Comparison of angioscopic findings and three-year cardiac events between sirolimus-eluting stent and bare-metal stent in acute myocardial infarction

The safety of sirolimus-eluting stents (SESs) in acute myocardial infarction (AMI) remains controversial. We compared long-term neointimal coverage after stent implantation for AMI evaluated by coronary angioscopy and 3-year clinical events between SESs and bare-metal stents (BMSs). Eighty-seven consecutive patients who received SESs or BMSs for AMI were enrolled. At 8 months after AMI coronary angiography with angioscopy was performed. Using angioscopy we evaluated maximum and minimum grades of neointimal coverage using an angioscopic score (0 to 3). We calculated the heterogeneity score as the maximum grade minus the minimum grade. We compared angioscopic parameters including minimum grade and heterogeneity score of neointimal coverage, thrombi and plaque color, serum parameters, and major adverse cardiac events for 3 years between the 2 groups. The restenosis rate of the SES group (n = 56) was significantly lower than that of the BMS group (n = 31, 9% vs 31%, p = 0.015). The SES group had a lower minimum grade of neointimal coverage and higher heterogeneity score and prevalence of thrombi than the BMS group, but from 8 months to 3 years after stent implantation there were no significant differences in major adverse cardiac events between the 2 groups. In conclusion, a lower minimum grade and greater heterogeneity of neointimal coverage and thrombi were shown for SESs compared to BMSs at 8 months after AMI. However, these findings did not correlate with cardiac events over a period of 3 years in our patients.