Background: Left ventricular dilatation and elevated plasma natriuretic peptide levels predict adverse prognosis and the development of congestive heart failure after myocardial infarction. Altered matrix metalloproteinase (MMP) activity has been implicated in the structural changes associated with development of heart failure after myocardial injury. The aims of this study were to investigate plasma MMP-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-1 concentrations following acute myocardial infarction and their relationships with measures of left ventricular function.
Methods and results: Plasma MMP-2, MMP-9, TIMP-1, and N-terminal proBNP (N-BNP) were quantified on 5 consecutive days in 60 patients with acute myocardial infarction (39 anterior). N-BNP was measured on day 3. Echocardiographic assessment of left ventricular wall motion index and volumes was performed during admission and 6 weeks later. Plasma MMP-9 showed peaks on days 1 and 4. MMP-2 levels, similar on each day, were higher after inferior myocardial infarction. Plasma MMP-2 showed strong, inverse correlation with left ventricular volumes during and after admission. Plasma MMP-9 correlated directly with N-BNP (P=.022) and inversely with wall motion index during admission (P=.05). TIMP-1 levels were higher after anterior (1269, 870-1466 ng/mL) compared with inferior (1183, 856-1419 ng/mL, P=.05) acute myocardial infarction and fell from day 1 through 5 (P <.0005).
Conclusion: Plasma MMP-9 concentration correlates with neurohormonal and echocardiographic measures of left ventricular dysfunction after myocardial infarction. Higher left ventricular volumes are associated with lower plasma MMP-2 concentrations. Circulating MMP concentrations may provide insights into left ventricular remodeling after acute myocardial infarction.