Evaluation of the one-minute exercise test to detect peripheral arterial disease

Background   Asymptomatic peripheral arterial disease (PAD) is common amongst the elderly and is a risk factor for cardiovascular morbidity and mortality. PAD can be assessed by non-invasive tests such as the ankle/brachial pressure index (ABPI) at rest and Doppler flow velocity (DFV) scanning, but these tests may underestimate the prevalence of PAD. The aim of this study was to estimate the added value, for the detection of PAD, of the one-minute exercise test, defined as positive if the drop of the ankle systolic pressure was more than 30 mmHg. We also investigated whether the combination of the ABPI at rest and the one-minute exercise test could replace DFV scanning. Materials and methods   We studied this in a random sample (n = 631) of a 50- to 75-year-old population. Results   Of these subjects 11% (66/631) had an abnormal ABPI (< 0·9) and 16% (102/631) had an abnormal DFV curve. Of this sample 72% of the subjects performed a one-minute exercise test. Of all subjects 6% (27/451) had an abnormal ABPI (< 0·9) and 12% (54/451) had an abnormal DFV curve. The one-minute exercise test revealed seven cases of PAD (beyond the 67 already identified) which were not detected by an abnormal ABPI at rest and/or DFV scanning. As a result the prevalence of PAD increased by 2%. All patients with an aortoiliac or femoropopliteal obstruction had an ABPI at rest < 0·9. The sensitivity of the combination of the ABPI at rest and the one-minute exercise test to detect abnormal DFV curves was low for crural obstructions. Conclusion   The one-minute exercise test slightly improves the detection of peripheral arterial disease in the general population.