Counterpoint: Detection of Myocardial Infarction—Is It All Troponin? Role of New Markers

Abstract

It has become good scientific practice to mention potential conflicts at the beginning of the presentation. My main conflict related to this topic is that I love cardiac troponin, for the very reasons listed by Giannitsis and Katus (1). Cardiac troponin is beyond a doubt the most important biomarker in cardiovascular medicine, even more so after the clinical introduction of sensitive assays (1–6). For the detection of acute myocardial infarction (AMI),2 the room for additional biomarkers, if any, seems to be small and restricted to add-on applications to be used in conjunction with cardiac troponin, clinical assessment, and the 12-lead electrocardiogram. Clinical settings in which there are still unmet needs include: ( a ) the early diagnosis of AMI, ( b ) differentiation of type I and type II AMI, and ( c ) risk stratification for death or recurrent AMI. Cardiac troponins are structural proteins. Their detection in peripheral blood indicates cardiomyocyte damage and likely cell death (1–7). Invariably, there is some time delay between the onset of AMI (coronary plaque rupture and coronary occlusion) and the appearance of cardiac troponin in the peripheral circulation. Because cardiac troponin signals cardiomyocyte damage regardless of the underlying cause, multiple nonischemic conditions can challenge the interpretation of increases in cardiac troponin, particularly mild ones (1, 7). Thus, we could benefit from information provided by additional biomarkers that ( a ) reflect myocardial ischemia (not necrosis), ( b ) indicate plaque rupture or other signals present at the very onset of AMI (e.g., endogenous stress), or ( c ) are associated with a specific pathobiology present in only a subset of AMI patients, thereby allowing more personalized and targeted patient management. Recent evidence suggests that markers fulfilling at least some of these properties might soon become clinically available. Copeptin, the C-terminal part of the vasopressin prohormone, is secreted stoichiometrically …