Exercise is beneficial in improving claudication and functional capacity in patients with peripheral arterial disease (PAD). However, the physiologic response during and after exercise testing in this patient population has not been fully described. This study examined the cardiovascular response to exercise and explored the potential contribution of vascular noncompliance to exercise-induced hypertension in 124 patients with PAD and claudication and 31 comparison (C) patients with PAD with no walking limitations. Maximal walking distance was determined by an exercise treadmill test. Heart rate and blood pressure were monitored before, during, and immediately after an exercise test. Vascular compliance of the small and large vessels was measured using pulse waveform analysis. Individuals with low supine resting heart rate had longer pain-free walking distance (r = -0.195, P = .019) and maximal walking versus the C group (62 beats/min, standard deviation [SD] = 10, P = .02). Systolic blood pressure during supine rest was significantly lower for the PAD group (mean = 141 mm Hg, ± SD = 22) versus the C group (mean = 153 mm Hg, ± SD = 20, P = .003). Vascular compliance of large vessels was higher in the C group (mean = 4.13 ± 4.13 mL/mm Hg × 100) compared with the PAD group (mean = 2.95 ± 1.6 mL/mm Hg × 100). This study describes the exaggerated exercise cardiovascular response and impaired vascular compliance in patients with PAD. These results provide further evidence supporting the importance of a monitored treadmill exercise test before initiation of an exercise program to ensure safe and accurate exercise recommendations, and to identify individuals that require more intensive pharmacotherapy to prevent exercise-induced hypertension and tachycardia.