The Role of Insulin-Like Growth Factor-1 and Pregnancy-Associated Plasma Protein-A in Diagnosis of Acute Coronary Syndrome and Its Related Morbidities

Pregnancy-associated plasma protein-A (PAPP-A) is a metalloproteinase that plays a role in atherosclerotic plaque destabilization. In recent studies, insulin-like growth factor-1 (IGF-1) has been introduced as a mediator of atherosclerosis. PAPP-A and IGF-1level may be importantdiagnostic indicatorsof acute coronary syndrome (ACS).

The present study tried to assess the diagnostic role of IGF-1 and PAPP-A biomarkersin ACS spectrum.

The serum level of IGF-1, PAPP-A and troponin I was determined in 121 consecutive patients with ACS. Relationships were assessed by t-test, ANOVA and the non-parametric equivalent. Accuracy of biomarkers was measured by the area under the ROC curve (AUC) and optimal cut-off points to diagnose STEMI and NSTEMI using Youden index.

In patients with acute ST segment elevation myocardial infarction (STEMI), all of these three biomarkers were significantly higher than those in patients with unstable angina (P= 0.028 for IGF-1, P<0.001 for PAPP-A and Troponin-I). Mean level of IGF-1 in patients with renal failure was significantly higher than that in patients without renal failure (137.9±35.1 vs 105.1±46.9, P=0.003), but PAPP-A and serum Troponin-I level had no significant difference in renal failure groups (P>0.05). ROC curve analysis showed that after Troponin-I, PAPP-A was a good discriminator between patients with STEMI and patients with unstable angina (AUC=0.79). Optimum cut-off value for PAPP-A was found to be 89.2 ng/ml, with sensitivity and specificity of 66.7% and 83.8%, respectively.

PAPP-A can be a novel biomarker for both identification of patients with STEMI and risk stratification in patients with ACS.