Rapid Submaximal Cardiopulmonary Exercise Testing in Older Adults Undergoing Noncardiac Surgery: Workflow Integration, Acceptability, and Physiologic Characterization in an Expanded Cohort

Background: Accurate preoperative assessment of functional capacity is important, yet self-reported activity and questionnaire-based estimates may not reliably reflect physiologic exercise capacity in older adults. We evaluated rapid submaximal cardiopulmonary exercise testing (smCPET) as a practical objective means of characterizing exercise capacity. Methods: In this single-center expanded cohort study, adults 60 yr or older presenting for noncardiac surgery completed a 6-min smCPET with breath-by-breath gas-exchange analysis. Participants completed the Duke Activity Status Index and modified Veterans Specific Activity Questionnaires, permitting comparisons of functional capacity estimates with smCPET measures. Process outcomes included recruitment (25% or greater of eligible participants), perceived exertion (Borg 3 or less), satisfaction with scheduling/task (1 to 10), adverse events, and session duration (20 min or lesser). Results: Among 265 enrolled participants, 226 (85%) yielded usable gas-exchange data. Median age was 70 yr (interquartile range [IQR]: 66 to 75) and 44.2% were female. Incompletions reflected participant (n = 22) or surgery cancelations (n = 8); technical/operator errors were uncommon (device: n = 2, operator: n = 3). Enrollment approached recruitment thresholds (24.6%, 95% CI, 22.0 to 27.2%). Sessions were a median of 18 min (IQR, 14.2 to 20). Perceived exertion was low (Borg median [IQR]: 2 [1 to 2]) and not correlated with peak ( r = −0.05, P = 0.46). Most participants reported tolerable exertion (Borg ≤ 3: 218/226 (96.4%), 95% CI, 92 to 98%); 75% reported light-to-moderate exertion (2 or lesser). Satisfaction was high (scheduling: 8 or greater/10 [98.6%] [223/226; 95% CI, 94 to 99%], task performance: 8 or greater/10 [97.7%] [221/226; 95% CI, 93 to 99%]). Despite all participants reporting the ability to climb two flights of stairs, smCPET identified substantial interindividual variability between self-reported and measured functional capacity. Conclusions: In older noncardiac surgical candidates, rapid smCPET was safe, well accepted, and operationally compatible with preoperative clinic workflow. Favorable self-reported functional status did not reliably reflect objectively measured exercise capacity. Whether smCPET provides incremental prognostic value beyond established tools remains to be determined in larger outcome-focused studies.