Association between the COVID-19 pandemic and cardiopulmonary function in acute coronary syndrome patients without SARS-CoV-2 infection

The COVID-19 pandemic disrupted cardiovascular disease management. This single-center cross-sectional cohort study evaluated cardiopulmonary function changes in acute coronary syndrome (ACS) patients post-percutaneous coronary intervention (PCI) without SARS-CoV-2 infection and explored pandemic-related influencing factors. We analyzed 7,650 ACS patients undergoing complete PCI revascularization and cardiopulmonary exercise testing (CPET) between October 2018 and December 2023, stratified into pre-pandemic (cut-off: February 1, 2020), during-pandemic, and post-pandemic (cut-off: December 31, 2022) groups. Propensity Score Matching (PSM) balanced baseline characteristics, yielding 4,503 patients for analysis. Clinical/laboratory data and CPET results were compared across groups using one-way analysis of variance (ANOVA). The primary CPET parameter, peak oxygen uptake per kilogram (peak VO₂/kg), was significantly lower in the during-pandemic group (15.07 ± 4.09 ml/min/kg) compared to the pre-pandemic group (15.56 ± 3.74 ml/min/kg) and the post-pandemic group (15.69 ± 4.04 ml/min/kg). Machine learning and multivariate logistic regression were used to select key variables related to cardiopulmonary function. The findings indicate that older age, female sex, higher BMI, elevated SYNTAX score, increased NT-pro BNP levels, elevated HbA1c, smoking, anxiety, and higher ACS severity classification were positively correlated with impaired cardiopulmonary function. These results highlight associations between the pandemic and cardiovascular rehabilitation outcomes, emphasizing the need for tailored interventions during healthcare crises.