Markers of cardiac ischemia and inflammation

Recent advances have identified many promising new molecular markers of ischemia and inflammation. Their clinical usefulness requires satisfaction of the following criteria: they must (1) be easily available, simple, and standardized assay, (2) have trial-based evidence of association with clinical end points, (3) be generalizable to various population groups, and (4) demonstrate adequate sensitivity and specificity. There is a growing recognition of the role of hsCRP in further risk assessment, particularly in patients at intermediate cardiovascular risk and for risk stratification in patients who have ACS. However, it has limited diagnostic usefulness in chest pain patients. Ischemia-modified albumin is now available clinically to rule out acute coronary ischemia in conjunction with standard troponin and ECG evaluation, and whole blood choline and MDA-modified LDL are two markers of plaque instability that have been shown in small trials to diagnose unstable angina with good sensitivity and specificity. However, larger clinical trials will be needed to validate their clinical value. As understanding of the pathophysiology of atherothrombosis evolves, the number of candidate markers meriting clinical consideration will increase exponentially. The hope is that these markers will permit earlier detection of disease, allowing time for interventions to circumvent myocardial damage and other complications. The challenge for clinicians will be to integrate marker testing into practice without overwhelming, or substituting for, clinical judgment and rational decision making.