Purpose: To investigate the levels of pregnancy-associated plasma protein A (PAPP-A) or insulin-like growth factor -1 (IGF-1) in patients with acute coronary syndrome.
Methods: Serum PAPP-A and IGF-1 was measured with biotin-tyramide-amplified enzyme immunoassay and Enzyme Linked Immuoserbent Assay, respectively, in patients with ST elevation acute myocardial infarction (STEMI, n=12), unstable angina (UAP, n=15), and stable angina (n=15). PAPP-A and IGF-1 was also measured in 16 healthy subjects (control group).
Results: The serum levels of PAPP-A in the STEMI (16.9+/-10.3 mIU/L) and UAP group (15.2+/-10.5 mIU/L) were higher than in the stable angina (8.5+/-3.1 mIU/L) or control group (8.4+/-2.0 mIU/L, P < 0.01). The serum levels of IGF-1 in the STEMI (132.3+/-40.9 microg/L) and UAP group (127.3+/-36.0 microg/L) were also higher than in the stable angina (44.9+/-18.5 microg/L) or control group (67.7+/-24.5microg/L, P < 0.01). There were no differences in serum levels of PAPP-A or IGF-1 among the single, double and three vessel lesion groups. The serum levels of PAPP-A (19.9+/-10.1 mIU/L) and IGF-1 (153.2+/-52.4 microg/L) after PCI were higher than those before PCI (15.1+/-10.0 mIU/L and 91.4+/-51.0 microg/L, respectively, P < 0.01). A positive correlation was found between PAPP-A and IGF-1 levels in the STEMI and UAP group before PCI (r=0.48P < 0.01).
Conclusion: PAPP-A and IGF-1 are elevated in patients with acute coronary syndrome. They may be used as biomarkers for vulnerable plaques in patients with coronary artery disease. Whether post-PCI elevation of IGF-1 can be used to predict restenosis of coronary arteries remains to be seen.