The usefulness of the modified steep ramp test as a practical exercise test for preoperative risk assessment in patients scheduled for pancreatic surgery

Background

The widespread implementation of a preoperative assessment of aerobic capacity requires a practical field test. This study investigated the validity of the modified steep ramp test (SRT) for evaluating preoperative aerobic capacity and to evaluate its usefulness for preoperative risk assessment in patients planned for pancreatic surgery.

Methods

Patients scheduled for pancreatic surgery who preoperatively performed cardiopulmonary exercise testing (CPET) and the modified SRT within 14 days were included. To assess its criterion validity, the correlation between the achieved work rate at peak exercise (WR_peak) at the modified SRT and oxygen uptake (VO₂) at peak exercise (VO_2peak) during CPET was determined. To evaluate the ability of the modified SRT to correctly classify patients as fit or unfit, receiver operating characteristic (ROC) analyses were performed based on the CPET VO_2peak cutoff 18.0 ml.kg⁻¹.min⁻¹ and VO₂ at the ventilatory anaerobic threshold (VAT) cutoff 11.0 ml.kg⁻¹.min⁻¹.

Results

Forty-eight patients (21 females) aged 68.7 ± 7.6 years were included. Modified SRT WR_peak (W/kg) demonstrated a very strong correlation with CPET VO_2peak (ρ = 0.865, r = 0.926). The modified SRT WR_peak cutoff to most accurately classify patients as fit or unfit was 2.095 W/kg for the CPET VO_2peak cutoff (area under the curve (AUC) of 0.948) and the CPET VO₂ at the VAT cutoff (AUC of 0.814).

Conclusions

The modified SRT is a valid short-term practical exercise test to preoperatively assess aerobic capacity in patients undergoing pancreatic surgery. A modified SRT performance below 2.1 W/kg seems clinically most suitable to select candidates for further preoperative CPET evaluation and/or prehabilitation, given its positive and negative predictive value.