Cardiopulmonary exercise testing for the evaluation of perioperative risk in non-cardiopulmonary surgery

The use of cardiopulmonary exercise testing (CPET) as a preoperative risk stratification tool for a range of non-cardiopulmonary surgery is increasing. The utility of CPET in this role is dependent on the technology being able to identify accurately and reliably those patients at increased risk of perioperative events when compared with existing risk stratification tools. This article identifies and reviews systematically the current literature regarding the use of CPET as a preoperative tool for stratifying risk in major non-cardiopulmonary surgery. Specifically, it focuses on evaluating the capacity of CPET variables to predict the risk of postoperative complications and mortality in comparison to other methods of risk assessment. Furthermore, the potential for combining results from CPET and non-CPET methods of risk prediction to enhance the capacity to identify high risk patients is considered. The review indicates that CPET can identify patients at increased risk of adverse perioperative outcomes. However, the selection of variables and threshold values to indicate high risk differ for different surgical procedures and underlying conditions. Furthermore, the available data suggest that CPET variables outperform alternative methods of preoperative risk stratification. Several studies also identify that CPET variables may be used in combination with non-CPET variables to increase perioperative risk prediction accuracy. These findings illustrate that CPET has the capacity to identify patients at increased risk of adverse outcome before a range of non-cardiopulmonary surgical procedures. Further research is required to optimise its use, potentially by combining CPET results with alternative methods of risk stratification.