Cardiopulmonary exercise testing in the evaluation of high risk patients with lung cancer

Background It is still unclear whether pulmonary function tests (PFTs) are sufficient for predicting perioperative risk,and whether all patients or only a subset of them need a cardiopulmonary exercise test (CPET) for further assessment.Thus,this study was designed to evaluate the CPET and compare the results of CPET and conventional PFTs toidentify which parameters are more reliable and valuable in predicting perioperative risks for high risk patients withlung cancer.Methods From January 2005 to August 2008,297 consecutive lung cancer patients underwent conventional PFTs(spirometry + single-breath carbon monoxide diffusing capacity of the lungs (DLCOsb) for diffusion capacity) and CPETpreoperatively.The correlation of postoperative cardiopulmonary complications with the parameters of PFT and CPETwas retrospectively analyzed using the chi-square test,independent sample t test and binary Logistic regressionanalysis.Results Of the 297 patients,78 did not receive operation due to advanced disease stage or poor cardiopulmonaryfunction.The remaining 219 underwent different modes of operations.Twenty-one cases were excluded from this studydue to exploration alone (15 cases) and operation-related complications (6 cases).Thus,198 cases were eligible forevaluation.Fifty of the 198 patients (25.2%) had postoperative cardiopulmonary complications.Three patients (1.5%)died of complications within 30 postoperative days.The patients were stratified into groups based on VOmax/pred(≥70.0%,<70.0%);VOmax·kg·min(≥20.0 ml,15.0-19.9 ml,<15.0 ml) and FEV1 (≥2.0 L,1.2-1.99 L,<1.2 L),respectively.The rate of postoperative cardiopulmonary complications was significantly higher in the group withVOmax/pred<70.0% or VOmax·kg·min<15.0 ml or FEV1<1.2 L than that in the group with VOmax/pred≥70.0% orVOmax·kg·min≥15.0 ml or FEV1≥1.2 L,respectively.Logistic regression analysis revealed that postoperativecardiopulmonary complications were significantly correlated with age,comorbidities,and poor PFT and CPET results.Conclusions FEV1 in spirometry,VOmax·kg·minand VOmax/pred in cardiopulmonary exercise tests can all beused to stratify the patients’ cardiopulmonary function status and to predict the risk of postoperative cardiopulmonarycomplications for the high risk patients with lung cancer.FEV1 and VOmax·kg·minare better than VOmax/pred inpredicting perioperative risk.If available,cardiopulmonary exercise testing is strongly suggested for high-risk lung cancerpatients in addition to conventional pulmonary function tests,and both should be combined to assess cardiopulmonaryfunction status.