Minute ventilation-to-carbon dioxide slope is associated with postoperative survival after anatomical lung resection

Objectives The aim of the study was to identify whether ventilation-to-carbon dioxide output (VE/V CO2) slope obtained from cardiopulmonary exercise test (CPET) as part of the preoperative functional workup was an independent prognostic factor for short and long-term survival after major lung resection. Patients and methods 974 consecutive patients undergoing lobectomy (n = 887) or segmentectomy (n = 87) between April 2014 to March 2018 were included. 209 (22%) underwent CPET, and pulmonary function tests and several clinical factors including age, sex, performance status and comorbidities were retrospectively investigated to identify the prognostic factors with a multivariable Cox regression analysis. Results Among the patients with measured VE/V CO2, the incidence of cardiopulmonary complications in patients with high VE/V CO2 slope (>40) was 37% (19 of 51) vs. 27% (33 of 121) in those with lower slope values (p = 0.19). The 90-day mortality in patients with high VE/V CO2 slope (n = 8) was 16% vs. 5% (n = 6) in those with lower slope values (p = 0.03). No overall difference in 2-year mortality was identified between the two groups (VE/VCO2 > 40: 70% (54–80) vs. VE/VCO2 ≤ 40: 72% (63–80), log-rank test, p = 0.39). In a Cox regression analysis VE/VCO2 values were associated with poorer 2-year survival (HR 1.05, 95% CI 1.01–1.10, p = 0.030). Conclusions We found that VE/V CO2 slope was an independent prognostic factor for the 90-day mortality and 2-year survival after anatomic pulmonary resection. This finding may assist during the multidisciplinary treatment decision-making process in high-risk patients with lung cancer.