Functional capacity in cardiac patients: Association of 6-MINUTE walk test and 2-MINUTE walk test with ejection fraction and age

Abstract Background and Aims Functional capacity is an important clinical indicator in cardiovascular disease. The 6-Minute Walk Test (6MWT) is widely used, while the 2-Minute Walk Test (2MWT) has emerged as a simpler alternative. Its relationship with clinical parameters and diagnostic performance remains unclear. To evaluate the association of 6MWT and 2MWT with ejection fraction (EF) and age, and to determine the diagnostic performance of 2MWT. Methods A cross-sectional study was conducted in 180 cardiac patients. Data included age, EF, and walking distances from 6MWT and 2MWT. Correlations were analyzed using Pearson test. Functional capacity was defined as 6MWT >240 m. ROC analysis assessed 2MWT performance. Results Mean age was 58.83 ± 9.96 years and EF 49.54 ± 12.40%. Age showed a significant negative correlation with 6MWT (r = -0.222; p = 0.003) and 2MWT (r = -0.208; p = 0.005). EF showed a weak correlation with 2MWT (r = 0.149; p = 0.046) and no significant correlation with 6MWT. A strong correlation was found between 6MWT and 2MWT (r = 0.741; p < 0.001). ROC analysis showed excellent discrimination (AUC = 0.898), with an optimal cut-off of 91 m (sensitivity 88.3%, specificity 88.5%). Conclusion Age is associated with functional capacity, while EF shows limited correlation. The 2MWT demonstrates excellent accuracy and may serve as a practical alternative to 6MWT.Figure 1.Factors Affecting Functional Capacity (6MWT & 2MWT) in Cardiac Patients (N = 180) Top row: Scatter plots for Age vs 6MWT, EF vs 6MWT, and EF vs 2MWT with regression lines. Middle row: Age vs 2MWT, 6MWT vs 2MWT correlation, and ROC curve for 2MWT predicting functional capacity. Bottom: Forest plot of Pearson's r for all variable pairs. Red = p < 0.05. Regression lines: red = significant (p < 0.05), gray = not significant.