The first serum marker [serum glutamic-oxaloacetic transaminase (SGOT), also known as aspartate transaminase (AST)] to facilitate the diagnosis of myocardial infarction (MI) was described in 1954. It took 20 years before the next significant development was documented in the form of creatine kinase (CK)-MB measurement. However, the pace of discovery of new markers of MI has since accelerated. We have seen the emergence of completely new, nonenzymatic MI markers, such as the cardiac troponins, during the past 10 years. Descriptions of experimental immunoassays for measuring other structural proteins of the myocardium are published almost daily. “Old” markers have been given new life in the form of CK-MB isoforms, and we are looking for biochemical markers that will predict imminent MI instead of documenting the fact that the myocardium has suffered an ischemic injury. Additionally, the new markers have redefined our understanding of the ischemic syndromes and are changing traditional therapeutic approaches. The change is so rapid that it is sometimes hard, even for the researcher interested in this field, to keep up with new developments. In fact, many relatively new clinical chemistry and pathology textbooks are outdated when discussing the biochemical markers of MI.
It was not a day too soon to publish a book that focuses on coronary artery disease (CAD) and the laboratory diagnosis of the related syndromes. Cardiac Markers, edited by Alan Wu, sets out to do this, and it does it well. Dr. Wu and the other authors of the book, some active researchers themselves in the field of cardiac markers, do an excellent job of reviewing the clinical and laboratory aspects of MI.
The book comprises four parts, which focus on the clinical aspects of CAD, traditional cytoplasmic markers, current structural markers of MI, and future markers. Each part is filled with essential information for laboratorians and clinicians alike. The book has an extensive list of references, although some chapters could have used a last-minute update of references because of the rapid pace of change in the field.
The first part of the book discusses the clinical aspects of ischemic changes of the myocardium and presents a general overview of the biochemical markers. Chapters 3 and 4 are a must for every laboratorian who performs biochemical marker testing for MI. Cardiologists and emergency room physicians will also find these chapters useful, despite the somewhat dated references in chapter 4.
Part II of the book deals with the traditional, or cytoplasmic, markers. It has a comprehensive list of methodologies. Two methods, the manual column chromatography method and the DuPont aca column chromatography/immunoinhibition method for CK isoenzyme measurement are not even in use any more in the US. I would have preferred that discussions of these methods indicate that these techniques have historical interest only. The other techniques, such as electrophoretic measurement of CK isoenzymes and the immunoinhibition method for CK-MB, mostly have been replaced by CK-MB mass assays. The chapter on lactate dehydrogenase (LDH) isoenzyme measurement also is more reflective of the practice of the past than that of today.
The last two parts of the book contain the most practical information for laboratory professionals. The first chapter of Part III describes the biochemistry of troponins I and T. The following two chapters each start with the currently available immunoassays for the cardiac troponins and then discuss the clinical utility of cardiac troponins T and I, respectively. The roles of the cardiac troponins in MI, unstable angina, cardiac contusion, and various other clinical conditions are presented. Ample clinical and analytical information based on up-to-date references is provided for the reader. The last chapter of Part III provides a balanced review of the myosin heavy and light chains. Part IV is dedicated to future assays and assay formats, including point-of-care assays. It is worth buying the book just for these two parts. No other publication that I know of has such a comprehensive collection of clinical and technical information available on the current and future biochemical markers of MI.
A few errors have escaped detection. Some are minor, such as the misspelling of names of referenced authors; others are potentially misleading for the readers, e.g., the TIMI grades in Fig. 5 on page 13.
My overall assessment is that Cardiac Markers is a very timely and important book. It should be in the library of every laboratory professional. I know I will use my copy regularly in my daily work and in my teaching, and I urge you to do the same.
- © 1999 The American Association for Clinical Chemistry
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