Evaluation of Physical Capability Using the Two-Minute Step Test in Heart Failure Patients

Area of Science:

• Cardiology
• Exercise Physiology
• Rehabilitation Medicine

Background:

• The six-minute walk test (6MWT) is standard for assessing functional capacity in chronic heart failure (CHF), but has logistical limitations.
• The two-minute step test (2MST) offers a more practical, space-efficient alternative for evaluating functional capacity.

Purpose of the Study:

• To establish an optimal cut-off point for the 2MST to identify reduced functional capacity in patients with CHF.
• To compare the physiological and perceptual responses of the 2MST with the established 6MWT.

Main Methods:

• A cross-sectional study involving 60 stable CHF patients who underwent 2MST, 6MWT, and quadriceps strength assessments.
• Receiver operating characteristic (ROC) analysis was used to determine the optimal 2MST cut-off value.
• Physiological and perceptual responses were recorded pre- and post-exercise, with adjusted regression analyses for functional associations.

Main Results:

• An optimal 2MST cut-off of ≥94 steps demonstrated good discrimination for reduced functional capacity (AUC=0.82).
• This cut-off was independently associated with greater six-minute walk distance and reduced post-exercise leg fatigue.
• The 2MST elicited greater post-exercise leg fatigue compared to the 6MWT, with similar cardiorespiratory responses.

Conclusions:

• The 2MST is a safe and feasible submaximal exercise test for assessing functional capacity in CHF patients.
• A 94-step threshold on the 2MST can aid in identifying individuals with diminished functional capacity, particularly in settings where the 6MWT is impractical.