Objective To investigate the value of baseline levels of aldosterone(ALD)in predicting the cardiovascular events and in-stent restenosis12 months after coronary stent implantation. Methods 268 patients with coronary heart disease admitted to the department of cardiology from January 2014 to July 2016 were selected (96 cases of stable angina pectoris and 172 cases of acute coronary syndrome).The ALD level in the preprocedural serum was detected before coronary stent implantation. According to the level of ALD,the patients were divided into two groups:ALD<130 pg/mL(n=127)and ALD≥130 pg/mL(n=141).The cardiovascular events(angina pectoris,myocardial infarction,death)and in-stent restenosis were observed and recorded 12 months after the procedures. Logistic regression analysis was done to analyze the independent risk factors of ISR. Results The baseline levels of ALD in the patients with acute coronary syndrome were significantly higher than those with stable angina pectoris[(160 ± 58)pg/mL vs.(118 ± 46)pg/mL,P < 0.05]. The cardiovascular events and those in in-stent restenosis in the patients with high baseline levels of ALD were significantly higher than those with normal baseline levels of ALD 12 months too(24.1% vs 3.1%;P<0.05;16% vs 7.4%;P<0.05).Logistic regression analysis showed that serum ALD levels were the strongest predictors of ISR,with the odds ratio of 2.56 per 10 pg/mL. Conclusions Preprocedural ALD level is a predictor for 12 months outcome of in-stent restenosis for the patents undergoing coronary stent implantation. It indicates that the complications and clinical restenosis in 12 months are markedly influenced by the activation of the rennin angiotensin aldostenone system.