An increase in certain microRNAs (miRNAs) circulating in the blood indicates injury to cardiac muscle, according to a study published online July 10 in the Proceedings of the National Academy of Sciences. While protein biomarkers, namely cardiac troponin, have served as the basis for diagnostic and prognostic evaluation of patients with heart muscle injury, the authors say that use of mRNAs may prove to be more sensitive and in the future may provide the basis for a “universal” test, rather than current assessment of single proteins. The researchers compared the composition of miRNAs in a cohort of patients with stable and advanced heart failure (HF; n = 35) to the composition of eight normal adult and five fetal samples. Heart failure patients were examined both before and after treatment with a left ventricular assist device (LVAD). The researchers identified three RNAs, known to originate in the heart, with potential for use as markers of heart injury. Heart- and muscle-specific circulating miRNAs (myomirs) increased up to 140-fold in advanced HF, which coincided with a similar increase in cardiac troponin I (cTnI). Three months after initiation of LVAD support, these extracellular changes nearly completely reversed. There was less than a fivefold difference […]