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 (β = −0.32, 95% confidence interval [CI] −0.57 to −0.26, p = 0.03) and a smaller baseline reference vessel diameter (β = 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 (Δ neointimal hyperplasia volume 5.4 mm3 [95% CI 2.7 to 28.1] vs 35.9 mm3 [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.