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

Background and Objectives: The six-minute walk test (6MWT) is widely used to assess functional capacity in chronic heart failure (CHF) but is limited by space and logistics. The two-minute step test (2MST) is a practical alternative. This study aimed to determine an optimal 2MST cut-off for reduced functional capacity and compare its responses with the 6MWT. Methods: In this cross-sectional study, 60 clinically stable patients with CHF (mean age 51.45±12.65 years; 77% male) completed the 2MST, 6MWT, and quadriceps maximal voluntary contraction assessments. Physiological and perceptual responses were recorded at baseline, immediately after, and five minutes post-test. Receiver operating characteristic analysis determined the optimal 2MST cut-off. Adjusted regression examined functional associations, and responses were compared between tests. Results: A 2MST cut-off of ≥94 steps showed good discrimination for reduced functional capacity (area under the curve, 0.82; 95% confidence interval, 0.71-0.92; sensitivity, 82.9%; specificity, 64.0%). In adjusted analyses, the cut-off remained independently associated with greater six-minute walk distance and lower post-exercise leg fatigue (p=0.001), but not with quadriceps strength. Compared with the 6MWT, the 2MST induced greater post-exercise leg fatigue (p<0.001), while other cardiorespiratory and perceptual responses were similar (p>0.05). Conclusions: The 2MST is a safe and feasible submaximal test for assessing functional capacity in CHF. A 94-step cut-off may help identify patients with reduced functional capacity, particularly when corridor-based testing is not feasible.