The use of cardiovascular biomarkers for the assessment of heart disease in men

Cardiovascular disease (CVD) is the leading cause of death in the Western World. CVD is not a disease of old age: evidence from autopsy studies demonstrated the presence of atheroma in coronary arteries in children as young as seven years old. CVD does not occur in isolated succinct episodes but occurs as a continuous spectrum, from initiation of atheroma formation, destabilization, development of cardiac ischemia through to cellular necrosis and cardiac dysfunction. The symptomatic part of the disease spectrum is known as the acute coronary syndrome (ACS). ACS is due to the rupture or erosion of atheroma. This produces, depending on its size, surrounding vascular anatomy and the degree of collateral vessels present, a mismatch between oxygen supply and demand resulting in tissue ischemia. This may progress to cardiomyocyte necrosis, known as a myocardial infarction (MI). Post-MI survival results in remodelling of the myocardium and the development of cardiac failure. A number of blood-borne biomarkers are available which can aid in the diagnosis of all of disease stages: the risk assessment of developing CVD, assessing the risk of plaque rupture, diagnosis and prognosis of ACS and the subsequent assessment of myocardial dysfunction. The most challenging stage with respect to biomarkers and one of current research focus is the detection of cardiac ischemia. A number of potential ischemia markers have been investigated. However, to date, only one, ischemia-modified albumin (IMA) has been clinically validated. The problem associated with developing an ischemia marker is that there is currently no reference standard for diagnosis. This is problematic when assessing the sensitivity and specificity of any candidate biomarker. Measurement of the cardiac structural proteins, the troponins is now recognised as the gold standard test for detection of myocardial necrosis. The sensitive nature of these tests has also revealed that myocardial necrosis is also found in a range of other clinical situations, including trauma, pulmonary embolism, renal failure, multiple organ failure or in cases of arduous physical exercise. This highlights the need to assess biomarker status in conjunction with the clinical picture at presentation. The natriuretic peptides, in particular the B-type and its N-terminal pro-hormone cleaved subunit are diagnostic and prognostic in both acute ACS and detecting post infarction myocardial dysfunction. The role of the B type natriuretic peptides in detection of cardiac failure, both acute and chronic, is well defined. Their role in ACS remains the subject of further studies