Salivary Biomarkers of Acute Myocardial Injury

Objective: We extended those findings by analyzing the kinetic profile of salivary and serum biomarker profiles in patients undergoing alcohol septal ablation and percutaneous coronary intervention (PCI) as models of acute myocardial injury. 

Method: Unstimulated whole saliva (UWS) and serum were obtained from ablation (n=19) and PCI (n=10) subjects and non-AMI controls (n=99).  Samples were procured from subjects at 0, 4, 8, 16, 24 and 48 hrs post-procedure.  Controls provided a saliva and blood sample. Thirteen biomarkers relevant to cardiovascular disease were determined using Luminex immunoassays. 

Result: Cardiac enzymes (troponin I [TnI], creatine kinase-MB [CK-MB], and myoglobin [MYO]) showed significant elevations in serum of ablation patients (5- to 800-fold increases; p<0.01), with corresponding profiles, albeit lower levels in UWS (p<0.05). Serum levels of cardiac enzymes were significantly elevated 8 to 24 hr after PCI (p<0.05), and 5- to 10-fold lower than ablation levels. In ablation patients, UWS C-reactive protein, IL-6, TnI and TNFa levels were significantly elevated between 8-24 hr, whereas significant decreases occurred in sCD40-L at 8 hr, and in IL-1b, sICAM-1, and adiponectin between 24-48 hr (p<0.05).  Biomarkers that ranked high and low in serum displayed similar profiles in UWS, following both procedures.  Also, at multiple time points and with both procedures, UWS CRP, MMP-9 and myeloperoxidase correlated positively (r>0.59) with serum concentrations (p<0.03). 

Conclusion: Biomarkers identified in UWS of ablation and PCI patients are similar to those we previously identified in UWS of AMI patients, with early UWS biomarkers of myocardial injury appearing to be MYO, CK-MB, TnI and sCD40L. These findings suggest that select UWS biomarkers may be useful for aiding in the identification of AMI.