ABSTRACT
OBJECTIVES: The availability of a sensitive and specific early marker of plaque instability, whose levels become elevated before or even in the absence of myocardial necrosis, should improve diagnostic and therapeutic decision making in Acute Coronary Syndromes. This analytic cross-sectional study was designed to estimate the serum levels of Pregnancy Associated Plasma Protein A (PAPP-A), highly sensitive C reactive protein (hs-CRP) and creatinine phosphokinase MB (CPK-MB) in patients of old myocardial infarction, unstable angina, non ST elevation and ST elevation myocardial infarction and to assess their correlation with plaque instability. METHODS: Male patients of Coronary Artery Disease aged between 40 to 60 years were recruited in to the four study groups: Healthy controls; Old Myocardial Infarction, not having features of acute coronary syndrome; Unstable Angina, non ST elevation myocardial infarction and ST elevation Myocardial Infarction. Appropriately timed blood sample collection was done and serum levels of PAPP-A, hs-CRP and CPK-MB were estimated. Qualitative cardiac troponin T was done in all patients. Appropriate statistical tests were applied and intergroup comparison was done. RESULTS: Serum levels of PAPP-A were found to be significantly different in all the four groups (p<0.001) with highest values observed in patients of ST elevation myocardial infarction (26.38 ± 4.10 IU/l) as compared to controls (3.29 ± 0.93).The serum levels of PAPP-A has a statistically significant positive correlation with the mean serum levels of CPK-MB with a correlation coefficient (R2) of 0.781 and a p value of <0.001. Thus, it may be useful in diagnosing ACS, especially in cardiac troponin T negative patients. CONCLUSION: Serum levels of PAPP-A is a sensitive and specific early marker of plaque instability, whose levels become elevated before or even in the absence of myocardial necrosis. This marker can improve diagnostic and therapeutic decision making in Acute Coronary Syndromes.
