[Exploring the characteristics changes of cardiopulmonary exercise testing in patients with acute coronary syndrome after PCI before and during the COVID-19 pandemic].

Objective: To investigate the changes in cardiopulmonary exercise testing (CPET) characteristics before and after the outbreak of COVID-19 in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI). Methods: This is a cross-sectional study that included ACS patients who underwent PCI at the General Hospital of the Northern Theater Command from July 2018 to February 2023. Based on the timeline of the COVID-19 pandemic, patients were divided into two groups: the pre-pandemic group and the during-pandemic group, with January 2020 as the dividing line. Clinical data were collected from both groups, and a comparative analysis was performed on their postoperative CPET outcomes, including peak oxygen uptake (peak VO₂), peak metabolic equivalents (peak MET), and other indicators. Weber's classification was used to assess cardiac function. In addition, the 7-tiem generalized anxiety disorder scale (GAD-7) and the patient health questionnaire-9 (PHQ-9) were used to assess the patients' psychological anxiety and depression states, respectively. Multivariate logistic regression was used to analyze the influencing factors of CPET after PCI. Results: A total of 4 310 post-PCI ACS patients were included, with an average age of (58.7±9.1) years, and 3 464 (80.37%) were male. There were 1 698 patients in the pre-pandemic group and 2 612 patients in the during-pandemic group. The main indicator of the CPET, peak VO₂ (15.04±3.93) ml·min^-1·kg^-1 in the during-pandemic group, was lower than that in the pre-pandemic group (15.52±3.68) ml·min^-1·kg^-1, and the difference was statistically significant (P<0.001). Multivariate logistic regression analysis showed that advanced age, female gender, high body mass index, elevated high-sensitivity C-reactive protein, reduced high-density lipoprotein cholesterol, smoking history, history of myocardial infarction, more severe ACS classification, and mild to moderate degree of depression were related to poor cardiopulmonary outcomes (P<0.05). Conclusion: The COVID-19 pandemic had a negative impact on the cardiopulmonary outcomes of ACS patients after PCI. Reduced physical activity, and increased psychological stress should be given consideration and attention regarding their impact on patients' cardiopulmonary function.