MODERN METHODS TO DIFFERENTIATE BETWEEN CHEST PAIN AND CARDIAC ISCHEMIA

Abstract

Acute coronary syndrome (ACS) is a group of conditions which often present with similar signs and symptoms while having different outcomes and complications. Therefore it is essential to differentiate between them as soon as possible and provide appropriate management. Acute coronary syndromes are classified into two categories: STE-ACS (ST segment Elevation Acute Coronary Syndrome) and NSTE-ACS (Non ST segment Elevation Acute Coronary Syndrome). STE-ACS stands for ST Elevation Acute Coronary Syndrome all of which demonstrate significant ST elevations on ECG due to complete blockage of artery by thrombus, while NSTE-ACS is due to partial occlusion of artery which exhibit ST segment depression and/or T wave inversions. Patients with NSTE-ACS who do not develop infarction are diagnosed with unstable angina, which itself is a precursor of myocardial infarction. Acute coronary syndromes are considered multifactorial and risk factors most commonly associated with development of acute coronary syndromes include: hypertension, smoking, diabetes, obesity, sedentary life-style, hereditary conditions etc. Chronic stress to the coronary endothelium eventually leads to inflammation and atherosclerotic plaque formation. Plaque at some point with additional stress will rupture and trigger thrombus formation. Probability of plaque rupture depends on its composition: stable plaques contain small fatty core and thick fibrous cap, unstable plaque have larger fatty cores and thin fibrous cap. Patients with acute coronary syndromes present with chest pain and/or discomfort and may experience tightness and pressure sensation; pain may radiate to left or both arms, jaw, back or stomach, sweating, dyspnea and dizziness are also common complaints. Whenever we suspect ACS first diagnostic tests is always ECG (Electrocardiography). If ST segment is persistently elevated STEMI (ST Elevation Myocardial Infarction) can be diagnosed and reperfusion therapy is indicated; but if ST segment is depressed and/or T wave inversion is present laboratory tests are necessary for diagnosis. Cardiac biomarkers mainly used in the clinic are Troponins and CK-MB (Creatine Kinase MB), yet LDH (lactate dehydrogenase), B-type natriuretic peptide and C-reactive protein can be used additionally. Several studies have been conducted in hopes to find other myocardial markers useful for diagnosis of ACS, one of which tested candidate biomarkers such as hFABP (Heart-type fatty acid binding protein), GPBB (Glycogen Phosphorylase Isoenzyme BB), S100, PAPP-A (Pregnancy-associated plasma protein A), TNF (Tumor Necrosis Factor), IL6 (Interleukin 6), IL18 (Interleukin 18), CD40 (Cluster of differentiation 40) ligand, MPO (Myeloperoxidase), MMP9 (Matrix metallopeptidase 9), cell-adhesion molecules, oxidized LDL (Low Density Lipoprotein), glutathione, homocysteine, fibrinogen, and D-dimer, procalcitonin. The idea of this study was to estimate usefulness of combining enzymatic markers with nonenzymatic ones in the clinical settings.