Chronic heart failure (HF) is a growing public epidemic with increasing incidence and prevalence. In the United States alone, it is estimated that >5 million people are affected by the diagnosis, with an estimated 825,000 new cases added domestically each year. Worldwide, the numbers are even grimmer, with nearly 29 million people affected by HF, with an expected prevalence of 42 million by 2018. Furthermore, despite important progress in recent decades, mortality remains high for patients with HF. While useful, established risk factors, such as New York Heart Association functional class, medication use, routine laboratory values, and left ventricular ejection fraction, do not fully explain the risk of patients with HF and do not estimate an individual’s prognosis. It is in this context that alternative means to evaluate, manage, and possibly prevent HF have been explored.
As a candidate for novel means for HF care, the use of biomarkers has grown. Beyond their value for informing the underlying biology of HF, risk stratification may be refined by the use of biomarkers that established clinical predictors of risk may not necessarily directly reflect. Indeed, the biomarkers that are currently available reflect at least 7 pathobiologic processes operative in HF, namely myocyte injury, myocyte stretch, myocardial fibrosis and remodeling, inflammation, oxidative stress, neurohormonal activation, and renal function. Natriuretic peptides (myocyte stretch) have evolved over the past 10 years to become part of the standard of care for evaluating patients with HF in both acute and ambulatory settings. Despite the well-documented successes and strengths of natriuretic peptides, there is plenty of room for improvement in the way we evaluate and risk stratify patients with or at risk for HF using biomarkers. Although a large number of candidate biomarkers have been evaluated to help fill this gap, few have survived the rigorous studies that are a prerequisite to allow for translation into the clinical realm. It now appears clear that ST2 (reflecting myocardial fibrosis and remodeling) is a biomarker that has successfully navigated this course and is recently emerging as a reliable tool for patient care.
The recent 2013 American Heart Association/American College of Cardiology Guidelines for the Management of Heart Failure give a recommendation for the measurement of ST2 in acute and ambulatory patients with HF, noting that ST2 is not only predictive of hospitalization and death in patients with HF but also additive to the natriuretic peptides in its prognostic value. The body of evidence surrounding ST2 in both acute and chronic HF is growing rapidly, and with this, its clinical use has increased.
Given the rapid increase in scientific reports discussing ST2 and heart disease, we felt it appropriate to propose an international working group focused on appropriate use of ST2 across a wide range of topics. Accordingly, the International ST2 Consensus Panel was gathered in March 2014 to discuss and update the increasing number of studies focused on the use of ST2. Lead international opinion leaders from the United States (J.L. Januzzi, E. Bajwa, L. Daniels, C. deFilippi, J. Ho, A. Jaffe, B. Ky, A. Maisel, D. Morrow, M. Sabatine, and T. Wang), Europe (A. Bayes-Genis, S. di Somma, A. Mebazza, T. Mueller, C. Muller, and D. Pascual-Figal), and Asia (A.M. Richards, P. Sritara, and Y. Zhang) reviewed ST2 from its biology, analytic considerations, and presence in the general population to ST2 in acute and chronic HF (prognosis, monitoring and multimarker testing), ST2 in pulmonary disease, ST2 in ischemic heart disease, and echocardiographic correlates of ST2.
