Background: The prognostic value of plasma concentrations of tissue type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), and C-reactive protein has been reported in patients with coronary artery disease. However, the association between cardiac events and these factors during the acute and subacute phases of myocardial infarction (MI) is unknown. The purpose of this study was to determine whether elevated plasma concentrations of t-PA, PAI-1, and C-reactive protein in patients with MI are associated with future recurrent MI or sudden cardiac death.
Methods: We studied 106 consecutive patients who survived a confirmed first MI between 1993 and 1998 in our hospital. The control group consisted of 50 patients who had no significant coronary artery stenosis. Blood samples were obtained at the time of admission for acute MI and on the 28th day after admission. Patients were followed for a mean of 50 months after these measurements. The primary end points were sudden cardiac death and fatal or nonfatal acute MI.
Results: Of the 92 patients who were available for follow-up, 10 had cardiac events. Both the plasma t-PA and PAI-1 concentrations were elevated on day 1 of acute MI compared to the control group and decreased by day 28, but remained higher than those in the controls. Plasma C-reactive protein concentration was also elevated on day 1 and decreased by day 28. Using a stepwise variable choice model of Cox proportional hazards analysis including these fibrinolytic factors and C-reactive protein, only the t-PA concentration in the subacute phase was a significant predictor of cardiac events (relative risk per S.D. 3.20, P<0.01). We further found that independent of other risk factors, an elevated t-PA concentration was predictive of cardiac events.
Conclusions: This study reveals that a rise in endogenous t-PA concentration during the subacute phase of MI could predict recurrent MI or sudden cardiac death.