In assessing the use of cardiac biomarkers, what units should you use? What are the value and minimum analytical requirements for point-of-care testing (POCT)? And what should labs consider in establishing the 99th percentile of a normal population for cardiac troponin testing?

Fred Apple, PhD, will discuss these issues during AACC's virtual conference on Nov. 12, “Acute Cardiac Biomarkers Update: Laboratory Guidelines Focused on Clinical Need,” sponsored by Roche. Laboratorians who attend this all-day event will get a tutorial about their expanding role in helping doctors treat patients at-risk for cardiovascular disease.

Apple is the medical director of clinical laboratories at Minneapolis-based Hennepin County Medical Center and professor of laboratory medicine and pathology at the University of Minnesota. During his session, he plans to address analytical issues that influence cardiac troponin assay use in clinical practice, emphasizing the high-sensitivity assays not yet approved for clinical use in the U.S. and the role of POCT assays.

Labs need to consider a number of things in setting the 99th percentile of a normal population, Apple told CLN Stat. This includes “defining minimal number and gender and ethnic/race diversity of apparently healthy subjects needed to establish 99th percentile upper reference limits, and how to use the literature or industry package insets in determining what cutoffs to use.”

On the role of POCT in suspected acute myocardial infarction cases, Apple said the use of this test will mostly depend on the need for around-the-clock turnaround time requirements—with the understanding that POCT assays are often not as analytically robust or as sensitive as central lab assays.

Turnaround time, along with clinical diagnostic accuracy, and imprecision characteristics at the 99th percentile, are the minimal analytical requirements for POCT for cardiac markers, he said.

The fact that not all assays are created equal is a big takeaway for laboratorians, Apple said. Labs should also be aware that multiple assays used within a hospital or healthcare system with different 99th percentiles might be very confusing to providers, he offered.

Register online to attend this full-day virtual conference on acute heart and kidney disease biomarkers.