Troponin not just a simple cardiac marker: prognostic significance of cardiac troponin

OBJECTIVE: The object of this study was to review the role of cardiac troponin as a prognostic factor in acute coronary syndrome patients of varying circumstances. DATA SOURCES: The data used in this review were obtained mainly from the studies of cardiac troponin reported in pubmed from 1981 to 2006. STUDY SELECTION: Relevant articles on studies of cardiac troponin were selected. RESULTS: Elevated cardiac troponin in patients with ST elevation and non ST elevation myocardial infarction was associated with adverse outcomes, including a higher incidence of congestive heart failure, shock, and death. Patients with elevated cardiac troponin value seemed to benefit more from invasive strategies including a percutaneous coronary intervention and bypass surgery, but elevated cardiac troponin was also correlated with adverse outcomes, including a higher degree of failure, shock, and mortality in patients undergoing percutaneous coronary intervention; a higher degree of perioperative myocardial infarction, low cardiac output syndrome, cardiopulmonary resuscitation, and new-onset ventricular arrhythmia in patients undergoing bypass surgery were also observed. Elevated troponin after a percutaneous coronary intervention seemed to be associated with short-term adverse outcomes rather than long-term adverse outcomes, unless the elevation of the troponin post percutaneous coronary intervention was quite high (about 5 times above normal). On the contrary, elevated cardiac troponin after bypass surgery was more confusing to analyze since it happened in almost all patients. Furthermore, differences in cutoff values and time measurements in some studies add more confusion; thus, further research is warranted. CONCLUSIONS: The prognostic value of cardiac troponin is demonstrated in almost all acute coronary syndrome patients. In addition to its high sensitivity and specificity, the prognostic value of cardiac troponin is another reason to make it the "golden cardiac marker" of this time.