Walking tests during the exercise training: specific use for the cardiac rehabilitation.

Walk tests, principally the six-minute walk test (6mWT), constitute a safe, useful submaximal tool for exercise tolerance testing in cardiac rehabilitation (CR). The 6mWT result reflects functional status, walking autonomy and efficacy of CR on walking endurance, which is more pronounced in patients with low functional capacity (heart failure - cardiac surgery). The 6mWT result is a strong predictor of mortality. However, clinically significant changes and reliability are still subject to debate - probably because of the ambiguity in terms of the target speed (either comfortable or brisk walking). Of the other time-based walk tests, the 2-minute-walk test is the only one applicable during CR, reserved for patients with severe disabilities by its psychometric properties. Fixed-distance tests (principally the 200m fast walk test) and incremental shuttle walking, tests explore higher levels of effort and may represent a safe and inexpensive alternative to laboratory-based tests during CR. These walking tests may be useful for personalizing prescription of training programs. However, the minimum clinically significant difference has not yet been determined. Lastly, walking tests appear to be potential useful tools in promoting physical activity and behavioural changes at home. Thus, validation of other walk tests with better psychometric properties will be necessary.

Reproducibility, validity and responsiveness of the 200-metre fast walk test in patients undergoing cardiac rehabilitation.

OBJECTIVE: To investigate the reliability, validity and responsiveness of the 200-metre fast walk test in patients with coronary artery disease engaged in a cardiac rehabilitation programme. DESIGN: Descriptive study. SETTING: Tertiary care hospital. SUBJECTS: Thirty stable patients with coronary artery disease (51.9 ± 8.7 years), referred to the cardiac rehabilitation department after an acute coronary syndrome. INTERVENTION: Not applicable. MAIN MEASURES: Six-minute walk test distance, time to perform the 200-m fast walk test, peak power output of the graded maximal exercise test, before and after the programme; SF-36 quality of life questionnaire at baseline. Walk tests were performed twice at baseline to assess reliability. RESULTS: The 200-m fast walk test was highly reliable (ICC = 0.97). It was significantly correlated with the graded maximal exercise test peak power and the 6-minute walk test at baseline (r = -0.417; P < 0.05; and r = -0.566; P < 0.01, respectively) and after the training programme (r = -0.460, P < 0.05; and r = -0.926; P < 0.01, respectively). At baseline, there was a strong correlation between the 200-m fast walk test time and the physical component score of the SF-36 (r = -0.77; P < 0.01), but not between the 200-m fast walk test time and the SF-36 mental component score. Mean 200-m fast walk test time was significantly different between the patients performing ≤90 W (n = 11) or ≥100 W (n = 19) at the baseline graded maximal exercise test (121.7 ± 13.6 vs. 115.5 ± 10.1 seconds; P < 0.05). The responsiveness was strong with a standardized response mean at 1.11. CONCLUSION: The 200-m fast walk test is a reliable, valid and responsive high-intensity walk test in patients with coronary artery disease after an acute coronary syndrome. It can thus give additional information to that given by the 6-minute walk test and the graded maximal exercise test.

Rehabilitation in patients with peripheral arterial disease.

Rehabilitation is a recommended first-line therapy for patients with peripheral arterial disease (PAD) and consists of supervised exercise training and therapeutic education. Proved benefits are significant: improve pain-free walking distance, functional status and quality of life; reduce cardiovascular risk factors and mortality. At least three sessions weekly are recommended during 3 months. Exercise conditioning (global training and lower limb resistance training) is tailored by the preliminary evaluation of walking ability (free walking test, treadmill tests, 6-min walk test) and of the cardiac tolerance (maximal effort tests). Then the exercise workload is progressively improved. The four main goals of therapeutic education are: smoking cessation, prolonged physical activity, Mediterranean diet and observing pharmacological therapies. The limited compliance of the patients with PAD is often an obstacle for educational needs. The chronic patients with important functional limitations and unchecked risk factors will be preferentially enrolled in such programs. When a revascularization is discussed, rehabilitation can serve as trial treatment. Despite its efficacy, rehabilitation is still underutilized in clinical practice and should be promoted.

