Maximal Exercise Testing Using the Incremental Shuttle Walking Test Can Be Used to Risk-Stratify Patients with Pulmonary Arterial Hypertension

Abstract

Rationale: Exercise capacity predicts mortality in pulmonary arterial hypertension but limited data exist on the routine use of maximal exercise testing. Objectives: This study evaluates a simple to perform maximal test, the incremental shuttle walking test, and its utility in risk stratification in pulmonary arterial hypertension (PAH). Methods: Consecutive patients with pulmonary hypertension were identified from the ASPIRE registry (2001-2018). Thresholds for levels of risk were identified at baseline, tested at followup and incorporation into current risk stratification approaches assessed. Results: Of 4524 treatment-naïve patients with pulmonary hypertension who underwent maximal exercise testing 1,847 patients had PAH. A step-wise reduction in one-year-mortality was seen between levels 1 (≤30m; 32% mortality) and 7 (340-420m; 1% mortality) with no mortality for levels 8-12 (≥430m) in idiopathic and connective tissue disease related PAH. Thresholds derived at baseline of ≤180m (>10%; high-risk), 190-330m (5-10%; intermediaterisk) and ≥340m (<5%; low-risk of one-year mortality) were applied at follow-up and also accurately identified levels of risk. Thresholds were incorporated into the REVEAL 2.0 risk score calculator and French low-risk approach to risk stratification and distinct categories of risk remained. Conclusion: We have demonstrated that maximal exercise testing in PAH stratifies mortalityrisk at baseline and follow-up. This study highlights the potential value of the incremental shuttle walking test as an alternative to the 6-minute-walk-test, combining some of the advantages of maximal exercise testing whilst maintaining the simplicity of a simple to perform field test.

2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension

“…The ISWT has a potential advantage over the 6MWT in that it does not have a ceiling effect; furthermore, it keeps the simplicity of a simple-to-perform field test, in contrast to CPET. However, the ISWT experience in PAH is currently limited [258].…”

Pulmonary Hypertension and Measurement of Exercise Capacity Remotely: Evaluation of the 1-min Sit-to-Stand Test (PERSPIRE) – a cohort study

“…Based on these values, assuming a Type I error rate of 0.05 and Type II error rate of 0.2, a sample size between n=22 (r=0.5) and n=15 (r=0.6) was indicated [ 16 ]. To capture participants with a range of exercise capabilities, a stratified sample was selected across three bands of ISWT distance: ≤180, 190–330 and ≥340 m [ 5 ]. To accommodate this, a total sample of 75 was sought, with a minimum of 22 participants in each of the three ISWT bands.…”

“…[17] To capture participants with a range of exercise capabilities, a stratified sample was selected across three bands of ISWT distance: ≤ 180m, 190m -330m, ≥ 340m. [6] To accommodate this, a total sample of 75 was sought, with a minimum of 22 participants in each of the three ISWT bands.…”

“…[2] A number of risk assessments exist -all include measures of World Health Organisation functional class (WHO-FC), exercise capacity and right ventricular function. Hospital-based objective measures of exercise capacity used in risk assessment in PAH include the sub-maximal 6-minute walking test (6MWT) [5] and maximal tests including the Incremental Shuttle Walk Test (ISWT) [6] and cardiopulmonary exercise testing (CPET). [7] In CTEPH, data has also shown that the 6MWT can be used in the risk assessment of patients.…”

Telehealth: A winning weapon to face the COVID-19 outbreak for patients with pulmonary arterial hypertension

“…Being a maximal test and do not suffering from the “ceiling effect”, the ISWT allows better assessment in patients with less severe symptomatic disease who have high baseline walk distance, as younger patients [ 44 ]. Recent finding demonstrated that in PAH the ISWT distance correlates with hemodynamic parameters, predicts survival [ 45 ] and stratifies mortality risk at baseline and follow-up [ 46 ]; The smartphone-based self-administered 6MWT (SA-6MWTapp), simple and easy to use. An instructional video describes the proper conduct of the test.…”