The analytics behind accurately assessing acute and chronic cardiovascular disease (CVD) and chronic kidney disease (CKD) will be the focus of the Journal of Applied Laboratory Medicine’s(JALM) Hot Topics of 2018 scientific session at the 70th AACC Annual Scientific Meeting & Clinical Lab Expo in Chicago.

Heart disease is the biggest killer of both men and women in the United States and in the Western world, session moderator Robert Christenson, PhD, JALM’s editor-in-chief, told CLN Stat. In addition, CKD kills about 90,000 individuals per year in America, which is more deaths than both prostate cancer and breast cancer combined. “There is a tightly linked, uneasy marriage between renal and cardiovascular systems. And when both are involved in a patient’s condition, a particularly high-risk profile results,” said Christenson, professor of pathology and professor of medical and research technology at the University of Maryland School of Medicine in Baltimore.

JALM’s scientific session, From the Kidney to the Heart: Analytical and Clinical Complexities of the Cardio-renal Systems (34109), will take place from 10:30 a.m. to noon on August 1 and is worth 1.5 CE hours. Three speakers affiliated with the journal will cover high-sensitivity troponin (hs-cTn) assay confounders as well as quality management issues and innovations in assessing cardiac and renal biomarkers.

Laboratory medicine plays a central role in both cardiac and renal disease, Christenson said. “For example, cardiac troponin measurements, the keystone for heart attack diagnosis, is entering into the era of high-sensitivity worldwide. Individuals and stakeholders who are involved with laboratory medicine must understand the implications of this transition to the high-sensitivity cardiac troponin assays,” he said.

Understanding renal function is also key. The session will cover recent findings on assessing renal function and injury, Christenson said. “Also, infectious disease is a player in this field. Effective treatments for HIV-positive patients have transformed this disease from an acute killer into a chronic disease. This is a victory of modern science and medicine,” he said. “It is clear, however, that these individuals are subject to accelerated atherosclerosis and are at high risk for heart disease at an earlier age. Biomarker strategies and discoveries will allow clinicians to better guide the care of these patients.”

Co-presenter John Toffaletti, PhD, DABCC, professor of pathology at Duke University Medical Center in Durham, North Carolina, plans to discuss the clinical value of measuring creatinine and cystatin C, and explore appropriate use of estimated glomerular filtration rate (eGFR) versus measured GFR (mGFR). There are several points to consider when comparing the pros and cons of eGFR versus mGFR to assess renal function, Toffaletti, who serves on JALM’s board of editors, told CLN Stat.

Despite its reputation as the gold standard, mGFR is actually a very mediocre diagnostic test. “While its reference range is at least as wide as serum creatinine, its within-individual variation is much greater than creatinine or cystatin C. Because of this variation in mGFR, true changes related to declining kidney function are obscured,” Toffaletti said. All mGFR tests, whether they’re done by clearance tests or by monitoring the decline in blood concentration over time, are time-consuming, cumbersome, expensive, and not suitable for any type of rapid result, he added.

The original staging of CKD based solely on mGFR had large overlaps between no apparent disease and those with some degree of kidney damage. Toffaletti suggested that the inclusion of urine albumin in the nomogram should improve clinical usefulness of this method.

In contrast eGFR uses a serum or plasma creatinine (and sometimes a cystatin C) result that’s been manipulated mathematically to resemble a quantity similar to mGFR. “However, eGFR and mGFR are physiologically very distinct parameters and show great variation with each other, as is clearly demonstrated by all comparisons of eGFRs to mGFRs,” Toffaletti explained. eGFR is much more stable over time with normal kidney function whereas mGFR varies throughout the day, as it should to maintain homeostasis in blood.

Toffaletti offered that serial monitoring of creatinine and/or cystatin C are most useful for detecting a change in kidney function, if available.

In another presentation, Paul Collinson, MD, PhD, FRCP, FADLM, a consultant with St George’s Hospital in London, will cover successful implementation of hs-cTn assays. Christopher deFilippi, MD, a cardiologist with the Inova Heart and Vascular Institute in Falls Church, Virginia, will discuss accelerated CVD in HIV-positive patients and the role of biomarkers in diagnosing, assessing prognosis, and treating these patients.

Learn more about the proper usage of cardiac and renal biomarkers at the 70th AACC Annual Scientific Meeting & Clinical Lab Expo July 29–August 2 in Chicago.