Impact of statin treatment on strut coverage after drug-eluting stent implantation

Abstract

Background: There is no human data to evaluate impact of statin treatment on strut coverage after drug-eluting stent (DES) implantation. Methods:A total of 60 patients were randomly treated with pitavastatin 2mg or pravastatin 20mg for 6 months after DES implantation. Selection of DES was also randomly assigned to sirolimus-eluting stents (SES) or biolimus-eluting stents (BES). The degree of strut coverage was assessed with 6-month follow-up optical coherence tomography (OCT) which was performed in 52 DES-treated patients. Results:Percentage of uncovered strut was 19.4±14.7% in pitavastain-treated patients (n=25) and 19.1±15.2% in pravastain-treated patients (n=27) (p=0.927); 23.3±16.6% in SES-treated patients (n=28) and 14.5±10.9% in BES-treated patients (n=24) (p=0.026). Lower percentage of uncovered struts was significantly correlated with lower level of follow-up low-density lipoprotein (LDL) cholesterol (r=0.486, p=0.009) and greater reduction of LDL cholesterol level (r=-0.456, p=0.015) in SES-treated patients, but not BES-treated patients. In SES-treated patients, the percentage of uncovered struts was significantly lower in those who follow-up LDL cholesterol level less than 70mg/dL at 6 months follow-up (10.1±12.4% vs. 26.9±15.6%, p=0.025); but there were no significant differences of percentage of uncovered struts between patients who had 6-month follow-up LDL cholesterol level less vs. greater than 70mg/dL in BES-treated patients (14.6±12.7% vs. 14.4±10.5%, p=0.971). Conclusion:lower level of follow-up LDL cholesterol, especially less than 70mg/dL, might have a protective effect against delayed strut coverage after DES implantation. This vascular healing effect of lower LDL cholesterol level could be different according to types of DES.