Magnetic Resonance Imaging of Myocardial Fibrosis in Heart Failure With Preserved Ejection Fraction

T he burden of heart failure with preserved ejection fraction (HFpEF) has markedly increased, and despite multiple trials completed over the last few decades, there is currently no proven effective pharmacologic intervention available for the treatment of this condition. A better understanding of the mechanisms that contribute to the pathophysiology of HFpEF is, thus, important. HFpEF is a heterogeneous syndrome, with different degrees of contribution from various pathophysiological processes, which may unfavorably influence average responses to pharmacologic therapies tested in clinical trials. Therefore, the use of noninvasive phenotypes capable of segmenting the HFpEF population into relevant pathophysiologic categories represents a promising approach to enhancing our clinical and therapeutic approaches to HFpEF (1). Myocardial fibrosis (MF) is believed to play an important role in HFpEF. Cardiac magnetic resonance (CMR) imaging has emerged as a powerful tool to assess MF noninvasively. Although the assessment of focal MF with late post-gadolinium enhanced imaging has been available for decades, the more recent