The maximum heart rate achieved during a 6-minute walk test fell within the target heart rate range derived from an ergometric test in 71.67% of cardiac rehabilitation patients (95% CI 62-79%).
Cross-Sectional (n=120)
Does the maximum heart rate achieved during a 6-minute walk test accurately estimate the target heart rate calculated from an incremental ergometric test in patients undergoing cardiac rehabilitation?
The 6-minute walk test can safely and correctly guide the initial exercise intensity in over 70% of cardiac rehabilitation patients when an ergometric test is unavailable or delayed.
Abstract Abstract In cardiac rehabilitation (CR) programmes, the correct exercise intensity is defined by the target heart rate (THR). After the index event and in conditions of clinical stability, an incremental ergometric test, limited by symptoms (ET) is performed. The THR can therefore be calculated using Karvonen's formula (KF). However, many patients (pts) are referred to CR without first undergoing a ET. Even after the rehabilitation programme has begun, this examination, which requires the presence of a cardiologist, may be delayed for organisational or clinical reasons. The six-minute walk test (6MWT) is a widely validated submaximal exercise test, which rehabilitation therapists can administer independently. The aim of our study is to verify whether information obtained from 6MWT, particularly the maximum heart rate (HR) achieved during the test, can help select the correct training intensity right from the initial stages of rehabilitation. Patient and methods a total of 120 pts (104 male and 16 female; mean age: 61.79 ± 9.89 years) were enrolled in the study and began outpatient CR consecutively between September 2024 and August 2025. A total of 76 pts (63.33% of the sample) had experienced acute coronary syndrome; 28 pts (23.33% of the sample) had undergone cardiac surgery; 14 pts (11.68% of the sample) had heart failure; one pt (0.83% of the sample) had suffered a massive pulmonary embolism; and one pt had obstructive peripheral artery disease (0.83% of the sample). All enrolled pts were eligible to perform both a 6MWT and a ET on a cycle ergometer, with a maximum interval of two weeks between the two tests. Finally, we verified whether the HR achieved at the end of 6MWT fell within THR range calculated using the KF from the ET data. To define the optimal THR, we considered a deviation of ± 5 beats per minute (bpm) to be insignificant. The maximum HR values achieved in the 6MWT that fall within or outside the THR) range, as calculated using the KF, were expressed as absolute numbers and percentages. 95% confidence intervals were also calculated to estimate the extent to which the results obtained from our sample can be generalised. Results our case series shows that 86 pts (71.67%; 95% CI: 62-79%) had a maximum heart rate (HR) at the end of the 6MWT that fell within theTHR range ± 5 bpm, as calculated using the KF from the ET. A maximum HF at the 6MWT below the THR range obtained from the ET was observed in 20 pts (16.67%). Only 14 pts (11.66%) had a maximum HR at 6MWT above the THR range obtained from the ET Conclusions it is possible that the cardiorespiratory fitness may be underestimated due to the selfpaced nature of a 6-MWT. Conversely, some pts may find walking more suitable than cycling. However, our study shows that the 6MWT can drive correctly and safely the first sessions of the CR programme in over 70% of cases. This is especially true when supplemented by another assessment tool, such as the Borg Scale of Perceived Exertion.
Rossini et al. (Mon,) conducted a cross-sectional in Cardiac rehabilitation (n=120). 6-minute walk test (6MWT) vs. Ergometric test (ET) was evaluated on Maximum heart rate at the end of the 6MWT falling within the target heart rate range ± 5 bpm calculated using Karvonen's formula from the ET (95% CI 62-79). The maximum heart rate achieved during a 6-minute walk test fell within the target heart rate range derived from an ergometric test in 71.67% of cardiac rehabilitation patients (95% CI 62-79%).