AIM  To investigate the influence factors of acute residual stent malapposition (ARSM) within the left main coronary artery (LMCA) using intravascular ultrasound (IVUS) and evaluate its impact on long-term prognosis in patients undergoing percutaneous coronary intervention (PCI).

METHODS This study collected clinical data and IVUS results of 154 patients who underwent PCI for LMCA disease at the Department of Cardiology, the First Affiliated Hospital of Shandong First Medical University from December 1, 2014 to October 31, 2020. The possible influencing factors of ARSM were assessed and its correlation with major adverse cardiac and cerebrovascular events (MACCE) was explored.

RESULTS Compared with the Non-ARSM group, the ARSM group had a lower proportion of LM lesions at the opening or body, and a higher proportion at the distal bifurcation (both P<0.05). There was no statistical difference between the two groups in age, gender, hypertension, diabetes, dyslipidemia, creatinine level, LVEF, troponin, previous blood supply reconstruction, preoperative diagnosis, number of vascular lesions and other clinical factors. Compared with the Non-ARSM group, the ARSM group had a higher proportion of stent symmetry>0.3 (P<0.01) and a lower proportion of stent involvement in the left coronary sinus (P<0.05). There was no statistically significant difference in terms of stent diameter, stent length, cumulative bifurcation of the stent, and the number of single stents. Logistic regression analysis showed a correlation between stent symmetry>0.3 and ARSM (OR=0.11, 95% CI: 0.03~0.43, P=0.001). The symmetry of the stent is positively correlated with the degree of calcification (B=0.02, 95% CI: 0.01~0.04, P<0.01), and negatively correlated with the minimum stent area (B=−0.01, 95% CI: −0.01~0.00, P<0.05). Kaplan Meier curve analysis showed no significant difference in survival rates between the ARSM group and the Non-ARSM group patients. COX proportional hazards regression analysis showed no clear correlation between ARSM and MACCE (HR=1.08, 95% CI: 0.44～2.66, P=0.872) and all-cause mortality (HR=8.03, 95% CI: 0.89～72.57, P=0.064), and there was no correlation between ARSM and non fatal myocardial infarction (HR=0.48, 95% CI: 0.09～2.53, P=0.388), non fatal stroke (HR=0.74, 95% CI: 0.13～4.28, P=0.735), and TVR (HR=1.59, 95% CI: 0.34～7.40, P=0.557).

CONCLUSION Stent symmetry >0.3 is an influential factor for ARSM. Limited ARSM is not associated with the long-term prognosis in patients of LMCA disease after PCI.