Agents such as histone deacetylase (HDAC) inhibitors, which potentiate cardiac myofibril relaxation, hold promise for the treatment of preserved ejection fraction (HFpEF), found a US study.
Researchers at the University of Colorado School of Medicine have identified a potential treatment target for patients with a common type of heart failure. They tested the effect of an investigational drug called givinostat in treating diastolic dysfunction, which is a heart relaxation abnormality that contributes to heart failure with preserved ejection fraction (HFpEF).
HFpEF refers to cases where the heart can pump blood normally, but is not able to fill as efficiently as a healthy heart. Millions of people worldwide suffer from HFpEF, which can be caused by hypertension, diabetes, aging or other conditions. Individuals with HFpEF die at an alarming rate and, unfortunately, there are no effective drugs to treat this form of heart failure.
By studying of the hearts of patients with diastolic dysfunction and HFpEF, the research team found that fibrosis, the commonly suspected culprit in these cases, is not the sole cause of diastolic dysfunction. Instead, their findings indicated that there was a defect in the ability of the muscle cells of the heart to relax.
To address whether this defect in the muscle cells could be treated, the researchers, led by CU faculty members Dr Mark Y Jeong, assistant professor of medicine, and Dr Timothy A McKinsey, associate professor of medicine, tested whether givinostat might improve the heart's ability to relax in the face of hypertension or ageing. They found that the investigational drug, tested in rat and mouse models, helped the heart relax properly. Thus, the findings hold promise for treating patients with diastolic dysfunction and HFpEF.
"These are exciting findings because we may be able to help patients with a form of heart failure that has been recalcitrant to standard-of-care therapies," said McKinsey. "Givinostat is currently in clinical development for the treatment of muscular dystrophy. Our data suggest the possibility that givinostat could be 'repurposed' for the treatment of HFpEF. Obviously, it is early days, but we are excited to test givinostat in a large animal model of HFpEF as the next step toward translating our findings to humans. Our data also reveal relaxation impairment of muscle cells as a previously unrecognized process that contributes to diastolic dysfunction of the heart. Thus, other therapeutic strategies that improve this defect could also be useful for the treatment of HFpEF."
Funding for researchers working on this study was provided by the National Institutes of Health, the Colorado Clinical and Translational Sciences Institute, the Hartford/Jahnigen Centre of Excellence in Geriatrics, a Sarnoff Endowment Fellow-to-Faculty Transition Award, the American Heart Association, and the Boettcher Foundation's Webb-Waring Biomedical Research Programme.
Abstract
There are no approved drugs for the treatment of heart failure with preserved ejection fraction (HFpEF), which is characterized by left ventricular (LV) diastolic dysfunction. We demonstrate that ITF2357 (givinostat), a clinical-stage inhibitor of histone deacetylase (HDAC) catalytic activity, is efficacious in two distinct murine models of diastolic dysfunction with preserved EF. ITF2357 blocked LV diastolic dysfunction due to hypertension in Dahl salt-sensitive (DSS) rats and suppressed aging-induced diastolic dysfunction in normotensive mice. HDAC inhibitor–mediated efficacy was not due to lowering blood pressure or inhibiting cellular and molecular events commonly associated with diastolic dysfunction, including cardiac fibrosis, cardiac hypertrophy, or changes in cardiac titin and myosin isoform expression. Instead, ex vivo studies revealed impairment of cardiac myofibril relaxation as a previously unrecognized, myocyte-autonomous mechanism for diastolic dysfunction, which can be ameliorated by HDAC inhibition. Translating these findings to humans, cardiac myofibrils from patients with diastolic dysfunction and preserved EF also exhibited compromised relaxation. These data suggest that agents such as HDAC inhibitors, which potentiate cardiac myofibril relaxation, hold promise for the treatment of HFpEF in humans.
Authors
Mark Y Jeong, Ying H Lin, Sara A Wennersten, Kimberly M Demos-Davies, Maria A Cavasin, Jennifer H Mahaffey, Valmen Monzani, Chandrasekhar Saripalli, Paolo Mascagni, T Brett Reece, Amrut V Ambardekar, Henk L Granzier, Charles A Dinarello, Timothy A McKinsey
[link url="https://www.sciencedaily.com/releases/2018/02/180207164033.htm"]University of Colorado Anschutz Medical Campus material[/link]
[link url="http://stm.sciencemag.org/content/10/427/eaao0144"]Science Translational Medicine abstract[/link]