The Intra-rater and Inter-rater Reliability of measures derived from Cardiopulmonary Exercise Testing (CPET) in patients with Abdominal Aortic Aneurysms (AAA).

Harwood AE; Totty J; Wallace T; Smith GE; Carradice D; Carroll S; Chetter IC;

Annals Of Vascular Surgery [Ann Vasc Surg] 2018 Nov 23. Date of Electronic Publication: 2018 Nov 23.

Introduction: Patients with abdominal aortic aneurysms (AAA) often have low exercise tolerance due to comorbidities and advance age. Cardiopulmonary exercise testing (CPET) is predictive of post-operative morbidity and mortality in patients with AAA. We aimed to assess the intra- and inter-rater reliability of both treadmill and cycle ergometer based CPET variables.
Methods: Patients with a AAA (>3.5cm) were randomised to treadmill or bike CPET. Participants were asked to perform two separate CPET tests seven days apart after a familiarisation protocol. All CPETs were carried out using a ramp cycle or modified Bruce treadmill protocol with breath-by-breath gas analysis.
Results: Twenty-two male and 2 female patients, aged 73.6 ± 6.0, completed the study. Intra-rater analysis (intraclass correlation coefficients) demonstrated high reliability on both the treadmill and bike for VAT (r = 0.834 and r = 0.975, respectively). All other CPET variables demonstrated high intra-rater reliability on both modalities bar the highest point for VE/VO2 on the treadmill (substantial agreement r = 0.755). Further, inter-rater reliability demonstrated high agreement for VAT on both the treadmill and cycle (r = 0.983 and 0.905, respectively). All other CPET variables demonstrated high intra-rater reliability on both modalities, with the exception of VO2PEAK on the cycle ergometer (fair agreement r = 0.400).
Discussion: CPET in AAA patients is reliable on short-term repeat testing patients and between CPET test reviewers for common testing modalities/protocols. These findings provide further support for the use of CPET, especially treadmill walking, as a clinical measure of peri-operative cardiorespiratory fitness in patients with AAA.