The objective of this study was to investigate the time profiles of plasma matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinases (TIMP-1 and -2), and pregnancy associated plasma protein A (PAPP-A) in patients with acute myocardial infarction (AMI), compared to patients with stable angina pectoris (AP), all treated with percutaneous coronary intervention (PCI) with stent.
Methods: Twenty patients with ST-elevation AMI and 10 patients with AP were included. Serum levels of the selected markers were measured before (only in the AP group) PCI, and 3 and 12 hours, 1,3,5,7 and 14 days after PCI in all patients.
Results: The levels of MMP-9 and MMP-9/TIMP-1 ratio, being higher in the AMI group compared to the AP group at 3 hours, were significantly reduced 1 day after PCI (p<0.01 for both), sustaining during the study period. A similar pattern was observed in PAPP-A levels with significant reduction after 12 hours (p<0.01). In the AP group only smaller changes were observed, except from an increase in PAPP-A levels from before PCI to 3 hours (p<0.001), followed by significant reduction. No significant correlations were found between any of the measured biomarkers and the infarct size, either evaluated in the acute phase or after 6 weeks.
Conclusion: AMI patients treated with PCI had an early significant reduction in MMP-9, MMP-9/TIMP-1 ratio and PAPP-A when compared to patients with stable angina pectoris treated with PCI. This indicates that the metalloproteinases may be involved in the early phase of the plaque rupture process, with limited influence of the PCI procedure.