Predictive value of cardiopulmonary fitness parameters in the prognosis of patients with acute coronary syndrome after percutaneous coronary intervention

OBJECTIVES: We aimed to determine the predictive value of cardiopulmonary exercise testing (CPX) in the prognosis of patients with acute coronary syndrome (ACS) treated with percutaneous coronary intervention (PCI). METHODS: We conducted a retrospective study including patients who underwent CPX within 1 year of PCI between September 2012 and October 2017. Patients were followed-up until the occurrence of a major adverse cardiac event (MACE) or administrative censoring (September 2019). A Cox regression model was used to identify significant predictors of a MACE. Model performance was evaluated in terms of discrimination (C-statistic) and calibration (calibration-in-the-large). RESULTS: In total, 184 patients were included and followed-up for a median 51 months (interquartile range: 36-67 months) and 32 events occurred. Multivariable analysis revealed that body mass index and Gensini score were significant predictors of a MACE. Four CPX-related variables were found to be predictive of a MACE: premature CPX termination, peak oxygen uptake, heart rate reserve, and ventilatory equivalent for carbon dioxide slope. The final prediction model had a C-statistic of 0.92 and calibration-in-the-large 0.58%. CONCLUSION: CPX-related parameters may have high predictive value for poor outcomes in patients with ACS who undergo PCI, indicating a need for appropriate treatment and timely management.