The value of treadmill exercise test parameters together in patients with known or suspected peripheral arterial disease

Background: Exercise test parameters (exercise ankle brachial index (ABI), walking distance and blood pressure response) separately are associated with long-term outcome in patients with known or suspected peripheral arterial disease (PAD). However, the clinical value of the combination of these parameters together is unknown.

Methods: 2165 patients performed a treadmill exercise test to diagnose or to evaluate their PAD. Resting ABI, exercise ABI, abnormal blood pressure response (hypotensive and hypertensive) and walking distance (impairment <150 m) were measured. The study population was divided into patients with a resting ABI ≥ 0.90 and patients with PAD (resting ABI < 0.90).

Results: The mean follow-up period was 5 years (0.5–14 years). Long-term mortality rate and risks increases when more exercise parameters became abnormal (p-value = 0.001). Patients with a normal resting ABI but with an abnormal exercise test had a higher mortality risk – HR 1.90 (1.32–2.73) – than patients with a normal exercise test. The highest mortality risk and cardiac death was observed in PAD patients with a walking impairment together with an abnormal blood pressure response – HR 3.48 (2.22–5.46).

Conclusion: Exercise tests give multiple parameters, which together provide important prognostic information on long-term outcome in both patients with normal resting ABI and PAD.