Cardiopulmonary exercise testing as a predictor of complications in oesophagogastric cancer surgery

Abstract

Introduction: An anaerobic threshold (AT) of <11 ml/min/kg can identify patients at high risk of cardiopulmonary complications after major surgery. The aim of this study was to assess the value of cardiopulmonary exercise testing (CPET) in predicting cardiopulmonary complications in high risk patients undergoing oesophagogastric cancer resection.

Methods: Between March 2008 and October 2010, 108 patients (83 men, 25 women) with a median age of 66 years (range: 38-84 years) underwent CPET before potentially curative resections for oesophagogastric cancers. Measured CPET variables included AT and maximum oxygen uptake at peak exercise (VO2 peak). Outcome measures were length of high dependency unit stay, length of hospital stay, unplanned intensive care unit (ICU) admission, and postoperative morbidity and mortality.

Results: The mean AT and VO2 peak were 10.8 ml/min/kg (standard deviation [SD]: 2.8 ml/min/kg, range: 4.6-19.3 ml/min/kg) and 15.2 ml/min/kg (SD: 5.3 ml/min/kg, range: 5.4-33.3 ml/min/kg) respectively; 57 patients (55%) had an AT of <11 ml/min/kg and 26 (12%) had an AT of <9 ml/min/kg. Postoperative complications occurred in 57 patients (29 cardiopulmonary [28%] and 28 non-cardiopulmonary [27%]). Four patients (4%) died in hospital and 21 (20%) required an unplanned ICU admission. Cardiopulmonary complications occurred in 42% of patients with an AT of <9 ml/min/kg compared with 29% of patients with an AT of ≥9 ml/min/kg but <11 ml/min/kg and 20% of patients with an AT of ≥11 ml/min/kg (p = 0.04). There was a trend that those with an AT of <11 ml/min/kg and a low VO2 peak had a higher rate of unplanned ICU admission.

Conclusions: This study has shown a correlation between AT and the development of cardiopulmonary complications although the discriminatory ability was low.

Figure 1

Flowchart of all patients undergoing cardiopulmonary exercise testing (CPET)

Figure 2

Mean anaerobic threshold (AT) and the presence of complications

Figure 3

Cardiopulmonary complications in each anaerobic threshold (AT) group

Figure 4

Receiver operating characteristic curve for predicting cardiopulmonary complications from anaerobic threshold (AT) and maximum oxygen uptake at peak exercise (VO₂ peak). The diagonal reference line indicates no discrimination.