Background: Bare Metal Stents (BMS) have been commonly used for recanalization of an infarct-related artery in Japanese patients with Acute Myocardial Infarction (AMI). We sought to examine predictors of binary restenosis and early Stent Occlusion (SO) in these patients.
Methods: Among 242 consecutive patients with AMI treated by BMS implantation as reperfusion therapy, 226 underwent either ischemia-driven or follow-up coronary angiography within 8 months. Restenotic change in the stented segment was found in 56. Among them, 10 patients had early SO on an angiogram. Multivariate analysis was performed to obtain predictors of restenosis and early SO.
Results: Predictors for restenosis were Left Anterior Descending Artery (LAD) involvement (odds ratio (OR) 2.32, p = 0.024), serum creatinine (SCr) on admission (OR 1.29 per 0.1mg/dl increase, p = 0.001), and stent size (OR 0.43 per 0.5mm increase, p = 0.001). Those for early SO were left main trunk or LAD involvement (OR 27.0, p = 0.029), SCr (OR 1.65 per 0.1mg/dl increase, p = 0.005) and leukocyte count (OR 1.28 per 1,000/microliter increase, p = 0.037) on admission. SCr was significantly higher in patients with early SO than in those with restenosis (median 1.05, Interquartile Range (IQR) 0.80-1.10 vs. median 0.80, IQR 0.70-1.00, p = 0.035).
Conclusions: In patients with AMI treated with BMS, both restenosis and early SO were increased by anterior wall involvement and elevation of SCr level. Higher SCr may be subject to more occlusive changes. It is suggested that in early SO, an inflammatory mechanism may be involved.