- Field of the invention: The present invention relates to levuglandin derivatives as antigens for raising antibodies useful in diagnostic assays. Background of the invention: Cardiovascular disease is a broad term encompassing many pathologies of the heart and vascular system, including hypertension, stroke, aneurysm, angina, myocardial infarction, and Raynaud's disease. During 1990, cardiovascular disease caused about 43% of the deaths (more than 900,000 people) in the United States. Thus, the number of deaths from cardiovascular disease was nearly as high as the number of deaths from all other causes combined. [J. T. Shepherd, et al., "Report of the Task Force on Vascular Medicine," Circulation 89 (1): 532-35 (1994)]. Cardiovascular disease is also a leading cause of morbidity. Both patients and their families suffer a great deal from the effects of cardiovascular disease. Furthermore, there is a tremendous economic impact associated with such illness. Both the high incidence and the often-severe manifestations of cardiovascular disease necessitate that a large portion of health care workers' time be devoted to the care of patients suffering from the disease state. Moreover, sufferers of cardiovascular disease lose countless numbers of productive hours each year due to their illness. It is important to remember that cardiovascular disease affects many people besides the elderly or those having a familial predisposition. The establishment of detailed guidelines directed solely to the evaluation of congenital cardiac problems in pre-adults illustrates that the young are not immune from cardiovascular disease. [D. Driscoll et al. "Guidelines for Evaluation and Management of Common Congenital Cardiac Problems in Infants, Children, and Adolescents," Circulation 90 (4): 2180-88 (1994)]. Currently used techniques for diagnosing cardiovascular disease include electrocardiography, imaging, and measurement of risk factors. Each of these techniques is plagued by significant drawbacks. A. Electrocardiography The traditional approach to diagnosing cardiovascular disease is electrocardiography, a relatively safe and easy method. However, the method, which records electrical currents traversing the heart muscle, has been associated with false-negatives and false-positives in particular patient populations. Though a good initial indicator of various disease states, electrocardiography is an indirect and imperfect measurement of the heart's electrical activity. [M. S. Remetz and R. A. Matthay, "Cardiac Evaluation," Disease-a-Month 38 (6): 338-503 (1992)]. B. Imaging Intravascular imaging is helpful as a diagnostic tool; many of the routinely used imaging methods are quite invasive. In addition, the imaging techniques are expensive, requiring costly equipment and extensively trained personnel to conduct the studies.