Cardiac troponin is extensively used as a biomarker in modern medicine due to its diagnostic capability for myocardial injury, as well as its predictive and prognostic value for cardiac diseases. However, heterophile antibodies, antitroponin antibodies, and macrotroponin complexes can be observed both in seemingly healthy individuals and patients with cardiac diseases, potentially leading to false positive or disproportionate elevation of cTn (cardiac troponin) assay results and introducing discrepancies in clinical interpretations with impact on medical management. In this review article, we describe the possible mechanisms of cTn release and the sources of variations in the assessment of circulating cTn levels. We also explore the pathophysiological mechanisms underlying antitroponin antibody development and discuss the influence exerted by macrotroponin complexes on the results of immunoassays. Additionally, we explore approaches to detect these complexes by presenting various clinical scenarios encountered in routine clinical practice. Finally, unsolved questions about the development, prevalence, and clinical significance of cardiac autoantibodies are discussed.

The use of transcatheter edge-to-edge mitral valve repair (TEER) in symptomatic patients with severe mitral regurgitation (MR) has dramatically increased over the last few years. Current guidelines consider TEER as a reasonable option in symptomatic patients with primary or chronic secondary severe MR with high or prohibitive surgical risk and favorable anatomy. However, several anatomical and morphological mitral features have restricted the use of this mini-invasive technique in its early experience. The latest fourth generation (G4) of the MitraClip system has been recently introduced and includes the possibility of independent leaflet grasping and 4 different sizes. This technical update offers the possibility of selecting and combining multiple devices for complex mitral valve anatomies and challenging procedures, which helps expand the applications of TEER. The present review describes the potential advantages and the help of the MitraClip G4 devices to overcome various anatomic and morphologic issues in challenging cases with complex primary and secondary MR procedures.