Role of conventional pulmonary function tests and cardiopulmonary exercise test in the prediction of postoperative cardiopulmonary complications in high risk thoracic cancer patients

Abstract

To evaluate and compare the value of cardiopulmonary exercise test and conventional pulmonary function tests in the prediction of postoperative cardiopulmonary complications in high risk patients with chest malignant tumors. From January 2006 to January 2009, 216 consecutive patients with thoracic malignant tumors underwent conventional pulmonary function tests (PFT, spirometry + DLCOsb for diffusion capacity) and cardiopulmonary exercise test (CPET) preoperatively. The correlation of postoperative cardiopulmonary complications with the parameters of PFT and CPET were retrospectively analyzed using Chi-square test, independent sample t-test and logistic regression analysis. The P value < 0.05 was considered as statistically significant. Of the 216 patients, 57 did not receive operation due to advanced stage diseases or poor cardiopulmonary function in most of them. The remaining 159 underwent different modes of operations. Thirty-six patients (22.6%) in this operated group had postoperative cardiopulmonary complications and 10 patients (6.3%) developed operation-related complications. Three patients (1.9%) died of the complications within 30 days postoperatively. The patients were stratified into groups based on V(O(2)) max/pred (≥ 65.0%, < 65.0%); V(O(2)) max×kg(-1)×min(-1) (≥ 20 ml, 15 - 19.9 ml, < 15 ml) and FEV1 (≥ 2.0 L, 1.2 - 1.99 L, < 1.2 L) according to the criteria in reported papers. There was statistically significant difference among these groups in the parameters (P < 0.05), the rates of postoperative cardiopulmonary complications were much higher in the groups with poor cardiopulmonary function (V(O(2)) max/pred < 65.0%; V(O(2)) max×kg(-1)×min(-1) < 15 ml or FEV1 < 1.2 L). It was shown by logistic regression analysis that postoperative cardiopulmonary complications were significantly correlated with age, associated diseases, poor results of PFT or CPET, operation modes and operation-related complications. FEV1 in spirometry, V(O(2)) max×kg(-1)×min(-1) and V(O(2)) max/pred in cardiopulmonary exercise test can be used to stratify the patients' cardiopulmonary function status and is correlated well with FEV1. V(O(2)) max×kg(-1)×min(-1) is the best parameter among these three parameters to predict the risk of postoperative cardiopulmonary complications in patients with chest malignant tumors and borderline cardiopulmonary function.