Cardiopulmonary Exercise Testing in a Prospective Multicenter Cohort of Older Adults

Abstract

ABSTRACT Purpose Cardiorespiratory fitness (CRF) measured by peak oxygen consumption (V̇O2 peak) declines with aging and correlates with mortality and morbidity. Cardiopulmonary exercise testing (CPET) is the criterion method to assess CRF, but its feasibility, validity, and reliability in older adults are unclear. Our objective was to design and implement a dependable, safe, and reliable CPET protocol in older adults. Methods V̇O2 peak was measured by CPET, performed using treadmill exercise in 875 adults ≥70 yr in the Study of Muscle, Mobility and Aging (SOMMA). The protocol included a symptom-limited peak (maximal) exercise and two submaximal walking speeds. An adjudication process was in place to review tests for validity if they met any prespecified criteria (V̇O2 peak <12.0 mL·kg−1·min−1; maximum heart rate <100 bpm; respiratory exchange ratio <1.05 and a rating of perceived exertion <15). A subset (N = 30) performed a repeat test to assess reproducibility. Results CPET was safe and well tolerated, with 95.8% of participants able to complete the V̇O2 peak phase of the protocol. Only 56 (6.4%) participants had a risk alert and only two adverse events occurred: a fall and atrial fibrillation. Mean ± SD V̇O2 peak was 20.2 ± 4.8 mL·kg−1·min−1, peak heart rate 142 ± 18 bpm, and peak respiratory exchange ratio 1.14 ± 0.09. Adjudication was indicated in 47 tests; 20 were evaluated as valid and 27 as invalid (18 data collection errors, 9 did not reach V̇O2 peak). Reproducibility of V̇O2 peak was high (intraclass correlation coefficient = 0.97). Conclusions CPET was feasible, effective, and safe for older adults, including many with multimorbidity or frailty. These data support a broader implementation of CPET to provide insight into the role of CRF and its underlying determinants of aging and age-related conditions.