Is the Two-minute Step Test an Alternative to the Six-minute Walk Test in Pulmonary Hypertension?

Pulmonary hypertension (PH) is a progressive cardiopulmonary disorder characterized by elevated pulmonary artery pressure, which can lead to right ventricular dysfunction and ultimately heart failure. Right heart catheterization is used to diagnose the disease, and individuals are diagnosed with PH when the mean pulmonary artery pressure is 20 mmHg or higher. Exercise intolerance is one of the key features of PH. The 6-minute walk test (6MWT) is the most commonly used test method in PH centers for assessing functional exercise capacity and plays a key role in the evaluation and management of PH. However, it has significant limitations in this context. Although the 6MWT is currently recommended for assessing functional exercise capacity independently of the environment, it is not feasible in most clinics, homes, and medical offices due to the requirement for a 30-meter-long corridor. The long-standing need for a practical and effective exercise assessment tool that is independent of physical space highlights the need for new methods to assess functional capacity. The 2-minute walk test was developed by Rikli and Jones in 1999. The test requires individuals to stand and step in place as quickly as possible for 2 minutes while raising their knees to a height between the patella and iliac crest. Performance in the test is defined as the number of steps taken on the right side within 2 minutes, reaching the criterion height. The validity and reliability of the 2-minute step test have previously been investigated in patients with back pain, cardiopulmonary rehabilitation patients, and hypertensive geriatric patients. The aim of this study is to evaluate the validity of the 2-minute step test in assessing functional capacity in PH.