Cardiac Myosin Activators in Heart Failure: Experimental Advances Amid Clinical Uncertainty

Area of Science:

• Cardiology
• Pharmacology
• Biochemistry

Background:

• Heart failure (HF) remains a major cause of death despite current treatments.
• Conventional therapies have limitations, including pro-arrhythmic and energetic costs.
• Cardiac myosin activators (CMAs) represent a novel therapeutic strategy targeting the cardiac sarcomere.

Purpose of the Study:

• To critically review the mechanistic basis, preclinical data, and clinical trial results of CMAs.
• To integrate current understanding of myocardial energetics and diastolic function with CMA effects.
• To identify future research directions for optimizing CMA therapy in heart failure.

Main Methods:

• Review of mechanistic rationale for CMAs.
• Appraisal of translational evidence from preclinical studies.
• Critical analysis of pivotal clinical trials involving Omecamtiv mecarbil and Danicamtiv.

Main Results:

• CMAs demonstrate dose-dependent improvements in systolic function and cardiac mechanics in early studies.
• Clinical trials revealed a narrow therapeutic window and potential diastolic/energetic trade-offs at higher doses.
• Modest or heterogeneous effects on clinical outcomes have tempered expectations, with no CMA approval to date.

Conclusions:

• While CMAs offer a distinct mechanism for HF treatment, clinical translation has faced challenges.
• Further research is needed to optimize dosing, identify patient phenotypes, and assess long-term safety.
• Next-generation myosin-targeting strategies may be required for successful integration into heart failure management.