Usefulness of Plasma Matrix Metalloproteinase-3 Levels to Predict Myocardial Infarction in Men With and Without Acute Coronary Syndrome

Matrix metalloproteinase-3 (MMP-3), or stromelysin-1, is a matrix metalloproteinase which is expressed in atherosclerotic plaques and which has been implicated in the pathogenesis of acute coronary syndrome (ACS). Functional polymorphisms in the promoter region of the human MMP-3 gene resulting in an increased expression of MMP-3 have been shown to predict the risk of incident myocardial infarction (MI). However, there have been no studies that have specifically examined the utility of baseline plasma MMP-3 levels for the prediction of long-term MI. In this study, baseline plasma MMP-3 levels were measured in 355 male patients who were referred for coronary angiography and followed prospectively for the development of enzymatically confirmed MI out to 5 years. After adjustment for a variety of baseline clinical, angiographic, and laboratory parameters, plasma MMP-3 levels were an independent predictor of MI at 5 years (hazards ratio 1.42, 95% CI 1.13 to 1.79; p = 0.0023). Furthermore, in 5 additional multivariate models that included a variety of contemporary biomarkers associated with adverse outcomes and MI, MMP-3 remained an independent predictor of MI at 5 years. Similar results were obtained when the analyses were restricted to the subpopulation of patients presenting with ACS. In conclusion, elevated levels of MMP-3 are associated with an increased risk of long-term MI in patients with and without ACS referred for coronary angiography. Furthermore, this association is independent of a variety of clinical, angiographic, laboratory variables, including biomarkers with established prognostic efficacy for the prediction of MI.