Evaluating Exercise Limitation, Gas Exchange Inefficiency and Recurrence Risk in PE Patients by Cardiopulmonary Exercise Testing

Abstract Background Pulmonary embolism (PE) which is a form of venous thromboembolism (VTE) can induce acute symptoms and post-PE syndrome. Cardiopulmonary exercise testing (CPET) can evaluate exercise responses of multiple systems, including respiratory, cardiovascular, hematopoietic and skeletal muscle systems. Methods We retrospectively collected 103 subjects’ data of demographics, hematologics, CT pulmonary angiogram (CTPA), pulmonary function test (PFT) and CPET at Shanghai Pulmonary Hospital from March 2015 to October 2021. The 103 subjects were composed of 10 healthy people as control, 25 patients who had been diagnosed with PE and 68 patients who were diagnosed with PE. The CPET performance differences of the three groups of subjects and subgroups of PE patients divided according to CTPA were analyzed. Spearman correlation test was performed to analyze the correlation between CPET and Blood test parameters of the enrolled subjects. Univariate logistic regression analysis, multivariable cox regression analysis and Kaplan–Meier cumulative survival analysis was used to find CPET parameters for predicting the risk of PE recurrence. Results The exercise tolerance (load @ peak), metabolic capacity (VO2 @ AT, VO2 @ Peak), ventilatory efficiency (VE/VCO2 @ AT, VE/VCO2 @ Peak, OUEP, LOWEST VE/VCO2), gas exchange (PETCO2 @ AT, PETCO2 @ Peak, PETO2 @ AT), and cardiovascular response (VO2/HR) of healthy people, Post-PE and PE subjects were different. The ventilatory efficiency (VE/VO2, VE/VCO2, LOWEST VE/VCO2, OUPE, VE/VCO2 slope), gas exchange (PETO2, PETCO2) of PE subgroups divided according to CTPA were also different. VO2 @ AT (% pred) can be used to predict the risk of PE recurrence. Conclusion CPET is an effective and responsible method for the assessment of pulmonary embolism.