User Perspectives of Cardiac Marker Point-of-Care Testing for Hospital-Based Chest Pain Diagnosis

The impact of new trends in POCTs for companion diagnostics, non-invasive testing and molecular diagnostics

Point-of-care diagnostics have been slowly developing over several decades and have taken on a new importance in current healthcare delivery for both diagnostics and development of new drugs. Molecular diagnostics have become a key driver of technology change and opened up new areas in companion diagnostics for use alongside pharmaceuticals and in new clinical approaches such as non-invasive testing. Future areas involving smartphone and other information technology advances, together with new developments in molecular biology, microfluidics and surface chemistry are adding to advances in the market. The focus for point-of-care tests with molecular diagnostic technologies is focused on advancing effective applications.

Point-of-care diagnostics - is this driven by supply or demand?

The diagnostic point-of-care testing (POCT) market is about one-third of the in vitro diagnostic (IVD) testing market but, although there are many different POCT products, most are for pregnancy and monitoring of diabetes (∼ 70% of all POCT). Despite the small contribution outside these areas there is huge investment from both suppliers and users of POCT to establish new products and increase the infrastructure for their use. The review is focused on determining the balance between the different drivers of supply and demand and how they have impacted the conflicts seen in POCT evolution. The conflicts have been based on a mix of analytical, regulatory, political and commercial aspects and here the supply and demand drivers are examined separately to determine whether the conflicts are real or whether there are hidden synergies. The focus is on recent publications, with reference to some key historical articles, so that the full environment can be assessed. It is concluded that the synergies between supply and demand now overcome the conflicts where clinical and economic benefit can be demonstrated.

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.