Cardiac markers: present and future

In the early twentieth century, acute myocardial infarction secondary to acute thrombotic coronary occlusion was considered a rare, fatal condition. Acute myocardial infarction is now one of the most-commmon serious illnesses in the industrialized world. Laboratory medicine now plays a crucial role in identifying risk factors, early events, and conditions triggering plaque rupture in coronary ischemic disease. However, the greatest progress in laboratory research has resulted from the discovery of new and more-promising biochemical markers of myocardial damage. The discovery of cardiac troponins, in particular, has heralded a new age in the diagnosis and treatment or management of a broad spectrum of diseases,;grouped together under the heading of acute coronary syndrome, and including stable and unstable angina, and non-Q wave infarction to Q-wave infarction. Cardiac troponins, which are selectively released by damaged myocardiocytes, have a specificity that has not only allowed an improvement in the diagnosis of acute cardiac ischemic disorders, but has also enabled us to make a more-reliable stratification of risk and prediction of outcome. It is generally agreed that two biochemical markers should be used: an early marker (and we recommend myoglobin for this) and a definitive marker, which is cardiac troponin (I or T). Future research is likely to include the standardization of methods for measuring current markers, troponin I in particular, the assessment of rapid bedside tests, and the investigation of the relationship between cardiac markers and emerging immunological and coagulation parameters. Thrombogenesis is now recognized as important in the final process of coronary atherosclerosis, and new markers of thrombogenesis should be used to evaluate the risk of plaque rupture and to monitor the outcome of thrombolytic therapy. Moreover, recent vascular biology studies have provided information on the developmental stages of atherosclerosis and emphasized the importance of the endothelium as a modulator of vascular reactivity, atherogenesis, and plaque stability. The different types of laboratory test (biochemical, immunological, and coagulative) now available, should soon allow improvement in the diagonsis and therapy of ischemic coronary diseases.