(227) Angiotensin 2 in Takotsubo Cardiomyopathy and Hypertrophic Outflow Tract Obstruction

Introduction: Takotsubo cardiomyopathy often mimics acute coronary syndrome (ACS) in presentation with chest pain, troponemia, and ST changes. One known complicating factor of Takotsubo cardiomyopathy is the development of a left ventricular outflow tract obstruction (LVOTO). This occurs during periods of intense adrenergic stimulation with hypercontractile basal segments causing obstruction and an increase in the LVOT pressure gradient resulting in a shock state that can be mistaken as cardiogenic shock of ACS. Traditional cardiogenic shock therapies that increase inotropy exacerbates the LVOTO and worsen the shock state. Giapreza, synthetic Angiotensin II, has been used to help patients with vasodilatory shock as it increases blood pressure by vasoconstriction however, its usage in patients experiencing obstructive shock from LVOTO is not well described.

Description: A 44-year-old female with history of heart failure with reduced ejection fraction (HFrEF) and hypertrophic cardiomyopathy (HOCM) presented to the Emergency Department as a STEMI activation. She was taken emergently to the cath lab and coronary angiography showed mild non-obstructive coronary disease. Despite receiving several boluses of IV fluids, she developed hypotension in the cath lab and was transferred to the CICU on a norepinephrine infusion, which quickly escalated to max dose without significant blood pressure improvement. POCUS performed in the CICU showed evidence of Takotsubo cardiomyopathy with a hyperdynamic base with evidence of LVOTO and systolic anterior motion of the mitral valve (SAM). Despite maximum doses of vasopressin and phenylephrine, she could not be weaned off norepinephrine. Angiotensin II, Giapreza, was then added which improved her hemodynamics significantly and allowed her to be weaned off norepinephrine completely and have significant reduction in all vasopressors. She was slowly weaned off the sedatives and vasopressors over six days and discharged with plans for post-hospital follow-up.

Discussion: This case demonstrates the usage of Giapreza, a novel angiotensin 2 receptor agonist, to increase afterload and reduce an LVOT obstruction caused by Takotsubo cardiomyopathy. By increasing peripheral vascular resistance, Giapreza shows promise as a therapeutic agent for managing LVOTOs.