Origin of Cardiac Troponin T Elevations in Chronic Kidney Disease

Plasma concentrations of cardiac troponins, the preferred biomarkers for the diagnosis of acute myocardial infarction, are often persistently elevated in patients with chronic kidney disease (CKD). The origin of these elevations is unknown: Is it the heart, by increased release, or the kidneys, by decreased renal elimination? In clinical practice, this equivocal view on troponin elevations in patients with reduced glomerular clearance underlies countless clinical discussions among physicians and may delay rapid initiation of adequate treatment when these patients present with chest pain. In the present study, we aimed to discriminate between increased cardiac release and reduced renal elimination as the main process underlying this phenomenon. Specifically, we used the recently demonstrated rhythmic diurnal oscillation pattern of troponin T as a model to assess the contribution of impaired renal elimination to persistently elevated cardiac troponin levels in patients with CKD.1 The diurnal troponin T rhythm is characterized by gradually decreasing concentrations throughout daytime and rising concentrations during nighttime.1 If decreased renal clearance, and not increased production, is the key driver of elevated troponins in patients with CKD, the increased half-life and subsequent accumulation of cardiac troponin T will fade its diurnal rhythm. …