Wei-Wei Zhu Run-Yu Tian Di-Chen Guo Ming-Ming Lin Qizhe Cai Yun- Yun Qin Xue-Yan Ding Xiuzhang Lv ^*

• Beijing Chaoyang Hospital, Capital Medical University, Beijing, China

Aims: This study applied exercise stress echocardiography (ESE) to identify risk factors associated with exercise intolerance in patients with chronic coronary syndrome (CCS).Methods and results: 90 CCS patients underwent a cardiopulmonary exercise test and ESE, assessing exercise capacity, left ventricular systolic and diastolic function, and systolic reserve.The patients were divided into two groups according to the percentage of predicted oxygen consumption (VO2) at peak (≥85%, normal exercise tolerance group; ＜85%, exercise intolerant group). The left ventricular ejection fraction, average mitral valve S', and left ventricular global longitudinal strain were lower in the exercise intolerant group than in the normal group, but no significant differences were observed in myocardial work parameters at rest. The average mitral valve E/e', EDVi/E/e', and proportion of abnormal diastolic function at the peak were higher in the exercise intolerant group than in the normal group. Moreover, the ∆SVi and flow reserve were lower, but the ∆average mitral valve E/e' was higher in the exercise-intolerant group. From univariate and multivariate logistic regression analysis, only peak EDVi/E/e' and ΔSVi correlated independently with exercise intolerance in CCS patients. With cutoff values of 8.64 ml/m 2 for peak EDVi/E/e' and 12.17 ml/m 2 for ΔSVi, the combination of these factors had an area under the receiver operating characteristic curve of 0.906 (95% confidence interval, 0.820-0.960) for the prediction of exercise intolerance in CCS patients.Hemodynamic changes during exercise in CCS patients were effectively evaluated using ESE. An elevated peak EDVi/E/e' and a decreased ∆SVi are independent risk factors for exercise intolerance in patients with CCS.