['Increased myocyte loss and extracellular matrix (ECM) turnover are central mechanisms that contribute to pathological myocardial remodeling in chronic heart failure (HF). We tested the hypothesis that episodes of acute HF syndrome (AHFS) are associated with transient increases in markers of myocyte injury and ECM turnover beyond those observed in chronic stable HF.', 'Markers of myocyte injury and ECM turnover were assessed in 80 patients prospectively divided into 3 groups: AHFS (n=39); chronic stable systolic HF (n=21); and control subjects without HF (n=20). Myocyte injury was assessed by measuring plasma troponin I. ECM turnover was assessed by measuring plasma matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases, and procollagen N-terminal type I and procollagen type III N-terminal peptides. In the AHFS group, biomarkers were obtained (1) at the time of hospital admission for an episode of HF decompensation, (2) at the time of hospital discharge, and (3) several weeks after discharge in patients who had returned to a chronic stable compensated state. In patients with stable HF (versus non-HF controls), there was a small increase in troponin I and little or no difference in any marker of ECM turnover. In patients with AHFS, troponin I and 3 markers of ECM turnover (matrix metalloproteinases-2, tissue inhibitors of matrix metalloproteinases-1, and procollagen type III N-terminal peptides) were elevated (versus chronic stable HF), and all fell toward chronic HF levels in patients who returned to a compensated state.'] Are episodes of acute heart failure syndrome associated with increased levels of troponin and extracellular matrix markers?