Incremental shuttle walk test in the assessment of patients for heart transplantation

Abstract

Objective-To compare the incremental shuttle walk test (ISWT) with treadmill exercise testing (TT) derived measurement of peak oxygen consumption (peak VO 2 ) in patients undergoing assessment for cardiac transplantation. Design-Prospective comparison. All investigations occurred during a single period of admission for transplant assessment. Setting-Single UK cardiothoracic transplantation unit. Patients-25 patients recruited (21 men). Mean age was 53 years. Interventions-Patients underwent two TT of peak VO 2 using the modified Naughton protocol and three (one practice) ISWT. Investigations were performed on consecutive days. Main outcome measures-Main outcome measures were repeatability of TT and ISWT assessments; relation between peak VO 2 and distance walked in the ISWT; and receiver operating characteristic (ROC) analysis to establish a distance walked in the ISWT that predicted which patients would have a peak VO 2 greater than 14 ml/min/kg. Results-Both the ISWT and the TT were highly reproducible. Following the first practice walk, mean (SD) ISWT distances were 400.0 (146) m (ISWT2) and 401.3 (129) m (ISWT3), r = 0.90, p < 0.0001. Mean peak VO 2 by TT was 15.2 (4.4) ml/kg/min (TT1) and 15.0 (4.4) ml/ kg/min (TT2), r = 0.83, p < 0.0001. The results revealed a strong correlation between distance covered in the ISWT and peak VO 2 obtained during TT (r = 0.73, p = 0.0001). ROC analysis showed that a distance walked of 450 m allowed the selection of patients with a peak VO 2 of over 14 ml/min/kg. Conclusions-This work confirms the utility of the ISWT in the assessment of exercise capacity in patients with severe heart failure undergoing assessment for cardiac transplantation. ISWT may provide a widely applicable surrogate measure for peak VO 2 estimation in this population. Shuttle distance walked may therefore allow the convenient, serial assessment of patients with heart failure before referral for transplantation.

Effect of Long-Acting Testosterone Treatment on Functional Exercise Capacity, Skeletal Muscle Performance, Insulin Resistance, and Baroreflex Sensitivity in Elderly Patients With Chronic Heart Failure

“…In a larger placebo-controlled trial, Malkin et al (9) found that a 12-month testosterone replacement therapy improved both distance walked at the shuttle walking test and forearm muscle strength in men with moderately severe CHF. Assessment of exercise capacity by means of effort tolerance tests such as the 6MWT and incremental shuttle walk test is easy to perform, correlates with peak VO 2 , and has been shown to be useful in prognostic stratification (27)(28)(29)(30). However, these assessments do not reflect the overall cardiovascular performance (30) and do not provide any information as to the ventilatory efficiency and cardiopulmonary matching during exercise, which play a relevant pathophysiological and prognostic role in CHF (11,12,30,31).…”

Recommendations on the use of exercise testing in clinical practice

“…In more severe CHF patients, baseline 6-MWT distance was a strong independent predictor of mortality and hospitalisation at 1 yr [235]. The feasibility of the SWT for selection for heart transplantation has been documented; a distance of .450 m equates to a V9O 2 ,peak for treadmill walking .14 mL?min -1 ?kg -1 [236].…”

The effects of supervised exercise training 12–24 months after bariatric surgery on physical function and body composition: a randomised controlled trial

“…Patients performed a practice ISWT beforehand to minimise the influence of learning effects. Participants were asked to walk for as long as possible until reaching test termination criteria while the assessor recorded the total number of shuttles performed 13 . The ISWT has been validated against VO 2 max and VO 2 peak in clinical populations 14 .…”