ObjectiveTo determine the ability of cardiopulmonary exercise testing (CPET) to distinguish chronic thromboembolic pulmonary hypertension (CTEPH) from chronic thromboembolic disease (CTED). MethodsFifty patients diagnosed with CTED and fifty-eight patients with CTEPH in the the First Affiliated Hospital of Guangzhou Medical University from April 2019 to February 2022 were retrospectively included. The basic characteristics including age, gender, body mass index, symptom duration, and N-terminal prohormone of brain natriuretic peptide (NTpro-BNP), parameters of arterial blood gas analysis, right heart catheterization, echocardiography, pulmonary function, and CPET were all compared between patients with CTED and those with CTEPH. ResultsPatients with CTEPH displayed longer symptom duration, increased NTpro-BNP, decreased arterial partial pressure of oxygen, larger right atrial and ventricular diameters, and impaired worse resting pulmonary diffusing function compared with those with CTED (P<0.05). However, there was no statistically significant difference in the resting pulmonary ventilation function between the two groups (P>0.05). Among the CPET parameters of the CTEPH group, peak exercise oxygen uptake per kilogram, oxygen uptake at anaerobic threshold, oxygen pulse, oxygen uptake efficiency slope and oxygen saturation were all decreased, while the minute ventilation-carbon dioxide production at anaerobic threshold (VE/VCO2@AT) and VE/VCO2 slope were increased (P<0.05). However, there was no statistically significant difference in heart rate reserve and breathing reserve (P>0.05). Furthermore, VE/VCO2@AT showed high accuracy for distinguishing CTEPH from CTED (sensitivity, 0.825; specificity, 0.860; and the area under the receiver operating characteristic curve 0.897). ConclusionsPatients with CTEPH showed more significant decreased exercise endurance, diffusion dysfunction, and hypoxemia during exercise and insufficient increase in cardiac output compared with CTED patients. Therefore, it is feasible to apply CPET as a new objective examination to distinguish CTED from CTEPH.
ObjectiveTo investigate the static pulmonary function and cardiopulmonary exercise function of convalescent patients with coronavirus disease 2019 (COVID-19) after discharge.MethodsPulmonary function and cardiopulmonary exercise capacity of COVID-19 patients who admitted to our hospital from January to March 2020 were analyzed. The patients were divided into a non-critical group (3 cases of moderate illness, 2 cases of severe illness) and a critical group (5 cases of critical illness). Five of the 10 patients completed spirometry on day 14 after discharge. All patients performed spirometry, diffusion capacity and cardiopulmonary exercise test around 28 days post-discharge. Ten healthy subjects were used as a control group.ResultsForced expiratory volume in one second of percent predicted (FEV1%pred), forced vital capacity of percent predicted (FVC%pred), the FEV1/FVC ratio (FEV1/FVC), peak expiratory flow of percent predicted (PEF%pred) and mean forced expiratory flow between 25% and 75% of percent predicted (FEF25%-75%%pred) of COVID-19 group were all within normal ranges, and there were no significant difference between COVID-19 group and the healthy group (P>0.05). Diffusion capacity (the carbon monoxide diffusion capacity of percent predicted, DLCO%pred) decreased in 3 patients. The peak oxygen uptake of percent predicted (PeakVO2%pred), oxygen uptake efficiency slope (OUES), Oxygen pulse of percent predicted (VO2/HR%pred) in COVID-19 group decreased and were statistically significantly lower than the control group (P<0.05), but there was no significant difference in ventilatory equivalents for carbon dioxide at anaerobic threshold (VE/VCO2@AT) and the slope of ventilatory equivalent for carbon dioxide (VE/VCO2 slope) between the two groups (P>0.05). Compared to the non-critical group, the critical group displayed significantly lower FVC%pred and VO2/HR%pred (P<0.05). A decrease in PeakVO2%pred was observed in critical group, but the difference did not reach statistical significance (P>0.05). The FVC%pred and PEF%pred were significantly improved in 5 COVID-19 convalescents on Day 28 after discharge when comparing with day 14 (P<0.05).ConclusionsIn the first month after discharge, recovered COVID-19 patients mainly presented decreased exercise endurance in cardiopulmonary function tests.There are also some survivors with reduced diffusion function, but the impaired lung function of COVID-19 patients might return over time.