Usefulness of the 6-minute walk test and the 200-metre fast walk test to individualize high intensity interval and continuous exercise training in coronary artery disease patients after acute coronary syndrome: a pilot controlled clinical study.

OBJECTIVE: To study the effects of three individualized exercise training prescriptions using either a percentage of maximal heart rate (HR), maximal 6-minute walk test (6MWT) HR, or maximal 200-metre fast walk test (200-mFWT) HR, on walking performance and exercise capacity in coronary artery disease (CAD) patients. DESIGN: Controlled clinical study. PARTICIPANTS: Twenty-seven outpatients enrolled in a rehabilitation programme after an acute coronary syndrome. SETTING: Cardiac rehabilitation unit. INTERVENTIONS: Three groups: (A): moderate intensity continuous exercise (MICE) at 70% of the maximal HR of the graded maximal exercise test (n = 10); (B): MICE at the maximal 6MWT HR (n = 8); (C): high intensity interval training (HIIT) based on the 6MWT and the 200-mFWT maximal HR (n = 9). Group B and C performed walk tests every 2 weeks, to readjust training HR (THR) if needed. MEASURES: 6MWT and 200-mFWT performances, peak VO(2) and peak power (Pmax). RESULTS: 6MWT and 200-mFWT performances improved significantly and similarly in all groups (P < 0.05). Peak VO(2) improved significantly in all groups (P < 0.05), this improvement being higher in group C (HIIT) versus A (P < 0.05). Group B was closer to the recommended THR during exercise sessions compared to group A. CONCLUSION: This pilot study showed that using the 6MWT and 200-mFWT HR to individualize MICE or HIIT prescription is feasible in CAD patients, and could lead them closer to THR objective, to similar improvements in walking performance, and greater peak VO(2) increase for HIIT. Future randomised studies should investigate long-term effects of programmes prescribed from walk tests HR, especially for HIIT modality.

The 200-m fast-walk test compared with the 6-min walk test and the maximal cardiopulmonary test: a pilot study.

OBJECTIVE: The 200-m fast-walk test has been proposed as a high- intensity performance test in healthy, elderly subjects. Adaptation of low-risk coronary artery disease patients during this test were compared with those in a 6-min walk test and a maximal cardiopulmonary exercise test. DESIGN: Thirty patients with stable coronary artery disease (51.9 +/- 8.7 yrs), referred to the cardiac rehabilitation department, performed a cardiopulmonary exercise test, then a 200-m fast-walk test and a 6-min walk test in a random order, before and after the training period (6 wks, 3 days per week). Heart rate was monitored during each test. Peak workload of cardiopulmonary exercise test, distance walked on the 6-min walk test, and time to perform the 200-m fast-walk test were measured. A subsample of ten patients performed the exercise test with gas exchange measurements, with ventilatory threshold determination. RESULTS: All subjects completed walk tests without complaint or incidents. Compared with the cardiopulmonary exercise test, the cardiac relative intensity was higher during the 200-m fast-walk test than during the 6-min walk test, both before (89.6% vs. 78.1% of cardiopulmonary exercise test maximal heart rate; P < 0.05) and after (83.8% vs. 74.3%; P < 0.05) training. Among the subsample of ten patients, the 200-m fast-walk test heart rate was significantly higher than the ventilatory threshold heart rate, which did not differ from the 6-min walk test heart rate. The 200-m fast-walk test time significantly decreased after training (-9.1%, P < 0.01). CONCLUSION: In patients with coronary artery disease at low risk, the 200-m fast-walk test explores higher levels of cardiorespiratory capacity than the 6-min walk test. Thus, this could be a useful field test in complement to the cardiopulmonary exercise test to assess functional capacity improvement and update training targets regularly during the course of high-intensity rehabilitation programs in this population.