The Role of Troponins in the Laboratory Diagnosis of Heart Failure

Abstract

Cardiac troponins, particularly troponin I and troponin T, have emerged as valuable biomarkers for diagnosing and prognosticating ventricular dysfunction and heart failure. The introduction of high-sensitivity assays has revealed that cardiac troponins are frequently detectable in various acute and chronic conditions, including cardiac and non-cardiac diseases. Troponin elevation occurs regardless of ischemic or non-ischemic etiology, indicating that elevated levels are not exclusively specific to ischemic injury. In acute heart failure, troponin elevation is hypothesized to signify cardiomyocyte injury and cell death, with proposed mechanisms including neurohormonal activation, inflammatory cytokines, increased wall stress, ischemia, and oxidative stress. Elevated troponin levels in acute heart failure provide incremental prognostic information beyond established risk factors and are associated with poorer outcomes. In chronic heart failure, high-sensitivity assays have dramatically increased the proportion of patients with detectable troponin levels, and elevated levels predict adverse outcomes. High-sensitivity troponin assays also offer significant prognostic value for assessing the likelihood of future heart failure in patients with stable coronary artery disease and aortic stenosis. While troponin measurement aids prognostication, specific interventions targeting elevated levels in heart failure remain unsupported by current data. Further research is needed to elucidate the mechanisms of troponin release and develop targeted therapeutic strategies.