The ventilatory efficiency slope (VE/VCO₂ slope) as a predictor of postoperative cardiopulmonary complications post lung segmentectomy in high-risk patients?

Background The ventilatory efficiency slope (VE/VCO₂) is an established prognostic marker for heart failure and pulmonary hypertension. It has been associated with postoperative risk after major lung resections. However, its predictive value in lung segmentectomy remains unclear. This study aims to assess the relationship between VE/VCO₂ slope and cardiopulmonary complications after segmentectomy, and to determine an optimal predictive threshold. Methods We conducted a retrospective, single-center study including patients over 18 years old, who underwent preoperative CPET before segmentectomy, between 2021 and 2025 in Nice. The primary endpoint was the association between VE/VCO₂ slope and cardiopulmonary complications occurring within 90 days. A subgroup analysis on grade II complications or more was conducted. Results Among 380 segmentectomy candidates, 27 patients with CPET were included (median age 68 years, 52% male, median FEV1 75% predicted). The median peak VO₂ was 16.4 ml/kg/min and median VE/VCO₂ slope was 33.5. Postoperative cardiopulmonary complications occurred in 8 patients (29%). Overall, VE/VCO₂ slope was not significantly different between patients with or without complications (38.0 vs. 33.9; p = 0.26). In subgroup analysis, VE/VCO₂ slope was significantly higher in patients with ≥ grade II complications (38.6 vs. 33.1; p = 0.046). A threshold of VE/VCO₂ ≥38 provided the best predictive performance (sensitivity 80%, specificity 81%, p = 0.02). Conclusion In high-risk patients undergoing segmentectomy, the VE/VCO₂ slope appears sensitive in predicting ≥ grade II complications. A threshold of 38 may be more appropriate. Larger prospective multicentred studies would be required to confirm these results. Trial registration : The Nice University Hospital and the ethical committee approved this retrospective, monocentric study (2025-EI-704, 2025-093, in May 2025)