Salivary troponin I as an indicator of myocardial infarction

BACKGROUND & OBJECTIVES Accurate and rapid diagnosis of acute myocardial infarction (MI) is of major clinical significance. The troponin is the biomarker of choice for detection of cardiac injury. The objective of this study was to identify salivary levels of cardiac troponin I (cTnI) in patients with acute MI. METHODS Thirty patients with acute MI and 28 normal healthy individuals were included in the study. cTnI levels were assayed in serum and saliva 12 and 24 h of acute MI by ELISA method. RESULTS In patients with acute MI, the serum and resting (unstimulated) saliva concentrations of cTnI, but not stimulated saliva cTnI, at both 12 and 24 h of onset of MI, were significantly higher than in controls. Resting saliva cTnI concentrations correlated significantly with serum cTnI levels (spearman rho = 0.34 and 0.45 in the total individuals and in the MI patients respectively). INTERPRETATION & CONCLUSIONS The present results suggest that saliva can be an analytical matrix for measurement of cTnI in patients with acute MI. Further studies may reveal capability of salivary cTnI for being used for developing point-of-care testing for early detection of MI in pre-clinical settings.