Comparison between sirolimus- and paclitaxel-eluting stent in T-cell subsets redistribution

We sought to investigate the effects of 2 different coronary drug-eluting stents on the distribution of central or effector memory T cells circulating in the coronary sinus of patients with coronary artery disease who underwent percutaneous coronary revascularization. We randomly assigned 43 patients (mean age 65.4 +/- 4.3 years; 34 men) presenting with stable coronary disease and angiographically proved stenosis of the left anterior descending artery to treatment with sirolimus- or paclitaxel-eluting stents. Heparinized blood samples were obtained from the coronary sinus before and 20 minutes after stent implantation. Analysis of surface phenotype was performed by 4-color flow cytometry, and data are expressed as the percentage of positive cells. The percentages of CD8+ and CD4+ effector memory T cells, as defined by the CD3+CD45RO+CD27- phenotype, were significantly reduced in patients who received a sirolimus-eluting stent compared with the basal values. Conversely, the percentages of CD8+, but not CD4+, central memory T cells (CD3+CD45RO+CD27+) were increased in the same treatment group after the revascularization procedure. No changes in the percentages of memory T-cell populations in the paclitaxel-eluting stent group were observed. These findings show that sirolimus-eluting stents rapidly induced a redistribution of memory T lymphocytes, with a significant decrease of proinflammatory effector memory T cells circulating within the coronary sinus.