Use of saliva-based nano-biochip tests for acute myocardial infarction at the point of care: a feasibility study.
BACKGROUND
For adults with chest pain, the electrocardiogram (ECG) and measures of serum biomarkers are used to screen and diagnose myocardial necrosis. These measurements require time that can delay therapy and affect prognosis. Our objective was to investigate the feasibility and utility of saliva as an alternative diagnostic fluid for identifying biomarkers of acute myocardial infarction (AMI).


METHODS
We used Luminex and lab-on-a-chip methods to assay 21 proteins in serum and unstimulated whole saliva procured from 41 AMI patients within 48 h of chest pain onset and from 43 apparently healthy controls. Data were analyzed by use of logistic regression and area under curve (AUC) for ROC analysis to evaluate the diagnostic utility of each biomarker, or combinations of biomarkers, in screening for AMI.


RESULTS
Both established and novel cardiac biomarkers demonstrated significant differences in concentrations between patients with AMI and controls without AMI. The saliva-based biomarker panel of C-reactive protein, myoglobin, and myeloperoxidase exhibited significant diagnostic capability (AUC = 0.85, P < 0.0001) and in conjunction with ECG yielded strong screening capacity for AMI (AUC = 0.96) comparable to that of the panel (brain natriuretic peptide, troponin-I, creatine kinase-MB, myoglobin; AUC = 0.98) and far exceeded the screening capacity of ECG alone (AUC approximately 0.6). En route to translating these findings to clinical practice, we adapted these unstimulated whole saliva tests to a novel lab-on-a-chip platform for proof-of-principle screens for AMI.


CONCLUSIONS
Complementary to ECG, saliva-based tests within lab-on-a-chip systems may provide a convenient and rapid screening method for cardiac events in prehospital stages for AMI patients.
Floriano
Pierre N
PN
Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78735, USA.
Christodoulides
Nicolaos
N
Miller
Craig S
CS
Ebersole
Jeffrey L
JL
Spertus
John
J
Rose
Beate G
BG
Kinane
Denis F
DF
Novak
M John
MJ
Steinhubl
Steven
S
Acosta
Shelley
S
Mohanty
Sanghamitra
S
Dharshan
Priya
P
Yeh
Chih-ko
CK
Redding
Spencer
S
Furmaga
Wieslaw
W
McDevitt
John T
JT
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis*; D001798:Blood Proteins / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D019095:Point-of-Care Systems; D040081:Protein Array Analysis / Q000379:methods*; D011506:Proteins / Q000032:analysis*; D012372:ROC Curve; D012463:Saliva / Q000737:chemistry*; D012680:Sensitivity and Specificity
D015415:Biomarkers; D001798:Blood Proteins; D011506:Proteins