ObjectiveTo discuss the potential relationship of plaque burden (PB) and coronary remodeling in acute coronary syndrome (ACS) patients.MethodsNinety-one patients with ACS in Qingdao Municipal Hospital during January 2011 to June 2014 underwent the conventional coronary angiography and intravascular ultrasonography (IVUS). The remodeling of 60 cases were positive (remodeling index [RI]>1) and those of 31 cases were negative (RI<1). All 91 patients were included in this study, including 9 cases (PB<60%), 19 cases (60%≤PB<70%), 48 cases (70%≤PB<80%) and 15 cases (PB>80%). The difference of plaque cross-sectional area (P-CSA), lumen cross-sectional area (L-CSA), external elastic membrane cross-sectional area (EEM-CSA), average EEM-CSA, PB between positive remodeling andnegative remodeling were compared by independent-samplest test. ANOVA was used to compare P-CSA, L-CSA, EEM-CSA and RI among patients with different PB. The relevance of PB, P-CSA, EEM-CSA, L-CSA and RI were analyzed by Pearson correlation analysis.ResultsThere were no signifi cant differences in P-CSA, L-CSA, EEM-CSA and PB between patients with positive remodeling and negative remodeling. Average EEM-CSA of patients with negative remodeling were signifi cantly greater than that of patients with positive remodeling ([13.24±1.98] mm2vs [17.30±3.16] mm2,t=2.46,P<0.05). P-CSA, EEM-CSA and L-CSA had signifi cant differences (F=24.56, 28.97 and 7.14,P<0.001) while RI had not statistical signifi cant difference among patients with different PB. With the increase of PB, P-CSA and EEM-CSA increased (P-CSA: [6.01±1.68], [9.12±2.00], [11.42±2.05] and [14.05±4.00] mm2, EEM-CSA: [11.43±1.90], [13.64±2.93], [15.14±2.64] and [16.64±4.08] mm2), L-CSA reduced ([5.44±0.89], [4.52±0.99], [3.72±0.74] and [2.60±0.63] mm2). PB was positively correlated with P-CSA and EEM CSA (r=0.76, 0.50,P<0.001), but was negatively correlated with L-CSA (r=-0.74, P<0.001). RI had no relationship with PB, P-CSA, L-CSA and EEM-CSA.ConclusionsCoronary artery remodeling is a very complicated dynamic process. Except the PB, other factors probably affect the direction of remodeling. RI is not suitable as the index for the assessment of vascular remodeling.