Circulating micro ribonucleic acids in cardiovascular disease: a look beyond myocardial injury
Laboratory markers are of significant clinical importance in the evaluation of patients with suspected cardiac diseases. They have evolved as essential tools in cardiology over the last 50 years, i.e., lipid testing for primary and secondary prevention, creatine kinase isoenzyme MB and subsequently the more sensitive and specific cardiac troponin (cTn) testing for the diagnosis and management of acute myocardial infarction (AMI), and more recently natriuretic peptide (NP) testing for the diagnosis (in particular exclusion), risk stratification, and monitoring of heart failure (HF) (1-3). We are beginning an era when it may be possible for biomarkers to direct treatment to optimize patient management. This is already the case with cTn (1,4) but should be the final goal with all cardiac biomarkers. However, there are still some open major clinical issues, e.g., the diagnosis of myocardial ischemia. Despite huge research efforts in recent years, which were triggered by the great clinical significance and economic impact of cardiac diseases, biomarkers for the prediction of coronary artery disease (CAD) and for risk stratification in stable CAD or the general population have not yet fulfilled their manifest promise so far (5). The most established marker in this respect is high-sensitivity C-reactive protein (hs-CRP) which still remains controversial (3,6).