Exercise treadmill test is one of the functional endpoints that CPC’s Endpoint Quality Intervention Program (EQuIP®) has a proven track record of successfully standardizing.

The exercise treadmill test (ETT) is the most rigorous evaluation of maximal walking ability and considered the gold standard test used in therapeutic trials for peripheral artery disease (PAD) and other cardiovascular diseases.

In particular, a graded ETT can effectively study a wide, dynamic range of exercise limitations and provides a consistent and controlled workload environment. Unlike time-limited exercise assessments, the peak walking time from an ETT can represent a true assessment of maximal physiologic performance. ETT is also a good surrogate for an individual’s day-to-day ambulatory function and quality of life.

Despite its advantages, an ETT is only accurate and reproducible if consistently and properly conducted across all sites.


Key challenges that introduce variability into ETT results were first identified by CPC in 2005:

Sites with Issues (%)

Hiatt WR1, Cox L, Greenwalt M, Griffin A, Schechter C. Quality of the assessment of primary and secondary endpoints in claudication and critical leg ischemia trials. Vasc Med. 2005 Aug;10(3):207-13.

CPC’s EQuIP® was specifically developed to decrease or eliminate these challenges. Reduced variability translates into more definitive signals thereby decreasing trial sample sizes and costs. EQuIP® has been successfully managing endpoint variability for more than a decade.

Learn more about CPC’s work with ETTs in clinical trials:

Eric P Brass, Jenny Jiao and William Hiatt. Optimal assessment of baseline treadmill walking performance in claudication clinical trials. Vascular Medicine 2007; 12: 97–104

Hiatt WR, Regensteiner JG, Creager MA, Hirsch AT, Cooke JP, Olin JW, Gorbunov GN, Isner J, Lukjanov YV, Tsitsiashvili MS, Zabel’skaya TJ, Amato T.  Propionyl-L-carnitine improves exercise performance and functional status in patients with claudication.  Am J Med. 2001;110:616-622.

Mohler ER, Hiatt WR, Gornik HL, Kevil CG, Quyyumi A, Haynes WG and Annex BH. Sodium nitrite in patients with peripheral artery disease and diabetes: Safety, walking distance and endothelial function. Vascular Medicine 2014;19:9-17. PMID:24363302

Brass EP, Anthony R, Cobb FR, Koda I, Jiao J, and Hiatt WR. The Novel Phosphodiesterase Inhibitor NM-702 Improves Claudication-Limited Exercise Performance in Patients With Peripheral Arterial Disease.  J Am Coll Cardiol, 2006;48:2539-2545

Emile R Mohler, III, John L Gainer, Kim Whitten, Luis H Eraso, Porama Koy Thanaporn, and Timothy Bauer. Evaluation of trans sodium crocetinate on safety and exercise performance in patients with peripheral artery disease and intermittent claudication. Vascular Medicine 2011 Oct; 16(5): 346–353

Hiatt WR, Nawaz D, Regensteiner J, Hossack K. The evaluation of exercise performance in patients with peripheral vascular disease. J Cardiopulmonary Rehabil 1988;12:525-32