An ever-growing reliance is placed on cardiac biomarkers as indicators of cardiovascular disease as exemplified by the pivotal diagnostic component of troponin of the new universal definition of myocardial infarction; however, well-chosen biomarkers require an understanding of not only the good points but also the limitations of their diagnostic power.
Although there has been an incentive within the biochemical societies to disseminate the knowledge about the right application of cardiac biomarkers to a broad audience of cardiologists, the theme has never acquired a strong platform within the cardiac societies.For that reason the ESC Working Group on Acute Cardiac Care has set up a Study Group on Biomarkers in Cardiology, chaired by Professor Kristian Thygesen in order to implement the area of cardiac biomarkers in the clinical everyday of cardiology.
With this end in view, the Study Group recently organised a Consensus Conference in Rome with a selected group of experts.The topic to be considered at the Consensus Conference was the use of biomarkers in patients with acute cardiac conditions. The work of this Consensus Group was a continuation, in a sense, of the work recently completed on the refinement of the definition of MI. The current meeting was a “brain storming” session to enunciate some principles with respect to the use of biomarkers in the setting of acute cardiac care that would eventually lead to the publication of a citable document for dissemination to the wider cardiology and medical world.
Biomarkers reflect pathophysiological events in cardiovascular disease patients. Cardiac troponin is central (one might even say the “gold standard”) for the recognition of myocardial necrosis. The troponin standard for diagnosing MI has changed the relative incidence of unstable angina vs. MI with troponin increasing the percentage of the latter at the expense of the former. As more and more sensitive troponin assays are developed, it might even occur that unstable angina without myocardial necrosis would become an unusual diagnosis. Biomarkers should enable us to improve diagnosis and eventually therapy of patients with acute cardiac syndromes.
There are multiple problems when we deal with biomarkers in the clinical situation. The diagnostic dilemma with chest discomfort patients is in whom do we rule out MI and in whom do we rule in MI? The limits of normal in the troponin assay produce the dividing point between MI present and MI ruled out. Clinicians interpret elevated troponin levels as myocardial injury, but it tells them nothing about the etiology of the myocardial damage: ischemia, trauma, chemotherapeutic agents, etc.
Biomarkers are important in predicting outcomes and prognosis in heart failure. Clinical symptoms are not very accurate in identifying patients with that condition. However, biomarkers can help us to define these patients more accurately. BNP is an excellent hemodynamic marker in heart failure as it reflects systolic and diastolic dysfunction. In the emergency department and community practice, BNP is particularly useful for distinguishing pulmonary from cardiac dyspnea. A recent Canadian study demonstrated that BNP use in the emergency department resulted in substantial reductions in cost of treating these pts by shortening the duration of hospitalization.
Multimarker strategies have also been formulated and may in some instances add more prognostic information while in other settings it has been shown that one elevated biomarker is enough for prognostication. Multiple biomarkers used include troponin, CRP, and BNP. Risk assessment is helpful in selecting therapy for the patient, for example, elevated troponin in an ACS patient usually results in coronary angiography. This is particularly true if the patient had both an elevated troponin value and ECG changes of ischemia. The question still remains whether BNP is needed if the patient already has an elevated troponin value. It would appear that troponin and BNP are the best markers for prognosis in patients with acute cardiac disease.
Future plans for the Study Group include drafting a position paper with input from the various members of the Consensus Group. We anticipate further meetings with perhaps an enlarged group of experts to assist ultimately in the preparation of the final document concerning the principles for the development and use of biomarkers in acute cardiac care.
ESC Working Group on Acute Cardiac Care
Our mission: To reduce the burden of cardiovascular disease
© 2017 European Society of Cardiology. All rights reserved