Hosted by Wyss Core Faculty David R. Walt, PhD, Diagnostics Grand Rounds brings clinicians with unmet needs to the Wyss Institute. The goal of these sessions is to inform technology developers about important clinical problems that can help them direct their technology development efforts. Presenters are asked to identify diagnostic needs that will have an impact on the quality of care they deliver.
Significant improvements have been made since the implementation of the first cardiac troponin I and cardiac troponin T assays for the diagnosis of acute myocardial infarction almost 40 years ago. Compared to the first generation, current assays are about hundred times more sensitive, time between specimen collection and result availability is shorter, and countless studies aimed at determining optimal diagnostic algorithms have been performed. Still, additional improvements in cardiac troponin testing are needed.
Despite decades of development, the tests are not standardized. It is impossible to directly correlate troponin I and T results, and it is not even possible to reliably compare troponin I assays developed by different vendors. While the sensitivity of tests on large laboratory analyzers is mostly adequate, performance of point of care assays needs improvement. Clinicians would benefit from robust platforms that would allow testing in patient’s home or during transfer to emergency department and reliable home tests would benefit patients who could assess their troponin levels. While the specificity of current assays is good with minimum interference from other analytes, they do not distinguish full size troponin molecules released during acute damage to cardiac myocytes from troponin fragments that may circulate for days.
Importantly, we may need different assays and different diagnostic cutoffs for multiple additional applications of cardiac troponins. In addition to reasonably well-established reference ranges and diagnostic cutoffs for the diagnosis of acute myocardial infarction, we should consider different cutoffs and even different assay types for cardiac troponin tests used, among others, to monitor cardiac damage during potentially cardiotoxic cancer treatments, to diagnose myocardial injury during non-cardiac surgery, or to predict future adverse events such as transition to later stages of heart failure in patients with type 2 diabetes.
Using the history of cardiac troponin testing as the leitmotif of this presentation, we will discuss multiple performance requirements of current and future automated immunoassays.