Active matrix metalloproteinases 3 and 9 are independently associated with coronary artery in-stent restenosis

ObjectiveThis study aimed to determine whether plasma levels of active matrix metalloproteinases (MMP) are predictors of in-stent restenosis (ISR) in New Zealand patients treated with bare-metal coronary stents.MethodsA group of 152 patients with a history of ISR were compared with 151 symptom free 1-year post-stenting patients (non-ISR). Demographic and angiographic characteristics were collected. Plasma samples were analyzed for the active forms of MMP-1, -2, -3 and -9 as well as tissue inhibitor of metalloproteinases (TIMP-1) using ELISA-based isoform sensitive assays.ResultsBoth active MMP-9 and active MMP-3 were independently associated with history of ISR. Elevated levels of both active MMP-3 and -9 had an adjusted odds ratio of 11.8 (95% CI: 4–35, p < 0.0001) for association with ISR, with 37% of ISR patients having such levels versus 11% on non-ISR. The addition of both of the MMP biomarkers significantly increased the area under the curve (AUC) of a receiver operator characteristic (ROC) analysis incorporating the significant demographic and angiographic variables (AUC 0.85 versus 0.78, p < 0.005).ConclusionMeasures of plasma active MMP isoforms appear to be independently associated with ISR, and assessment of multiple MMP markers yields cumulative utility.