Implementation of Brief Submaximal Cardiopulmonary Testing in a High-Volume Pre-surgical Evaluation Clinic: A feasibility study.

Background: Precise functional capacity assessment is a critical component for preoperative risk stratification. Brief submaximal cardiopulmonary exercise testing (smCPET) has shown diagnostic utility in various cardiopulmonary conditions. Objective: The objective of this study was to determine if smCPET could be implemented in a high-volume pre-surgical evaluation clinic, and, when compared to structured functional capacity surveys, if smCPET could better discriminate low functional capacity (<4.6 METs). Measured endpoints were: operational efficiency by time of experimental session < 20 minutes, modified Borg survey of perceived exertion of <7 indicating no more than moderate exertion, high participant satisfaction with smCPET task execution, represented as a score of >8 (of 10), and high participant satisfaction with smCPET scheduling, represented as a score of >8 (of 10). Methods: After institutional approval, 43 participants presenting for noncardiac surgery who met the following inclusion criteria: age > 60 years old, revised cardiac risk index of <2, and self-reported metabolic equivalents (METs) of >4.6 (self-endorsed ability to climb 2 flights of stairs), were enrolled. Subjective METs, Duke Activity Status Index (DASI) surveys, and a 6-minute smCPET trial were performed. Student's t test was used to determine significance of the secondary endpoint. Correlation between comparable structured survey and smCPET measurements were assessed using Pearson's correlation coefficient. A Bland-Altman analysis was used to assess agreement between methods. Results: Session time was 16.9 minutes (±6.8). Post-test modified Borg survey was 5.35 (±1.8). Median (IQR) patient satisfaction [on a scale of 1 (worst) to 10 (best)] was 10 (10,10) for scheduling and 10 (9, 10) for task performance. Subjective METs were higher, when compared to smCPET equivalent (extrapolated peak METs) [7.6 (±2.0) vs. 6.7 (±1.8), df 42, P<.001]. DASI-estimated peak METs was higher when compared to smCPET peak METs [8.8 (±1.2) vs. 6.7 (±1.8), df 42, P<.001]. DASI-estimated peak VO2 was higher than smCPET peak VO2 [30.9 ml.kg-1.min-1 (±4.3) vs. 23.6 ml.kg-1.min-1 (±6.5), df 42, P<.001]. Conclusions: Implementation of smCPET in a pre-surgical evaluation clinic is both patient-centered and clinically feasible. Brief smCPET measures, supportive of published reports regarding low sensitivity of provider-driven or structured survey measures for low functional capacity, were lower than structured surveys. Future studies will analyze prediction of perioperative complications and cost effectiveness. Trial Registration: ClinicalTrials.gov NCT05743673. https://clinicaltrials.gov/study/NCT05743673.