Cardiopulmonary Exercise Testing Versus Frailty, Measured by the Clinical Frailty Score, in Predicting Morbidity in Patients Undergoing Major Abdominal Cancer Surgery

Abstract

The primary outcome of this study is to investigate the association between the cardiopulmonary exercise testing (CPET) variables: anaerobic threshold (AT), peak oxygen uptake (VO2 peak), peak work rate (WR), ventilatory equivalence of CO2 (VE/VCO2) at the anaerobic threshold (AT) with frailty, measured by the clinical frailty scale (CFS) in patients planned to undergo major abdominal cancer surgery. The secondary outcome is to compare the CPET variables (VO2 peak, peak WR, VE/VCO2 at AT) with frailty measured by the CFS in predicting postoperative surgical morbidity in patients following major abdominal cancer surgery. This study was a single-centre prospective cohort analysis of consecutive adult patients undergoing CPET and CFS scoring as part of their pre-operative work-up for major abdominal cancer surgery. A total of n = 317 patients underwent CPET and CFS assessment ahead of planned abdominal oncological surgery. Negative correlations were observed between the CPET variables: AT - 0.42 p < 0.01; VO2 peak - 0.53 p < 0.01; peak WR - 0.54 p < 0.01 with CFS scores and a positive correlation betweenCFS scoresand VE/VCO2 0.29 p < 0.01. Only CFS remained statistically significant in a multivariate model OR 2.11 (1.42-3.15) 95% CI associated with Clavien-Dindo (CD) ≥ 1 defined morbidity including the significant univariate variables (VO2 peak, peak WR and CFS scores). No variables were associated with CD ≥ 3 morbidity. In patients scheduled to have major abdominal cancer surgery there was a weak association between poor performance on CPET and increasing frailty measured by the CFS. The CFS score unlike CPET was associated with all post-operative morbidity, but not major complications alone, in these patients. This suggests that CFS may be used as a less expensive alternative to CPET for predicting any postoperative morbidity in major abdominal cancer surgery.