Troponin and BNP: Diagnostic laboratory testing in Cardiovascular Disease Management

Abstract

Heart failure (HF) is a prevalent and costly syndrome resulting from structural or functional cardiac disorders that impair the heart's ability to maintain physiological circulation. Diagnosis relies on clinical judgment combining history, physical examination, and appropriate investigations, with natriuretic peptides, particularly B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP), serving as first-line biomarkers. BNP and NT-proBNP levels indicate treatment effectiveness and are strongly recommended for prognostic purposes. Elevated cardiac troponin levels, measured using high-sensitivity methods, are associated with worse clinical outcomes in HF patients. Additional biomarkers, such as galectin-3 and soluble ST2, have been suggested for risk stratification. A multi-marker approach combining multiple biomarkers is considered the most effective model for individual cardiovascular risk prediction. However, developing reliable and robust measurements for cardiovascular biomarkers poses significant challenges due to their low concentrations and heterogeneity in circulation. Standardization efforts aim to establish reference measurement procedures and materials to enhance comparability and reliability. Harmonization, defined as a reduction in heterogeneity among results from different methods, may be attainable through deeper insights into the biochemical properties and pathophysiological roles of candidate biomarkers. The B-type cardiac natriuretic peptide system exemplifies the complexity of biomarker measurement, with numerous proBNP-derived fragments identified in human plasma. Developing more specific assays for active BNP1–32 and concurrent measurement of proBNP and BNP could improve harmonization and understanding of cardiac endocrine dysfunction in HF. Rigorous evaluation of new methods in clinical trials, following evidence-based principles, is essential to determine their utility compared to existing assays.