NPPB and hydrops fetalis: Circulating cardiac troponin levels are excellent biomarkers of myocardial injury, including ischemia.6, 7 As such, several studies have used high-sensitivity troponin T (hsTnT) or high-sensitivity troponin I assays as a proxy for subclinical myocardial damage in investigating causes of HF.8, 9, 10, 11, 12 However, it is not clear from the existing literature what information troponin measurement adds to N-terminal pro–B-type natriuretic peptide (NT proBNP).