The clinical value of pregnancy associated protein A in patients with acute coronary syndrome

Objective To investigate the clinical value of pregnancy-associated plasma protein A (PAPP-A) in patients with acute coronary syndrome (ACS). Methods The study subjects comprised of 249 patients with ACS ［50 patients with ST elevation acute myocardial infarction(STEMI), 43 patients with non-ST elevation acute myocardial infarction (NSTEMI), 156 patients with unstable angina pectoris (UAP)］ from July 2008 to December 2009 at Shanghai East Hospital affiliated to Tongji University.The patients were divided into single-vessel lesions group, double-vessel lesions group and three-vessel lesions group according to the coronary artery stenosis.A group of 205 healthy subjects admitted for health physical examination were used as controls.Blood samples were collected from ACS patients and control subjects.Serum PAPP-A, creatine kinaseisoenzyme MB (CK-MB), high-sensitivity troponin-T(hs-TnT) were measured by electrochemiluminesence and high-sensitivity C-reactive protein (hs-CRP) was measured by immune scatter turbidity method.Analysis of variance ANOVA and Kruskal-Wallis H test were used for statistical analysis. Results Serum PAPP-A in the STEMI, NSTEMI, UAP and normal control group were 10.45(5.54-16.08), 6.56(4.68-9.55), 5.70(4.12-8.50), 5.23(4.00-5.88) mIU/L, respectively， and the difference was statistically significant (H=43.94，P<0.01).Pairwise comparison showed that PAPP-A in STEMI, NSTEMI, UAP were significantly higher than the healthy control group and differences were statistically significant (t=6.80, 2.46, 1.72, P<0.05).The PAPP-A had a sensitivity of 52.2% and specificity of 80% in diagnosis of ACS.The positive rate of PAPP-A was 44.5%(69/155) in patients with negative hs-TnT.The serum levels of PAPP-A in the three-vessel lesions group ［7.72（5.03-12.46） mIU/L］ was higher than that in the single, double groups ［5.35（4.14-8.59），6.05（4.42-9.58） mIU/L］，and the difference had statistical significance（t=2.00，1.57, P<0.05）.There was obvious correlation between the level of serum PAPP-A and the level of hs-CRP (r=0.524, P<0.05), and there was weak correlation between the PAPP-A and CK-MB or hs-TnT (r=0.326, 0.343, P<0.05). Conclusions The results shows that PAPP-A is elevated in patients with ACS.It may be used as a serum biomarker for vulnerable plaques in patients with ACS and has a clinical value for ACS diagnosis especially in patients with negative hs-TnT.(Chin J Lab Med, 2012，35：359-363) Key words: Acute coronary syndrome; Pregnancy-associated plasma protein-A; Troponin T