Serial change and its determinants of residual plaque characteristics under sirolimus-eluting stent: a coronary angioscopic study

Objectives: To examine serial change in the residual plaque behind the sirolimus-eluting stent (SES) using coronary angioscopy in patients with SES implantation and to identify its baseline determinants.

Background: Previous coronary angioscopic studies have demonstrated that SES enhances the yellow grade of residual plaque during follow-up period.

Methods: A total of 42 patients with stable angina pectoris or silent ischemic heart disease, who had a successful SES implantation were examined by coronary angioscopy both at the baseline (SES implantation) and the follow-up period (9-14 month follow-up). The patients were divided into three groups as: worsened group (WS: yellow color grade of coronary plaque at the follow-up period was worsened compared to the baseline period, n=15), no change group (NP: no change compared to the baseline, n=16), and improved group (IP: improved compared to the baseline, n=11). Then, the determinants of the nominal change of yellow color grade were examined by multiple regression analysis.

Results: The low-density lipoprotein cholesterol (LDL-C) level in IP group at the follow-up was significantly decreased compared to baseline (from 120.0±29.8mg/dl to 74.3±16.7mg/dl, p=0.0005), and was the lowest among three groups (WS: 103.5±16.4mg/dl, NC: 105.7±18.7mg/dl, and IP: 74.3±16.7mg/dl). Multiple regression analysis revealed that family history, statin administration, baseline serum creatinine, baseline 'in-stent' thrombus, and follow-up LDL-C were significant determinants to the nominal change of yellow color grade after the SES implantation (p<0.0001).

Conclusions: Serial change in tissue characteristics within residual plaque under SES is determined by several factors, especially LDL-C level as well as statin administration. Adequate management of LDL-C by statins might be crucial for stabilizing residual plaque after SES implantation.