Exercise capacity and Doppler pressure measurements in symptomatic peripheral arterial obstructive disease

Doppler pressure measurements are a useful diagnostic tool in peripheral arterial obstructive disease. The aim of our study was to determine whether these pressure values do predict the degree of impairment of the walking capacity in symptomatic patients.

We compared the claudication distances (CDI: initial claudication distance, CDA: absolute claudication distance) of 939 patients (63 +/- 11 years) with stable intermittent claudication (Fontaine IIb) with the ankle pressure values at rest (APR) and after exercise (APE), with the ankle/brachial pressure index at rest (ABIR) and after exercise (ABIE), and with the ratio (ABIRATIO = ABIE/ABIR). Ankle systolic pressures were obtained using an 8 MHz Doppler probe. CD was measured by a treadmill test at constant-load conditions (3 km/hr; inclination 12%). Brachial systolic pressures were obtained using an automated blood pressure monitor. The values of the objectively worse leg were correlated with CDI and CDA.

Low Doppler pressure values were not accompanied by significantly shorter walking distances in symptomatic patients. The resting pressure values (APR, ABIR) did not correlate with the claudication distances (CDI: 54 +/- 31 m; CDA: 87 +/- 41 m). For the exercise values (APE, ABIE), even a very slight inverse correlation with the claudication distances was found. In addition, the correlation between the pressure index ratio and the walking distances (ABIRATIO vs. CDI: r = -0.25, p < 0.01; ABIRATIO vs. CDA: r = -0.20, p < 0.01) was inverse, too, but slightly more pronounced.

In patients with intermittent claudication the ankle artery pressures and the indices derived from these pressure values do not predict the walking distance. Therefore, the decision for angioplasty or bypass surgery should be made with regards to the impairment of quality of life rather than Doppler pressure values.