Association Between Frailty Scoring and Cardiopulmonary Exercise Testing: A Retrospective Cohort Study

Introduction: Cardiopulmonary exercise testing (CPET) is the gold-standard assessment of functional capacity and predicts postoperative outcomes in major abdominal and thoracic surgery, as well as in older individuals undergoing elective surgery for colorectal cancer. However, CPET is resource-intensive and not universally available. Simpler objective assessments of functional capacity, such as Clinical Frailty Scale (CFS) scoring, predict postoperative complications and may be useful in aiding shared decision and perioperative planning. Objectives: This study aimed to assess local cohort data and investigate the association between Clinical Frailty Scoring, CPET outcomes, and length of hospital stay. Methods: We conducted a retrospective cohort analysis of all patients who had received a cardiopulmonary exercise test as part of their preoperative assessment for major abdominal and thoracic surgery between May 2018 and December 2022 in four district general hospitals. Results: This study featured 174 patients, age 73 (mean), CFS 3 (mean), who underwent CPET with associated CFS scoring. The CFS scores were weakly correlated with the anaerobic threshold, VO2 peak, and ventilatory equivalents, coefficients measuring −0.34, −0.36, and 0.31 (all p < 0.001), respectively. Linear regression demonstrated a negative coefficient for the association of CFS with the VO2 peak and the AT, measuring −1.22 and −1.70, respectively, both p < 0.001. The CFS score was not predictive of 1-year mortality in this group. In a subgroup analysis (n = 59), there was no association between the CFS score and the length of stay. Conclusions: Our data suggest a weak relationship between the CFS score and the CPET results. Further investigations with larger prospective datasets are required to explore the use of CFS as a surrogate for CPET and its use as an independent predictor for perioperative outcomes. This study supports the limited literature available on this subject.