Cardiac troponins--biochemical markers of cardiac toxicity after cytostatic therapy.

Cardiotoxicity is a serious adverse effect of chemotherapy that encompasses a spectrum of disorders, ranging from relatively benign arrhythmias to potentially lethal conditions such as myocardial ischemia/infarction and cardiomyopathy. The toxicity of chemotherapeutic drugs can cause loss of myocytes' sarcolemmal integrity, release of bioactive markers into the extracellular environment (tissue and circulation) and ultimately leading to the necrosis of myocytes. The extent and severity of the necrosis can be monitored by the levels of bioactive markers. Therefore current research is aimed at finding biochemical markers with absolute cardiac specificity, high sensitivity and predictive value that can be used in early detection of patients with treatment-induced myocardial damage. Routinely used biomarkers like CK, CK-MB, and myoglobin do not meet the stated criteria. Their role in early diagnosis of chemotherapy- induced myocardial toxicity is controversial and limited. However, cardiac troponins, new nonconventional markers, have shown promising results in assessment and monitoring of both, early and late, clinical and subclinical damage to myocardium after chemotherapy. The article reviews clinical studies evaluating the role of cardiac troponins in the diagnosis of cardiotoxicity and their use in the management of cancer survivors.