Background and objective. Enhanced external counterpulsation (EECP) has shown promise in facilitating postoperative recovery in patients after percutaneous coronary intervention by improving the hemodynamic environment within the stents. However, understanding of the hemodynamic environment across patient profiles, encompassing geometric features of the stent (e.g., length, diameter, and curvature) and patient demographics (e.g., height, age, and weight), has yet to be fully elucidated. Methods. A multidimensional 0/1D–3D coupled model was developed using clinical data from 18 subjects. This model integrated a 0/1D model for assessing the blood perfusion and pressure in coronary arteries with a 3D model to predict the intricate in-stent hemodynamic environment. Results. The simulation results showed increases in time-averaged wall shear stress (TAWSS), transverse wall shear stress, and oscillatory shear index and a decrease in relative residual time under the effect of EECP. Moreover, TAWSS consistently decreased with increasing length and stent diameter while decreasing with increasing stent curvature. Conclusions. A surrogate model based on polynomial chaos expansion, which provides valuable tools for expedited clinical decision-making, was developed from the numerical results for TAWSS enhancement ratio. This model incorporated both the physiological characteristics of the subjects and the geometric features of the stent.