Comparison of neointimal hyperplasia with drug-eluting stents versus bare metal stents in patients undergoing intracoronary bone-marrow mononuclear cell transplantation following acute myocardial infarction

The aims of this study were to assess the safety of drug-eluting stent (DES) use and to compare the incidence of in-stent restenosis (ISR) and neointimal hyperplasia formation according to the type of stent implanted (DES vs bare-metal stents [BMS]) in patients who underwent intracoronary bone marrow mononuclear cell transplantation after acute ST elevation myocardial infarction. Fifty-nine patients with successfully revascularized ST elevation myocardial infarction (37 using BMS and 22 using DES) underwent paired angiographic examinations at baseline and 6 to 9 months after the intracoronary injection of 91 million +/- 56 million autologous bone marrow mononuclear cells. A subgroup of 30 patients also underwent serial intravascular ultrasound examinations. Off-line angiographic assessment showed 4 cases of binary ISR, primarily in BMS (3 cases), and no major adverse cardiac events were associated with stent type (mean follow-up period 41 +/- 10 months). At follow-up, angiographic late luminal loss was significantly lower in patients with DES than in those patients with BMS (0.35 +/- 0.66 vs 0.71 +/- 0.38 mm, p = 0.011). Multivariate analysis identified the use of DES (beta = -0.32, 95% confidence interval [CI] -0.57 to -0.26, p = 0.03) and a smaller baseline reference vessel diameter (beta = 0.29, 95% CI 0.04 to 0.54, p = 0.02) as independent predictors of lower late loss. Moreover, intravascular ultrasound showed a significant reduction of in-stent neointimal hyperplasia formation related to DES use compared with BMS use (Delta neointimal hyperplasia volume 5.4 mm(3) [95% CI 2.7 to 28.1] vs 35.9 mm(3) [95% CI 22.0 to 43.6], p = 0.035). In conclusion, these findings suggest that the use of DES is safe and may prevent ISR and neointimal hyperplasia formation in patients who undergo intracoronary bone marrow mononuclear cell transplantation after a successfully revascularized ST elevation myocardial infarction.