"Targeting the Heart" in Heart Failure: Myocardial Recovery in Heart Failure With Reduced Ejection Fraction.

Myocardial recovery in heart failure (HF) is possible, but its determinants are not fully defined. At least partial functional improvement is possible with current evidence-based therapies. However, once significant HF symptoms develop, patients have varied trajectories, including: 1) structural and functional recovery; 2) stabilization (remission); and 3) acceleration to end-stage HF/death. All 3 trajectories may be interrupted by sudden death. These trajectories may represent the interplay of heterogeneous causality, genetic predeterminants, and disease phenotypes. Enhanced phenotypic description with cardiac magnetic resonance imaging, molecular imaging, or circulating biomarkers of the heterogeneous HF population may provide insights regarding specific biological targets amenable to existing and novel therapeutic strategies. The identification of patients in "remission," before progression to the end stage of predominantly nonviable tissue (e.g., fibrosis), has implications for clinical practice and future trials because such patients may be more likely to experience myocardial recovery (cardiac reserve). The identification of dysfunctional but viable myocardium and its diverse pathophysiological causes may provide opportunities to investigate existing and novel therapeutics aimed at enhancing myocardial recovery.