Graduate student Nippon Veterinary and Life Science University musashino, Tokyo, Japan
Abstract: Background – Heart failure (HF) treatment involves various strategies, including inotropic agents and diuretics. Conventional inotropic agents raise concerns about side effects such as arrhythmias and myocardial ischemia. Selective cardiac myosin activators in human medicine enhance contractility without adverse events. If novel agents prove effective or better than traditional ones, it may impact treatment in veterinary medicine.Objectives – This study aimed to compare the effects of novel inotropic drugs with conventional HF medications.Animals – This study involved five clinically healthy cats. Methods – Employing a prospective cohort study design, cats were administered omecamtiv mecarbil (OM), dobutamine, pimobendan, and milrinone, and underwent echocardiographic examination.Results – OM significantly reduced heart rate compared to other inotropic agents (p = 0.044). No significant differences were observed in blood pressure among the drugs. Tricuspid valve annulus and mitral annular septal systolic velocity significantly increased with dobutamine compared to other inotropic agents (p = 0.044). Mitral annulus post-systolic excursion significantly increased with OM and dobutamine compared to milrinone (p = 0.044). Left ventricular ejection time was significantly prolonged with OM compared to milrinone (p = 0.044). Left ventricular global longitudinal strain (GLS) significantly increased with dobutamine compared to milrinone (p = 0.044). GLS exhibited comparable increases with OM and dobutamine.Conclusions and clinical importance – OM demonstrates inotropic effects similar to dobutamine and pimobendan, with a stronger contractile enhancement than milrinone. With its inotropic effects and rate control, OM holds promise as a veterinary therapy.
